1 soil & environments 1 st day

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What does it look like?What does it look like?

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COST OF CORROSION

Catastrophic failure

Leakage leading to environmental pollution Corroded rotor leading

to equipment failure


COST OF CORROSION

Soil collapse due corrosion of a municipal water underground steel pipe


Case HistoriesCase Histories


SRB Corrosion MechanismSRB Corrosion MechanismElectrochemical ReactionsElectrochemical Reactions

Step oneStep one-:-: Fe Fe → → FeFe++++ + 2 + 2ee-- (Anodic Reaction) (Anodic Reaction)..

4H4H22O O ↔↔ 2H 2H++ + 2OH + 2OH-- (Water Dissociation) (Water Dissociation)..

2H2H++ + 2e + 2e- - →→ HH2 2 (Cathodic Reaction)(Cathodic Reaction)..

2H+H2 2H 2H+

2e-

2e-


SRB Corrosion MechanismSRB Corrosion MechanismStep twoStep two-:-:

SOSO44---- + 8H + 8H ↔ ↔ SS2-2- + 4H + 4H22O (Bacterial Consumption)O (Bacterial Consumption)..

COPYRIGHT PETROLITE CORP 1993C

S2-


SRB Corrosion MechanismSRB Corrosion MechanismStep threeStep three-:-:

FeS (Corrosion Product)FeS (Corrosion Product)..Thus the theoretical amount of ferrous sulfide that may be formed from Thus the theoretical amount of ferrous sulfide that may be formed from

a given amount of sulfide isa given amount of sulfide is::

ppm SOppm SO44---- / 96 (MW SO / 96 (MW SO44

---- ) X 88 (MW FeS) = ppm FeS ) X 88 (MW FeS) = ppm FeS

S2- + Fe++ FeS


COST OF CORROSION

NACE study in 1998 showed that the cost of corrosion in U.S.A. is $ 276 billion / year

Corrosion cost :

Direct cost

materials selection

corrosion control method(s)

manufacturing


COST OF CORROSION


MANAGING CORROSION

To reduce risk of equipment failures, corrosion control is to be dealt with by implementing a “ “ Predictive / Proactive Corrosion Predictive / Proactive Corrosion ManagementManagement ProgramProgram “ “ in both :

Design phase

Running/ operative phase


DESIGN PHASEDESIGN PHASE RUNNING PHASERUNNING PHASE

Materials Selection& Corrosion Control Dept.

Operation Dept.

Inspection Dept.

Corrosion Monitoring

Process flowStream analyses

Service conditions

Past experience, case studies

Codes, standards, specifications, textbooks,

handbooks, vendors recommendations

Predictive Design

Predictive mode Predictive Maintenance

-Effective corrosion control-Extended service life

Reduced CostHigh Profitability

Overall Predictive Management Program


MANAGING CORROSION

Corrective: unplanned. Most costly

Preventive: planned on a fixed time scale

PredictivePredictive (Proactive): on a (Proactive): on a sliding time scale. Least sliding time scale. Least costlycostly

Relative Cost Of Maintenance

0.25

0.50

0.75

1.00

Corrective Preventive Predictive

Types of Maintenance


Consequences of Management on Operation & Production

MANAGING CORROSION

Proper ManagementMismanagement

1Pro-activeReactive

2Farsighted - long term planningNo vision- “out of sight, out of mind” attitude

3“Early warning” of corrosion problems

Sudden, unexpected costly failure , i.e. unplanned shutdown

4Increased production capacityDecreased production capacity

5High quality productsLow quality products due to contamination

6Responsible environmental and safety records

Environmental and safety hazards

7“Pay a little now”“Pay a lot later”


Causes of Corrosion Failures

based leading chemical company investigation outcome

Causes %Freq

APoor design/ wrong material/ bad operation

36

BWrong specification16

CBad inspection10

DHuman error12

EPoor planning14

FOthers4

GUnforeseen8

AA

EE

CC

DD

FF

BB

GG

MANAGING CORROSION


92% of corrosion failures are PreventablePreventable if the Predictive Corrosion Management Program is strictly implemented during Design and Running phases

Only 8% of unforeseen causes to be dealt with

Results: significant reduction in maintenance Results: significant reduction in maintenance activities and lower cost activities and lower cost

MANAGING CORROSION


metal Pipemetal Pipe((Gº)Gº) EnvironmentEnvironment

Metal Corrosion Metal Corrosion productproduct

THEORY OF CORROSION


Engineering MaterialsEngineering Materials

MetallicMetallic

FerrousFerrous Non-FerrousNon-Ferrous

Non- MetallicNon- Metallic

PVCPolyethylene

PolypropyleneTeflon

GRE / GRPCeramics

Copper AlloysNickel Alloys

Aluminum

Cast IronsCarbon Steels

Stainless SteelsLow alloy steel

THEORY OF CORROSION


CORROSION THEORYCORROSION THEORY

THEORY OF CORROSION


THEORY of corrosionTHEORY of corrosion


Chemical PropertiesMetals-

-Usually have 1-3 electrons in their outer shell .-Lose their valence electrons easily .

-Form oxides that are basic .-Are good reducing agents .

-Have lower electro negativities

Nonmetals

-Usually have 4-8 electrons in their outer shell .

-Gain or share valence electrons easily .

-Form oxides that are acidic .

-Are good oxidizing agents .

-Have higher electro negativities


Non-metals are the elements in groups 14-16 of the periodic table. Non-metals are not able to conduct electricity or heat very well. As opposed to metals, non-metallic elements are very brittle, and cannot be rolled into wires or pounded into sheets. The non-metals exist in two of the three states of matter at room temperature: gases (such as oxygen) and solids (such as carbon). The non-metals have no metallic luster, and do not reflect light. They have

oxidation numbers of ±4, -3, and -2 .The Non-Metal elements are :

HydrogenCarbonNitrogenOxygenPhosphorusSulfurSelenium


Metals are solids at room temperature with the exception of mercury

and gallium, which are liquids at room temperature.

HardnessAll metals are hard except sodium and potassium, which are soft and can be cut with a knife.

ConductionMetals are good conductors because they have free electrons. Silver and copper are the two best conductors of heat and electricity. Lead is the poorest conductor of heat. Bismuth, mercury and iron are also poor conductors


Non-Metallic Vessels e.g. Fiber glass

THEORY OF CORROSION

Not concern


Not concern

Non-Metallic Pipes

PVC pipingAbove-ground GRP piping

Under-ground GRP pipeline

Soil & environments


PVC Piping Connections

1- Heating the sedges 2- Pressing the sedges 3- Fusion Weldment

4- Shaving 3- Fusion Completed

Not concern

Soil & environments




THEORY OF CORROSION


Iron Oxide to Steel to Iron Oxide CycleIron Oxide to Steel to Iron Oxide Cycle

Iron OxideIron Oxide

EnergyEnergy(Blast Furnace)(Blast Furnace)

Steel PipeSteel Pipe((Gº)Gº) EarthEarth Iron OxideIron Oxide

BessemerBessemer Pipe MillPipe Mill

THEORY OF CORROSION


The extracted free metal has a high energy content. i.e. active stateactive state

Blast furnace of reducing iron

ore to iron

Electrolytic reduction of Al oxide to Al

THEORY OF CORROSION


O/S Separators

FWKO

Biocide Squeeze

Subsea Intrafield P/Ls

•Pigging,Biocide and C.I.

•Some pigging

•Some C.I. injection.

•C.P.

•Manual Cleaning, or P.D.

•C.P. + Coating

Trunk Lines

•Pigging

•Biocide

•Pigging, C.I., Biocide(M-8, M-36)

•C.I., PD (M-1, M-55)

•C.P.

•Manual Cleaning

•Sand Jet

•C.P. + Coating

•Biocide, C.I., P.D.

42”/30”

•Rotation

•Manual Cleaning

GOS CORROSION MITIGATION STATUS

HEMIS

•Fiber Glass Lining

•Chemical Cleaning

36” Suction Header

Biocide, C.I., P.D., Rotation & Replacement.

Mothballing equipment

DESALTERS•C.P.+ Coating

Deposits

ITALIC BOLD: PLANNEDROMAN : COMPLETED Draft : M.H.Eid

Chem. & Corr. Dept.R321\C:\Data\General\CS.ppt

H.EX

2nd Stage

OILTKs

•Fiber Glass Lining

1 st Stage

PROBLEMAREA

PROBLEM AREA

Soil & environments


Soil & environments


Soil and environments

Take cure


Soil and environments Characteristics


Soil & environments


Piles

Subsea Pipelines

Jackets



Sacrificial Anode Cathodic Protection for External Side

of Tank Bottom



Sacrificial anodes for vessel internals

Sacrificial Anode

Mist Eliminator



Corrosive Formation Water

Crude Oil

Vapor

Air in as Tank Breathes

Sever Corrosion Due to Condensed Aerated Moisture

Protective Coatings

Coatings + CP Sacrificial Anodes





THEORY OF CORROSION


Iron oxidesIron oxides

+

Mining & Extraction

SteelSteel

+

Corrosion

Iron oxidesIron oxides

Oxides, Ore thermodynamically stable

Mining & Extraction

Equipment fabrication, thermodynamically unstable

Corrosion

Corrosion Thermodynamic Cycle

Why Metals Corrode?

THEORY OF CORROSION


And the


What is corrosion?

Reaction of a metal with its environment (degradation)** Aqueous corrosion (with water)

** Atmospheric corrosion (with air+water+salts)** High temperature corrosion (with oxygen or other gases)

We will mainly concentrate on Aqueous corrosion

We will focus on metals especially carbon steel and CRAs used on the underground and immersed on the sea water


* *Corrosion is the return of metals to their Corrosion is the return of metals to their natural states, i.e., the ores from which natural states, i.e., the ores from which they are obtainedthey are obtained..

** Corrosion involves oxidation of the metalCorrosion involves oxidation of the metal

** Corroded metal loses its structural Corroded metal loses its structural integrity and attractivenessintegrity and attractiveness..

** Metals corrode because they oxidize Metals corrode because they oxidize easilyeasily..

What is corrosion?


Production and Production and degradation of steeldegradation of steel

Plates, pipes,profiles, etc.

Energ

y

Man

ufac

turing

Water /humidity

Oxygen

Raw materialIron ore Rust

Reaction between the material and the surrounding environment takes place

The presence of water / humidity and Oxygen is a pre-requisite for corrosion of steel


Corrosion is a reaction betweenCorrosion is a reaction between

MaterialMaterial

andand

Surrounding environmentSurrounding environment

under formation of corrosion productsunder formation of corrosion products

What is corrosion?


Some metals form a protective oxide coating, Some metals form a protective oxide coating, preventing the complete corrosion of the metal.preventing the complete corrosion of the metal.

* * Aluminum is the best example, forming AlAluminum is the best example, forming Al22OO33, , which adheres to, and protects the aluminum.which adheres to, and protects the aluminum.

* Copper forms an external layer of copper * Copper forms an external layer of copper carbonate, known as patina.carbonate, known as patina.

* Silver forms silver tarnish which is silver * Silver forms silver tarnish which is silver sulfide.sulfide.

* Gold does not corrode in air.* Gold does not corrode in air.

What is corrosion products?


Rusting of steelRusting of steel• corrosion product (rust) is solid but not corrosion product (rust) is solid but not

protectiveprotective Reaction of aluminium with waterReaction of aluminium with water

• corrosion product is insoluble in water, so corrosion product is insoluble in water, so may be protectivemay be protective

Burning of magnesium in airBurning of magnesium in air• high temperature oxidationhigh temperature oxidation



Corrosion of Iron or Steel by SRB BacteriaCorrosion of Iron or Steel by SRB Bacteria

FeSFeS

224 H O4 H O

FeSFeS

S S ++ 8 H8 H ++ 44SOSO

DesulfovibrioDesulfovibrio

8 H8 H 8 e8 e++ 8 H8 H

SOLUTIONSOLUTION

++++3Fe(OH) 3Fe(OH)

22

4Fe 4Fe 4Fe 4Fe --

--

Corrosion ProductCorrosion Product

Corrosion ProductCorrosion Product

8 OH8 OH ++--

8 H O8 H O22

8 H8 H++SOSO 44 S S ++ 224 H O4 H O

8 H8 H8 e8 e ++8 H8 H

++++

++--

DesulfovibrioDesulfovibrio

++ --8 H O8 H O22

++8 OH8 OH

2-2- 2-2-2-2-2-2-

4Fe 4Fe CathodeCathodeAnodeAnode

4Fe 4Fe

8 e8 e 8 e8 e --

4Fe 4Fe CathodeCathodeCathodeCathode

Cathodic DepolarisationCathodic DepolarisationCathodic DepolarisationCathodic Depolarisation


Copper, gold, silver, and platinum Copper, gold, silver, and platinum are relatively difficult to oxidize, are relatively difficult to oxidize,

hence the term noble metalshence the term noble metals..

Noble MetalsNoble Metals



What is corrosion?


In a chemical reaction :

Reactants Products

∆G = Gprod – Greact

In all corrosion reactions

Gprod < Greact.

Therefore,

∆G is –ve

Hence, the corrosion reaction is :

spontaneous

irreversibleirreversible

Thermodynamics of Corrosion

Reactant

Product

Reactants Products = Corrosion?


Active free metals tend to react easily to produce compounds, such as salts and oxides.

Metals in the compounded forms have less energy content, i.e. stable state.

Corrosion is governed by the Law of Conservation of Energy :

Energy Gained = Energy LostEnergy Gained = Energy Lost

THEORY OF CORROSION

F

G E

o

cell n


Corrosion Cell potential is Related to the Change in Gibb’s Free Corrosion Cell potential is Related to the Change in Gibb’s Free EnergyEnergy

where:where:EEcellcell == corrosion cell potential (volts or joules/coulomb)corrosion cell potential (volts or joules/coulomb)

nn == number of charges transferred in the oxidation reaction number of charges transferred in the oxidation reaction

FF == Faraday’s constant – 96,500 coulombs of chargeFaraday’s constant – 96,500 coulombs of charge

GGoo == change in Gibb’s free energy (joules)change in Gibb’s free energy (joules)

F

G E

o

cell n

THEORY OF CORROSION


Behavior of metals immersed on environments (electrolytes)

Delta consultingDelta consulting

Metal/Aqueous Solution InterfaceMetal/Aqueous Solution Interface

OH_

OH_

OH_

H+

IronIon

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++Electrons

O

O- -H+ H+

O- -H+ H+

O- -H+ H+

O- -H+ H+

- -H+H+

Fe++

IronIon

H+

H+

The Electrode Potential Across a Metal Electrolyte InterfaceThe Electrode Potential Across a Metal Electrolyte Interface


Corrosion Forming Ferrous HydroxideCorrosion Forming Ferrous Hydroxide

OH_

OH_

OH_

H+

H+

IronIon

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++Electrons

O

O- -H+ H+

O- -H+ H+

O- -H+ H+

O- -H+ H+

- -H+H+

Fe++

H+

H+OH_


Iron Corrosion CellIron Corrosion Cell

OH_

OH_

OH_H+

H+

H+

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++Fe Fe

O- -H+ H+

O- -H+ H+

O- -H+ H+O- -

H+ H+

O- -H+ H+


OH_

OH_

OH_H+

H+

H+

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++Fe Fe

O- -H+ H+

O- -H+ H+

O- -H+ H+

O- -H+ H+

O- -H+ H+

Fe(OH)2

H+ H+

H0

H0

AnodeAnode

CathodeCathode

Direction of Conventional CurrentDirection of Conventional Current(positive charge flow)(positive charge flow)

Icorr


Corrosion Cell ComponentsCorrosion Cell Components

An An anodeanode (where the oxidation reaction occurs) (where the oxidation reaction occurs)

A A cathode cathode (where the reduction reaction occurs)(where the reduction reaction occurs)

An An electronic pathelectronic path that allows electrons to flow from the that allows electrons to flow from the anode to the cathode (inside the metal)anode to the cathode (inside the metal)

An An electrolytic pathelectrolytic path that allows ions to flow between the that allows ions to flow between the anode and cathode (in the electrolyte)anode and cathode (in the electrolyte)

A corrosion cell has the following 4 components:A corrosion cell has the following 4 components:


Direction of Conventional CurrentDirection of Conventional Current(+ve charges) in a Corrosion Cell(+ve charges) in a Corrosion Cell

OXIDATI

ON

Anode

REDUCTI

ON

C athode

E lectro lyte

Icorr

Icorr


H+Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++

Fe++

Fe

Fe

Fe

Fe

Fe

OH+ H+

OH

OH+ H+

OH

H+

H+

OH+ H+

OH

OH

EE c,occ,oc

AA

cellcellEE

EE a,oca,oc

Fe

Fe

Fe

Fe

Fe

Fe Fe++

Open Circuit Open Circuit Corrosion CellCorrosion Cell

Cathode


H+

H+

H+

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe++

AnodeAnode

Fe++

Cathode

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

Fe

FeCathodeCathode

OH+ H+

OH

OH+ H+

OH

H+

H+

OH+ H+

OH

OH

EEc,ccc,cc

AAcorrcorrII +

e

e

Closed Circuit Closed Circuit Corrosion CellCorrosion Cell


Evans Diagram for a Corrosion Cell Under Cathodic ControlEvans Diagram for a Corrosion Cell Under Cathodic Control

Ea ,cc

E

0 I1 I2 I3 Icorr

C orrosion C urrent

Ec ,cc

Ea ,oc

Ec ,oc

Ep,c

Ep,a

Ecell

E - Polarizationcell


E

Icorr

Corrosion Current

(a) Anodic Control

E

Icorr

Corrosion Current

(b) Mixed Control

Ea,cc

Ec,cc

Ec,oc

Ea,oc

Ea,cc

Ec,cc

Ec,oc

Ea,oc

Evans Diagram for Corrosion Cells under Anodic and Mixed Evans Diagram for Corrosion Cells under Anodic and Mixed ControlControl


Fe2+

Fe2+

Fe2+

Atmospheric O2

O2

O2

OH-OH-OH-

e-e-e- e-

Anodic Area Metal Dissolution

Fe(OH)2Cathodic Area

Dissolved Oxygen Reduction

The Corrosion Cell : in Aerated Natural Water

The Corrosion Cell : in Aerated Natural Water

THEORY OF CORROSION


Corrosion Process

A. Anodic Reaction (metal dissolution)

Fe Fe 2+ + 2e-

B. Cathodic Reaction

1. Oxygen reduction reaction

O2 + 2H2O + 4e- 4 OH- Predominates in aerated

Near-Neutral solutions pH > 5

2. Hydrogen Evolution Reaction

THEORY OF CORROSION

Anodic Area

Cathodic Area

Fe(OH)2


Very important


Corrosion Process

Due to the electrochemical nature of corrosion, there shall be electron transfer

Electron transfer requires presence of anode sitesanode sites and cathode sitescathode sites on the metal surface

Due to potential difference ( ∆V ) between anodesanodes and cathodescathodes electrons migrate from anodesanodes to cathodes

Electrons liberated at anodesanodes should be consumed at cathodescathodes

THEORY OF CORROSION


THEORY OF CORROSIONTHEORY OF CORROSION

Oxidation Is Loss of electrons Reduction Is Gain of electrons

OILRIGOILRIG

Corrosion Process

@@ Anode SitesAnode Sites :

Surface defects

More -ve potentials

Metal atoms have high energy, i.e. unstable & active

Thus, metal atoms ionize by losing their electrons, i.e.

oxidation reactionoxidation reaction : M0 Mn+ + ne-

As a result, metal loss occurs, i.e. metal dissolutionmetal dissolution


Corrosion Process

@ Cathode Sites@ Cathode Sites :

Intact ( un-defected ) surface areas

More +ve potentials

Metal atoms have low energy, i.e. stable & un-active

Receive electrons to be consumed, i.e. reduction reactionreduction reaction

As a result, no metal loss occurs, i.e. no corrosion

THEORY OF CORROSION

Oxidation Is Loss of electrons Reduction Is Gain of electrons

OILRIGOILRIG


THEORY OF CORROSION

The corrosion process involves two reactions:

A. Anodic Reaction : occurs @ anode sites

Metal Dissolution : M 0surface M n+

solution + ne-

Oxidation Reaction : involves loss of electrons

B. Cathodic Reaction : occurs @ cathode sites

Reduction Reaction : involve gain of electrons

Oxygen reduction : gain of electrons by dissolved O2

Hydrogen evolution: gain of electrons by H+ ions


Faraday’s LawFaraday’s Law

corrt I F

M W t

n

where:

Wt = total weight loss at anode or weight of material produced at the cathode (g)

n = number of charges transferred in the oxidation or reduction reaction

Icorr = the corrosion current (A)

F = Faraday’s constant of approximately 96,500 coulombs per equivalent weight of material (where equivalent weight = M )

M = the atomic weight of the metal which is corroding or the substance being produced at the cathode (g)t = the total time in which the corrosion cell has operated (s)

n


Consumption Rate is Proportional to Consumption Rate is Proportional to Corrosion CurrentCorrosion Current

corrmcorrt IK I

F

M

W

nt

corrt I F

M W t

n multiplied by t

1 then the expression becomes:

Km= constant for each metal


Theoretical Consumption Rates of Various Theoretical Consumption Rates of Various Metals & Substances on an Ampere-Yr. BasisMetals & Substances on an Ampere-Yr. Basis

Reduced Species

Oxidized Species

Molecular Weight, M

(g)

Electrons Transferred

(n)

Equivalent Weight, M/n

(g)

Theoretical Consumption Rate

(Kg/A-y) Al Al+++ 26.98 3 8.99 2.94 Cd Cd++ 112.4 2 56.2 18.4 Be Be++ 9.01 2 4.51 1.47 Ca Ca++ 40.08 2 20.04 6.55 Cr Cr+++ 52.00 3 17.3 5.65 Cu Cu++ 63.54 2 31.77 10.38 H2 H+ 2.00 2 1.00 0.33 Fe Fe++ 55.85 2 27.93 9.13 Pb Pb++ 207.19 2 103.6 33.9 Mg Mg++ 24.31 2 12.16 3.97 Ni Ni++ 58.71 2 29.36 9.59

OH- O2 32.00 4 8.00 2.61 Zn Zn++ 65.37 2 32.69 10.7


ExampleExampleUsing the following equation to calculate the weight consumed Using the following equation to calculate the weight consumed

by 1 ampere of stray DC current discharging from an iron by 1 ampere of stray DC current discharging from an iron structure in 1 yearstructure in 1 year..

corrt I nF

M W t

where:where:t = 1 year = 60 s/min x 60 min/h x 8,760 h/y = 31.5 x 106 sM = 55.85 g (from Table)n = 2F = 96,500 coulombs

then:then:

kg 9.12 g9115 coulombs 96,500 2

A1 s10 31.5 g55.85 W

6

t


substituting the above equation into the Faraday equation substituting the above equation into the Faraday equation yields the following relationshipyields the following relationship::

t

Q I

where: Q ........ charge in coulombs t .......... time in seconds

corrnQ

F

M Wt

Other Corrosion-Related RelationshipsOther Corrosion-Related Relationships


Similarly, if the Faraday equation is multiplied by the termSimilarly, if the Faraday equation is multiplied by the term::

A = surface area of the anode or cathode t = time in seconds

where:where:

Then the following relationship results:Then the following relationship results:

t A

1

A

I

F

M

A

W corrt nt


NACE International Ranking for Steel Corrosion

Corrosion Rate (mpy)

Level of corrosion

<1Low

1-5Moderate

5-10Severe

>10Intense

NACE= National Association for Corrosion Engineers

THEORY OF CORROSION


Energy Metal/alloy Potential Corrosion (volts) *

Least energy required

for refining

High energy required

for refining

GoldSilverTitaniumStainless steel (316, active)Ni-Al- BronzeCopperCarbon steelAluminium (pure)Zinc (anode alloy)Aluminium (anode alloy)Magnesium (anode alloy

+0,500- 0,205- 0,225- 0,235- 0,380- 0,435- 0,600- 0,800- 1,080- 1,140- 1,550

Least corrosive

Very corrosive

* Potential in seawater measured versus a Copper / Copper Sulphate reference electrode

Galvanic Series in Sea WaterGalvanic Series in Sea WaterTHEORY OF CORROSION


THEORY OF CORROSION


Before answering


Thank You and Good Luck

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cost of corrosionsoil

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cost of corrosionnace