A new method of joining stainless steels using Ni micro-plating bonding and the mechanical properties of the joint

Abstract Stainless steel is applied in a wide range of fields as a material with high heat and corrosion resistance. Welding, brazing, and solid-phase bonding are the most common joining techniques for stainless steel. Conventional joining methods have issues such as local thermal distortion of the joining area and the need for high-temperature heat treatment at 800–1000 °C. In this paper, we investigated a new joining technique for stainless steel. With the aim of establishing a new joining technology for stainless steel, we joined stainless steel using the Ni Micro-Plating Bonding method (NMPB) and evaluated the shear stress and the tensile stress of the joints. The joining process is performed at about 55 °C, followed by heat treatment at a relatively low temperature of 300 °C or higher. Shear and tensile tests were conducted on the NMPB joined SUS304, and the results showed that the shear stress was 114 MPa and the tensile stress was 77 MPa without annealing. After heat treatment at 300–400 °C for 1.5h, the shear stress of 200 MPa and the tensile stress of 240 MPa were obtained. In addition, the heat treatment at 600–800 °C for 1.5h resulted in the shear stress of 230 MPa and the tensile stress of 400 MPa. The plating crystallographic structure before heat treatment showed preferential orientation to <001>, but after heat treatment, recrystallization progressed beyond the boundary interface at 400 °C or higher, and a non-oriented crystalline was observed.