Simulation and Experimental Validation of EBW Studies in Austenitic Stainless Steel AISI-321

Abstract

Electron beam welding of austenitic stainless steel AISI-321 has been studied with butt weld configuration. The numerical simulation is done in both thermal and structural analysis modes using ANSYS™ software for welding as well as tensile testing. Optimization of the process parameters such as the welding speed, power, beam offset and number of passes was carried out to obtain a sound weld joint using bead on trials and also through welding simulation to get a full penetration weld. Voltage of 60 kV with current of 90–95 mA was found to be optimum parameters for electron beam welding for the welding of a 4-mm-thick plate. The microstructure examination of various weld zones has been carried out. The tensile tests were carried out on the welded samples at room temperature and elevated temperatures (1173 K, 1223 K and 1273 K). It is observed that, with increasing strain rate, there is an increase in strength of the weldment at elevated temperatures indicating positive strain rate sensitivity. Further, a comparative study between the simulated and experimental results of room temperature tensile tests has been carried out. A good match in ambient temperature engineering stress–strain curves obtained through simulation and experimentation has been observed. The fractography analysis of the ambient temperature tensile tested specimens was carried out. It has been observed that the material exhibits necking and a cup cone fracture with fine dimples indicating a ductile fracture.