Prediction of Creep Lifetime for Butt-Welded Joint of Type 304 Stainless Steel by Finite Element Method Incorporating Damage Variable

抄録

A computational method of predicting creep lifetime is presented for welded joints.
In the present method, time-incremental computations of stress by a finite element method and simultaneous cumulations of a variable as a measure of creep damage are reiterated up to the critical time for the cumulative value to exceed a specified limit. This critical time is regarded as the creep lifetime.
A butt-welded joint of 50 mm thick Type 304 stainless steel was prepared by SAW with depositing a 308 wire. Specimens cut from the joint were subjected to creep tests at 823 K under applied stresses of 200 to 300 MPa. The obtained data was compared with the computations.
The comparison showed that the creep lifetime of the joint predicted from the computations is within the factor of two (one half to two times) of that measured.