Joining of dissimilar material having its own challenges including different chemical composition, uneven dilution tendency, different oxidation resistance, variation in coefficient of thermal expansion, variation in solvus points & solidification temperature. These factors lead to uneven welding stress and increase possibility of welding crack due to formation of undesirable intermetallic compound.

Controlling weld chemistry, weld thermal cycle and heat input during dissimilar metal welding are important to get defect free and sound weld joint of required properties.

This paper includes establishment and optimization of welding parameter, to achieve adequate mechanical and metallurgical properties for SS304 to S690QL weld joint, made with GTAW process using ER309L consumable as a filler.

Results showed that it is possible to weld above combination without degradation of property by controlling heat input and dilution. Tensile fracture of all specimens indicated that fracture did not occur in the fusion zone and weld has higher strength than SS304 itself.

This article is shared by Ayush Verma, Raj Vora, Deepak Adakmol, Prashant Nikalje, Ramesh Gondha and A D Mokashi