高锰奥氏体钢板表面脱皮与裂纹成因分析
Analysis on the Causes of Surface Peeling and Cracking of High Manganese Austenitic Steel Plate

高锰奥氏体不锈钢热轧板和冷轧板常见的表面脱皮缺陷对后续产品合格率有着极大的影响。采用金相显微镜、扫描电镜等手段，观察并分析该脱皮缺陷处的宏观形貌、微观组织及元素成分，探究脱皮缺陷的形成原因。结果表明，热轧板脱皮缺陷表面及纵截面存在明显的嵌入型Cr、Mn金属氧化物与保护渣特征元素，属板坯表面横裂纹原因导致的缺陷。冷轧板裂纹缺陷来源于形成钢带截面Mn元素分布不均的隐性缺陷，其与连铸环节中包温度偏高造成的板坯中心偏析严重有关。通过降低连铸中间包浇铸温度和优化二冷配水制度，可有效降低这类高锰钢轧材表面的脱皮和裂纹缺陷比例。
The common surface peeling defects of hot-rolled and cold-rolled high manganese austenitic stainless steel sheets have a significant impact on the subsequent product qualification rate. By using metallographic microscopy, scanning electron microscopy, and other means, the macro-scopic morphology, microscopic structure and element composition of the peeling defect are observed and analyzed, and the causes of the peeling defect are explored. The results indicate that there are obvious embedded Cr and Mn metal oxides and characteristic elements of protective slag on the surface and longitudinal section of the peeling defect of the hot-rolled plate, which belongs to the defect caused by transverse cracks on the surface of the slab. The crack defect in the cold-rolled sheet originates from the hidden defect of uneven distribution of Mn elements in the cross-section of the steel strip, which is related to the severe central segregation of the slab caused by the high temperature of the ladle in the continuous casting process. By reducing the casting temperature of the continuous casting tundish and optimizing the secondary cooling water distribution system, the proportion of peeling and crack defects on the surface of such high manganese steel rolling materials can be effectively reduced.