Optimization of Process Parameter for Electrode Tip Diameter in Resistance Spot Welding of Coated Steel

Abstract

A review of the resistance spot welding process is given, followed by a literature study of the known issues
when welding galvanized coated steels and some of the methods explored to address those issues. This study presents a
systematic approach to determine effect of process parameters on tip diameter as a primary & initial measure of weld
quality and subsequently ultimate tensile strength. To achieve the objective an attempt has been made to select important
welding parameters like weld current, weld cycle, hold time using quality tools, available literature and on scientific
reasons. On the selected parameters, Experiment have been conducted as per Taguchi method and fixed the levels for the
parameters. The experiment has three factors and all factors are at two levels. To have wide spectrum of analysis and
variability with time experiments are conducted. Optimum welding parameters determined by Taguchi method improved
electrode tip life. Taguchi Analysis has been used for determining most significant parameters affecting the spot weld
parameters. Study of the degradation mechanisms of the uncoated electrode revealed that electrode tip life was due to
more than the typical alloying and material loss as well as gross electrode deformation.