Parametric investigation into the mechanical characteristics of dissimilar steel joints produced using SMHH-based joining technology

Selective microwave hybrid heating (SMHH)-based joining technology was utilized to fabricate dissimilar joints between SS2205 and SS304. The joining process involved exposing the materials to a 2.45 GHz frequency and 900 W of power for 720 s under atmospheric conditions, with SS304 powder used as the filler material. SMHH principles were employed to melt and fuse the filler powder with the interfaces of the joining specimens. To assess the joint properties, various characterizations were conducted, including X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), microhardness and tensile testing. XRD revealed the presence of carbides and intermetallics in the joint region. SEM revealed that the complete melting of powdered particles with the joining interface resulted in good metallurgical bonding between the joining specimens. The Vicker’s microhardness measured in the joint region was determined to be 515.2 HV, indicating a substantial increase as compared to the microhardness value of the joining specimens. The average measured ultimate tensile strength of dissimilar joints was 584.15 MPa, with an elongation of 20.27%. The SMHH-induced dissimilar welds between SS2205 and SS304 demonstrated promising microstructural and mechanical properties, indicating the effectiveness of this joining method in industrial applications.