Stress Corrosion Cracking Behavior of Carbon Steel in Aqueous Dipa and in Dipa-Sulfolane-Water Solutions

Potentiostatic polarization and slow-strain-rate tests have been used to assess the likelihood of stress corrosion cracking of mild steel immersed in aqueous solutions of di-isopropanolamine (dipa) and in solutions of dipa in tetrahydrothiophene sulfoxide (sulfolane) and water, saturated with CO2 at different potentials and strain rates, at 95°C. Dipa-sulfolane-water solutions show no tendency for stress corrosion cracking either at the free corrosion potential or at potentials of maximum electrochemical reactivity. However, an aqueous solution of 25% dipa saturated with CO2 was found to cause transgranular stress corrosion cracking of carbon steel at the potential of -0.60V (SCE) which is located in the region of maximum anodic electrochemical reactivity.