An Investigation on Corrosion and Stress Corrosion Cracking initiation of a Ferritic Stainless Steel in a Tertiary Amine Solution

The present study focused on stress corrosion cracking (SCC) and corrosion behavior of ferritic stainless steel (grade 430) in activated methyl diethanolamine (aMDEA) solution, which is classified as a tertiary amine. In this regard, cyclic polarization and U-bend tests were performed in CO2 loaded aMDEA with different concentrations at 25 and 70 °C to observe corrosion behavior and also the possibility of crack initiation. Based on the obtained results, it was found that the corrosion rate increased in concentrated amine solutions. Also, by increasing temperature from 25 to 70 °C both corrosion rate and susceptibility to SCC initiation were intensified. Increment of amine concentration and also increase in temperature led to more absorption of CO2, generating a more acidic solution. Overall it could be stated that while for the grade 430 stainless steel investigated in this study corrosion and cracking was observed Therefore it could be concluded that in amine-containing environments this steel is not a very suitable alternative for carbon steels, which are commonly used in these environments.