65Mn连铸薄板坯偏析特征分析

Analysis on characteristics of center segregation of 65Mn continuous-casting billet

运用连铸坯低倍酸蚀法、钻孔取屑化学分析法、原位分析法、金相检验4种方法,全面了解65Mn连铸薄板坯的中心成分偏析分布情况,分析65Mn连铸薄板坯中心偏析的形貌特点,研究连铸坯中心偏析对板材偏析的影响。本次试验的65Mn薄板坯中心偏析带主要是C、S偏析,Mn、Si存在散点状负偏析。65Mn薄板坯中心偏析带并不是连续、通长存在的。C元素最大偏析指数为1.057,S元素最大偏析指数为1.049,Mn元素最大偏析指数为1.021,Si元素最大偏析指数为1.028。同时发现,铸坯中心的成分偏析对轧材的心部组织偏析的形成有直接的影响。

With the method of macrostructure testing by etching for continuous casting billet,drilling crumbs of chemical analysis,original position statistic distribution analysis（OPA）and metallographic examination,a comprehensive understanding of center segregation of 65 Mn continuous casting billet was obtained. Based on the analysis of the morphology characteristics of center segregation of 65 Mn continuous casting billet,the effect of continuous casting billet center segregation on the sheet blank segregation was studied. The main center segregation of 65 Mn continuous casting billet is the C segregation and S segregation,Mn and Si showed the dispersed negative segregation. The center segregation of65 Mn continuous casting billet is discontinuous. The largest segregation indexs of C,S,Mn and Si are 1.057,1.049,1.021 and 1.028,respectively. At the same time,it is found that the center component segregation of continuous casting billet would impact the formation of microstructure segregation.