Numerical Simulation and Experimental Research on the Quenching Process of 1045 Steel Based on Thermo–Fluid–Solid Coupling Model

In the numerical simulation research on quenching, the heat transfer coefficient is an important input parameter. However, owing to its complexity and various influencing factors, the measured results are not universal and will significantly increase the simulation complexity and error. This article proposes a new numerical simulation method for quenching processes by extending the simulation domain and introducing the coupled heat exchange between the liquid quenching medium and workpiece, replacing the role of the heat transfer coefficient in the numerical simulation. The method is validated through experimental studies on 1045 steel rod quenched in water, with the maximum relative errors of the simulation results compared to the experimental results being 3.6%, 9%, and 5.1% for hardness, cooling curve, and residual stress, respectively. Furthermore, the article investigates the effect of different flow parameters of quenching media on the quenching effect. Under the studied conditions, the 1045 steel rod has the lowest risk of cracking and the highest hardness value when quenched in water at 50 °C. The proposed method improves the universality and convenience of numerical simulation for the quenching process and can be used to guide the formulation of quenching process parameters when the heat transfer coefficient is unknown.