**3. Numerical Methods**

The numerical model for calculating the temperature field was created using the ESI Welding Simulation Suite (R 13.5, ESI Group, Paris, France). This software package is based on the Visual-Environment platform, which includes the pre-processing module Visual-Mesh for generating the three-dimensional geometry and the mesh of the model, the module Visual-Weld for defining the welding process, and the post-processing module Visual-Viewer for visualizing the results. The numerical calculation was performed with the finite element (FE) software SYSWELD (R 2017.5, ESI Group, Paris, France).
