The application of bainite rail is restricted due to its weldability. In order to adapt to the application and development trend of bainite rail in track laying and maintenance engineering, the weldability of dissimilar steel welding between bainite rail and pearlite rail is studied by pneumatic welding method.The microstructure morphology, element diffusion law and mechanical properties of the weld interface were investigated by optical microscope (OM), scanning electron microscope (SEM), impact and tensile tests. The results show that the weld interface metal of dissimilar steel welded joints of bainite rail and pearlite rail can form common grains in solid state, which can achieve good metallurgical bonding, and the bonding degree of rail foot is poor compared with other parts. U20Mn WZ (U20Mn side weld) area is mainly composed of martensite (66.2%) and bainite ferrite (33.8%), and the highest hardness value is 500 HB; the impact toughness of the joint is 4.1 J; the tensile strength is 961 MPa ,and the elongation is 8%.
gas pressure weldingwelding of U20Mn / U95Cr dissimilar steelmicrostructuremechanical property