Analysis of residual stress relief in linear friction welded Ti17 during post weld heat treatment by Norton-Bailey creep model

Abstract

Post weld heat treatment (PWHT) is frequently employed to relieve residual stress, which affects the service performance of linear friction–welded Ti17. In this work, a Norton-Bailey creep model was introduced into the finite element analysis to investigate the mechanism of residual stress relief in linear friction–welded Ti17 during PWHT. The results show that the Norton-Bailey model can accurately predict the residual stress after PWHT, as verified by experiments. The primary mechanism of residual stress relief is stress reduction induced by the development of creep strain. Most of the residual stress relief occurs during the heating stage and the initial holding stage due to the sufficient development of creep strain. The increase in PWHT temperature is beneficial for residual stress relief. However, as the PWHT temperature exceeds ~ 630 °C, the improvement of residual stress relief is no longer significant. The relationship regarding PWHT temperature and residual stress relief is developed, which can be applied to the rapid prediction of residual stress in linear friction–welded Ti17 after PWHT.