Direct Drive Friction Welding Joint Strength of AISI ۳۰۴

The present study describes the effect of friction welding process on mechanical and metallurgical properties of AISI ۳۰۴ steel. The joints were made by direct drive friction welding (DDFW) machine, while the characteristics of friction welded joints were evaluated by macro-microstructure, microhardness, tensile test with ۴ mm and ۶ mm effective diameter, and scanning electron microscope (SEM). The results showed severe flash formation at stationary side related to rotating side, highly plastically deformed zone (HPDZ) was revealed at the interface with large dimension of ۱۱۰ µm. Maximum microhardness values were recorded at welded center and increased from peripheral to central zones. Reducing ratio of ultimate tensile strength (UTS) and ductility for welded joint related to AISI ۳۰۴ were ۸۶ and ۶۷%, respectively. Tensile fractures occurred adjacent to the interface at thermo-mechanically affected zone (TMAZ). Fracture morphologies by SEM were discovered cleavage features and mostly ductile mode with micro-porosities of different forms and dimensions

Keywords:

Austenitic stainless steel , Micro-hardness , Ultimate Tensile Strength