改善70钢连铸小方坯芯部质量的工艺实践  

Process practice to improve the quality of billet core of 70 steel continuous casting

作　　者：陈健[1] 戴宇航 袁文武 张国庆 李浩 孙涛[1] CHEN Jian;DAI Yuhang;YUAN Wenwu;ZHANG Guoqing;LI Hao;SUN Tao(Maanshan Iron and steel Co.,Ltd.,Maanshan 243000,Anhui,China)

机构地区：[1]马鞍山钢铁股份有限公司,安徽马鞍山243000

出　　处：《四川冶金》2024年第5期52-56,共5页Sichuan Metallurgy

摘　　要：为了改善70钢连铸方坯的芯部质量,通过调整拉速、过热度、二冷比水量和压下工艺进行工业试验研究。结果表明:当压下工艺为2/2/4/7/7时,通过低过热度、高拉速或降低二冷比水量均可以改善铸坯中心碳偏析;但是在2.60 m/min高拉速或0.46 L/kg低二冷比水量浇注时,降低了铸坯的冷却速度,导致1#拉矫机处的固相率较低,坯壳厚度不足,压下时产生中间裂纹。当从2#拉矫机开始实施压下,压下工艺为0/2/5/7/6时,不仅中间裂纹有明显的改善,而且中心碳偏析也得到有效的控制,测得中心碳偏析度仅为1.02,铸坯芯部质量较好。In order to improve the core quality of 70 steel continuous casting billet,industrial experiments were carried out by adjusting the drawing speed,superheat,secondary cooling specific water quantity and pressing process.The results show that when the process is 2/2/4/7/7,the central carbon segregation can be improved by casting with low superheat,high drawing speed or lower secondary cooling specific water volume.However,when casting at 2.60 m/min high drawing speed or 0.46 L/kg low secondary cooling water ratio,the cooling speed of the casting billet is reduced,resulting in low solid phase ratio at the 1#drawing leveler and insufficient thickness of the billet shell,resulting in intermediate cracks during pressing.When the process is 0/2/5/7/6,not only the middle crack is obviously improved,but also the center carbon segregation is effectively controlled,and the measured center carbon segregation is only 1.02,and the quality of the billet core is good.

关 键 词：70钢 小方坯 中心碳偏析 中间裂纹 轻压下 

分 类 号：TG777.3[金属学及工艺—刀具与模具]