Numerical investigation of temperature distribution and melt pool geometry in laser beam welding of a Zr–1% Nb alloy nuclear fuel rod end cap

Abstract

Zr–Nb alloys are used in the nuclear and chemical industries, in which the welding of an end cap to a fuel rod is a critical issue in manufacturing processes. To identify the optimal process parameters for achieving good-quality welds, it is necessary to investigate the thermal environment in the fusion and heat-affected zones. A three-dimensional computational fluid dynamics analysis is performed with a volumetric heat source by simulating the interaction of the heat source and the material and by accounting for the phase change during welding. The model incorporates the buoyancy force and Marangoni stress and generates the temperature distribution, weld bead geometry and fluid flow in the weld pool during the laser welding process.