Basic Equation for Sulfide Stress Cracking

[Montana1]

Can anyone provide a basic equation for sulfide stress cracking (SSC) in carbon steel? How does the H2S react with the iron to form H+ ??????

 

[metengr]

Use the internet

http://www.aws.org/wj/jan04/still_feature.html

 

[strider6]

Actually is not H+ but H (atomic or nascent Hydrogen) that diffuse into the material and causes, with the contribute of Stress, SSC.
H2S is a weak acid that corrodes Fe (iron), the raction is:

Fe + H2S ---> FeS + H2

When H2S is present the "recombination" reaction of atomic H with another H is "inhibited" and the H instead of recombine into molecular H2 diffuse into iron (carbon steel)

http://www.corrosionist.com/Corrosion_Control_Offshore_Oil_Gas.htm

S

Corrosion & Rust Prevention Control