Experimental investigation and optimization of submerged arc welding on Windmill tower using Genetic Algorithm

Abstract

Submerged arc welding (SAW) is a high quality, high deposition rate welding process commonly used to join plates of higher thickness. In this research endeavour, Submerged arc welding process which has high industrial utility particularly in the area of welding of thick plates and pipes is optimised and the degree of influence of critical welding parameters on the quality of weld for Windmill towers is studied and estimated. Submerged arc welding has enough scope of potential research as it involves complex interaction of different welding parameters. The targets of this research attempt are to perform experimental investigations to analyse the impact of selected critical submerged welding parameters viz. Current Voltage, Standoff distance and Travel speed on the quality of welded bead, their level of influence and finally the optimum values to create best quality weld in thick pipes to make Windmill towers. the output of the research will benefit the Windmill tower manufacturing industries and the practising engineers of the same Field.The final experimental setup is the design of experiments (DOE) where an orthogonal array is constructed for four input process parameters a) Welding current, b) Voltage c) Standoff distance, d) Travel speed to the value of temperature. A Mild Steel (material specification S355/S355 NL+ Z25) is selected for analysis in 09 experiments where ultrasonic testing is performed to find the defect in welded joints. A probability distribution curve is drawn with the help of MINITAB software to ascertain the validity of the experiments where the results fall close to the mean value. Using the ANOVA, regression and RSM model a linear equation is obtained and feeding this equation in Genetic Algorithm to get final equation. To get desired to be minimum uses of resources, investigation into effect of process parameter on performance parameter and its optimization is necessary.