Numerical and Experimental Investigations of Welded Butt Joints of (AISI304)

Abstract

Simulation of welding process (TIG or GTAW) of butt joint using finiteelement analysis is presented. The base metal is ST(304). The numerical modeldeveloped by include moving heat source, temperature dependent materialproperties, phase change and transformation, and mechanical analysis. Theparameters studied numerically were welding current ranging between (80-150A)depending on, welding velocity, plate thickness (2.5mm -5mm), and material of theheat sink (carbon steel and copper). The numerical results show that increasing thewelding current with increasing of welding speed decreases the fusion zone area.Using copper plate underneath the welded plates acts as a dissipation heat sinkwhich generates stronger heat gradient compared with carbon steel plate. Theexperimental results show that increasing welding current leads to increasing themicro hardness, and the microstructure becomes smaller. Due to increasing coolingrate the microhardness have maximum value at the boundary between the Fusionzone and heat affected zone.