Selection of the optimal heat treatment conditions using advanced phase transformation models

The paper focuses on the problem of optimal cooling cycle selection for steel sheets after hot rolling in order to obtain a given phase composition using complex numerical model. The proposed model driven by diffusion of carbon with the moving boundary (Stefan problem) was designed and implemented on the basis of Level Set equations coupled with diffusion equation. Application of implicit method for interface evolution allows to overcome the limitations associated with the complicated representation of material microstructure, but also in a natural way reflects the impact of front curvature and influence of chemical forces on the velocity of the interface. The article discusses the details of the model as well as the applied optimization technique. Three test scenarios are analyzed and the results are discussed. (paper)