GREY RELATIONAL ANALYSIS TO OPTIMIZE WELDING PARAMETERS FOR DISSIMILAR SHEETS OF MATERIAL IN RESISTANCE SPOT WELDING

Resistance spot welding (RSW) is a very popular technique for joining two or more than two sheets of metal in production industries. This research mainly focuses on the grey relational analysis with Taguchi method for optimizing heat affected zone (HAZ) with tensile shear strength. (HAZ) developed nearby weld nugget diameter. Increase of (HAZ) may cause the changes in microstructure properties, appearance and chemical composition of materials. To avoid such type of defects must be eliminating. By grey relational analysis it can be possible to eliminate such type of defects. Both characteristics (HAZ) and tensile shear strength are analysed by grey relational based Taguchi method. In this research main aim is to decrease (HAZ) and to increase tensile shear strength for weld quality. For experimentation dissimilar sheets of material AISI304 and mild steel were selected. There are four inputs welding parameter weld time, hold time, weld current and electrode force were selected at their three respective level. Orthogonal array L27 is designed for parameter on basis Taguchi method [3]. ANOVA table are calculated for significant parameter affects weld performance of weld joint on base of grey relational method. Grey relational grade have been determine to find out optimal value. Ultimately confirmation test shows improvement in grey relational grade. Improvement in grey relational grade indicates quality characteristics of weld joint.