review article predicting and preventing flow accelerated...

Review ArticlePredicting and Preventing Flow Accelerated Corrosion inNuclear Power Plant

Bryan Poulson

School of Chemical Engineering and Advanced Materials University of Newcastle Benson BuildingNewcastle upon Tyne NE1 7RU UK

Correspondence should be addressed to Bryan Poulson bryanpoulsonnclacuk

Received 28 May 2014 Accepted 28 July 2014 Published 13 October 2014

Academic Editor Thomas Schulenberg

Copyright copy 2014 Bryan Poulson This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Flow accelerated corrosion (FAC) of carbon steels in water has been a concern in nuclear power production for over 40 yearsMany theoretical models or empirical approaches have been developed to predict the possible occurrence position and rate ofFAC There are a number of parameters which need to be incorporated into any model Firstly there is a measure defining thehydrodynamic severity of the flow this is usually the mass transfer rate The development of roughness due to FAC and its effecton mass transfer need to be considered Then most critically there is the derived or assumed functional relationship between thechosen hydrodynamic parameter and the rate of FAC Environmental parameters that are required at the relevant temperature andpH are the solubility of magnetite and the diffusion coefficient of the relevant iron species The chromium content of the steel isthe most important material factor

1 Introduction

Flow accelerated corrosion (FAC) of carbon steels in waterhas been a major concern in civil nuclear power productionfor over 40 years [1 2] The important features of FAC arethe linear or increasing rate with time and the generationof a scalloped surface Its effects have been unique in twoimportant ways Firstly it has affected nearly every reactortype worldwide and sometimes in more than one locationFigure 1 shows some examples [3ndash6] Secondly it is probablythe only corrosion mechanism that has led to accidents thathave caused fatalities There have been pipe ruptures leadingto a release of steam and deaths of workers but it must beemphasized that such fatalities are not unique to nuclearplants

The occurrence of FAC or erosion corrosion as it issometimes known is critically dependent on the followingthe temperature and chemistry of the environment (pH andoxygen content) the hydrodynamics of the system and thecomposition of the steel particularly the chromium contentthis is shown schematically in Figure 2

There are various approaches to predicting the possibilityand the rate of flow accelerated corrosion Testing has

involved either actual components or a chosen specimenIn addition there are theoretical or empirical models somecomputer based available to allow the prediction of attack

It is readily apparent that any review must be veryselective other reviews are available [7ndash10] This reviewhas tried to cover areas that the author has been involvedwith over the last 40 years that have been neglected or arecontentious It follows earlier reviews [11ndash14] but focuseson FAC of steels in the nuclear power plant industry Forboth practical and mechanistic reasons there is a need toidentify the hydrodynamic parameter which controls theoccurrence and rate of erosion corrosion It was previouslysuggested [12] that there was a spectrum of mechanismswhich could be involved in erosion corrosion This reviewconcentrates on the corrosion end of the spectrum It isargued that for dissolution based mechanisms the importanthydrodynamic parameter is the mass transfer coefficient (119870)The relationship between the rate of FAC and 119870 is discussedin some detail and the development and effect of surfaceroughness on both 119870 and FAC are considered Finally someaspects of the solubility of magnetite and the prediction andprevention of FAC are discussedThis review is not a best buyguide to predictive programs

Hindawi Publishing CorporationInternational Journal of Nuclear EnergyVolume 2014 Article ID 423295 23 pageshttpdxdoiorg1011552014423295

2 International Journal of Nuclear Energy

Plant ComponentParameters

pH Re

a

(a) (b)

(d)(c)

Hinkley SG tube inlet with

AVT secondary water155 156

bMihama

Condensate water pipe after orifice 540

cSurry

reducing T-piecein condensate system

190 305

dBend after end-

fittingoutlet feeder pipe primary water

AGR3

PWR4

PWR5

CANDU6

dd0 = 1612

orifice dd0 = 328

O2 d (mm)

sim2ppb

4ppb

sim0

T (∘C)

2 times 105

58 times 106

107 ish

38ndash90102ndash108305ndash315

91ndash94

86ndash93140ndash142

89ndash90

35ndash77 times 106

lt5ppb

90∘ bend after

Figure 1 Examples of FAC in nuclear power plants

2 Hydrodynamics

The various hydrodynamic parameters that have been cred-ited with controlling the occurrence and rate of flow assistedcorrosion are as follows

(i) Velocity (119881)(ii) Reynolds number (Re)(iii) Mass transfer coefficient (119870)(iv) Surface shear stress (120591)(v) Intensity of turbulence (TI)(vi) Freak energy density (FED)

An attempt to describe how each of these parameters mightbe measured is given in Table 1 It is widely accepted thatit is neither the velocity nor the Reynolds number that iscritical Both the surface shear stress and the mass transfercoefficient are widely believed to be important The formerin the oil and gas field the latter in the power generatingindustry But recently 120591 has gained some devotees [15] in thepower generating industry However there are some workers[16] who believe the following

Themass transfer coefficient is intimately linked towall shear stress and the two cannot be practically

International Journal of Nuclear Energy 3

Table 1 Possible important parameters and some measurement techniques

Parameter Some measuring techniques References

The velocity (119881)(i) Calculated from flow rate and flow area(ii) Ultrasonic sensors(iii) Pitot tube

[11 17 18]

Reynolds number (Re) Calculated from velocity diameter of tube andkinematic viscosity [11 17 18]

Mass transfer coefficient (119870)Requirements

(1) Use of realistic geometries(2) Measurement of both smooth and rough surfaces(3) Use in two-phase flow

(i) Dissolution of sparingly soluble solid(ii) Limiting current(iii) Analogy with heat transfer(iv) Computational

[12 19ndash23]

The surface shear stress (120591)Requirements as for 119870

(i) On isolated surface element using force transducer(ii) Pressure drop(iii) Various types of heat transfer sensors(iv) Limiting current density on isolated smallelectrode but not for separated flows(v) Computational

[12 18ndash20 24 25]

Intensity of turbulence (TI)Requirements as for 119870

(i) Analysis of fluctuations in limiting current densityon isolated small electrode(ii) Hot wire(iii) Laser-Doppler anemometer

[11 18ndash20]

Freak energy density (FED)Requirements as for 119870

Complex analysis of fluctuations in limiting currentdensity on isolated small electrode single author use [26ndash28]

Environmentalfactors

Hydrodynamic parameters

pHTemperatureOxygen content

Chromium content

Magnetitesolubility

Materialcomposition

K = rate of transport controlled reactionconcentration driving force

Mass transfer coefficient K

Sh = aRex Scy

Figure 2 Factors influencing FAC

separated either experimentally or mathemati-cally [16]

This view has been challenged by a number of workers[25 29] based on the breakdown of the analogy betweenmass heat and momentum in detached flow The conse-quences of this are that in detached flow the surface shearstress cannot be calculated from the measured limitingcurrent density (LCD) at an isolated microelectrode wherein normal flow 120591 is proportional to the cube of the limitingcurrent density (Leveque equation) this is demonstratedin Figure 3 This problem seems to have been ignored bySchmitt and Gudde [30] whose approach was to obtain afunctional relationship between shear stress and limitingcurrent density for a normal flow situation (Figure 4) Thento use the same relationship to convert LCDs measured

in disturbed flow to shear stresses (Figure 4) Apart frombeing invalid this approach involved the extrapolation of amaximum shear stress in the channel wall of under 60Nm2to over 14000Nm2 in the disturbed flow

One way of refuting the importance of 120591 is its variationfor example downstream of an orifice where the FAC andshear stress profiles are fundamentally different (see Figures 3and 5) This refutation of the importance of 120591 has apparentlybeenmisunderstood [32] A similar rejection of the dominantrole of 120591 has been made by Matsumura et al [33 34] in workwith an impinging jet Another reason to believe that 120591 isunimportant is because it seems that the surface shear stressis not sufficient to produce the effects ascribed to it namelymechanically disrupt a surface film

For copper alloys in seawater Matsumura showed thatthe FAC profile did not correspond to the measured shearstress distribution on an impinging jet specimen but could beexplained by the forces measured with a pressure transducerdue to the peak in turbulence intensity at about 2 jet diametersfrom the centre of the specimen Of course mass transfer iscaused by bulk convection and turbulent convection so whileruling out the primacy of the importance of shear stress thisdoes not prove the importance of mechanical factors It mustbe remembered that increased mass transfer can dissolveaway a protective surface layer this was elegantly analysed byConey [35]

Schmitt and Mueller initially proposed [36] a fatiguebasedmodel for oxide failure and it is not clear to this authorwhy such an approach was apparently rejected for the freakenergy density (FED) model Although this was applied tothe oil and gas industry [27] his ideas have been publishedin power plant chemistry [28] and thus warrant discussion


0

1

2

3

0 1 2 3 4 5Distance downstream of orifice in tube

diameters

Incorrect 120591 measured withsmall isolated electrode andLeveque equation

Correct 120591 measured withspecially designed duelelectrode This agrees withCFD profile known flowstructure and position ofstagnation point

Surfa

ce sh

ear s

tress

(Nmminus2)

minus1

minus2

Figure 3 Correct and incorrect electrochemical measurements ofsurface shear stress after [25]

60

50

40

30

20

10

00 10 20

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140

Channel wall results

Limiting current densitiesmeasured at leading edge ofcavity used to obtain wallshear stress by using the120591 = constant times LCD2

obtained at channel wall

times103

Wal

l she

ar st

ress

(Nmminus2)

Limiting current density (mA cmminus2)

Figure 4 Schmittrsquos measurement of surface shear stress in detachedflow (after [30])

The FED model is conceptually similar to Matsumurarsquos viewon the importance of the turbulent flow generating high localstresses

It was found that forces in high energy microtur-bulence elements oriented perpendicularly to thewall are finally responsible for the scale destruc-tion (freak energy density (FED) Model) Themaximum FED in a flow system can be measuredwith appropriate tools however in practical cases

272mm 838mm

pH 904 115∘C Re = 104times 105

Oxide thickness

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

Erosion corrosion rate

Oxi

de th

ickn

ess (120583

m)

Distance from ferrule down tube (mm)0 10 20 30 40 50 60 70 80

12

10

08

06

04

02

0

12

10

08

06

04

02

0

006 Cr 001 Mo 019 Cu

Figure 5 Correlation of FAC rate and oxide thickness ([31])

this is not necessary because in a given flow systemthe FED is proportional to the wall shear stressby a factor in the order of 105 to 106 Thus forpractical application and flow system evaluationswall shear stresses can be used to quantify flowintensities in given flow systems [27]

FED is a derived freak value from measuring the noisein the limiting current density (LCD) on isolated small pointelectrodes (ISPE) It appears [27 28] that this is a complexprocess involving wavelet transforms simulations and phas-ing in of waves The net result is a freak current densityvalues of as high as 500A cmminus2 have been quoted Theenergy density of a freak wave volume element acceleratedtowards the surface can be expressed according to classicwave dynamics from

119908 =119889119864

119889119881= 05120588119860

22 (1)

where119908 is energy density (Pa) 120588 is density (kgm3)119860 is waveamplitude (m) and is wave frequency (sminus1) Both energydensity and wall shear stress have the unit Pascal in commonIt was therefore assumed that the same relation used in theLeveque equation can be used to calculate the freak energydensity from the freak current density For the freak currentdensity of 500A cmminus2 a freak energy density of 3GPa wasderived

Such an approach can be questioned on a number ofimportant points

(1) Although there are time response limitations involvedin LCDmeasurements it might be expected that somefreak events could at least be partially detected afterall real freak waves can be observed

(2) No attempt to measure such high stresses was madefor example by fast response pressure transducers asMatsumura did

(3) The use of the Leveque equation to obtain freakenergy densities from freak current densities is highlyquestionable


0

1

2

3

0 1 2 3Corrosion rate (mmyear)

Frea

k en

ergy

den

sity

(GPa

)

VSL = 6msVSG = 0ndash18ms

VSG = 6msVSL = 0ndash9ms

1M NaCl 1bar CO2 RT

Figure 6 No single relationship between freak energy density andFAC from specimens exposed to gas pulsed impinging jet (after[27])

(4) There is not a single relationship between 120591 and FED[27 28] and from a practical point of view this wouldhave to be obtained for each geometry of interestAnd measuring surface shear stresses in detachedflow is as outlined earlier not possible using Schmittrsquostechnique

(5) How rough surfaces that develop naturally duringcorrosion are dealt with is unclear

Also as yet there has been no data that supports the use ofFED to predict FAC indeed Figure 6 from a 2009 paper [27]appears key since it suggests that there is not a single rela-tionship between corrosion rate and FED for two differentflow conditions in the same environment Finally there is amechanistic problem in what exactly happens when a surfacelayer is cracked Schmitt has suggested the following

Once removed the high local flow intensitiesprevent the re-formation of protective layers andhence start fast mass transport controlled localmetal dissolution (FILC also called erosion cor-rosion)

For steels in pure boiler water there is good evidence thatthe protective magnetite layer is thinned (not cracked) andthe FAC rate correlates with this thinning [31] and the masstransfer coefficient (Figure 5) There is also the possibilitythat the mass transfer could be large enough to lead to thefilm being completely removed by dissolution In this casethe subsequent rate of attack would probably be limitedby activation kinetics This film dissolution appears to haveoccurred on carbon steel exposed to sodium nitrate solutionsunder an impinging jet [11]

Of course in most situations in which corrosion isoccurring the surface undergoes some roughening thisthen raises the question of how to measure the changesin the hydrodynamic parameter as the roughness developsRoughness development and other considerations (Table 1)led the current author to develop justify and apply thedissolution of copper in ferric chloride solutions [21 37ndash41]

Roughness can develop without any risk of erosion

Maximum (from wall penetration time) ormean corrosion rate can be measured

Anodic reaction Cathodic reactionto the surface is rate controlling

Transport of Fe3+

Fe3+ rarr Fe2+ + eminusCu rarr CuCl2minus or CuCl3

2minus

Figure 7 Copper specimen used to measure 119870 in acid ferriccontaining solutions ([21 37ndash41])

Lap joint close to seal weld

(a)

Flow

(b)

Re sim 4 times 104

Re sim 3 times 105

(c)

Figure 8 Typical copper specimens after testing in single phaseflow (a) Reducer (39 to 256mm) Re 28 times 105 in larger tube ([40])(b) 180∘ 25 D bend at Re of 70000 ([37]) (c) Impinging specimensat 95mm from 95mm diameter jet ([40])

(Figure 7) to the measurement of mass transfer coefficientstypical specimens from single-phase and two-phase studiesare shown in Figures 8 and 9

Because some predictive models use an enhancementfactor to describe a geometries effect relative to a straighttube such a factor is often quoted It must be emphasised thatthis factor is usually a function of the Reynolds number and


Penetration

(a)

Flow

(b)

Figure 9 Typical copper specimens after testing in two-phase flow(a) 10-bar submerged gas jet at 1mm from specimen ([13]) (b)Annular two-phase flow ([39])

its use has nothing to do withmdashthe mass transfer coefficientat the point of interest becomes difficult to measure or evendefine so ldquoenhancement factorsrdquo over the straight-pipe valuesare employed [32]

Recently there has been an increasing tendency to usecomputation fluid dynamics (CFD) techniques to obtainhydrodynamic parameters for subsequent use in FAC assess-ments CFDhas the ability to investigate very high Rersquos whichoften cannot be reached in experimental studies HoweverCFD results must be shown to agree with well establisheddata before it can be applied to the higher flows A number ofapplications of CFD are listed in Table 2 unfortunately someof these computations have been carried out without anycomparison to well established experimental data in somecases there are significant differences This is particularlyevident after the Mihama-3 FAC failure downstream of anorifice the mass transfer characteristics of which have been

0 1 2 3 4 5 6 7 8 9 10Distance in tube diameters

Value calculated from

[42]

[43]

With D = 562 times 10minus5 cm2 sminus1

Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033

Figure 10 Comparison of mass transfer profile for Mihama

1

10

Reynolds number Re

Re at Mihama failure

Data points obtained using copper-ferric chloride experimental technique

Enhancement values derived from published

CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019

Figure 11 Comparison of accepted mass transfer correlation andresults from CuFe3 experiments and CFD values for Mihama

studied by a number of workers and reviewed by othersFigures 10 and 11 are a summary of and comparison withexcepted correlations The difference between the two CFDpredictions is of some interest the higher results may be amisprint in units as the other data agrees very well witha simple calculation for fully developed flow It is of greatinterest that the CFD predicted enhancements are muchhigher than those from expected correlations downstreamof an orifice yet no comparison with the well establishedlower Reynolds number data weremade Also in this authorsrsquoview CFD has not been shown to be capable of modellingthe roughness and its effects that develops naturally by metaldissolution or oxide deposition

Roughness development in situations where a solid isdissolving under mass transfer control has been investigatedby a number of workers One theory attributes roughnessto the imprinting of the fluid on the surface [48] and theother to the role of surface defects [49] Criteria for thedevelopment of roughness have not been fully developed andit is perhaps overlooked that there is a tendency for leveling ofany surface which is dissolving under diffusional control [39]For example consider an isolated roughness element exposedto single phase flow It would be expected that the rates of


Table 2 Examples of the use of CFD in FAC

Authors Purpose Comments References

Uchida et al Prediction of FAC with Mihama as testcase

No comparison with existing data and itsextrapolation to high Rersquos or effects ofroughness

[42]

Hoashi et al Prediction of FAC with Mihama as testcase


[43]

Pietralik and SmithPietralik and Schefski

PredictionexplainingCANDU feeder FAC

Compares with some but not all benddata Attempts to deal with roughnessdevelopment and component interactions

[44 45]

Nesic and Postlethwaite Predict e-c following sudden expansion Makes key point that profiles of 119870 andshear stress do not correlate [29]

Zinemams and Herszaz Predict FAC in bifurcation and nozzleLimited detail to check results but claimsthere is agreement effects of roughnessnot considered

[46]

Yoneda Predict FAC in PWR and BWR of 45∘elbow

Interesting but again no comparison withothers or the effects of roughness [47]

dissolution of both the peak of the roughness element and theregion after the roughness element were both higher than theregion upstream For roughness to develop the region afterthe roughness peak must dissolve faster than the roughnesspeak itself In two phase flow it is probable that the annularfilm would leave the wall after the peak rather than inducingseparated flow as in single phase conditions Thus it wouldseem reasonable that in annular two-phase flow roughnessdevelopmentwould bemore difficult andwould tend to occuronly when the thickness of the wall film was such that arecirculation zone could form

It is the effect of roughness that is of general relevanceand our findings [37ndash41] can be summarized as follows

(1) While defects can produce surface roughness they arenot a requirement The roughness that develops usu-ally reflects the flow structure For example Figure 7illustrates the symmetrical peaks at the inlet to the180∘ bend and evidence of counter rotating vorticesin the bend region

(2) There appears to be a critical Re required for rough-ness to developThe critical Re valuesim5times 104 in 8mmdiameter tubing [40] is significantly higher than thatfound using dissolving plaster of Paris [22] whereroughness developed at the lowest Re tested of 19 times

104 in 25mm diameter tubing

(3) There are other indications [39] that using the dissolv-ing plaster of Paris technique can give misleadinglyhigh values of 119870 due to erosion of the plaster occur-ring

(4) If the surface roughens the mass transfer can increaseand there are indications [40] that the roughnessbecomes more important then than the geometry ininfluencing mass transfer

Symbol Geometry Technique Ref25d 180 bend

in 226mm tube95mm d impinging

jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution

Poulson and Robinson 1988

Poulson 1990

Kapperesser et al 1971

Wilkin and Oates 1985

Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106

Figure 12 Poulsonrsquos rough surface correlation ([38])

(5) An upper bound mass transfer correlation for allrough surfaces has been proposed [38] as shown inFigure 12

Sh = 001Re Sc033 (2)


Table 3 Differences between normal and separated flow

Normal flow Separated flowShear stress and 119870 Related Not relatedTurbulence created Near wall Away from wallRoughness effectson 119870 and Δ119875

Both increase Evidence for increaselacking

Roughness effectson FAC

Limited clearevidence of increase

Evidence for increaselacking

But in all probability there will be a number of situations that are betweenthese two extremes

(6) There is some evidence Table 3 [41] that the develop-ment of roughness has a smaller effect on geometrieswhere flow is separated as compared to normal flowIn the former turbulence is generated away from thewall while in normal flow it is generated close to thewall This was first realized with the region down-streamof an orifice in that some enhancement inmasstransfer occurred in some tests but again nowherenear a Reo dependency (Figure 10) Also for a multi-impinging jet and a cylinder in restricted cross flowthe rough surface mass transfer correlations all have aReynolds number dependency with an exponent lessthan one Figure 13 with

Sh = 0195Re065Sc033 Multi-impinging jets

Sh = 0019Re087Sc033 Cylinder in restricted cross flow

(3)

(7) If roughness develops the height (120576) and wavelength(120582) of the roughness elements decrease with increas-ing Re [40] This means that the enhancement inmass transfer caused by roughness does not increasewith increases in 120576119889 There is a suggestion [50] thatthe roughness that develops at any Re produces themaximum resistance to flow

(8) If roughness develops the enhancement factor ofany geometry over a straight tube is not a constant[37] and will usually increase with the Reynoldsnumber For the region downstream of an orifice theenhancement decreases with increases in Re for bothsmooth and rough surfaces

In summary the initial surface roughness (or defects) willinfluence the subsequent development of dissolution inducedroughness which will occur at lower flow rates for rougherinitial surfaces However the final or equilibrium roughnessthat develops as a result dissolution will probably be largelydependent on the flow rate with smaller scallops as theReynolds number increases The effect of roughness devel-oping in increasing the rate of mass transfer and thus therate of FAC is expected to be less for geometries where flowseparation or detachment occurs

In two-phase flow it is not immediately obvious how themass transfer data can be simply incorporated since there

2 times 104 6 times 104 2 times 105 3 times 105 5 times 105 66 times 105 73 times 105

(a)

(b)

Figure 13 Examples of specimens after testing under detached flow(a) Cylinders in cross flow at stated Rersquos Shmax = 0019Re087Sc033(b)Multi-impinging jet (119889 = 15mmat distance of 2mm) Shaverage =

0195Re065Sc033

is some evidence [39] that Chenrsquos correlation is not validFigure 14 shows a simple model can apparently be used torelate the tightness of bends to the resulting influence of theannular flow on the mass transfer at bends There is evidencethat mass transfer effects dominate at least up to 50m sminus1but clearly mechanical damage will occur above some criticalvelocity which needs to be defined this leads to the concept ofa spectrum of mechanisms as suggested earlier [12] Modelsascribing droplet impingement causing mechanical damageare referenced later in predictive models but are outside thescope of this paper

The relationship between 119870 and FAC must not beassumed to be linear this is discussed later in this review

3 Environmental Variables

It is widely accepted as shown schematically in Figure 1that the three most important environmental parametersinfluencing the occurrence and rate of FAC are as follows

(i) Temperature(ii) pH(iii) Oxygen content


06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm

Radial distance (mm)

VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)

Predicted rate = isokinetic annular flow jet rate times sin120579120579 is obtained from bend geometry bycos120579 = r(r + 05d) times [1 + 1bend tightness]

0 01 02 03 04 05 06

Measured K (mm sminus1)

0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)

Figure 14 (a) Isokinetic annular flow impinging jet specimens ([39]) (b) Prediction of mass transfer at bends from jet data ([39])

Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m

Figure 15 Typical equipment for solubility measurements (after [53]) and possible problems Typical potential problems might include (1)fine particles passing through filters (2) fine grain size and surface energy effects (3) purity of materials and (4) corrosion of equipmentinfluencing results (5) Bignold ([54]) suggested that magnetite is a mixture of ferrous and ferric ions Ferric ion solubility is very low and onisolated magnetite ferric ions will build up on surface Is it possible that this could lead to apparently low solubility and the true solubilityshould be obtained from magnetite coated iron

These have been discussed in detail and further discussionis beyond the scope of this review However each of thesevariables probably exerts their influence through their effecton the solubility of magnetite It is believed that this has beena neglected topic For example in one of the first reportedcases of FAC at 300∘C it was suggested [51] to be the resultof high mass transfer and low Cr content in the steel withlittle consideration to the reduced solubility of the magnetiteat that temperature A similar situation occurred in a recentpaper [52] describing low temperature FAC

In general solubilityrsquos can be calculated from availablethermodynamic data or measured For a very sparinglysoluble oxide like magnetite the preferred option has beento experimentally determine it using equipment such as thatshown in Figure 15 There are a number of experimentaldifficulties such as the need to establish steady state condi-tions under controlled redox conditions the problems withcolloidal material and the influence of trace impurities Suchsolubility data for example Figure 16 is then used to obtainthermodynamic data for the various possible dissolving


minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)

Figure 16 Typical results of solubility measurements (after [53])

8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14

pH at 25∘CpH at 300∘C in gray

Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+

Ferrous species red ferric species blue

4 5 6 7 9 10

Figure 17 Defining dissolving species (after [53])

species for example Figure 17 The total solubility of ironspecies can then be modeled and predictions can be made(Figure 18)

From an examination of the key papers [53 55ndash58] thereare certain key facts some are well known for example 1 and2 and form the basis of controlling of deposition in primarycircuits others are not yet they could significantly influencethe ability to predict FAC

(1) The gradient of solubility with respect to pH changesfrom negative to positive at a critical pH producinga typical U-shaped curve Figure 16 The pH valuethis occurs at is of intense interest an estimate (usingTampLeB data [53]) can be obtained from

pH = 6456 + 16365 exp(minus119879∘C

88518) (4)

(2) The gradient of solubility with respect to increasingtemperature changes from negative at lower pH topositive at higher pH Figure 18 this occurs at sim

94 and 99 at temperatures of 300∘C and 150∘Crespectively [53]

(3) There are various functional relationships betweeniron solubility and hydrogen content which arise

10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126

At low temperatures no effect of hydrogen

At high pHs hydrogen effect reversed this is a function of temperature

Under most conditionssolubility increases as [H]05

P[H2] in atmospheres

Figure 18 Examples of model predictions (after [55])

Table 4 Possible variations in magnetite solubility dependency onhydrogen concentration

Regiem Hydrogen dependency ReferenceNormally [H]13 [53 55 56]At high pHs above sim220∘C [H]minus16 [53 55]At temperatures belowsim80ndash110∘C Independent [55]

At high temperatures abovepHsim98 Less than [H]13 [55]

Such effects could influence both dissolution and deposition

because of the details of the stable species and thenature of the oxide dissolution reaction Table 4 andFigure 18

(i) Usually [53 56] the solubility is proportional to[H2]13

1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2

larrrarr Fe(OH)119887

2minus119887+ (

4

3minus 119887)H

2O

(5)

(ii) As pHs increases the solubility is predicted [53]to become proportional to [H

2]minus16 and that

will occur above a certain temperature [55]Consider1

3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)

However the data appears to be insufficient tomake accurate predictions of pHrsquos and temper-aturersquos and the expectation is that the transitionwill be gradual

(iii) Solubility is independent of [H2] at low temper-

atures below sim83∘C [55] But this temperature


0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9

with NH3 Sweeton and Baes

Tremaine and LeBlancpH25∘C = 105

with LiOH

Temperature (∘C)

Figure 19 Comparison of solubility data ([2] with additions)

minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3

minus600 minus500 minus400 minus300 minus200 minus100 0 100 200 300

Potential (mV versus nhs)

Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C

pH was stated to be neutral

150∘C

Figure 20 Effect of potential on solubility ([59])

increases with increases in [H2] This is due to

the activity of ferrous ions in solution beingcontrolled by a hydrous ferrous oxide phaserather than magnetite [55]

(4) There appear to be significant differences betweenthe two most quoted data sets as shown in Figure 19In particular the values of Tremaine and LeBlanc(TampLeB) are lower than those of Sweeton and Baes(SampB) and mirror the temperature dependency ofFAC more closely

(5) Under conditions where ferrous ions are dominantthe effect of potential [59] Figure 20 or oxygencontent of the water is profound and of great practicalimportance the solubility of haematite is exceedinglysmall

(6) There is no solubility data available for magnetitecontaining chromium such data might allow the roleof chromium to be clarified

There are different functional relationships between pHRTand pHHT for ammonia morpholine ethylamine andlithium hydroxide which depend on basicity volatility tem-perature and steam quality which need to be considered thishas been discussed recently by Bignold [60]

012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858

d = 407852 times 10minus09 e = 137186 times 10minus07 f = minus183557 times 10minus14

FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C

Figure 21 Examples of calculated diffusion coefficients moleculardata from [22 61] ionic data-current work

As indicated earlier another important parameter influ-enced by the environment is the diffusion coefficient (119863) ofthe relevant dissolving iron species This is rarely discussedeither the value utilized or how it was obtained One of thefew relevant discussions was presented by Coney [61] it wasindicated that there were a number of possible dissolvingions and diffusion coefficients were calculated using bothanionic and cationic data As Newman [62] and others[12] have pointed out it is the ionic diffusion coefficient(cm2s) which should be calculated using theNernst-Einsteinequation

119863119894=

119877120582119894119879

119899119894119865

(7)

where 119877 the universal gas constant is 83143 Jmole deg 120582means the ionic equivalent conductance is in ohm-cm2equiv119879 is the temperature in degrees Kelvin 119899 is the charge on theion and 119865 is Faradayrsquos constant 96487Cequiv The effectsof temperature are usually calculated using Stokes-Einsteinequation or Wilkes rule (119863120583119879 = constant) and this has beencompared to an activation energy approach and found inreasonable agreement [12]

In Figure 21 the results of Coney are shown and comparedto the recalculated values for FeOH+ which Coney suggestsis the most relevant species It appears that the recalculatedvalues are approximately half of the earlier values and acorrelating equation obtained using Table 119862119906119903V119890lowast is given

Temperature also influences the density and viscosity ofwater such values are readily available in the literature

4 Material Influences

It has been known for some considerable time that thechromium content of steel [63 64] has an important rolein influencing flow accelerated corrosion typical results areshown in Figures 22 and 23 There is some evidence [63] thatunder some situations copper and molybdenum may also bebeneficial Suggested correlations for the fractional reduction(FR) in FAC caused by alloying include

FRFAC = (83Cr089Cu025Mo02)minus1

FRFAC = (061 + 254Cr + 164Cu + 03Mo)minus1(8)


001

01

1

10

0001 001 01 1 10Cr content weight ()

Relat

ive F

AC ra

te

Laboratory tests atlow mass transfer

Laboratory tests athigh mass transfer

Some plant data

Figure 22 Effect of steels Cr content on FAC ([65] with modifications)

200 120583m 200120583m

(a) (b)

(c)

(d) (e)

Figure 23 Effect of 1Cr on FAC specimens after 2280 hours at 155∘C at pH 91 (a) Surface of carbon steel (b) Surface of 1Cr05 Mo steel(c) Section of orifice holder (d) Section through carbon steel-stainless steels (e) 1Cr05Mo-stainless steels


Figure 24 High pressure and high temperature flow loop for FACstudies on British AGR components

It is of considerable interest that welds can have weld metallower or higher in chromium than the parent metal thisneeds to be considered in any assessment

In general water chemistry changes are so much easierto implement than material changes it is only in new orreplacement components that material changes can be made

It is believed that the first instance when the possibil-ity of FAC influenced indeed determined the choice ofmaterial (1Cr12Mo) was for the economizers for theBritish advanced gas cooled reactors (AGRs) once throughboilers at Torness and Heysham 2 This was substantiatedby long term tests (22800 hour) in laboratory rigs on-siterigs and in situ SGs exposure Both tight 180∘ bends andorifice geometries were utilized Figure 24 Interestingly thefeedwater system for the British PWR at Sizewell orderedlater was specified as carbon steel While there is no disputeas too the benefits of chromium additions there have been atleast three suggestions as to its mechanism

(i) It slowly enriches at the dissolving magnetite surfaceand limits the solubility [66 67]

(ii) It alters the kinetics of oxide dissolution possibly afterenriching at the surface [68]

(iii) It changes the oxide porosity [69]

5 Predictive Approaches

51 Testing There are two possible approaches The first isto test all geometric features of interest under realistic andaccelerated conditions to obtain margins of safety Figure 24shows such a rig used to test AGR components at design andtwice design velocities for times up to 22800 hours

The alternative approach is to use a specimenwith a rangeof mass transfer rates as illustrated in Figure 25 or a singlespecimen over a range of flow rates In all cases it is goodpractice to check any relationship between the suspected

hydrodynamic parameter and the rate of FACwith tests usinga different specimen geometry

The author can see no point in using a specimen forwhichthere is no mass transfer data available It is important in allcases to ensure the following

(1) Tests are carried out long enough to obtain realisticsteady state rates

(2) The method of measuring the corrosion rate hasthe required precision various methods have beensuggested [12]

(3) The environmental conditions in the test rig reallydo correspond to the practical situation The use ofa marker geometry that is one which corrodes at aknown rate has much to commend itself

The advantage of the first approach is that real componentscan be tested and the dependency between corrosion rate andmass transfer will be established if the latter is known It mustbe emphasized that this might change if the environmentalconditions change The advantage of the second approachis that it might prove possible to obtain the FAC versus 119870

relationship with a single specimen where high precisionmeasurements are possible One difficulty in using specimensis that the development of roughness can be significantlydifferent between geometries The specific example of usingsmall diameter tubes to obtain data relevant to large diameterpipes has been covered in some detail [40]

52Theoretical BasedModels There appears to be reasonablywidespread agreement that the basic mechanism of FAC isthe enhanced transport of dissolved ferrous ions away fromthe metal surface This causes the protective magnetite filmto be thinned down and results in essentially linear kineticsThis is to be compared to parabolic kinetics during normalcorrosion

The simplest formulation of an FAC model gives thecorrosion rate as the product of the mass transfer coefficient(119870) and the solubility driving force (Δ119862) where Δ119862 isdifference between the solubility and the bulk solution level

FACrate = 119870Δ119862 (9)

119870 is usually obtained from correlations of the general form

Sh = constant Re119909Sc119910 (10)

where Sh (the dimensionless mass transfer Sherwood num-ber) is given by 119870(119889119863)

Re (the dimensionless Reynolds number) is given by119881(119889120574) and Sc (the dimensionless Schmitt number) is givenby 120574119863

119881 is the relevant velocity (m sminus1) 119889 is the characteristicspecimen length (m) 120574 is the kinematic viscosity (m2 sminus1)and119863 is the diffusivity of the relevant species (m2 sminus1)

Substituting for119870

FACrate = constant 119881119909119889119909minus1120574119910minus1199091198631minus119910Δ119862 (11)


Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d

Impinging jet Rotating disc

H

sim2

Figure 25 Specimens with mass transfer gradients ([12])

So in principal if the mass transfer is known and the con-centration driving force is known the only other parametersrequired are the diffusion coefficient of the relevant ionicspecies and the appropriate kinematic viscosity

However most if not all the predictive models involveadditional processes shown in Figure 25 The differences inthe variousmechanistic models arise in the way the processesare quantified and combined in particular in the explanationof the key environmental parameters especially the tempera-ture and how the flow dependency of themeasured FAC ratescan be explained

From a predictive aspect a very important difference isthat some theories predict a linear relationship between masstransfer and flow accelerated corrosion rate a nonlinear rateis predicted by other models particularly the CEGB theory ofBignold Garbett and Woolsey Other workers have arguedthat a greater-than-linear dependency of rate onmass transferequates to a mechanical contribution probably in removingoxide

TheCEGBmodel [10 54 66 67 70 71] (Bignold Garbettand Woolsey) was developed because the maximum FACrate and the measured FAC profile downstream of an orificecould not be explained by the available magnetite solubilitydata and a linear relationship between FAC and masstransfer In addition to explain the decrease of FAC at lowertemperatures it was postulated that the rate of magnetitedissolution (119877 of Fe

3O4dissolution) controls the rate of FAC

at low temperatures

1

FACrate=

1

119870Δ119862+

1

119877 of Fe3O4dissolution

(12)

There is strong evidence that the solubility of magnetite is afunction of the hydrogen content of the waterThus it appearsthat the process could be self-accelerating in that the higherthe corrosion rate is the more hydrogen is produced locallyand this could enhance the solubility of the magnetite Anelectrochemical model was developed which indicated thatthe solubility ofmagnetite could be proportional to the squareof the mass transfer coefficient

Thus the FAC rate could be proportional to the cube of themass transfer coefficient or in general with n being a variablebetween 1 and 3

FACrate = 119870119899Δ119862 (13)

High resolution measurements of the FAC rate down-stream of a ferrule or orifice suggested that the rate did notincrease with time as the surface roughened Figure 27 androughness effects do not appear to have been incorporatedinto the CEGB model

The EDF model [65 69 72ndash76] has been developed witha number of modifications most importantly the incorpora-tion of the oxide porosity 120579 oxide thickness 120575 and 119896 the rateconstant for magnetite dissolution as important parametersThe original formulation in 1980 was

FACrate = 119870 (119862 minus Co)

FACrate = 2119896 (Ceq minus 119862) (14)

From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)

Then this was modified after the Sanchez Calder model totake account of oxide porosity

FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)

And if mass transfer is the rate controlling step [1119896 ≪

05(1119870+120575119863)] and for thin oxides (1119870 ≫ 120575119863) this reducesto

FACrate = 2119870120579Δ119862 (17)

The solubility of magnetite is obtained from Sweeton andBaes Mass transfer coefficient is obtained by using a straighttube correlation modified for surface roughness and anenhancement factor to account for the component geometry

119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)

times component enhancement factor(18)


Thickness 120575Porosity 120579

2H2O + 2eminus = H2 + OHminus

Fe3O4 is an intrinsic

Both Fe2+and Fe3+

Metal Oxide

Semiconductor with

Solution boundary layer Bulk solution

(1) Steeloxidation

(2a) Ferrous ion diffusion in oxide

(2b) Ferrous ion diffusion through pores

(5) Cathodic reaction

(3) Oxide dissolutionsolubility of ferric ionsis very low

(4) Ferrous ion mass transfer

(6) Water transport to MMO interface

Figure 26 Schematic diagram of possible reactions in FAC

Early versions of their model appeared to explain the varia-tion of FAC with temperature and alloying effects particu-larly the effect of chromium by varying the values of oxideporosity 120579 and thickness 120575 In the latest description of themodel the following is stated [65]

The porosity behavior with temperature is difficultto model It appears to be temperature dependentand not linear Based on many experiments usingthe CIROCO test loop taking into account differ-ent temperatures mass transfers and chemicals(16) has been simplified as

FACrate = 2119870 sdot 119891 (Cr) sdot 119867 (119879) sdot Δ119862 (19)

where119867(119879) is a temperature-dependent functionnormalized to 119870 and which leads to a hydrogencontent (in mg kgminus1) equivalent for increasing theiron solubility Only experiments can lead to thisfunction and data are not shown

The Sanchez Calder model [77] was developed to predictthe rate of FAC in steam extraction lines It incorporatedmost of the processes shown in Figure 26 with an equationsimilar to the EDF model and highlighted their view of theimportance of the oxide porosity which was subsequentlyincorporated into some other models

Workers at Penn state Uni [79] pointed out the basicSanchez Calder model predicted rates that were 100 to 1000times smaller than measured rates and suggested changes tothe model including

(i) improved magnetite solubility data(ii) assumption that porosity was a function of oxygen

content of water(iii) introduction of several piping configurations and

surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns

Linear loss rate 065mmyearjust upstream of maximum rate

3898Kghour at 115 ∘C pH 904 O2 lt 2ppband Fe sim 05ppb with 287mm diameterferrule in 834mm diameter tube

Figure 27 Linear FAC loss rate at orifice specimen ([78])

Since the occurrence of FAC at the outlet headers in thecarbon steel primary circuit of CANDU reactors and thefailure of a condensate pipe downstream of an orifice atMihama PWR various other mechanistic approaches havebeen formulated

Burrill and Cheluget [80] followed a similar approach toCEGB workers in having the magnetite solubility (calculatedusing SampB) as a function of potential and thus the corrosionrate However under CANDU condition of high pH and hightemperature the dependency of magnetite solubility could beless than the normally accepted [H]

13 relationship

CanadianJapanese Approach [4 15 32 81 82] Lister andLong suggested that an earliermodel [83] which incorporatedboth film dissolution and mass transfer could not explainthe occurrence of FAC on CANDU outlet feeders This wasbecause the film dissolution step was not sufficiently fast tokeep up with the observed FAC rates In addition because theFAC rate was a function of the velocity to a power of 15ndash2 it


was stated that the surface shear stress (120591)must be importantin causing magnetite removal The stages in this model arethus as follows

(1) Some magnetite dissolution occurs

(2) Dissolution loosens magnetite crystals

(3) Surface shear stress spalls or erodes crystals

(4) Thinned magnetite is less protective

An electrochemical model was developed which could pre-dict corrosion potentials magnetite solubilityrsquos and FAC rates

Subsequent work in collaboration with Japanese workersincluding Uchida has subsequently developed their ownevaluation program because Unfortunately details of their(other models) theoretical basis and of the data bases of theprogram packages are classified due to intellectual propertyrights Both traceability of the computer program package andits validation are required for making policy on plant reliabilitywhen applying the package calculations

A paper covering the evaluation of FAC simulation codebased on verification and validation has been published [82]which describes the steps involved as follows

Step 1 Define flow velocities and temperatures in system 1DCFD code RELAPS used

Step 2 Calculate O2levels ECP and so forth 1D O

2-hydra-

zine reaction code CORRENV used

Step 3 Distribution of mass transfer coefficients 3D CFDcode PLASY MTCEXTRA used

Step 4 Danger zone evaluation chart analysis DRAW-THREE-FAC

Step 5 Distribution of wall thinning wall thinning codeWATH

Step 6 Evaluation of residual life and effect of countermeasures final evaluation DRAWTHREE-FAC

Interestingly this paper appears to indicate the impor-tance of obtaining themass transfer rate but does notmentionthe importance of the surface shear stress

53 EmpiricalModels TheKellermodel [84ndash86]was probablyone of the first predictive models The basis for the formula-tion was a combination of experience gained from damage inwet steam systems and the pressure drops expected at variouscomponents

FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)

where119870119888is a component geometry factor and119870119904 is a constant

thatmust be exceeded for FAC to occur119883 is the steamquality119879 is the temperature and 119881 is the velocity

This was clearly inadequate since no environmental influ-ence was included andwas subsequentlymodified by Kastneret al [85] to include the following

(a) Environmental factors(b) A modified 119870

119888 which also included downstream

influencesFACrate = 119870

1198881198911(119881119879 material composition)

times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)

After the Surry failure this was developed intoWATHEC andis used in conjunction with DASY to manage data obtainedfrom NDT examination

EPRI CHEC [2 87 88] (Chexal and Horriwtz) After theSurry failure EPRI collected all British French and Germanexperimental data together with USA plant data Otherthan being consistent with mechanistic understanding nopresumptions were made as to the form of the correlationbetween FAC rate and all the influencing variables resultingin the formulationFACrate = 119891

1(119879) 1198912(material composition) 119891

3(119870) 1198914(O2)

times 1198915(pH) 119891

6(component geometry) 119891

7(120572)

(22)

where 120572 is a factor for void fraction in two-phase flow Therehave been various modifications and improvements made tothis code and its use in plant examination

54 OtherModels A trained artificial neural network (ANN)was used [79] to make predictions but the details of theresults were only given in graphical form The following wassuggested

The combination of a deterministic model whichreflects a mechanistic picture of FAC and a purelynondeterministic ANN model which reflects bestexperimental representation of the phenomenonare the best tools for extracting information fromcomplex phenomenon such as FAC [79]

ARussian programECW-02 based onCHECWORKShasbeen developed and a Ukrainian programKASESC based onWATHEChas also been produced RAMEK is amore originalRussian approach that has been described and reviewed [8]that appears to combine a loss rate due to mass transfer witha loss rate due to the surface shear stress peeling of the oxidelayer

Various models [89ndash91] have been developed to predictdroplet attack at bends in two-phase flow but they appearto ascribe damage to be mechanical in nature As outlinedearlier the conditions causing such attack as opposed tocorrosion need defining

The relative usage of the various programs is that CHEC-WORKS is used inUSACanada Taiwan Japan SouthKoreaCzechia Slovakia and Slovenia sim153 units EDF is only usedin France but in all 58 units and COMSY is used in GermanySpain Finland Hungary and Bulgaria sim17 units


6 Discussion

A simplified summary of how the prediction schemes dealwith some of the variables that have been dealt with in thisreview is given in Table 5 and suggested reasons for thebell shaped dependency of FAC rate with temperature aresummarized in Figure 29

61 Importance of Mass Transfer It is widely agreed thatthe mass transfer coefficient is the hydrodynamic parameterthat controls the occurrence and rate of FAC A relationshipbetween rate of FAC and the mass transfer coefficient witha power dependency of greater than one is an erroneousreason to invoke the importance of 120591 the surface shearstress It is believed that there are more cogent reasons toreject the involvement 120591 as an important parameter Thesehave been dealt with in detail earlier and elsewhere Brieflythe variations in 120591 119870 turbulence level and flow assistedcorrosion rate with distance downstream of an orifice aresufficient to confirm that 120591 is not important It is probablethat a similar statement will be found for other regions wheredetached flow occurs and the relationship between masstransfer heat-transfer and pressure drop breaks down

62 Relationship between FAC and Mass Transfer and Mag-netite Solubility It is clear that there is not always a simplelinear relationship between the FAC rate and the masstransfer rate for example the variation in FAC downstreamof an orifice Of the various predictive schemes only the EdFmodel appears to suggest a linear model and the position ofthe EPRI code is unclear Figure 28 compares some CEGBand EDF data

It has been suggested that at low temperatures the FACrate is limited by the magnetite dissolution rate However anempirical fit of the data produced an activation energy thatwas a function of the mass transfer rate [70] At temperaturesabove the FACpeak it has been suggested that redox reactionscould become more important than the corrosion potentialin determining the rate of FAC Both of these situationswould produce a lower dependency on mass transfer thanat the peak temperature where the highest value of 119899 isassociated with the maximum feedback between the FACrate the corrosion potential the production of hydrogen andthe solubility of magnetite

Except for very high plateau FAC rates at low pHrsquos(Figure 30) there is no convincing evidence for the impor-tance of any processes other thanmass transfer andmagnetitesolubility The importance of magnetite dissolution kineticsbeing limiting at low temperatures appears to result from thewidespread use of the solubility data of Sweaton and BaesMost importantly this data suggests that magnetite solubilityincreases with decreasing temperatures down to about 60∘CHowever the data of Tremaine and LeBlanc show a bellshaped magnetite solubility curve (Figure 19) which moreclosely resembles the temperature dependence of FAC Inaddition there are theoretical reasons why solubility shouldnot be related to hydrogen partial pressure at low temper-atures Other reasons proposed to explain the temperaturedependence of the FAC rate are summarized in Figure 28

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20

8mm diameter tube5mm impinging jet

K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10

d0Re = 252 times 105

dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)

Figure 28 Suggested correlations between 119870 and FAC rate (a)French data ([74]) (b) British data ([12])

63 Influence of Roughness Development The way the differ-ent models deal with roughness development mass transferand the influences on the rate of FAC is summarised inTable 5 It appears that only the WATHEC model does notincorporate roughness effects However it is not clear howthe smooth to rough surface transition is handled by any ofthe models The EdF model incorporates a formulation verysimilar to Figure 12 with the factor 001 being replaced with0193(120576119889)

02 This would appear a reasonable formulation inline with pressure drop formulations However it is clear thatthat as Re increases the size of scallops produced by FACdecreases although the mass transfer enhancement over asmooth surface is increased this appears inconsistent exceptpossibly during the initial stages of attack


Table 5 Models and how they deal with key variables

Model FAC function of 119881119898or 119870119899 Roughness effects Solubility relationship

Cause of FACreduction at

Low T and High TCEGB[54 66 67 70 71]

Nonlinear119899 gt 1 lt 3

Acknowledged but notspecifically integrated S and B MDRlowast Solubility

EdeF[65 69 72ndash76]

Linear119899 = 1 or less

Yes and specifiedrelationship S and B Porosity Porosity

MDR

Sanchez Calder [77] Linear 119899 = 1 or less Apparently not S and B Porosity PorosityMDR

Penn S[79]

Mechanisticmodel-linearANN modelnonlinear

Yes but not specified

Their own which is bellshaped at pH 7 and

increases withtemperature at pH 9

Unclear

EPRI[2 87 88]

Not stated but119898apparently between

06 and 07

Yes but suggested anddid not occur

Unclear which or ifincorporated into modelthough clearly identifieddifferences between Sand B and T and LeB

data

MDR Solubility

SiemensKWU [84ndash86]

FACrate 119890119888119881

where 119888 is complex 119891

of time andtemperature

Apparently not Unclear which or ifincorporated into model Unclear

Lister and Lang [15]and Uchida et al [81]

Nonlinear 119899 gt 1 dueto shear stress on

oxideYes S and B or T and LeB Unclear

lowastMDR is magnetite dissolution reaction

0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility

Rate reduces with increasing temperature due to

SolubilityPorosity

Temperature (∘C)

change in control from Ecor to Eredox

Rate reduces with decreasingtemperature because of

activation energy for oxide dissolutionchange in n in FAC rate = Kn998779C

FAC

rate

(mm

yea

r)

Figure 29 Effect of temperature on FAC with possible reasons

64 Mechanistic Comments on Prediction Models It is sur-prising that after over 40 years of investigation and devel-opment there is no widespread agreement on a number ofimportant mechanistic aspects which have an impact on theability to predict the rate of FAC these include the following

6 625 65 675 7 725 75pH in liquid at temperature

FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C

Single phase 150 ∘C

Figure 30 Effect of pH on FAC rate ([60])

(1) The relevance of various processes particularly oxideporosity

(2) The relationship between FAC and 119870(3) Which solubility data to use(4) The mechanism of improvement due to Cr content of

the steel(5) The importance and treatment of roughness develop-

mentThus despite the ability to prevent its occurrence to say thatFAC is well understood is somewhat premature


200120583m 10120583m

Figure 31 Typical magnetite deposit

65 Relationship of FAC to Deposition and SCC The rough-ness that develops during both FAC and the deposition ofrippled magnetite both increase the resistance to flow Sucheffects are usually represented graphically in terms of thefriction factor (119891) as a function of the Reynolds numberthe friction factor relates the pressure drop and thus 120591 tothe velocity Such a diagram was constructed by Moody forpipes having roughness elements of varying heights and dis-tributions Similar diagrams can be constructed for surfaceswith uniform roughness for example with sand grainsThereare some differences between these two types of diagrams[18] However in both cases under turbulent conditions thefriction factor increases with the relative roughness (120576119889) anddecreases with increases in Reynolds number A simplifiedequation was recommended [18] to estimate such effects

1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)

For surfaces that roughen as a result of dissolution ordeposition the relative roughness produced decreases withincreasing flow or Re The evidence is that such roughnessproduced a greater resistance than expected from its 120576119889

value From the upper bound mass transfer correlation andthe analogy with heat andmomentum transfer a single upperbound value of 119891 can be estimated as a function of Re as 119891 =

002Re but this has not been tested It has been suggestedand there is some evidence for the resistance peaking atthe Reynolds number at which the roughness was formed[50 92]

The difficulties predicting the occurrence of depositionhave been indicated [64] although a velocity below 16ndash29ms was stated [93] as necessary to prevent the occur-rence in straight tubes otherwise pressure drop increasesof 20 times at a Re of 106 could occur Deposition appearspreferentially at regions of high mass transfer and it has beensuggested [94] that this is due to electrokinetically generatedcurrents at regions of separated flow but deposition doesoccur on straight pipes and bends Figure 31 If electrokinet-ically currents are important deposition might be expectedto occur at any dissolved iron levels (like electrodeposition)However there is still some debate about the roles of solubleor particulate iron Like FAC deposition can be controlled by

the addition of oxygen to the water or pH changes reducingthe iron solubility

The SCC of highly stressed experimental orifice holdersundergoing FAC was reported [12] It was suggested thatthe electrochemical conditions for FAC and SCC are oftensimilar For example it was shown that the potential rangepromoting SCC and FAC of carbon steels in carbonatesolution is identical Also both SCC and FAC of carbonsteels occur in carbonate nitrate and caustic solutions Therelationship between oxide solubility and crack propagationhas also been suggested [95] However from a practicalviewpoint for carbon steels in water it is clear that cracking isfavored by oxidizing conditions which inhibit the occurrenceof FAC The occurrence of both FAC and SCC assumedimportance by the occurrence of both FAC and SCC on theoutlet headers of a CANDU plant as yet there does not seemto be a full understanding of such cracking

7 Preventing the Occurrence of FAC

If the three major influences on FAC are considered that ismaterial environmental and hydrodrodynamic as shown inFigure 2 then how to prevent its occurrence is straightfor-ward and depends if at the design stage or postconstructionand into operation

The history of the British AGRs once through steamgenerators illustrates this rather well Damage was firstobserved at and downstream of the flow control orificeassemblies situated in the feedwater inlet headers These areaccessible and the problemwas corrected by a redesign whichincluded a stainless steel section of tubing downstream ofthe orifice However this problem highlighted the risk to thecarbon steel bends in the economizer section of the boilerwhich was controlled initially by raising the pH Althoughthis appeared successful it limited the life of ion exchangebeds It was known that oxygen additions to the feedwatercould be beneficial in terms of general corrosion [96 97]A large program demonstrated that adding a small amountof oxygen prevented FAC [78 98] High resolution surfaceactivation measurements of FAC rate confirm this as shownin Figure 32 In addition it was shown that additions ofoxygen and hydrazine could be made together and that the


Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)

Loss rate110mm yminus1



Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)

Figure 32 Effects of oxygen level on FAC rate and potential ([78])

10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected

FAC inhibited whenconcentration of O2 gt FAC rateKO2 times P

[ppb times 120588w]Where P =

(ncna) times (MaMc)

120588Fe

FAC rateKO2 times 120588w

Figure 33 Suggested correlation for oxygen effect at 150∘C (after[78]) 119899119888 119899119886 and 119872119886 119872119888 are the number of electrons and themolecular weights of the anodic and cathodic species involved in thecharge transfer steps 120588Fe is the density of iron and 120588

119908is the density

of water

oxygen would inhibit FAC in the economizer prior to beingreduced by the hydrazine and thusminimise the possibility ofSCC at oxidising potentials Thus very cleverly two additionscan be made to the secondary water having opposite effectsand preventing two forms of corrosion occurring in differentregions of the boiler

It was postulated that the amount of oxygen that wasneeded to be added to prevent FAC was related to the FACrate by Faradic equivalence

Concentration of O2gt

FACrate119870O2times 119875

(24)

where 119875 is a constant as defined in Figure 33 Note thatthe concentration (weightvolume) of oxygen is given byO2ppmtimes120588waterThe slope of the line in Figure 33 is a function

of five parameters and its value seems to be an unreliableway of obtainingmechanistic information about the reactionsinvolved

The success of such oxygen additions has been described[99] and the approach has been adopted in other situations[100] Later AGR boilers were constructed using a 1Cr

05Mo steel after extensive testing had confirmed its suit-ability The use of 1Cr 05Mo steel has the advantagethat no postweld heat-treatment is usually required unlike225Cr 1Mo and higher alloyed steels

8 Conclusions

(1) The available evidence continues to support the use ofthe mass transfer coefficient (119870) as the best hydrody-namic parameter to characterize FAC in power plant

(2) The fundamental relationship between 119870 and therate of flow accelerated corrosion continues to be asignificant difference between the different predictiveschemes However there is strong evidence that therate of FAC is not always a simple linear function ofthe mass transfer rate

(3) With normal flow as roughness develops mass trans-fer increases and the rate of FAC increases There isnow more evidence that this is much less importantwith detached flow

(4) It is clear that the influence of the environmentalparameters such as temperature pH and oxygencontent is through their effect on the solubility ofmagnetite However the details of this and the vari-ation of magnetite solubility deserve closer atten-tion In particular it might prove possible to explainthe temperature dependency of FAC in terms ofmagnetite solubility and its relationship to hydrogenpartial pressure without having to invoke a change inthe rate controlling step

(5) There is the possibility that at higher pHrsquos and tem-peratures for instance those in the CANDU primarysystem the effect of hydrogen partial pressure onmagnetite solubility might not be proportional to[H2]13 As pH increases at high temperatures there

will be a gradual reversal in the effect of hydrogencontent on solubility from being proportional to[H2]13 to [H

2]minus16

(6) The beneficial effect of chromium continues to bedemonstrated under all conditions However it is notclear if this effect is due to a reduction in the solubilityof the magnetite a change in the kinetics of oxidedissolution or its influence on the oxide porosity

(7) It is clear that oxygen additions can prevent FAC butsuch additions to the environmentmight lead to otherproblems

(8) There is still no agreement on a number of importantmechanistic aspects The mechanistic models appearto have adjustable parameters particularly the119891(119879) inthe EDF code and the 119899 in the 119870

119899 dependency of theFAC rate in the CEGB model

(9) The pragmatic models do not give enough informa-tion to completely understand their operation


Conflict of Interests

The author declares that there is no conflict of interestsregarding the publication of this paper

References

[1] in Proceedings of the Conference on Corrosion-Erosion of Steelsin High Temperature Water and Wet Steam P H Berge and FKhan Eds Electricite de France Paris France 1983

[2] ldquoFlow-accelerated corrosion in power plantsrdquo TR-106611 EPRI1996

[3] G J Bignold C H de Whalley K Garbett et al ldquoErosion-corrosion of mild steel ammoniated waterrdquo in Proceedings of the8th International Congress onMetallic Corrosion pp 1548ndash1554Mainz Germany 1981

[4] S Uchida ldquoEvaluation method for FAC of components bycorrosion analysis coupled with flow dynamics analysisrdquo inProceedings of the Annual Meeting of the Executive Committeeand Working Groups of the International Association for theProperties of Water and Steam (IAPWS rsquo06) Witney UKSeptember 2006

[5] B Poulson B S Greenwell B Chexal and G HorowitzldquoModelling hydrodynamic parameters to predict flow assistedcorrosionmdashwater reactorsrdquo in Proceedings of the 5th Interna-tional Conference on Environmental Degradation of Materials inNuclear Power Systems American Nuclear Society La GrangePark Ill USA 1992

[6] J P Slade and S T Gendron ldquoFAC and cracking of carbonsteel piping in primary water-operating experience at the PointLepreau Generating stationrdquo in Proceedings of the 12th Interna-tional Conference on Envirinmental Degradation of Materials inNuclear Power Systems-water Reactors T R King P J King andL Nelson Eds pp 773ndash784 2005

[7] G Cragnolina ldquoA review of erosion-corrosion of steels in hightemperature waterrdquo in Proceedings of the 3rd EnvironmentalDegradation of Materials in Nuclear Power SystemsmdashWaterReactors G J Theus and J R Weeks Eds pp 397ndash406 TheMetallurgical Society 1988

[8] I Betova M Bojinov and Saario ldquoPredictive modeling of flow-accelerated corrosion-unresolved problems and issuesrdquo VTTresearch report No VTT-R-08125-10 2010

[9] Y S Garud ldquoIssues and advances in the assessment of flowaccelerated corrosionrdquo Proceedings of the 14th InternationalConference on Environmental Degradation 2008

[10] G J Bignold ldquoErosion-corrosion history causes and remediesrdquoModern Power Systems vol 25 no 2 pp 11ndash15 2005

[11] B Poulson ldquoElectrochemical measurements in flowing solu-tionsrdquo Corrosion Science vol 23 no 4 pp 391ndash430 1983

[12] B Poulson ldquoPredicting the occurrence of erosion corrosionrdquo inPlant Corrosion Prediction of Materials Performance J E Struttand J R Nichols Eds pp 101ndash132 Ellis Harwood ChichesterUK 1987

[13] B Poulson ldquoAdvances in understanding hydrodynamic effectson corrosionrdquo Corrosion Science vol 35 no 1ndash4 pp 655ndash6611993

[14] B Poulson ldquoErosion-Corrosionrdquo in Corrosion L L ShrierR A Jarman and G T Burnstein Eds chapter 1ndash11 Butter-worthHeinnmann Oxford UK 3rd edition 1994

[15] DH Lister and L C Lang ldquoAmechanisticmodel for predictingFA and GC of carbon steel in reactor primary coolantsrdquo in

Proceedings of the International Conference on Water Chemistryof Nuclear Reactor Systems (CHIMIE rsquo02) Societe FrancaisedrsquoEnergie Nucleaire Avignon France 2002

[16] D C Silverman ldquoRCE-an approach for predicting velocitysensitive corrosionrdquo in Flow Induced Corrosion FundamentalStudies and Industrial Experience K J Kennelley R H Hauslerand D C Silverman Eds NACE Houston Tex USA 1992

[17] G F Hewitt Measurement of two phase flow parametersAcademic Press London UK 1978

[18] B MasseyMechanics of Fluids Taylor amp Francis London UK8th edition 2006 Revised by J Ward-Smith

[19] A A Wragg ldquoApplications of the limiting diffusion currenttechnique in chemical engineeringrdquoChemical Engineer no 316pp 39ndash49 1977

[20] T Mizushina ldquoThe electrochemical method in transport phe-nomenardquo Advances in Heat Transfer vol 7 pp 87ndash161 1971

[21] B Poulson and R Robinson ldquoThe use of a corrosion process toobtain mass transfer datardquo Corrosion Science vol 26 no 4 pp265ndash280 1986

[22] MW E Coney S JWilkin andH S OatesThermal-hydrauliceffects on mass transfer behaviour and on erosion corrosionmetal loss rate paper 13 in ref 1 1983

[23] D DWang ldquoCharacterization of local mass transfer rate down-stream of an orificerdquo Open Access Dissertations and ThesesPaper 7142 2012 httpdigitalcommonsmcmastercaopendis-sertations7142

[24] A Etebari ldquoRecent innovations in wall shear stress sensortechnologiesrdquo Recent Patents on Mechanical Engineering vol 1no 1 pp 22ndash28 2008

[25] S M Chouikhi M A Patrick and A A Wragg ldquoTwophase turbulent wall transfer processes downstream of abruptenlargements of pipe diameterrdquo in Proceedings of the Interna-tional Conference on the Physical Modelling of Multi-Phase FlowCoventry BHRA Cranfield UK 1983

[26] G Schmitt C Werner and M Bakalli ldquoFluid mechanicalinteractions of turbulent flowing liquids with the wall-revistedwith a new electrochemical toolrdquo Paper 5344 NACE HoustonTex USA 2005

[27] G Schmitt and M Bakalli ldquoMaximum flow intensities at toolsfor measuring flow influenced corrosionrdquo Paper 9472 NACEHouston Tex USA 2009

[28] G Schmitt andM Bakalli ldquoA critical review of measuring tech-niques for corrosion rates under flow conditionsrdquo PowerPlantChemistry vol 9 no 6 pp 89ndash106 2007

[29] S Nesic and J Postlethwaite ldquoHydrodynamics of disturbedflow and erosion-corrosion part I single-phase flow studyrdquoTheCanadian Journal of Chemical Engineering vol 69 no 3 pp698ndash702 1991

[30] G Schmitt and T Gudde ldquoLocal mass transport coefficientsand local wall shear stresses at flow disturbancesrdquo paper 102 atCorrosion NACE Houston Tex USA 1995

[31] I S Woolsey Private communication 1983[32] D H Lister and S Uchicia ldquoReflections on FAC mechanismsrdquo

Power Plant Chemistry vol 12 no 10 pp 590ndash597 2010[33] M Matsumura and Y Oka ldquoMechanism of erosion corrosion

of copper alloysrdquo in Proceedings of the Pacific Corrosion Mel-bourne Australia 1987

[34] M Matsumura Y Oka S Okumoto and H Furuya ldquoJet-in-slittest for studying erosion corrosionrdquo STP866 ASTM 1985

[35] M Coney CERL Report RDLN19780 1980


[36] G Schmitt and M Mueller Critical Wall Shear Stresses inCO2Corrosion of Carbon Steel Paper 44 Corrosion 99 NACE

Houston Tex USA 1999[37] B Poulson and R Robinson ldquoThe local enhancement of mass

transfer at 180∘ bendsrdquo International Journal of Heat and MassTransfer vol 31 no 6 pp 1289ndash1297 1988

[38] B Poulson ldquoMass transfer from rough surfacesrdquo CorrosionScience vol 30 no 6-7 pp 743ndash746 1990

[39] B Poulson ldquoMeasuring and modelling mass transfer at bendsin annular two phase flowrdquo Chemical Engineering Science vol46 no 4 pp 1069ndash1082 1991

[40] B Poulson B S Greenwell B Chexal and G HorowitzldquoRoughness effects on flow assisted corrosionrdquo in Proceedingsof the International Conference on Interaction of Iron BasedMaterials with Water and Steam B Dooly and A Bursik EdsEPRI Palo Alto EPRI TR 102102 1993

[41] B Poulson ldquoComplexities in predicting erosion corrosionrdquoWear vol 233ndash235 pp 497ndash504 1999

[42] S Uchida M Naitoh Y Uehara H Okada and D H ListerldquoEvaluation method for FAC of components by corrosionanalysis coupled with flow dynamics analysisrdquo in Proceedings ofthe 13th International Conference on Environmental Degradationof Materials in Nuclear Power Systems CNS Whistler CanadaAugust 2007

[43] E Hoashi S Yoshihashi-Suzuki T Kanemura et al ldquoDevel-opment of 3D CFD technology for flow-assisted corrosionrdquo inProceedings of the Conference on Water Chemistry of NuclearReactor Systems (NPC rsquo08) Berlin Germany 2008

[44] J M Pietralik and B A W Smith ldquoCFD application to FAC infeeder bendsrdquo inProceedings of the 14th International Conferenceon Nuclear Energy (ICONE rsquo06) Miami Fla USA 2006

[45] J M Pietralik and C S Schefski ldquoFlow and mass transfer inbends under FAC wall thinning conditionsrdquo in Proceedings ofthe 17th International Conference on Nuclear Energy (ICONErsquo09) Brussels Belgium 2009

[46] D Zinemams and A Herszaz ldquoFlow accelerated corrosionflow field and mass transport in bifurcations and nozzlesrdquo inProceedings of the International Conference on Water Chemistryfor Nuclear Reactor Systems NPC Berlin Germany 2008

[47] K Yoneda ldquoEvaluation of hydraulic factors affecting flowaccelerated corrosion and its verificationwith power plant datardquoin Proceedings of the ASME 2009 Pressure Vessels and PipingConference PVP Prague Czech Republic 2009

[48] J R L Allen ldquoBed forms due tomass transfer in turbulent flowsa kaleidoscope of phenomenardquo Journal of Fluid Mechanics vol49 pp 49ndash63 1971

[49] P N Blumberg and R L Curl ldquoExperimental and theoreticalstudies of dissolution roughnessrdquo Journal of Fluid Mechanicsvol 65 no 4 pp 735ndash751 1974

[50] R M Thomas ldquoSize of scallops and ripples formed by flowingwaterrdquo Nature vol 277 no 5694 pp 281ndash283 1979

[51] L Tomlinson and C B Ashmore ldquoErosion corrosion of carbonand low alloy steels by water at 300 degree Crdquo The BritishCorrosion Journal vol 22 no 1 pp 45ndash52 1987

[52] H M Crockett and J S Horowitz ldquoLow temperature FACrdquo inProceedings of the ASME PVampP Div (PVP rsquo09) ASME PragueCzech Republic 2009

[53] P R Tremaine and J C LeBlanc ldquoThe solubility of magnetiteand the hydrolysis and oxidation of ferrous ions in water to300∘Crdquo Journal of Solution Chemistry vol 9 no 6 pp 415ndash4411980

[54] G J Bignold ldquoErosion-corrosion of steels in feedwatermdasha broader application of the theoryrdquo in Proceedings of theInternational Conference on Interaction of Iron Based Materialswith Water and Steam B Dooly and A Bursik Eds EPRI TR102102 EPRI Palo Alto Calif USA 1993

[55] S E Ziemniak M E Jones and K E S Combs ldquoMagnetitesolubility and phase stability in alkaline media at elevatedtemperaturesrdquo Journal of Solution Chemistry vol 24 no 9 pp837ndash877 1995

[56] F H Sweeton and C F Baes Jr ldquoThe solubility of magnetiteand hydrolysis of ferrous ion in aqueous solutions at elevatedtemperaturesrdquoThe Journal of ChemicalThermodynamics vol 2no 4 pp 479ndash500 1970

[57] G Bohnsach Solubility of Magnetite in Water and AqueousSolutions of Acid and Alkalies Vulkan Essen Germany 1987

[58] S M Walker and E WThorton ldquoReanalysis of oxide solubilitydatardquo in Proceedings of the Water Chemistry of NRS vol 5 pp89ndash95 BNES London UK 1989

[59] M Bojinov P Kinnunen K Lundgren and G WikmarkldquoCharacterisation and modelling of oxide films on stainlesssteels and Ni alloys in light water reactorsrdquo VTT Report NoBTU073-041285 2004

[60] G J Bignold ldquoDistribution of solutes between water andsteam- influence on two phaserdquo in Proceedings of the FAC8th International Conference Combined Cycle Plants with HeatRecovery Systems EPRI Calgary 2006

[61] M Coney ldquoErosion-Corrosion the calculation ofmass-transfercoefficientsrdquo CERL Report RDLN19780 1980

[62] J Newman ldquoMass transport and potential distributions ingeometries of localized corrosionrdquo in Proceedings of the U REvans Conference on Localized Corrosion R W Staehle B FBrown and J Kruger Eds vol 3 pp 45ndash61 NACE HoustonTex USA 1974

[63] WMM Huijbregts ldquoThe influence of chemical compositionofcarbon steel on erosion corrosion in wet steamrdquo in Proceedingsof the Conference on Corrosion-Erosion of Steels in High Tem-perature Water and Wet Steam P H Berge and F Khan EdsElectricite de France Paris France 1983

[64] B Poulson H Gartside and R Robinson ldquoCorrosion aspectsassociated with orifice plates and orifice assembliesrsquordquo in Pro-ceedings of the Conference on Corrosion-Erosion of Steels in HighTemperature Water and Wet Steam P H Berge and F KhanEds paper no 10 Electricite de France Paris France 1983

[65] S Trevin FAC in Nuclear Power Plant Components in NuclearCorrosion Science and Engineering Damien Feron WoodheadPublishing Cambridge UK 2012

[66] G J Bignold KGarbett RGarnsey and I SWoosey ldquoErosion-corrosion in nuclear steam generatorsrdquo INIS Collection Searchpp 1ndash14 1981

[67] J G Bignold C H DeWhalley K Garbett and I WoolseyldquoMechanistic aspects of erosion corrosion under boiler feedwa-ter conditionsrdquo inWater Chemistry vol 3 pp 219ndash226 BritishNuclear Energy Society London UK 1983

[68] K A Burrill E L Cheluget and M Chocron ldquoModelling theeffect of Cr on FAC in reactor circuitsrdquo in Proceedings of theWater Chemistry of NRS BNES pp 528ndash537 Bournemouth UK1999

[69] M Bouchacourt ldquoImprovements in ECmechanisticmodel roleof surface filmrdquo inWater Chemistry of Nuclear Reactor Systemsvol 6 pp 338ndash340 BNES London UK 1992


[70] G J Bignold K Garbett and I S Woolsey ldquoErosion corrosionin boiler feedwater comparison of laboratory and plant datardquoin Proceedings of the UK Corrosion Conference Institute ofCorrosion Science and Technology Birmingham UK 1983

[71] A J Bates G J Bignold K Garbett et al ldquoCEGB single phaseerosion-corrosion research programmerdquo Nuclear Energy vol25 no 6 pp 361ndash370 1986

[72] B J Ducreux and P Saint-Paul ldquoEffects of chemistry onerosion-corrosion of steels in waterrdquo in Proceedings of theWaterChemistry of NRS 2 BNES pp 19ndash23 London UK

[73] J Ducreux ldquoThe influence of flow velocity on the corrosion-erosion of carbon steel in pressurized waterrdquo in Proceedingsof Water Chemistry of Nuclear Reactor Systems pp 227ndash233British Nuclear Energy Society London UK

[74] M Bouchacourt and F-N Remy EDF Study of FAC for theFrench PWR Secondary Circuit Predicting the life of CorrodingStructures NACE Cambridge UK 1991

[75] E-M Pavageau O de Bouvier S Trevin J-L Bretelle andL Dejoux ldquoDejoux Update of the water chemistry effect onthe FAC rate of carbon steel iinfluence of hydrazine boricacid ammonia morphine and ethanolaminerdquo in Proceedings13th International Conference on Environmental Degradation ofMaterials in Nuclear Power Systems CNS Whistler CanadaAugust 2007

[76] E Ardillon B Villain and M Bouchacourt ldquoProbabilisticanalysis of FAC in French PWR the probabilistic version ofBRT-CICERO version 2rdquo

[77] L E Sanchez-Caldera P Griffith and E Rabinowicz ldquoThemechanism of corrosion-erosion in steam extraction lines ofpower stationsrdquo Journal of Engineering for Gas Turbines andPower vol 110 no 2 pp 180ndash184 1988

[78] I S Woolsey G J Bignold C H de Whalley and K GarbettldquoThe influence of oxygen and hydrazine on E-C behaviourand electrochemical potentials of carbon steel under boilerfeedwater conditionsrdquo in Proceedings of the 4th InternationalConference on Water Chemistry of Nuclear Reactor SystemsBritish Nuclear Energy Society 1986

[79] M Urquidi-Macdonald D V Vooris and D D MacdonaldldquoPrediction of single phase erossio corrosion in mild steel pipesusing artificial neural networks and a deterministic modelrdquoCorrosion 95 paper 546 NACE 1995

[80] K A Burrill and E L Cheluget ldquoCorrosion of CANDU outletfeeder pipesrdquo in Proceedings of the JAIF International Conferenceon Water Chemistry NPP Kashiwazaki Japan 1998

[81] S Uchida I M Naito Y Uehara H Okada S Koshizuka andD H Lister Evaluation of Flow Accelerated Corrosion of PWRSecondary Components by CorrosionAnalysis Coupledwith FlowDynamics Analysis Springer Berlin Germany 2008

[82] S Uchida M Naitoh H Okada T Ohira S Koshizuka andH Derek ldquoLister evaluation of FAC simulation code based onverification and validationrdquo Power Plant Chemistry vol 12 no9 pp 550ndash559 2010

[83] W G Cook D H Lister and J M McInerney ldquoThe effects ofhigh liquid velocity and coolant chemistry onmaterial transportin PWR coolantsrdquo in Water Chemistry of Nuclear ReactorSystems vol 8 BNES London UK 2000

[84] H Keller ldquoErosionskorrosion in Nassdampfturbinenrdquo VGBKraftwerkstechnik vol 54 no 5 pp 292ndash295 1974

[85] W Kastner M Erve N Henzel and B Stellwag ldquoCalculationcode for erosion corrosion induced wall thinning in pipingsystemsrdquo Nuclear Engineering and Design vol 119 no 2-3 pp431ndash438 1990

[86] H Nopper and A Zanderepri ldquoLifetime evaluation of plantcomponents affected by FAC with the COMSY coderdquo in Pro-ceedings 13th International Conference on Environmental Degra-dation of Materials in Nuclear Power Systems CNS WhistlerCanada August 2007

[87] C Schefski J Pietralik T Dyke and M Lewis ldquoFlow-accelerated corrosion in nuclear power plants applicationof checworks at darlingtonrdquo in Proceedings of the 3rd CNSInternational Conference on CANDU Maintenance TorontoCanada November 1995

[88] H M Crockett and J S Horowitz ldquoDetermining FAC degra-dation from NDE datardquo in Proceedings of the ASME PressureVessels and Piping Conference pp 909ndash918 Prague CzechRepublic July 2009

[89] T Ohira R Motira K Tanji et al ldquoPrediction of liquid dropletimpingement erosion (LDI) trend in actual NPPrdquo in Proceedingsof the AMSE PVP Prague Czech Republic 2009

[90] R Morita F Inada and K Yoneda ldquoDevelopment of evaluationsystem for liquid droplet impingement erosion (LDI)rdquo inProceedings of the AMSE PVP 20009 Prague Czech 2009

[91] M Satou T Sato and A Hasegawa ldquoRole of oxide layer on wallthinning caused by liquid droplet impingement (PVP rsquo09)rdquo inProceedings of the AMSE Pressure Vessels and Piping ConferencePrague Czech Republic 2009

[92] W Schoch H Wiehn R Richter and H Schuster ldquoIncreasein pressure loss and magnetite formation in a benson boilerrdquoBritish Corrosion Journal vol 6 pp 258ndash268 1971

[93] L M Wyatt Materials of Construction for Steam Power PlantApplied Science Publishers London UK 1976

[94] M I Woolsey R M Thomas K Garbett and G J BignoldldquoOccurrence and prevention of enhanced oxide deposition inboiler flow control orificesrdquo in Proceedings of the 5th Interna-tional Conference on the Water Chemistry of Nuclear ReactorSystems vol 1 pp 219ndash228 BNES London UK

[95] J R Weeks B Vyas and S H Isaacs ldquoEnvironmental factorsinfluencing SCC in boiling water reactorsrdquo Corrosion Sciencevol 25 pp 757ndash768 1985

[96] R K Freier ldquoProtective film formation on steel by oxygen inneutral water free of dissolved solidsrdquo in Proceedings of the VGBFeedwater Conference pp 11ndash17 1969

[97] G M W Mann ldquoThe oxidation of Fe base alloys containingless than 12Cr in high temperature aqueous solutionsrdquo inHigh Temperature High Pressure Electrochemistry in AqueousSolutions NACE-4 pp 34ndash47 NACE Houston Tex USA 1976

[98] G M Gill J C Greene G S Harrison D Penfold and M AWalker ldquoThe effects of oxygen and iron in feedwater on erosion-corrosion of mild stel tubing paper 15rdquo in Proceedings of theConference on Corrosion-Erosion of Steels in High TemperatureWater and Wet Steam P H Berge and F Khan Eds Electricitede France Paris France 1983

[99] G P Quirk I S Woolsey and A Rudge ldquoUse of oxygen dosingto prevent flow-accelerated corrosion in advanced gas-cooledreactorsrdquo Power Plant Chemistry vol 13 no 4 2011

[100] W Ruhle H Neder G Holz and V Schneider ldquoOxygeninjection into reheater steam of moisture separator reheatersrdquoPowerPlant Chemistry vol 7 no 6 pp 355ndash363 2005

TribologyAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Advances in

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Submit your manuscripts athttpwwwhindawicom


StructuresJournal of


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EnergyJournal of


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International Journal ofPhotoenergy


Nuclear InstallationsScience and Technology of


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Nuclear EnergyInternational Journal of


High Energy PhysicsAdvances in

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Plant ComponentParameters

pH Re

a

(a) (b)

(d)(c)

Hinkley SG tube inlet with

AVT secondary water155 156

bMihama

Condensate water pipe after orifice 540

cSurry

reducing T-piecein condensate system

190 305

dBend after end-

fittingoutlet feeder pipe primary water

AGR3

PWR4

PWR5

CANDU6

dd0 = 1612

orifice dd0 = 328

O2 d (mm)

sim2ppb

4ppb

sim0

T (∘C)

2 times 105

58 times 106

107 ish

38ndash90102ndash108305ndash315

91ndash94

86ndash93140ndash142

89ndash90

35ndash77 times 106

lt5ppb

90∘ bend after

Figure 1 Examples of FAC in nuclear power plants

2 Hydrodynamics

The various hydrodynamic parameters that have been cred-ited with controlling the occurrence and rate of flow assistedcorrosion are as follows

(i) Velocity (119881)(ii) Reynolds number (Re)(iii) Mass transfer coefficient (119870)(iv) Surface shear stress (120591)(v) Intensity of turbulence (TI)(vi) Freak energy density (FED)

An attempt to describe how each of these parameters mightbe measured is given in Table 1 It is widely accepted thatit is neither the velocity nor the Reynolds number that iscritical Both the surface shear stress and the mass transfercoefficient are widely believed to be important The formerin the oil and gas field the latter in the power generatingindustry But recently 120591 has gained some devotees [15] in thepower generating industry However there are some workers[16] who believe the following

Themass transfer coefficient is intimately linked towall shear stress and the two cannot be practically





[11 17 18]





[12 19ndash23]



[12 18ndash20 24 25]



[11 18ndash20]






Chromium content

Magnetitesolubility

Materialcomposition



Sh = aRex Scy









0

1

2

3


diameters



Surfa

ce sh

ear s

tress

(Nmminus2)

minus1

minus2


60

50

40

30

20

10

00 10 20

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140




times103

Wal

l she

ar st

ress

(Nmminus2)





272mm 838mm

pH 904 115∘C Re = 104times 105

Oxide thickness

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)


Oxi

de th

ickn

ess (120583

m)


12

10

08

06

04

02

0

12

10

08

06

04

02

0

006 Cr 001 Mo 019 Cu




119908 =119889119864

119889119881= 05120588119860

22 (1)







0

1

2

3


Frea

k en

ergy

den

sity

(GPa

)



1M NaCl 1bar CO2 RT











Transport of Fe3+


2minus



(a)

Flow

(b)

Re sim 4 times 104

Re sim 3 times 105

(c)





Penetration

(a)

Flow

(b)






[42]

[43]


Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033


1

10

Reynolds number Re




CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019









[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















[11 17 18]





[12 19ndash23]



[12 18ndash20 24 25]



[11 18ndash20]






Chromium content

Magnetitesolubility

Materialcomposition



Sh = aRex Scy









0

1

2

3


diameters



Surfa

ce sh

ear s

tress

(Nmminus2)

minus1

minus2


60

50

40

30

20

10

00 10 20

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140




times103

Wal

l she

ar st

ress

(Nmminus2)





272mm 838mm

pH 904 115∘C Re = 104times 105

Oxide thickness

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)


Oxi

de th

ickn

ess (120583

m)


12

10

08

06

04

02

0

12

10

08

06

04

02

0

006 Cr 001 Mo 019 Cu




119908 =119889119864

119889119881= 05120588119860

22 (1)







0

1

2

3


Frea

k en

ergy

den

sity

(GPa

)



1M NaCl 1bar CO2 RT











Transport of Fe3+


2minus



(a)

Flow

(b)

Re sim 4 times 104

Re sim 3 times 105

(c)





Penetration

(a)

Flow

(b)






[42]

[43]


Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033


1

10

Reynolds number Re




CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019









[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0

1

2

3


diameters



Surfa

ce sh

ear s

tress

(Nmminus2)

minus1

minus2


60

50

40

30

20

10

00 10 20

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140




times103

Wal

l she

ar st

ress

(Nmminus2)





272mm 838mm

pH 904 115∘C Re = 104times 105

Oxide thickness

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)


Oxi

de th

ickn

ess (120583

m)


12

10

08

06

04

02

0

12

10

08

06

04

02

0

006 Cr 001 Mo 019 Cu




119908 =119889119864

119889119881= 05120588119860

22 (1)







0

1

2

3


Frea

k en

ergy

den

sity

(GPa

)



1M NaCl 1bar CO2 RT











Transport of Fe3+


2minus



(a)

Flow

(b)

Re sim 4 times 104

Re sim 3 times 105

(c)





Penetration

(a)

Flow

(b)






[42]

[43]


Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033


1

10

Reynolds number Re




CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019









[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0

1

2

3


Frea

k en

ergy

den

sity

(GPa

)



1M NaCl 1bar CO2 RT











Transport of Fe3+


2minus



(a)

Flow

(b)

Re sim 4 times 104

Re sim 3 times 105

(c)





Penetration

(a)

Flow

(b)






[42]

[43]


Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033


1

10

Reynolds number Re




CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019









[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















Penetration

(a)

Flow

(b)






[42]

[43]


Re = 5767 times 106

dd0 = 1612

d = 54 cm120574 = 0002119 cm2 sminus1

01

1

10

100

Mas

s tra

nsfe

r coe

ffici

ent (

mm

sminus1)

K = Dd00165Re086 Sc033


1

10

Reynolds number Re




CFD results

[42]

[43]dd0 = 267

dd0 = 133

100E + 03 100E + 04 100E + 05 100E + 06 100E + 07

Enha

ncem

ent(dd

0)067

Enhancement(dd0)

067= 1673 Reminus019









[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of






















[42]



[43]




[44 45]



[46]












jet at height of 1d

Rotating cylinder

d

120598= 87

90mm pipe

Copper corrosion

LCDT

Plaster dissolution


Poulson 1990



Re

Sh Sc

minus0

33

Sh = 001Re Sc033

103

102

103 104 105 106



Sh = 001Re Sc033 (2)












(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




























(3)






(a)

(b)


0195Re065Sc033







06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















06

K(m

ms

)

12

11

09

08

07

05

04

03

02

01

020 10 0 10 20

1 cm

1 cm

13mm

325mm

23mm


VL = 0995msVG = 39msX = 008

VL = 0063msVG = 76msX = 066

(a)


0 01 02 03 04 05 06


0

01

02

03

04

05

06

Pred

icte

dK

(mm

sminus1)

25D bends

73D bends

(b)


Feed solution

H2

H2

Pump

P

P P

P

Filter025 120583m

Coil

Pt catalyst

Oven

Fe3O4 bed

Ti frit

BypassHeaters

Condenser

Cation exchange

Filter 1120583m

Capillary 50120583m





minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















minus9

minus8

minus7

minus6

minus5

minus4

minus3

3 4 5 6 7 8 9 10 11 12 13

pH at 25∘C

Iron

conc

entr

atio

n lo

g (m

mkg

minus1)


8

0

01

02

03

04

05

06

07

08

09

1

2 3 4 5 6 7 8 9 10 11 12 13 14


Frac

tion

of sp

ecie

s

Fe2+Fe(OH)minus4

Fe(OH)minus3

Fe(OH)2

Fe(OH)3FeOH+


4 5 6 7 9 10





pH = 6456 + 16365 exp(minus119879∘C

88518) (4)




10

101

0 100 200 300

Temperature (∘C)

Iron

conc

entr

atio

n (p

pb)

100

10

1

0

pH 85

pH 98

pH 126












1

3Fe3O4+ (2 minus 119887)H+ + 1

3H2


2minus119887+ (

4

3minus 119887)H

2O

(5)


2]minus16 and that


3Fe3O4+ (3 minus 119887)H+


3minus119887+

1

6H2+ (

4

3minus 119887)H

2O(6)





0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















0

20

40

60

80

100

120

140

50 100 150 200 250 300

Solu

bilit

y (p

pb) pH25∘C = 9



with LiOH

Temperature (∘C)


minus11

minus10

minus9

minus8

minus7

minus6

minus5

minus4

minus3



Iron

solu

bilit

y lo

g (m

M)

1ppb Fe

300∘C


150∘C








012345678910111213141516

0 50 100 150 200 250

For FeOH+

fitted byDx = D2512058325(Tx + 273)298120583x

D = (a + cT2 + eT4)(1 + bT2 + dT2 + fT6)

a = 0573095855 b = 0000526383 c = 0000900858


FeOH+ OHminus

Fe(OH)2

Fe++(OHminus)2

Diff

usio

n co

effici

ent

(10minus9

m2

sminus1 ) o

r (10

minus5

cm2

sminus1 )

Temperature (∘C)

08944 at 25∘C



119863119894=

119877120582119894119879

119899119894119865

(7)









001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















001

01

1

10


Relat

ive F

AC ra

te



Some plant data


200 120583m 200120583m

(a) (b)

(c)

(d) (e)






















FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





































FACrate = 119870Δ119862 (9)









Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















Orifice

d0

x

x

Sh

ShSh

xd xd

1 2 3 4 5 6 7Hd lt 5

Hd gt 5

d

d


H

sim2







at low temperatures

1

FACrate=

1

119870Δ119862+

1


(12)



FACrate = 119870119899Δ119862 (13)





From which one gets

FACrate = 2119896119870

2119896 + 119870 (Ceq minus Co) (15)


FACrate =120579Δ119862

[1119896 + 05 (1119870 + 120575119863)] (16)



FACrate = 2119870120579Δ119862 (17)


119870component = 00193[120576

119889]02

Re Sc04 (119863

119889)






Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of





















Both Fe2+and Fe3+

Metal Oxide

Semiconductor with


(1) Steeloxidation
















surface finishes

0 100 200 300 400 500 600 700 800Time (hours)

0

10

20

30

40

50

60

Cor

rosio

n lo

ss m

icro

ns






13 relationship













2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




























2-hydra-








FACrate = [119891 (119879) 119891 (119883)119881119870119888] minus 119870119904 (20)








times 1198912(pH) 119891

3(O2) 1198914(time) 119891

5(119883)

(21)




3(119870) 1198914(O2)

times 1198915(pH) 119891


7(120572)

(22)








6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















6 Discussion






Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

08

06

04

02

0 05 10 15 20


K (mm sminus1)

180 ∘CpH 9

0025Cr 002Mo 002Cu

(a)

Eros

ion

corr

osio

n ra

te (m

m ye

arminus1)

K (mm sminus1)

180 ∘C

10

01

00101 1 10


dd0 = 267 pH 94

003Cr 032Cu

d = 127mm

(b)














MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of



























MDR


Penn S[79]





Unclear

EPRI[2 87 88]


06 and 07



data

MDR Solubility


FACrate 119890119888119881








0

1

2

3

80 90 100 110 120 130 140 150 160 170 180

PorositySolubility


SolubilityPorosity

Temperature (∘C)




FAC

rate

(mm

yea

r)




FAC

rate

(mm

yea

r)

100

10

1

01

Two-phase

175 ∘C

150 ∘C








200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















200120583m 10120583m



1

11989105= minus36 log

1069

Re+ (

120576

371119889)111

(23)











Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of


















Met

al lo

ss (120583

m)

minus200

minus400

minus600

minus800

minus1000

minus1200

minus1400

10

8

6

4

2

0

24

20

16

12

8

4

020 60 100 140 180

Time (h)




Potential

1 2 3 4 5

1 2 3 4 5

Mea

sure

d ox

ygen

(120583g k

gminus1 )

Pote

ntia

l(m

V v

ersu

s Ag

AgC

l)


10

9

8

7

6

5

4

3

2

1

0

Oxy

gen

(ppb

)

0 10 20 30 40 50 60 70 80

Slope is 0070

FAC unaffected



(ncna) times (MaMc)

120588Fe




of water





(24)





8 Conclusions







2]minus16









References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of




















References













































































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

























































































FuelsJournal of







Advances in



Journal of


Renewable Energy





RotatingMachinery


EnergyJournal of

















review article predicting and preventing flow accelerated...

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