Abstract：Based on industrial testing，the reasons of serious central segregation of wide heavy slab with soft reduction were discussed. Different value between measured results of roll gap and displacement sensor at the same point of one segment was found out. Relatively large errors occurred in the difference values at different points of segment, which was the important reason of serious central segregation. Through the optimization of the one gap calibration method for segments，the roll-gap real value and the measured value at different parts of each segment were kept on the standard deviation a guaranteeing the accurate controlling of the roll-gap and the accuracy of soft reduction amount. After optimization of the gap calibration method, the internal quality of slab was improved remarkably.
2015, Vol. 25 
