Effect of Filler Composition and Post Weld Heat Treatment on Mechanical and Metallurgical Properties of GTA Welded AISI 409M Stainless Steel Joints

Abstract

The effect of filler composition and post weld heat treatment on mechanical and metallurgical properties of Gas Tungsten Arc welded AISI 409 Stainless Steel was studied. Rolled plates of 4mm thickness have been used as the base material for preparing double pass one is root pass and second is cover pass butt welded joints. Welding of ferritic stainless steel plate has been performed in three phases. During 1 st phase of welding, 409M ferritic stainless steel with similar filler metal is used at direct current of 100A, during 2 nd phase of welding of base plates by using 309L austenitic stainless steel filler metal is used and during 3 rd phase of welding, 410 martens tic stainless steel filler metal is used at a direct current. Maximum UTS value of welded joints possessed by the welded joints which is fabricated with 409M filler, maximum Impact strength value possessed by the welded joints which is fabricated with 309L, and maximum average hardness is recorded in WJ 2 (342VHN) in as-welded condition. Grain coarsening effects was revealed in the microstructures images that had been taken by the optical microscope in all the welded joints after PWHT as compared to the microstructure images of welded joints in as-welded condition.