连铸M2高速钢碳化物和宏观偏析热模拟  

Thermal simulation of carbide and macrosegregation in continuous casting M2 high-speed steel1

作　　者：李志聪 陈杨珉 陈湘茹 仲红刚 李莉娟 翟启杰 LI Zhicong;CHEN Yangmin;CHEN Xiangru;ZHONG Honggang;LI Lijuan;ZHAI Qijie(Center for Advanced Solidification Technology,School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学材料科学与工程学院先进凝固技术中心,上海200444

出　　处：《钢铁研究学报》2023年第10期1228-1240,共13页Journal of Iron and Steel Research

基　　金：国家自然科学基金重点资助项目(52130109);河北省重点研发计划资助项目(20311006D)。

摘　　要：M2高速钢碳化物粗大且分布不均匀制约了该钢种采用连铸-连轧工艺生产。采用基于特征单元热相似性的连铸坯枝晶生长热模拟试验机研究了连铸M2高速钢凝固过程及组织形成规律,并且使用光学显微镜和金属原位分析仪分析了过热度和二冷区比水量对其碳化物分布和尺寸及宏观偏析的影响。实验结果表明,铸坯碳化物分布和尺寸及宏观偏析受到过热度与二冷区比水量的显著影响。过热度每减小10℃,凝固末端的碳化物面积占比减小约1.5%,碳化物网交汇处平均尺寸减小约7.5μm。随着二冷区比水量由0.36 L/kg增加至0.54 L/kg,凝固末端的碳化物面积占比减小约2.8%,碳化物网交汇处平均尺寸减小约23.8μm。降低过热度和提高二冷区比水量有利于C、W、Cr、V元素均匀分布和降低中心偏析。The carbides in M2 high-speed steel(HSS)are coarse and unevenly distributed,which limits the application of the‘continuous casting-rolling'process in M2 HSS production.The solidification process and microstructure evolution of continuous casting M2 HSS were investigated by a thermal simulation device based on the thermal similarity of the characteristic unit.The effects of superheat and water consumption rate at secondary cooling zone on the distribution and size of carbide and macrosegregation were analyzed by optical microscope and metal original position analyzer.The results show that the distribution and size of carbide and macrosegregation in the cast billets are significantly influenced by the superheat and water consumption rate at secondary cooling zone.For every 10℃ drop in superheat,the percentage of carbide area at the solidification end reduces by about 1.5%,and the average size of the carbide network intersection decreases by about 7.5μm.With the secondary cooling zone water consumption rate increase from 0.36 L/kg to 0.45 L/kg,the percentage of carbide area at the solidification end decreases by about 2.8%,and the average size of the carbide network intersection decreases by about 23.8μm.Reducing the superheat and increasing the secondary cooling zone water consumption rate are beneficial to the uniform distribution of C,W,Cr and V elements and reduce the central macrosegregation.

关 键 词：M2高速钢 连铸 热模拟 凝固 碳化物 宏观偏析 

分 类 号：TF777[冶金工程—钢铁冶金]