Abstract
Heat treatment is one of the important manufacturing processes that determine the quality of metallic products. However, the heat treatment processes are usually based on artisan skills and experiences on the manufacturing floor, and therefore, it sometimes is costly and time-consuming to design the processes. There is room to refine the design of processes by simulation techniques. Here we describe a way to streamline the processes of heat treatment using a simulation technique. We developed a method for estimating the hardness of heat-treated steels. To predict the steel hardness after heat treatment, it is necessary to develop a heat transfer analysis procedure and to set up a database of required steels. First we built a heat treatment simulation program using the finite difference method. Then, to simulate the hardness after the heat treatment, we built a database using the Jominy test and the tempering parameter. Some examples of simulated results on heat-history and hardness of carbon steel cylinders during water-quenching and tempering are presented, and the validity of the program is evaluated by comparing the calculated values with the experimental values. The calculated hardness agreed well with the experimental values.
