Investigation on dissimilar welding of AISI 409 ferritic stainless steel to AISI 316L austenitic stainless steel by using grey based Taguchi method

Welding of dissimilar metals has attracted attention of the researchers worldwide, owing to its many advantages and challenges. There is no denial in the fact that dissimilar welded joints are expected to offer more flexibility in the design and production of the commercial and industrial components. Several welding techniques have been employed to join dissimilar metal combinations. In the present work, dissimilar joints between AISI 409 ferritic stainless steel and AISI 316L austenitic stainless steel, are made by GMAW (Gas metal arc welding) using ESAB AUTO Rod 316L as filler wire. Welding has been conducted as per L9 orthogonal array of Taguchi method. Three levels of the input parameters: welding current, gas flow rate and nozzle to plate distance, have been selected. After welding, visual inspection and X-ray radiographic test has been conducted on weld specimens, in order to detect surface and sub-surface defects of weld specimens made of dissimilar stainless steels. The quality of the weld has been evaluated in terms of yield strength, ultimate tensile strength and percentage of elongation of the welded specimens. The observed data have been interpreted, discussed and analyzed by grey-Taguchi methodology.