Effect of oxide scale on temperature-dependent interfacial heat transfer in hot stamping process

Abstract

An optimization-based numerical procedure was developed to determine the temperature-dependent interfacial heat transfer coefficient (IHTC). The effects of temperature, pressure and oxide scale thickness were analyzed, for oxide thickness between 9μm and 156μm and pressure from 8MPa to 42MPa. Oxide scales and contact pressure both show distinctive effects on IHTC in the cooling process. The average IHTC decreases about 2461W/(m2°C) with the increase of oxide scale thickness and increases 2620W/(m2°C) with the increase of pressure. Based on the two-way ANOVA, the effect of contact pressure influences the IHTC most. Their mutual interaction is negligible. The IHTC decreases when the average temperature between the blank and die surface is above 250°C and increases when the latent heat release.