稀土Ce对高强工程机械用钢夹杂物和高温塑性的影响  

Effect of rare earth cerium on inclusions and hot ductility of high-strength steel for construction machinery

作　　者：臧若愚 李晶[1] 黄飞 ZANG Ruoyu;LI Jing;HUANG Fei(State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China;China Iron and Steel Association,Beijing 100010,China)

机构地区：[1]北京科技大学钢铁冶金新技术国家重点实验室,北京100083 [2]中国钢铁工业协会,北京100010

出　　处：《有色金属科学与工程》2024年第3期449-456,共8页Nonferrous Metals Science and Engineering

基　　金：国家自然科学基金资助项目(52074026)。

摘　　要：通过向高强工程机械用钢中加入稀土合金,研究了Ce对夹杂物和高温塑性的影响。通过扫描电镜、能谱分析、夹杂物自动分析系统和热力学计算对夹杂物的类型、数量和尺寸进行分析。利用Gleeble1500热模拟机测定了实验钢的高温塑性,并使用光学金相显微镜和扫描电镜观察断口形貌及组织。结果表明,加入Ce后,钢中夹杂物由不规则的Al_(2)O_(3)、MnS和Al_(2)O_(3)+MnS复合夹杂物转变为球状或椭球状的Ce_(2)O_(2)S和CeS,数量增多,尺寸减小了37.64%。650~1050℃范围内含Ce钢的断面收缩率均高于无Ce钢,具有更好的高温塑性。这是由于Ce处理生成的小球状稀土夹杂物减轻了应力集中,与基体能够协调变形,同时它们能够诱导晶内铁素体形核,最终高温塑性得到改善。The effect of cerium on inclusions and hot ductility was studied by adding rare earth alloy to high-strength steel for construction machinery.The type,quantity,and size of inclusions were analyzed by scanning electron microscope(SEM),energy dispersive spectrometer(EDS),automatic detection system of non-metallic inclusion,and thermodynamic calculation,respectively.The hot ductility of the experimental steel was measured using a Gleeble1500 thermal simulation tester,and the tensile fracture morphology and microstructure were observed with an optical microscope(OM)and scanning electron microscope.The results show that the addition of Ce modifies the inclusions in the steel from irregular complex inclusions consisting of Al_(2)O_(3),MnS,and Al_(2)O_(3)+MnS to spherical or ellipsoidal Ce_(2)O_(2)S and CeS,with an increase in quantity and a decrease in size of 37.64%.The reduction in cross-sectional area of Ce-containing steel within the range of 650-1050℃ is higher than that of Ce-free steel,indicating better hot ductility.This is attributed to the fact that the small spherical rare earth inclusions generated by the Ce treatment reduces the stress concentration,coordinates the deformation with the matrix,and induces the intragranular ferrite nucleation,ultimately improving the hot ductility of steel.

关 键 词：高强工程机械用钢 稀土 夹杂物 高温塑性 晶内铁素体 

分 类 号：TF762.3[冶金工程—钢铁冶金]