Numerical simulation for the residual stresses of Stellite hard-facing on carbon steel

Hard-facing is an effective method for modifying the surface properties of metal parts, such as valves. The residual stresses in the hard-facing layer are important factors affecting the service properties and service life of the parts. This research has studied the decrease in the tensile residual stress in the hard-facing layer as well as the residual stress distributions and their affecting factors using a numerical simulation method with the aid of the commercial software abaqus. The computed results indicated that the residual stresses in the hard-facing layer are dependent on several factors, which include the heat-transfer coefficient, the thermal expansions of the materials, the thickness of the base metal and the pre-heating temperature, etc. In addition, local post-heating on the base metal surface can effectively reduce the tensile residual stress and this tensile stress can also be cut down if there is an austenitic stainless steel interlayer between the carbon base metal and the Stellite hard-facing layer. These results indicate that the numerical simulation method is a useful and convenient means by which to investigate the residual stresses of the hard-facing process.