Dr. K.K. Ramachnadran, Professor, Department of Mechanical Engineering, Government Engineering College Thrissur, India

Title: Mechanical and Microstructural Characteristics of Dissimilar GTA Welded HSLA Steel/AISI316L Steel Butt Joints

Abstract: Austenitic stainless steels and high strength low alloy (HSLA) steels have wide range of combined application in the marine, automotive and locomotive sectors. In spite of having excellent weldability individually, dissimilar fusion welded HSLA steel/austenitic stainless steel joints by conventional techniques are prone to complications such as grain coarsening, sensitization, stress corrosion cracking, hot cracking etc. Thus, in the present research, 3 mm thick plates of AISI 316L austenitic steel and HSLA steel, IRSM 42- 93 were dissimilar GTA welded and the tensile strength, yield strength and microstructural properties were investigated. The experimental trials were carried out as per the Taguchi experimental design and the welding current, welding speed, wire feed rate and filler material were selected as the factors of the experiment. The results showed that the highest joint strength of 610 MPa is obtained at welding current of 100 A, welding speed of 90 mm/min and wire feed rate of 1.6 m/min with AISI304 steel as the filler material. The analysis revealed that the welding parameters have significant interaction effect on the joint strength.