Welding between TA2/304 Stainless Steel and TA2/T2 Bimetallic Sheets by Laser-Induction Heating Technology

During the welding of TA2/304 stainless steel (SS) and TA2/T2 bimetallic sheets, the formation of brittle Ti-Fe and Ti-Cu intermetallic compounds in transition layer reduces the performance of the welded joint. The laser-induction heating welding technology was used to join the bimetallic sheets. For base metal TA2, laser butt welding was used, the cladding layer metals 304 SS and T2 were joined by using induction heating equipment to melt BCuP-2 wire to fill the groove. Because the melting points of TA2 and BCuP-2 wire have a large difference, the base metal TA2 and its weld will not melt during the process of melting the wire by induction heating, only a small amount of element diffusion occurs and a very narrow transition layer forms at the interface between the base metal's weld. And brittle Ti-Fe and Ti-Cu intermetallic compounds are not formed in the transition layer. The microstructures of the welded joint were analyzed by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The structure of the transition layer is mainly composed of Cu, Cu₃P and α-Ti. Specimen was taken along the direction perpendicular to the weld, and the tensile test was carried out. The tensile strength of the joint is 600 MPa.