Quenching Heat Treatment Modelling of Thick-Section Parts by CFD Methods with a Semi-mechanistic Boiling Model

Heat treatment of metallic parts is one of the most important processes to enhance the mechanical properties. Quenching is the key step in a full heat treatment process, and it largely determines the properties of the final product. Successful computer simulations of quenching can significantly improve the production efficiency as well as the research and development progress of industrial manufacturers. However, despite the great efforts that have been made to study simulation of quenching, this complicated process which is involved with multiple physical mechanisms has not been fully understood.
The main goal of this project is to develop robust models which are capable of predicting the temperature evolution of both small- and large-scale samples during a quench cooling process without requiring any experimentally acquired data prior to the simulation. The models are designed to be based on CFD methods and FEM and are constructed and solved by the ANSYS software packages. The heat transfer and boiling effects are mainly solved by a semi-mechanistic model, but an empirical model is also applied to discuss the difference between the performance of these two methods.
The simulated process of this paper is the immersion quench cooling of cylindrical workpieces of different sizes in liquid water at 20 ℃. According to the sample size, the models are divided into two groups: small-scale models and large-scale models. Proper mathematical models are applied to simulate the fluid flow and heat transfer processes in the real world. The influence of multiple parameters on the performance of the prediction is investigated in detail. Finally, the optimal model set-up for both the small- and large-scale models are reported.