Abstract
The nondestructive method to predict the time when the austenitic stainless steel welded joint exceeds a critical degree of sensitization at a low temperature is investigated by the mathematical model and experimental tests.
The material used in this experiment is type 304 stainless steel without cold working. To measure the degree of sensitization, the electrochemical potentiokinetic reactivation (EPR) test was used. To determine the intergranular etch ratio, the 10% oxalic acid etch test was employed.
From the mathematical analysis, the following results were obtained. The time when welded joint exceeds a critical degree of sensitization is predicted from the results of the accelerated test with the test pieces having the intergranular etch ratio similar to that of the welded joint at a temperature below 873 K. In the case where the intergranular etch ratio of welded joint is less than 0.7, this method is useful.
From these experimental tests, we were able to predict the time using the method based on the mathematical analysis.
