Optimisation of resistance spot welding process parameters on mild steel by Taguchi method

Abstract

The paper represents experimental to investigate in studying the optimisation of resistance spot welding process parameters by using taguchi method. The mild steel was selected in this project. The process parameters such welding current, welding time and hold time was choosed as process that control the result in this investigations. The testing was be conducted using visual inspection of nugget diameter, tensile test to determine the strength of weld joint and hardness test. The taguchi method use to optimisation the process parameter and lastly to save cost and avoid from waste the time doing many experiment. In taguchi method the L9 orthogonal array was selected. The signal noise ratio was determined that the larger is better be used in this project. The result of visual inspection of nugget diameter size show the larger nugget diameter is 4.77mm at experiment nine. Based on tensile test and hardness test show that experiment eight was the best result which 7.044 kN for ultimate tensile strength and 271.95 Hv for Vickers micro hardness. The ratio for tensile strength is 16.95 and 48.69 for hardness strength. The quality characteristics are tensile strength and hardness of materials of the spot welded joint has been considered. The process parameters are optimized to improving the nugget quality characteristics. The approach is based on Taguchi method, the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to study the performance characteristics of RSW processed. The experimental was using the L9 orthogonal array(OA). The data were analyses using signal-to-noise (S/N) ratio to get optimum level of RSW parameters combination ANOVA and F- test been used for deterimining the significant parameters that affect spot weld quality characteristics.