Numerical simulation and optimization of vacuum heat treatment for C-shaped SKD61 steel

This study investigates the vacuum quenching process of C-shaped SKD61 hot work tool steel components using DEFORM finite element simulation. The objective is to analyze the effects of quenching parameters – particularly temperature, chamber pressure, and cooling fan speed – on temperature distribution, displacement, strain development, and dimensional stability. The simulation tracks thermal and mechanical responses at critical points in the geometry, including surface and core locations across sections of varying thickness. Results show that lower quenching temperatures (180°C) generate steeper thermal gradients, leading to increased displacement and strain in all spatial directions due to accelerated martensitic transformation and transformation-induced plasticity. Conversely, higher quenching temperatures (300°C) promote more uniform cooling, reducing residual stress and distortion while maintaining acceptable mechanical properties. The findings highlight that precise control of quenching parameters, combined with adequate holding times, is essential to balance hardness, strength, and dimensional accuracy. This research demonstrates the value of simulation-assisted optimisation in minimising trial-and-error during industrial heat treatment, reducing manufacturing costs, and extending tooling life.