OPTIMIZATION OF SOME ENERGY CONSUMPTION AND WELD QUALITY RESPONSE PARAMETERS IN GAS TUNGSTEN ARC WELDING by Simranjit Singh
Welding is most commonly adopted process for fabrication in the manufacturing industries and it is highly energy intensive in nature. During welding, there is considerable amount of energy losses which reduce the energy efficiency of the welding process. Most of the research has been focused on the parameters for weld quality but very less attention has been paid on energy consumption parameters related to welding. In the present research study, optimization of three energy consumption response parameters viz. power factor (PF), active power consumption (APC), active energy consumption (AEC) and three weld quality response parameters viz. tensile strength, bending strength, hardness has been carried out for gas tungsten arc welding (GTAW) of stainless steel 304. L9 orthogonal array of Taguchi method has been used for the design of experiments and analysis for the optimization by ANOVA at 95% confidence level. Three welding input parameters have been selected for the study which are welding current, gas flow rate and travel speed. Experimental conditions for optimum PF (0.58 Leading) have been found to be at 95 amps welding current, 5 lpm gas flow rate and 25 cm/min travel speed. Combination values for welding input parameters for optimum APC (1588.54W) are found to be welding current at 85 amps, gas flow rate at 10 lpm and travel speed at 21.17 cm/min. For optimum AEC (27.04Wh), values for welding input parameters are found to be welding current at 85 amps, gas flow rate at 10 lpm and travel speed at 25 cm/min. Optimum tensile strength (846.66MPa) has been found to be at welding input parameters of 95 amps welding current, 7 lpm gas flow rate and 13.84 cm/min travel speed. For optimum bending strength (57.75kgf), values for welding input parameters are found to be welding current at 90 amps, gas flow rate at 5 lpm and travel speed at 13.84 cm/min. Optimum value of hardness (277Hv) has been found to be at the welding input parameters of 85 amps welding current, 5 lpm gas flow rate and 25 cm/min travel speed. Taguchi analysis reveals that welding current is the most critical welding input parameter for PF, APC and hardness. Travel speed is found to be the most critical parameter for AEC, tensile strength and bending strength. Travel speed is found to be the significant factor for AEC. It has been found that there is 5.45% increase in PF from lowest value of PF which is a good improvement to tackle with the penalties in the electricity bills. There is 17.75% reduction in APC from highest value of APC by adopting values of welding input parameters for optimum APC. Validated experimental values of optimum APC and optimum bending strength are 5.70% and 2.18% higher than the predicted values respectively, but experimental value of optimum hardness is 0.63% lower than the predicted value. The effect of welding input parameters on tensile strength and
hardness are found to be similar as in the literature.