STUDY THE MICROSTRUCTURE OF WELDING JOINT OF DIS-SIMILAR METALS

This article is about studying the microstructure of welding joint of dissimilar metals, stainless steel to low carbon steel that is thickness (4mm) for both by using the metal active gas (MAG) spot welding process. The welding wire (E80S-G) is used and have (1.2mm) diameter depend of (AWS), and Co2 gas was used as shielded gas with (7L/min) flow rate in all times used in this study. In this work, we select many samples from the welding joints from welding region and heat effective zone, these samples will change in there welding from the welding time, current and the wire feed. A different region that represents regions of joint interface between the two metals, and heat effected zone we noted that. The ratio of pearlite in low carbon steel more than in base metal and the ratio of ferrite is less than in parent metals. Furthermore, the microstructure of stainless steel has no change as compact with low carbon steel because most of heat concentrated in the low carbon steel.