小方坯连铸纵裂与结晶器保护渣性能关系的研究

Study between Longitudinal Crack of CC Billet and Performance of Mold Flux

对小方坯纵裂纹的成因进行分析,发现产生纵裂的主要原因是有剩余碳进入液态保护渣后恶化了保护渣的流动性能。为此开发了低碳连铸保护渣,该保护渣具有高碱度、高结晶性和低粘度的特点,高结晶性增大了渣膜的热阻,使铸坯在结晶器内得到缓慢冷却,从而减少了铸坯的纵裂发生率。

The paper analyses the causes on longitudinal crack of continuously cast billet. It was found that the primary cause to the corner cracking is that Residual carbon in flux may worse fluidity of mold flux. A kind of mold powder for low carbon was developed,which has high basicity,high crystallization rate and low viscosity. High crystallization rate increases the heat resistance of slag film,which makes billet cool mildly in mold so the longitudinal-crack-rate of slab is decreased.