Numerical Analysis of the Effect of Fusion-Welded Component Geometric Dimension on Electroslag Fusion Welding Based on Multiphysics-Field-Coupled Modeling

In this study, a coupled multiphysics field model combining finite-element and finite-volume modeling is developed to investigate the effect of fusion-welded component geometric dimension on electroslag fusion welding (ESFW) process, and the reliability of the model is verified experimentally. In the results, it is shown that for fusion-welded parts with definite geometrical dimensions, the vertical fusion welding scheme reduces the amount of slag and welding current, but the total welding time is long and the heat-affected zone is large; the horizontal scheme is the opposite. The preset rated welding current increases nonlinearly with increasing workpiece length. Increasing workpiece length decreases the average slag pool temperature uniformity and affects the slag pool flow, Lorentz force distribution, and increases the horizontal depth of fusion and depth of slag pool; increasing thickness increases the heat capacity and also affects the changes in the aforementioned physical quantities. The height during slag replenishment is related to the part length and thickness, while the recommended thickness is related to the part length, ESFW height, and slag replenishment mechanism. To avoid thermal distortion, the maximum cross-section horizontal depth of fusion should be less than 1/3 of the thickness of fusion-welded component.