CSP流程薄板坯原位统计分布技术分析

 以冷轧冲压用钢薄板坯为研究对象，观察了低倍组织，用原位分析仪研究了铸坯的宏观偏析、致密度和夹杂物，用扫描电镜分析了夹杂物的形貌和成分。结果表明，铸坯心部有2~3个蚀孔，细密树枝晶占74%，柱状晶凝固末端向上倾斜10~20°。碳、硫、铝元素最大偏析度大于3，偏析位置并非分析面的中心对称点。碳、硫元素在厚度中心处有较严重的岛状偏析，铝为多点状偏析，硫、铝元素偏析重合处为CaS MnS Al2O3复合夹杂物，其余元素偏析不明显。横截面板厚中心疏松存在硫和铝的富集。

Original Position Statistic Distribution Analysis for Thin Slab Produced by CSP

Macrostructure, macrosegregation, density and inclusion of thin slab for cold rolled steel have been investigated by acid etching and OPA (original position statistic distribution analysis). The micrographs and composition of inclusions have been analyzed by SEM (scanning electron microscope) with EDS (energy dispersive X ray spectrometer) system. It was found that 2-3 corrosion pits were found in the center of thin slab (equiaxial crystal zone) and fine dendrite made up 74% volume, terminal of column dendrite tilted up at an angle of 10-20° due to upflow of liquid phase. Maximum segregation degree of C, S, Al was more than 3 and location of segregation was not in the center of the analyzed surface. Serious island like segregation of C, S was detected in the middle of thickness and numerous scattered spotty segregation of Al was also found. The segregation of S and Al was observed in the same area; moreover, it was considered as complex inclusions of CaS MnS Al2O3. No obvious segregation except for C, S, Al was found. Enrichment of S and Al was detected at porosities of central thickness.