高碳中锰耐磨钢凝固过程溶质微观偏析模型  

Microsegregation models of solute elements during the solidification of high-carbon,medium-magnetic wear-resistant steel

作　　者：李民 刘洪波 车晓锐 刘颖 张杰[2] 张彩东 田志强 徐浩 LI Min;LIU Hongbo;CHE Xiaorui;LIU Ying;ZHANG Jie;ZHANG Caidong;TIAN Zhiqiang;XU Hao(Materials Technology Research Institute,HBIS Group,Shijiazhuang 050023,China;School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;Institute of Engineering and Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]河钢材料技术研究院,石家庄050023 [2]北京科技大学冶金与生态工程学院,北京100083 [3]北京科技大学工程技术研究院,北京100083

出　　处：《工程科学学报》2024年第6期1089-1096,共8页Chinese Journal of Engineering

基　　金：河北省自然科学基金资助项目(E2021318004);中央引导地方科技发展资金资助项目(216Z1009G)。

摘　　要：通过定向凝固、电子探针(EPMA)、Factsage等多种实验与理论计算相结合的手段对中锰耐磨钢凝固过程溶质元素微观偏析行为进行了系统研究.研究表明在定向凝固试验中当拉速为50μm·s-1时,中锰钢的二次枝晶间距平均值为59.77μm;中锰钢凝固过程组织转变为L→L+γ→γ属于奥氏体凝固模式,无包晶反应的发生,也无铁素体相及其他相的出现;中锰钢定向凝固过程中Mn、Cr在枝晶间的含量明显高于枝晶内,表明Mn、Cr元素发生了明显的正偏析行为;通过对各特征参数求解,构建了中锰钢溶质元素微观偏析模型,发现中锰钢定向凝固过程中Mn元素偏析指数与Brody–Flemings模型符合较好,而Cr元素偏析指数与Clyne–Kurz模型分布较为一致.The microsegregation behavior of solute elements during the solidification of medium manganese wear-resistant steel has been systematically studied using directional solidification,electron probe microanalysis(EPMA),Factsage,and other experiments.The results showed that the solidification structure of Fe–8.5Mn–2.1Cr–0.95C medium manganese steel was dendrite,and no interconversion occurred between the cell and dendrite.Furthermore,the average secondary dendrite arm spacing of medium manganese steel was 59.77μm when the pulling speed was 50μm·s-1 during the directional solidification experiment.The results calculated using Factsage showed that the microstructure transformation of medium manganese steel during solidification was L→L+γ→γ,which belonged to the austenite solidification mode,and no peritectic reaction,δphase,or other phases appeared.Based on the equilibrium cooling and IF modes,the liquidus and solid temperatures of medium manganese steel calculated using Factsage were 1422.93℃and 1280.98℃,respectively.Furthermore,the EPMA experiments indicated that the Mn and Cr contents at the edges of secondary dendrites were considerably higher than those at the center.Specifically,the Mn content decreased from 9.13%to 7.49%,and the Cr content decreased from 2.03%to 1.68%simultaneously.This result indicates that the positive segregation behavior of Mn and Cr occurred during the directional solidification of medium manganese steel.Microsegregation models of Mn and Cr in medium manganese steel were established by solving the characteristic parameters during solidification.The segregation indexes of Mn calculated using the Scheil model were much higher than the experimental EPMA values when the solidification fraction was close to 1.However,the results obtained from the Lever–ruler,Brody–Flemings,Clyne–Kurz,Ohnaka,and Won–Thomas models were closer when the solidification fraction was lower than 0.5.Furthermore,when the solidification fraction was less than 0.7,the segregation indexes of Cr c

关 键 词：中锰耐磨钢 电子探针 定向凝固 二次枝晶间距 微观偏析模型 

分 类 号：TG142.71[一般工业技术—材料科学与工程]