In the present work, a two-dimensional heat transfer model to describe the thermal behaviour of the wide thick slab during continuous casting process was developed, in which the boundary conditions for secondary cooling zone were calculated from the realistic water flux along the transverse surface of slab. The accuracy of the model calculation results were verified and calibrated by infrared thermography and nail shooting results. Furthermore, the slab temperature distribution under typical casting conditions were investigated numerically, and based on the hot ductility of microalloyed steel, the different arrangements of nozzles were optimized and designed to reduce the slab transverse corner cracks. The plant results showed that the defect rate of rolled plate corner and edge cracks were reduced from 12?6 to 3?5% with the optimised nozzles configurations.

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