Mechanical Behavior of Overlap-Welded of Dissimilar Steels (Structural-Stainless) under Monotonic Load

Abstract

The research shows the characterization of mechanical properties in dissimilar steel welded unions: a structural steel ASTM A537 (I) overlap welded with an austenitic stainless steel ASTM A240 (304L) through semiautomatic electrical arc welding process protected by inert gas (GMAW); Argon is used as a protecting gas and austenitic stainless steel ASTM A240 (308L) as a supplier material. Samples were tested in not welded conditions so as to characterize the materials involved in the research, and they were also tested in welded conditions, not being submitted to pre and post welding Thermal Treatment (TT). Welded-based material samples were characterized through Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), an inspection of Not Destructive Test (NDT) with penetrating liquids and ultrasound was also conducted. The following mechanical tests were completed, not only on the Base Metals (BM), on the Welding Join (WJ) as well: Vickers micro hardness profile, tension, and face bending test. Results showed a proper mechanical steel behavior, welded by GMAW procedure, under monotonic, in spite of the relatively high values of microhardness in the Heat Affected Zone (HAZ), specifically near the fusion line between weld and stainless steel.