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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