Corrosion and stress corrosion cracking initiation of grade 304 and 316 stainless steels in activated Methyl Diethanol Amine (aMDEA) solution

This study concerns corrosion and stress corrosion cracking (SCC) initiation of type 304 and 316 austenitic stainless steels in activated Methyl Diethanol Amine (aMDEA) solution. Corrosion and stress corrosion cracking behavior of stainless steels are less known in aMDEA solution. In this regard constant deflection U-bend specimens were used for micro-crack initiation tests. Cyclic polarization test were performed to evaluate corrosion performance of 304 and 316 stainless steels. Results showed that increase in aMDEA solution concentration from 30 to 50 wt% had minor effect on corrosion and crack initiation of 304 and 316 stainless steels. Increase in temperature from 25 to 70 °C raised the corrosion rate near two folds. Grade 304 stainless steels was more susceptible to SCC crack initiation compared to 316 stainless steel, since longer cracks were formed. This was explained by the SCC film rupture mechanism.