Stress State in Deposited Steel Cast Rolls with High Surface Hardness after Argon Plasma-Jet Hard-Facing

The method based on the stress redistribution from principal to new ones near the machined groove combined with X-ray diffraction analysis is used to investigate the stress state of the cast rolls deposited with the Р2 М9 steel having a high surface hardness obtained by the plasma-jet hard-facing in argon. It is shown that the stress state in the deposited cast rolls is more favorable for their operation than that in rolls fabricated by the conventional technique. The stress distribution over the deposited cast roll is characterized by a gradual transition from compressive residual stress of 600 MPa in the deposited layer to tensile stress of 200 MPa in the base metal. The increase in the wear resistance of the deposited cast rolls can be explained by the α-Fe solid solution and finely dispersed iron, tungsten, chromium, molybdenum, and aluminum carbonitrides presenting in the steel structure and the favorable stress state in the surface layer formed by the thermal cycle of the argon plasma-jet hard-facing accompanied by the low-temperature heating followed by high-temperature tempering.