Experimental and numerical investigation of resistance spot welding of AISI 304 AISI 316l stainless steel sheets

Abstract

Resistance spot welding process is widely used in the manufacture of automobiles and railway bodies. The importance of resistance spot welding is emphasized by the fact that each car undergoes 5000 to 7000 spot welds. Austenitic stainless steels AISI 304 and AISI 316L are widely used in industries like the automobile industry, food processing industry and Pharmaceutical Industry due to its mechanical properties , corrosion resistance and low cost. AISI 316L has superior corrosion resistance with better mechanical properties due to the presence of molybdenum. It is more expensive than AISI 304 and widely used in marine applications and chemical industries. Automobile industries are focusing on manufacturing passenger vehicles at low cost with enhanced features such as reliability, build quality without compromising on safety. Resistance spot welding of dissimilar metals like AISI 304 and AISI 316L improves the engineering properties at minimal cost. As the AISI 304 stainless steel is more prone to corrosion attack due to the formation of chromium oxide at the boundaries, it is not suitable for coastal applications and undercarriage of the vehicles. In order to get the assembly with superior corrosion resistance at low cost, AISI 316L sheets can be welded to AISI 304 sheets. The sections which are more prone to corrosion can be made of AISI 316L and the remaining sections can be made of AISI 304. Since the resistance spot welding is a complex process which involves simultaneous interaction of electrical, physical and thermal phenomena, an extensive research is needed to successfully spot weld AISI 304 and AISI 316L sheets. newline