Optimization of weld bead geometry in plasma transferred arc hardfaced austenitic stainless steel plates using genetic algorithm

Plasma transferred arc hardfacing has attracted increasing attention for its effective protection against corrosion, thermal shock, and abrasion. The quality of hardfaced components depends on the weld bead geometry and dilution, which have to be properly controlled and optimized to ensure better economy and desirable mechanical characteristics of the weld. These objectives can be fulfilled by developing mathematical equations to predict the dimensions of the weld bead. This paper highlights the development of such mathematical equations using multiple regression analysis, correlating various process parameters to weld bead geometry in PTA hardfacing of Colmonoy 5, a nickel-based alloy over stainless steel 316 L plates. The experiments were conducted based on a five factor, five level central composite rotatable design matrix. A genetic algorithm (GA) was developed to optimize the process parameters for achieving the desired bead geometry variables.