Isotherm Study on Pulse Current GMA welding of Dissimilar Austenitic Stainless Steel and HSLA Steel

Dissimilar metal weld between austenitic stainless steel (γ-SS) and, high strength low-alloy (HSLA) steel are widely used in high-temperature applications in power station and petrochemical plants. Fusion welding is one of the most widely used methods for the joining of dissimilar metal. Therefore, continuous efforts are made to apply this method to the joining of dissimilar metal of various combinations, despite many difficulties encountered. These difficulties include problems associated with basic thermal aspects dictating the metallurgical mechanical characteristics of the weld joint are not well understood so far. Considering the lack of such knowledge some understanding in this regard has been presented in reference to dissimilar Austenitic stainless steel (γ-SS) and high strength low alloy (HSLA) steel under controlled pulsed current GMAW. The work demonstrates the weld isotherm as a function of controlled pulse current GMA welding. The observations show some superiority of using pulse current GMA welding over the conventional one with respect to the weld quality which can be explored in preparation of weld joint of HSLA and γ-SS of improved characteristics.