| The majority of cracks generated in the continuously cast strands are caused by tensile strains imposed either thermally or mechanically at the solidification front. It is well accepted that the thermal crack is generated as the reheat exceeds about 100℃ on the strand surface. To characterize the surface temperature profile, the cooling part between two supporting rolls of the spray cooling zone was subdivided into four sub-zones and the characteristic heat transfor coefficient in each sub-zone was applied accordingly. By means of computer simulation, effects of parameters, such as spray distance, casting speed, and pouring temperature on the reheating as well as the solidification rate were investigated separately at the spray cooling zone. Results thus obtained were discussed with respect to the cracking susceptibility of the cast strand. |
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