Viscosity Effect On Displacements And Residual Stresses Of A Two-Pass Welding Plate

The highly localized transient heat and strongly nonlinear temperature fields in both heating and cooling processes cause nonuniform thermal expansion and contraction, and thus result in plastic deformation in the weld and surrounding areas. Consequently, residual stress, strain and distortion are permanently produced in the welded structures. High tensile residual stresses are known to promote fracture and fatigue, while compressive residual stresses may induce undesired, and often unpredictable, global or local buckling during or after the welding. It is particularly evident with large and thick panels, as used in the construction of nuclear building. These adversely affect the fabrication, assembly, and service life of the structures. Therefore, prediction and control of residual stresses and distortion from the welding process are extremely important for the nuclear installation’s security.~~~This study focuses on the three-thermo-mechanical behavior of 316L stainless steel, during a TIG welding process. In this paper, we investigate the effect of the heat modeling source, thermal exchanges and viscous property on experimental and numerical results. Therefore, a parallel experimental and numerical study is carried out on an industrial 24-25 mock-up benchmark [4], a test more representative of a real welding operation, considering repair welding, is implemented to validate three-dimensional numerical effect. The TIG process, with 316L material filler, is considered. Comparative analyses through numerical simulations using finite element code (version 7.4 code_Aster from EDF) are performed.