含钒钢连铸坯内部质量提升的优化  

Optimization of internal quality improvement of continuous casting billets containing V steel

作　　者：孙风杰 张骜 张明博 贺保堂 李耀 孙立根 陈伟 朱立光 SUN Fengjie;ZHANG Ao;ZHANG Mingbo;HE Baotang;LI Yao;SUN Ligen;CHEN Wei;ZHU Liguang(College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063000,Hebei,China;Hebei Province High Quality Steel Continuous Casting Engineering Technology Research Center,Tangshan 063000,Hebei,China;Chengde Branch,HBIS Company Limited,Chengde 067002,Hebei,China;School of Material Science and Engineering,Hebei University of Science and Technology,Shijiazhuang 050091,Hebei,China)

机构地区：[1]华北理工大学冶金与能源学院,河北唐山063000 [2]河北省高品质钢连铸工程技术研究中心,河北唐山063000 [3]河钢股份有限公司承德分公司,河北承德067002 [4]河北科技大学材料科学与工程学院,河北石家庄050091

出　　处：《连铸》2024年第6期14-20,共7页Continuous Casting

基　　金：国家自然科学基金资助项目(51974133);河北省自然科学基金资助项目(E2019209543)。

摘　　要：为了解决含钒钢在连铸过程中易出现的内部裂纹问题,采用热力学计算、凝固组织模拟、二冷配水调控的方法开展了HRB500E螺纹钢的铸坯凝固过程分析、组织预测和表面温度控制研究。结果发现,螺纹钢中V(C,N)的热力学析出温度为1 118℃和最大析出量(质量分数)为0.06%,表明钒具有析出强化和固溶强化的双重作用;铸坯的组织分析表明,钒质量分数由0增至0.089%时晶粒半径减少了2倍,晶粒数增加了2.8倍,中心等轴晶提高了2.2%。说明钒的添加能细化晶粒、改善组织性能和增益冶金性能;同时发现产生裂纹等缺陷的原因主要在于二冷配水不合理导致的铸坯表面返温过大,在此基础上提出了相应的二冷配水工艺优化并引入长度为2.9 m的二冷三段的方案,最终设计出了1.4~2.7 m/min拉速水表,铸坯的表面返温低于100℃,返温满足冶金准则。工业生产证明通过二冷配水优化方案极大的提升了铸坯内部质量。In order to solve the problem of internal cracking of vanadium-containing steel in the continuous casting process,the solidification process analysis,organization prediction and surface temperature control of HRB500E rebar steel were carried out by using thermodynamic calculations,solidification organization simulation and the method of second-cooling water distribution control.It was found that the thermodynamic precipitation temperature of V(C,N)in the rebar steel was 1118℃and the maximum precipitation amount was 0.06 wt%,which indicated that vanadium had the dual raction of precipitation strengthening and solid solution strengthening;the organization analysis of the as-cast billet showed that when vanadium was increased from 0 wt%to 0.089 wt%,the grain radius was reduced by 2 times,the number of grains was increased by 2.8 times,and the central equiaxial crystal was increased by 2.2%.It shows that the addition of vanadium can refine the grain,improve the organizational properties and gain metallurgical properties;at the same time,it is found that the reason for cracks and other defects is mainly due to the unreasonable water distribution of the second cold,resulting in the surface of the billet return temperature is too large.Based on this,a corresponding optimization of secondary cooling water distribution process has been proposed,along with the introduction of a three-section program for 2.9 m length of secondary cooling process,and ultimately designed a 1.4-2.7 m/min pulling rate of the water table,the surface of the billet return temperature was below 100℃and the return temperature met the metallurgical guidelines.Industrial production has proved that the internal quality of billet has been greatly improved by the optimization of water distribution in the secondary cooling.

关 键 词：含钒钢 连铸坯 内部裂纹 二冷配水 优化 

分 类 号：TF777[冶金工程—钢铁冶金]