50CrMo钢Φ600 mm连铸圆坯中心裂纹分析及工艺改进  

Analysis and Process Improvement of Center Crack of 50CrMo SteelΦ600 mm Continuous Casting Round Bloom

作　　者：张洪才[1] 林鹏[1] 翟万里[1] 许正周 牟泽锋 许光乐 Zhang Hongcai;Lin Peng;Zhai Wanli;Xu Zhengzhou;Mou Zefeng;Xu Guangle(Technology Center,Huaigang Special Steel Co.,Ltd.,Jiangsu Shagang Group,Huaian 223002)

机构地区：[1]江苏沙钢集团淮钢特钢股份有限公司技术中心,淮安223002

出　　处：《特殊钢》2022年第5期43-46,共4页Special Steel

摘　　要：钢厂90 t LD-LF-VD-CC流程生产的Φ600 mm钢50CrMo连铸圆坯中心裂纹比率达到30%,分析得出:连铸圆坯中心裂纹全部出现在内弧一侧。主要原因是该钢种柱状晶发达,内弧柱状晶基本延伸到圆坯中心,在矫直时圆坯中心产生开裂并向内弧侧扩展。通过采取将结晶器电磁搅拌电流由260 A提高到400 A,中间包钢水过热度由30~50℃降到15~30℃,拉速由0.34 m/min降到0.28 m/min,进拉矫机前支撑辊及拉矫机辊道对弧精度由0.40~1.00 mm降到0.20 mm以下等措施,50CrMo钢Φ600 mm连铸圆坯中心裂纹全部消除。The central crack ratio of theΦ600 mm 50CrMo steel continuous casting round bloom produced by 90 t LD-LFVD-CC flow sheet at steel plant reaches up to 30%.It is obtained by analysis that the central cracks of the continuous casting round bloom all appear on the inner arc side.The main reason is that developed columnar crystal of the steel,the inner arc columnar crystals basically extend to the center of the round bloom,leading to the round bloom center cracking and expanding to the inner arc side during straightening.By increasing the electromagnetic stirring current of the crystallizer from 260 A to 400 A,the superheat of the tundish liquid reducing from 30~50℃to 15~30℃,and the casting speed lowering from 0.34 m/min to 0.28 m/min,and the accuracy of the roller table of the tension leveling machine reducing from 0.40~1.00 mm to below 0.20 mm,etc,the center crack of theΦ600 mm 50CrMo steel continuous casting round bloom is completely eliminated.

关 键 词：50CrMo钢 连铸圆坯 柱状晶 电磁搅拌 过热度 中心裂纹 

分 类 号：TF777[冶金工程—钢铁冶金]