Abstract:
The welding repair effect of cast steels is related to the service life of bogie components. In order to determine the appropriate welding repair process, the metallographic structures, tensile properties, hardness and impact properties of the repair welded joints of E260-450-MS cast steel obtained by using three different weld repairing processes are compared. The results show that there is no obvious difference in the microstructures of the weld seam, heat affected zone and base metal among the joints by the three processes. The tensile strengths of the joints are all higher than 450 MPa, the elongations after fracture are more than 20%, and the fractures are all located in the base metal. The distribution of the joint hardness is consistent. From the base metal to the center of the weld, the Vickers hardness value increases first and then decreases, and the peak hardness of the three kinds of joints are less than 250HV3. The impact absorption energy of the weld seam is the highest, that of the heat affected zone lower, and that of the base metal the lowest. The impact fracture of the weld seam is dimple fracture, and those of the heat affected zone and base metal are cleavage fracture. The optimal welding repair process is no preheating before welding, heat-insulating and slow cooling after welding with no heat treatment.