Optimization of Percentage Dilution in Butt Welds to Prevent Weld Porosity Using Response Surface Methodology

Abstract

A detailed analysis to optimize percentage dilution in butt welds in order to prevent weld porosity has been carried out in this study. The response surface steepest ascent was used to optimize values of percentage dilution in a butt weld using gas tungsten arc welding process. Predictions for percentage dilution were made using the second order mathematical model for response surface methodology and results obtained showed that percentage dilution value of 45.73% was able to eradicate weld porosity in butt welds. Overall results of percentage dilution analyzed, recorded an optimal value of 45.73% with values of welding current, welding voltage and welding speed as 131.5amperes, 17.4 volts and 100mm/min respectively. A defined quantity of percentage dilution value of 45.73% established in this study should be used at a GTAW process to provide sufficient amount of dilution for controlled solidification of molten metal during welding operation in order to produce porosity-free welds. This work presented results that revealed percentage dilution values that will prevent weld porosity in butt welds with no gas traps or voids in welded joints produced.