Process optimization and thermomechanical simulation of residual stresses and temperature distribution in the laser-beam penetration welds of 61Ni-21Cr-9Mo alloy and 99.3Fe-0.45Mn-0.2C steel joints

Laser welding is one of the important welding processes in industries for joining similar or different metals. Demand of dissimilar metal welding has increased now a days from high performance, cost saving and efficiency point of view. Various parameters like speed, beam power, spot diameter affect the quality, strength and cost of welding process. In this paper the influence of speed, beam power and spot diameter over strength of welded specimen is studied using Taguchi orthogonal array method. Two dissimilar metals such as 61Ni-21Cr-9M o alloy and 99.3Fe-0.45M n-0.2C steel is welded using laser beam. The experiments are carried out as per Taguchi orthogonal array design matrix to predict optimum process parameters Analysis of variance (ANOVA) is carried out to determine significantly affecting parameter and the mathematical model to estimate ultimate tensile strength has been developed using Regression method. The simulation of welding process to predict temperature distribution and residual stresses is predicted.