连铸坯凝固偏析的原位统计分布分析

Analysis of Original Position Statistic Distribution on Solidification Segregation of Cast Billet

应用金属原位统计分布分析技术研究了40Cr钢（％：0．38～0．40C、0．90～0．91Cr、0．015～0．029P、0．009～0．014S）240mm×240mm连铸坯中C、S、P和Al的宏观偏析规律。研究表明，在铸坯45％～63％等轴晶率下中间包钢水过热度〈5～32℃）对C的宏观偏析没有显著影响，但对S、P宏观偏析产生明显影响。S呈中心正偏析，P呈中心负偏析，低过热度（5℃）不能减轻S和P的偏析程度。Al元素中心正偏析主要是Al2O3夹杂向连铸坯中心聚集所致。

The macrosegregation law of C, S, P and A1 in 240 mm×240 mm cast billet of steel 40Cr （ 0. 38 ～ 0. 40C, 0. 90～0. 91Cr, 0. 015～0. 029P, 0. 009 ～0. 014S） has been studied by using the technology of original position statistic distribution analysis （OPA）. The study indicated that with 45% ～63% equiaxial crystal rate in billet, there has not any effect of overheating temperature （5 ～ 32 ℃ ） of molten steel in tundish on macrosngrngation of C, but there has an obvious effect on macrosegregation of S and P. The S presents center positive segregation, P presents center negative segregation, and low overheating temperature （5℃ ） could not decreases S and P segregation. Al2O3 inclusions concentrated at center of cast billet leads to Al element center positive segregation.