Numerical Simulation of Quenching and Hardness Evolution in AISI ۱۰۴۵ Steel Plates with Varying Thicknesses

This study presents a Python-based numerical simulation of the quenching behavior and hardness evolution of AISI ۱۰۴۵ steel plates with thicknesses of ۲۰ mm and ۶۰ mm. A one-dimensional transient heat-conduction model was implemented to predict the cooling response under water and oil quenching, using representative thermophysical properties and established heat-transfer coefficients. Martensite formation was computed through the Koistinen–Marburger relation, and the resulting hardness was estimated using a mixture-rule approach. The results show that plate thickness and quenchant severity strongly affect cooling rates, transformation kinetics, and final hardness profiles. The ۲۰ mm plates achieved nearly full martensite and uniform hardness in both media. In contrast, the ۶۰ mm plates exhibited pronounced thermal inertia, delaying transformation and producing incomplete martensite under oil quenching, which resulted in significant hardness gradients across the thickness. These findings highlight the critical influence of section size and cooling intensity in achieving effective hardening in medium-carbon steels.

کلیدواژه ها:

AISI ۱۰۴۵ steel ، Quenching ، Heat transfer modeling ، Martensitic transformation ، Koistinen–Marburger model ، Explicit finite difference method ، Section thickness ، Quench media