Microstructures and properties of 310 stainless steel layer deposited on Q235 steel by CMT surfacing

H12Cr26Ni21Si stainless steel surfacing layer was prepared on Q235 steel plate with automatic cold metal transfer (CMT) welding. The parameters were welding current of 108 A, arc voltage of 15.8 V, swing wide of 12 mm，swing speed of 23 mm/s，welding speed of 2 mm/s and overlap quantity of 7 mm. A sound and defect-free surfacing layer was obtained. The microstructures and chemical composition of the surfacing layer were analyzed. The hardness and bonding strength of the interface were tested. The results show that the microstructures of the surfacing layer consist of dendritic and equiaxed austenite and the essential elements in the surfacing layer are Ni, Cr and Fe. The hardness of the surfacing layer is higher than that of the matrix and the bonding strength of the interface is greater than 405 MPa.