Design and validation of superhard and hard-to-be-machined Mo-V high-speed steel for mill roll ring based on digital simulation

Purpose Mo-V high-speed steel (HSS), a high-carbon, high-molybdenum and high-vanadium alloy steel, was selected in this study to meet the requirements of high hardness, high wear resistance and good red-hardness for mill roll rings. Design/methodology/approach Through a combination of empirical formulas and JMatPro software, this study determines the optimum composition (C: 2.3%, W: 6.0%, Mo: 6.0%, V: 7.0%, Cr: 5.5%, Mn: 0.5%, Si: 1.0%, Ni: 0.8%) and heat treatment process parameters (the annealing temperature: 790 ± 10 °C, the tempering temperature: 580 ± 30 °C) of Mo-V HSS, subsequently optimizes the carbon content selection of HSS, and then analyzes the phase composition diagrams at different temperatures to determine the optimum pouring and quenching temperatures (1,110 ± 150 °C). In addition, the results of the optimized alloy composition were verified through microstructure analysis and mechanical property tests. Findings Using JMatPro software, the phase diagrams and heat treatment process parameters of Mo-V system HSS were simulated and calculated, and compared and verified with laboratory data to ensure the accuracy of the simulation results. The mechanical properties of samples were measured, the Vickers hardness and tensile strength are 683 HV and 1,016 MPa, respectively. The novelty of this work lies in the design of a new type of high-speed steel (HSS) for the roller ring of the Mo-V series hot strip mill using the JMatPro software. The phase diagram and heat treatment process parameters were simulated and calculated, and the microstructure and mechanical properties were experimentally verified. The results are consistent with the simulation predictions, providing a new type of high-performance roller material for the steel rolling industry. Originality/value A new Mo-V system HSS mill roll ring was successfully designed in this study, and its performance was experimentally verified to be consistent with the simulation prediction, providing a new high-performance roll material for the steel rolling industry.