Pitting corrosion and stress corrosion cracking of austenitic stainless steel in acidic chloride environment

摘要

The investigation of austenitic stainless steel attacked by acid chloride containing environment was done. The 304 austenitic stainless steel was experimented in acid hydrogen chloride aqueous solution with mixing ratio 1:6 by mole. External applied stress by U-bending was also applied to specimen in order to further study stress corrosion cracking phenomenon. The result showed two distinguished characteristics: pitting corrosion and stress corrosion cracking. Pitting corrosion could be found principally on bent surface but it varied in pit sizes. Intergranular and transgranular cracking manners was found at above (high level of tensile stress area) and around neutral bending axis (low level of tensile stress) respectively, but it was rarely detected at below neutral bending area because of compressive stress initiation after bending.