TREATMENT FOR ANTIISTRESS CORROSION CRACKING IN TWOOPHASE STAINLESS STEEL

摘要

PURPOSE:Micro-cathode current is passed through two-phase stainless steel, thereby forming a coating layer having anti-stress corrosion property which is maintained after it returned to natural potential. CONSTITUTION:Micro-cathode current (5 to 10 mA/cm2) is passed through two- phase austenite-ferrite stainless steel for 5 minutes, thereby forming a coating layer having anti-stress corrosion cracking, such property being maintained after the current is stopped for a period of time remarkably longer, as compared to non-treated material. For example, the lowest limit stress value for anti-stress corrosion cracking is 50 kgf/cm2 for the treated material, while for non-treated material only 21 kgf/cm2 is obtained. In another example, the non-treated material failed after 2 hours at a certain load, while the treated material maintained its integrity without failure after 100 hours of current stop at the same loading condition.