MIG welding and MIG brazing of different austenitic stainless steel grades

Abstract

Weldability aspects of different Cr-Mn alloyed high strength austenitic steel grades were investigated in our present work and compared to conventional Cr-Ni alloyed grades. In our experiments two Cr-Mn alloyed high strength (+N alloying) austenitic steel grades (1.4371 and 1.4376) and as comparison; Cr-Ni alloyed high strength (1.4318) and normal strength (1.4301) austenitic steel grades were used. Similar and dissimilar joints were made with metal inert gas (MIG) welding and MIG brazing. The produced butt joints were evaluated according to their tensile- hardness- and microstructural properties. The different steel grades showed quite different behavior regarding the mechanical and microstructural properties. The MIG brazed specimen showed higher weld metal hardness than the welded ones, the hardness values decreased with decreasing Mn-content in the base metals. In case of MIG welding also the tensile strengths and the fracture elongation of the joints decreased with decreasing Mn-content.