Multi-scale Modeling of the Stress-Strain State During Welding of Ni-Based Alloys

Numerical modeling of changes of stress-strain state in welding of alloys of Ni-Cr–Fe alloying system at macro- and mesoscales was carried out. The kinetics of changes of stresses and deformations in the weld and heat-affected zone at sites of probable formation of hot cracks was considered. Calculations data of the stress-strain state at the macroscale were used in modeling of thermal-deformation processes at the mesoscale. During modeling the experimental data on anisotropy of physical properties were used depending on crystallographic orientation of grains in the heat affected zone of a real welded joint. The modeling was performed considering the changes of properties of the material depending on temperature. It was shown that depending on anisotropy of physical and mechanical properties of the metal in the limits of neighboring grains, the non-uniform distribution of plastic deformation becomes apparent. The change of deformation exhibits a gradient with localization of deformation near the grain boundaries.