Enegide, Fergus Uche,; Achebo J, and Osaremwinda, J.O, Nigeria
serious micro structural changes, embrittlement at the heat affected zone and more. Therefore, optimizations of the weld process parameters are one sure way to reduce the adverse effect of fast cooling rates.
This study was carried out with the aim of optimizing and predicting thermal properties of low carbon (mild) steel weldments. The purpose of this study is to develop a model that maximize cooling rate using Response Surface Methodology (RSM). Twenty sets of experiments were carried out, adopting the central composite experimental design. Tungsten inert gas welding equipment was used to produce the welded joints; Argon gas was supplied to the weld to shield it from atmospheric interference. Mild steel plates of 60x40x10mm were cut and welded together. The k-type thermocouple was used to determine the ambient, solidus and liquid us temperatures.
At the end, the model produced a numerical optimal solution of current 120.00 Amp, voltage of 23.79 volt and a gas flow rate of 15.71 L/min resulting in a welded material having a calculated cooling rate of 17.1786 0C/sec.