Simulation of solidification microstructure in twin-roll casting strip

The twin-roll strip casting is regarded as the most prospective technology of near-net-shape casting. The control of the grain structure is of primary importance in twin-roll strip casting because the solidification microstructure has great influence on the quality and mechanical properties of strips. In this paper, a three-dimensional cellular automation (CA) finite-element (FE) model within CALCSOFT3D package is used to simulate the microstructure of steel strip twin-roll casting. The Gaussian distribution of nucleation sites is adopted both at the mold surface and in the melt. The KGT model is used to describe the growth kinetics of dendrite tip. Then the influence of the casting conditions such as pouring temperature and heat transfer coefficient between the rolls and the solidified strip on the strip solidification microstructure is detailed investigated. The predictions show that the temperature profile and solidification microstructure are most sensitive to the pouring temperature. And with the increase of the pouring temperature, grain density obviously increases. However, the influence of three bottom cooling conditions on microstructure formation has little difference in this study.