2D Sheet Temperature Estimation for Multi-Stage Press Hardening in a Progressive Die

During a multi-stage press hardening process, where a metal sheet undergoes rapid austenitization, tempering, and forming, the spatial-temporal temperature development is a driving factor and its control enables it to reach desired product properties. A two-dimensional model extension is proposed, which enables a precise and computationally efficient temperature modeling along the whole metal sheet. Thereupon, a Kalman filter with a time-varying stage dependent output matrix is used to estimate the spatial-temporal temperature development of the sheet based on measurements from a thermal imaging camera. Both the proposed modeling approach and the estimation scheme are validated experimentally.