QUANTIFICATIONS OF EFFECTS ON WELD BEAD GEOMETRY AND METALLURGICAL INVESTIGATIONS

Abstract

This experimental study was carried out to analyse the effects of various process parameters of gas metal arc welding (GMAW) process on weld bead geometry in mild steel plates. The study of weld bead geometry is important, as it determine the stress carrying capacity of a weld. Fractional factorial technique of design of experiment was used to develop relationship for predicting weld bead geometry, which enables to quantify the direct and interaction effects. The response factors, namely bead penetration, weld width, reinforcement height, weld penetration shape factor and weld reinforcement form factor as affected by arc voltage, wire feed rate, welding speed, gas flow rate and nozzle-to-plate distance have been investigated and analysed. The models developed have been checked for their adequacy and significance by using the F-test and the t-test, respectively. Main and interaction effects of the process variables on weld bead geometry are presented in graphical form. The developed mod...