SENSITIVE TEMPERATURES FOR INTERGRANULAR CORROSION OF TYPICAL STAINLESS STEELS

Electrochemical potentiodynamic reactivation(EPR)test,sulphuric acid-sulphate of copper(GB4334.5-90) and scanning electron microscope were utilized in this paper to study the intergranular corrosion susceptibility of 202,304 austenitic stainless steels and 409,430 ferritic stainless steels at different sensitive heat treatment temperatures,at which intergranular corrosion will be induced.The results show that the sensitive temperature of austenitic stainless steels and that of ferritic stainless steels are different.The sensitive temperature of austenitic stainless steel is about 650℃,while that of ferritic stainless steel is around 950℃.The results provide scientific criterion for correctly evaluating the intergranular corrosion susceptibility of stainless steel and optimizing the production technology.