corrosion in carbon containing atmospheres – metal …home.agh.edu.pl/~grzesik/fhtc/10_corrosion...

CORROSION IN CARBON CONTAINING

ATMOSPHERES – METAL DUSTING

Metal dusting corrosion mechanism for iron and low-alloying steels

1. H.J. Grabke: Mat. Corr. Vol. 49, 303 (1998).2. H.J. Grabke, E.M. Müller-Lorenz, B. Eltester, M. Lucas: Mat. High Temp., 17, 339

(2000).3. Wei Gao and Zhengwei Li ”Developments in high-temperature corrosion and

protection of metals”, Ed, Woodhead Publishing Limited, Cambridge, England, 2008.

4. R. Cottis, M. Graham, R. Lindsay, S. Lyon, J. Richardson, J. Scantlebury, F. Stott, „Basic Concepts, High Temperature Corrosion, vol. I” in „Shreir’s Corrosion”, Elsevier, Amsterdam, 2010.

a C

a C

a C ( F e 3 C - F e )

a C

s t e e l g a s

C O + H 2 H 2 O + C ( )i n s t e e l

a = 1C

C O + H 2 H 2 O + C ( )i n c e m e n t i t e

c e m e n t i t e

C O + H 2 H 2 O + C ( )i n g r a p h i t e

g r a p h i t e

C + 3 F e F e 3 C

a C

C O + H 2 H 2 O + C ( )i n g r a p h i t e

g r a p h i t e

+

F e

C + 3 F e F e 3 C

a )

b )

c )

d )

s t e e l

c e m e n t i t e s t e e l

s t e e lc e m e n t i t eg r a p h i t e

Metal dusting corrosion mechanism for iron and low-alloying steels

steel

Fe3C

graphite

Fe

Fe/Fe3C

graphite

Image of nanostructural dust formed during metal dusting corrosion of a low-alloying steel

(T = 650 oC, t = 3 hrs)

5 0 n m

5 0 n m

F e

G r a f i t

Image of a graphite fiber built of iron nanoparticles, formed during metal dusting corrosion of an austenitic steel

(25%Cr-32%Ni) at 800 oC after 4 hrs

Fe

Graphite

5 0 m

Typical corrosive destruction

Low-alloying steel

High-alloying steel

5 0 m

2 c m 2 c m

Typical corrosion damages

2 c m 2 c m

1 c m

Typical corrosion damages

5 0 0 m

Typical corrosion damages

Rapid degradation of a low-alloying steel (2.25 %Cr, 1 %Mo) in CO-H2-H2O atmosphere after 3 hours of corrosion (T = 650 oC)

1 c m

Z. Zeng, K. Natesan, V.A. Maroni: Oxid. Met. Vol. 58 (2002), p. 147

Z. Zeng, K. Natesan: Chem. Mat. Vol. 15 (2003), p. 872

C.H. Toh, P.R. Munroe and D.J. Young: Mat. High Temp. Vol. 20 (2003), p. 527

C.H. Toh, P.R. Munroe and D.J. Young: Oxid. Met. Vol. 58 (2002), p. 1

Criticism of the metal dusting corrosion mechanism for iron and low-alloying steels, proposed by Grabke et al.

Criticism of the metal dusting corrosion mechanism for iron and low-alloying steels, proposed by Grabke et al.

p o d ł o ż e

m e t a l

a t m o s f e r an a w ę g l a j ą c a

Criticism of the metal dusting corrosion mechanism for iron and low-alloying steels, proposed by Grabke et al.

carburisingatmosphere

substrate

metal

CO, H2O, H2

CH4, H2O, H2

Atmospheres that cause metal dusting corrosion:

Methods of limiting metal dusting corrosion

•inserting small amounts of sulfur into the atmosphere

•growing a protective layer built of Cr2O3 lub Al2O3 on the

steel surface

Role of sulfur in inhibiting metal dusting corrosion

F e C3

ż e l a z o s i a r k a w ę g i e l

A t m o s f e r a n a w ę g l a j ą c a

z a w i e r a j ą c a s i a r k ę b e z d o d a t k u s i a r k i

Carburizing atmosphere

with sulphur without sulphur

Fe S C

Effectiveness of sulfur in inhibiting corrosion

0 , 2

0 , 4

0 , 6

0 , 8

1 , 0

0

a = 4 5 8 0C

a = 1 0 0 0C

a = 1 0 0C

0 p p m H S2

0 , 2

0 , 4

0 , 6

0 , 8

1 , 0

0

0 , 2

0 , 4

0 , 6

0 , 8

1 , 0

0

0 , 2

0 , 4

0 , 6

0 , 8

1 , 0

02 , 5 5 , 0 7 , 5 1 0 , 0 1 2 , 5 1 5 , 0 2 0 4 0 6 0 8 0 1 0 0

0 p p m H S2

0 , 0 3 p p m H S2

0 , 1 p p m H S2

0 p p m H S2

6 p p m H S2

8 p p m H S2

1 1 p p m H S2

2 5 5 0 7 5 1 0 0 1 2 5 1 5 0 1 7 5 2 0 05 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0

0 p p m H S2

0 , 1 p p m H S2

0 , 3 p p m H S20 , 5 p p m H S2

0 , 7 5 p p m H S2

1 p p m H S2

t [ h ]

t [ h ] t [ h ]

t [ h ]

Metal dusting corrosion mechanism for high-alloying steels

s t e e l s t e e l

s t a b l e c a r b i d e s

s t e e l

s t a b l e c a r b i d e sm e t a - s t a b l e c a r b i d e s

C C

s t a b l e c a r b i d e sm e t a - s t a b l e c a r b i d e s

g r a p h i t e

s t e e l

s t a b l e c a r b i d e sm e t a - s t a b l e c a r b i d e s

n a n o s t r u c t u r a l d u s t

C r O2 3

F e C 3 F e + C3

s t e e l

C r O2 3

C r O2 3 C r O2 3 C r O2 3

Metal dusting corrosion of high-alloying steels

2 5 0 m 1 m m

Investigations performed at KFCS WIMiC AGH

Studied materials:

• Carbon steel (97 at. % Fe, 2.5 at. % C and 0.5 at. % Si)• 9Cr-1Mo steel (9.32 wt. % Cr; 0.99 wt. % Mo; 0.10 wt. % C; 0.44 wt. % Mn; 0.39 wt. % Si; 0.0095 wt. % P; 0.008 wt. % S; Fe – bal.)• Fe-10Cr, Fe-30Cr, Fe-50Cr

Applied carbon-containing atmospheres:

• CH4, CH4-1%H2O, CH4-H2

• CH4-C2H6

• C3H8-30%C4H10

Corrosion tests:

773-1173 K

Morphology and phase composition analysis of corrosion products

Microthermogravimetric apparatus for investigating metal dusting corrosion processes

CH

-30

%C

H3

84

10

He

He

H2

>

M i x e r

F u r n a c e

B u l b s

S a m p l e

M i c r o b a l a n c eM a n o m e t e rF l o w m e t e r s

O u tP u m p

0 50 1000

1000

2000

3000

T = 923 K

T = 973 K

T = 1023 K

T = 1073 K

m/S

[

g m

-2 ]

Time [ h ]

0 2 4 6 80

50

100

T = 923 K

T = 973 K

T= 1023 K

T = 1073 K

m/S

[

g m

-2 ]

Time [ h ]

Corrosion kinetics of metal dusting of carbon steels

Time [h]

8 9 10 11 1210-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

k l

[ g

m-2

]

T-1/ 104 [ K-1 ]

1173 1073 973 873 T [ K ]

Temperature dependence of metal dusting corrosion rate for carbon steel

0 1 2 3 4 50

50

100

150

200

1023 K

923 K973 K

1073 K

m

/S

/ gm

-2

Time / h

Corrosion kinetics for metal dusting of 9Cr-1Mo steel

Time / h

8 9 10 11 1210-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

k l /

g m

-2 s-1

T-1 104 / K-1

1173 1073 973 873 T / K

.

Temperature dependence of metal dusting corrosion rate for 9Cr-1Mo steel

0 1 2 3 40

50

100

1023 K

1073 K

m

/S

/ g

m-2

Time / h

Fe Fe-9Cr-1Mo

Time / h

Comparison of metal dusting corrosion rates for carbon steel and 9Cr-1Mo

Image of a carbon steel sample after 3 hours of reaction at 1173 K in a propane-butane mixture

10 mm

Image of 9Cr-1Mo steel after 3 hours of reaction at 1173 K in a propane-butane mixture

Morphology of the following samples:a)carbon steel and b)9Cr-1Mo steelafter 3 hours of reaction at 1173 K in a propane-butane mixture

Metal dusting corrosion of carbon steels

Metal dusting corrosion of carbon steels

Subsequent stages of carbon steel corrosion at 1073 Kin a propane-butane mixture

Forms of carbon steel corrosion products after exposure to a propane-butane gas mixture at 1073 K

Metal dusting corrosion of carbon steels

SUMMARY

In spite of several years of investigations on metal dusting corrosion, a rational basis for limiting this form of high-temperature corrosion has not yet been developed. Therefore, it is necessary to carry out further studies in order to gain control over this undesired phenomenon.

THE END