Optimization of secondary cooling scheme of combined caster

In this paper,the defects existing in the secondary cooling scheme of the rectangular bloom/slab combi-caster in Valin Xiangtan Iron Steel Co.,Ltd.,are described,the reasons for internal corner cracks of rectangular bloom analyzed,and the secondary cooling parameters optimized.The production practice indicates that the secondary cooling scheme has already been optimized and excellent results achieved as well.The internal corner cracks of the rectangular bloom are eliminated basically,the proportion of qualified macroscopic sample increased from 24.7% to 97.7%,the ratio of the central segregation(≤1.0) increases from 52.1% to 98.9%;and the unqualified rate of round-rod rolling steels caused by the defects in rectangular bloom reduced from 38.7% to 1.53%.