Effects of vibratory weld conditioning on residual stresses and transverse contraction distortions in multipass welding

摘要

For the full welded valve, the last procedure is welding, therefore, it is important to control the residual stresses and distortions in order to ensure spool rotation, valve watertightness, the stress corrosion resistance and non-deformability in active service. In the present study, effects of vibratory weld conditioning (VWC) on the residual stresses and transverse contraction distortions compared with normal welding were studied in submerged arc multipass welding. The results show that VWC can relieve the residual stresses greatly and make the distribution of residual stresses uniform. Moreover, VWC can also reduce transverse contraction distortions greatly. According to the analysis of microstructure and dynamic mechanical properties test, the reasons that VWC reduces the residual stresses and transverse contraction distortions were discussed.