Numerical simulation of temperature field and residual stress in multi-pass welds in 2.25cr-1mo-0.25v steel plate and comparison with experimental measurements

The 2.25Cr-1Mo-0.25V steels are widely used in the petroleum chemical industry for the manufacturing of pressure vessels. The multi-pass welding is a critical type of fabrication in hydrogenation reactor. However, very complicated residual stresses could be generated during the multi-pass welding process. The presence of residual stresses could have significant influence on the performance of welded product. In the present work, the transient temperature distribution and residual stress distribution in welding of 2.25Cr-1Mo-0.25V steel are analyzed by using numerical method. An uncoupled thermal-mechanical two-dimensional (2-D) FEM is proposed under the ABAQUS environment. The transient temperature distribution and the residual stress distribution during the welding processes are determined through the finite element method. A group of experiments by using the blind-hole method have been conducted to validate the numerical results. The results of 2-D model agree well with the experiment. The result shows that the maximum welding stress generated at heat affected zone (HAZ) both at the top and bottom surface whether to transverse stress or longitudinal stress.