Modelling of the Microstructure and the Mechanical Property Variation across the Transverse Direction of Hot Rolled Steels and the Effect of Edge Shielding.

A computer–aided simulation model which can predict the temperature variation and the microstructural evolution in the process of hot rolling was developed by combining a metallurgical model and a thermal model. The developed model was utilized to analyze the variation of temperature and microstructure during hot rolling process and the mechanical properties of the final products across the transverse direction of a strip. The results of the simulation along with those of the mill trial tests indicated that the mechanical properties across the transverse direction were significantly influenced by the metallurgical inhomogeneities developed in the stage of recrystallization and grain growth during rolling as well as the stage of transformation during cooling. In addition, the effect of the edge shielding during water cooling was quantitatively estimated by the present simulation model and the edge shielding was found to be effective in achieving uniform microstructure and mechanical properties in the hot rolled steels, especially, steels with high hardenability.