New Aspects of Stress Corrosion Cracking in Monoethanolamine Solutions

Abstract Based primarily on slow strain rate test results, a mechanism for intergranular stress corrosion cracking of carbon steel in alkanolamine solutions is proposed. The mechanism involves the presence of carbon dioxide in the gas phase and carbonates, weak sulfiding agents, chlorides and/or cyanides in solution. Weak sulfiding agents studied are thiosulfate in the 0.03 to 0.21 percentage range and thiocyanate in the 0.14 and 0.28 percentage range. By themselves, these solution components are innocuous, but in the presence of chlorides and/or cyanides they initiate stress corrosion cracking in carbon steel. The amine strength of the solvent influences crack intensity and cracking mode.