Experimental Study and Analysis of Resistance Spot welding of Dissimilar Metals for Various Range Thicknesses

Abstract

The continuously increasing demand for vehicle body structure often requires the newlinecombination of dissimilar metals with different thickness to reduce the body weight. The newlineresistance spot welding of dissimilar metals is challenging due to differences in physical, newlinechemical and mechanical properties. The objective of this research work is to understand the newlineinfluence of weld process parameters on weld strength and quality. The spot-welding newlineexperiments are carried out using the Central Campsite Design Matrix (CCD) on mild steel newline(MS) and austenitic stainless steel (ASS 304) sheets of various thickness to determine weld newlinestrength and weld quality. The effect of weld parameters such as weld current, weld time and newlineweld force on strength of dissimilar metals welds. An empirical relationship is developed to newlinepredict the weld strength by using Minitab 19 and R-language. The weld joints are newlinecharacterized in terms of weld strength, nugget diameter, microstructural changes and variation newlinein microhardness across the weld nugget. The ANOVA is carried out to identify significantly newlineaffecting process parameters on weld strength. The optimum weld strength of different thick newlinesheets is validated by conducting confirmatory test. The findings of this research are useful to newlineunderstand the change in weld characteristics and its properties to obtain better weld joints newlinequality. newlineKey words: Dissimilar Metals, Spot Weld, Tensile Strength, Microhardness, newlineMicrostructure. newline