Modeling and Analysis of Dissimilar Laser Welding Using FEM: A Case Study on Inconel 718 and SS321

This work provides an extensive finite element analysis (FEA) of laser welding of dissimilar metals AISI 321 stainless steel and Inconel 718 to analyze the thermal characteristics and temperature field under transient conditions. A 3D butt joint configuration was modelled using ANSYS 19®. The temperature-dependent material properties from 25 °C to 1500 °C were considered during simulation. A double-ellipsoidal heat source was simulated with 80% efficiency and a laser power of 1200 W. Thermal cycles and heat flow were examined at different time intervals, revealing peak temperatures ranging from 1813 °C to 1854 °C during welding. Transverse temperature profiles indicated HAZ peak temperatures of 1182 °C for Inconel 718 and 1005 °C for SS321 at 45 seconds. Sectional analysis further revealed interface temperatures of 1501 °C on the Inconel side and 1252 °C on the SS321 side. Experimental results confirmed asymmetric heat transfer due to differences in thermal conductivity. Inconel retained heat longer, resulting in a thinner HAZ, while SS321 cooled faster with wider heat spread.