What is the effect of Ni containt in steel in corrosion resistance at carbon dioxide atmosphere for low carbon dioxide partial pressure (0.1 bar). We have to select a material for condensate vapour return system and the composition of the vapour is having 15 mol% of carbon dioxide and 2 mol% of water and oxygen. I have selected 3.5 % Ni steel. Will it be suitabl in this atmosphere or what will be the corrosion rat of this alloy in 0.1 bar partial pressure of carbon dioxide atmosphere.
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What is the effect of Ni containt
- Thread starter rinu
- Start date
Nickel.
QUOTE:
In sufficient quantities, nickel is used to stabilize the austenitic form of iron and so produce austenitic stainless steels. A corrosion benefit is obtained as well, because nickel is effective in promoting repassivation, especially in reducing environments. Nickel is particularly useful in promoting increased resistance to mineral acids. When nickel is increased to about 8 to 10% (a level required to ensure austenitic structures in a stainless which has about 18% chromium) resistance to stress-corrosion cracking is decreased. However, when nickel is increased beyond that level, resistance to stress-corrosion cracking increases with increasing nickel content.
END QUOTE
QUOTE:
In sufficient quantities, nickel is used to stabilize the austenitic form of iron and so produce austenitic stainless steels. A corrosion benefit is obtained as well, because nickel is effective in promoting repassivation, especially in reducing environments. Nickel is particularly useful in promoting increased resistance to mineral acids. When nickel is increased to about 8 to 10% (a level required to ensure austenitic structures in a stainless which has about 18% chromium) resistance to stress-corrosion cracking is decreased. However, when nickel is increased beyond that level, resistance to stress-corrosion cracking increases with increasing nickel content.
END QUOTE
You mention 'condensate', what temperature do you expect?
3.5% Ni alloy steels are not 'stainless' and are not renouned for resisting corrosion in hot humid conditions. The main effect of the Nickel in this alloy is to increase toughness rather than corrosion resistance.
3.5% Ni alloy steels are not 'stainless' and are not renouned for resisting corrosion in hot humid conditions. The main effect of the Nickel in this alloy is to increase toughness rather than corrosion resistance.
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