宽厚板连铸坯表面裂纹的产生原因及控制

针对近期包钢薄板坯连铸连轧厂宽厚板微合金钢铸坯出现的批量表面裂纹问题,通过考察表面缺陷类型,裂纹形貌特征,结合连铸工艺条件、钢水质量及设备状况,分析了板坯表面裂纹的主要原因,提出了优化振动参数,控制钢水氮含量,提高振动精度,调整保护渣性能以及提高二次冷却水水质等改善铸坯表面缺陷等措施,取得了比较明显的效果,其铸坯表面裂纹得到了有效控制。

Causes and control of surface crack on continuous casting billets of wide and thick plates

In view of the surface cracks in batch in the thin slab continuous casting and rolling mill of CSP Plant of Baotou Steel. main causes of surface cracks on the slab were analyzed by investigating the types of surface defects, crack morphologies and characteristics, combined with the continuous casting process conditions, molten steel quality and equipment conditions.The measures of optimizing the vibration parameters, controlling the nitrogen content of molten steel, improving the vibration accuracy, adjusting the performance of protective slag and improving the quality of secondary cooling water were put forward to improve the surface defects of the casting billet, and the obvious results were obtained, and the surface cracks of the casting billet were effectively controlled.