薄板坯表面纵裂纹影响因素研究  

Study on affecting factors of CSP thin slab surface longitudinal crack

作　　者：彭其春[1] 童志博[1] 刘炳宇[2] 钱龙[2] 李具中[2] 何金平[2] 

机构地区：[1]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081 [2]武汉钢铁(集团)公司,湖北武汉430080

出　　处：《炼钢》2012年第4期54-58,共5页Steelmaking

摘　　要：结合国内某钢厂CSP生产实践,对其表面纵裂纹的影响因素进行了统计分析。统计认为降低钢水硫、氮含量,使w(Mn)/w(S)提高到62以上,并使w(N).w(AlS)<0.015×10-6有利于裂纹的减少;降低拉速的波动频率和范围,控制拉速在4 m/min左右时裂纹最低;随着结晶器传热强度的提高,裂纹发生率上升,故建议结晶器传热采用弱冷;保护渣的液渣层厚度及耗渣量不足,故应对保护渣的性能进行优化;结晶器的流场下部过强,向上分流带入的热量不足,保护渣熔化不好,导致卷渣。通过采取相应的解决措施,CSP铸坯表面质量得到很大改善,纵裂纹发生率降低到了0.59%。In combination with the CSP producing practice in domestic steel the factors leading to occurrence of slab surface longitudinal cracks are analyzed by statistical data. The statistical results show that the longitudinal cracks can be lessened by reducing the sulphur and nitrogen content, increasing w（Mn）/w（S） in the limit of over 62 and con- trolling the ze（N） ＂w（Als） in less than 0. 015 ×10^-6 and the cracks can also be cut to the lowest level by lowering the fluctuation rate and scope of the drawing speed and control- ling the drawing speed in 4 m/min; and since the crack occurrence rate rises with the in- crease of the heat transfer intensity of the mold it is strongly recommended that mild cooling should be adopted for the heat transfer of the mold; and the properties of mold flux need to be optimized because the thickness of liquid slag layer and the slag con- sumption are insufficient; and slag entrapment occurs because the lower portion of the flow field of the mold is over strong and the heat carrying over from the upper branch is not sufficient, thus the mold flux is not properly molten. By taking proper counter measures the surface quality of the CSP slab is already greatly improved and the occur- rence rate of the cracks is lowered to 0.59 ~.

关 键 词：CSP 表面纵裂纹 低碳钢 

分 类 号：TF777.7[冶金工程—钢铁冶金]