MODELLING AND OPTIMIZATION OF A BATCH FURNACE FOR HOT STAMPING

摘要

Non-uniform heating during the austenization stage of hot-stamping can lead to inhomogeneous mechanical properties, coating thickness variations, and residual stresses in the stamped components. This paper presents a heat transfer model of an electrically-powered batch austenization furnace, with the objective of diagnosing and correcting factors that cause non-uniform blank heating. Radiation view factors are calculated with the Monte Carlo method. Convection with the furnace air and conduction through the blank and furnace door is also incorporated into a transient global domain energy balance. The model incorporates temperature- and phase-dependent radiative and thermophysical properties of the steel blanks and ceramic insulation of the furnace walls. The heat transfer model is validated with data obtained from instrumented blanks in an actual production cycle. The model is then used to optimize heater settings for the existing furnace using simulated annealing.