镧铈混合稀土对20MnCrNi2Mo铸钢凝固过程的影响  

Effects of Lanthanum-cerium Mischmetal on Solidification Process of 20MnCrNi2Mo Cast Steel

作　　者：计云萍[1] 李超[1] 亢磊 宋艳青 靳晓艳[1] JI Yunping;LI Chao;KANG Lei;SONG Yanqing;JIN Xiaoyan(College of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China;Grikin Advanced Materials Co.,Ltd.,Beijing 102200,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010 [2]有研亿金新材料有限公司,北京102200

出　　处：《热加工工艺》2020年第4期21-24,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51261018,51761034);内蒙古自然科学基金项目(2017MS0512).

摘　　要：针对未加稀土及添加镧铈混合稀土的20MnCrNi2Mo低合金耐磨铸钢,采用FactSage软件系统的Phase Diagram模块计算M-C(M代表Fe-0.49%Si-1.03%Mn-1.16%Cr-1.90%Ni-0.54%Mo)伪二元相图。采用NETZSCH STA 449C型示差扫描量热仪测定实验钢的DSC曲线,研究其凝固模式。分析稀土对凝固过程的影响,探讨了稀土的作用机理。结果表明,20MnCrNi2Mo低合金耐磨铸钢的凝固模式为:L→L+δ→L+δ+γ→L+γ→γ;总量为0.0327%的镧铈混合稀土不改变20MnCrNi2Mo铸钢的凝固模式,但使得液相线温度降低、固相线温度升高,使结晶温度区间显著缩小。凝固过程中镧铈混合稀土提高了包晶转变的开始温度和终了温度,这对结晶区间显著缩小起到决定性作用。研究结果能为镧铈混合稀土在低合金耐磨铸钢中的有效应用提供理论和实验依据。Aiming at 20MnCrNi2Mo low alloy wear-resistant cast steel with and without adding lanthanum-cerium mischmetal,the phase diagram module of thermodynamic software FactSage was chosen to calculate the pseudo binary phase diagram of M-C(M represents Fe-0.49%Si-1.03%Mn-1.16%Cr-1.90%Ni-0.54%Mo).The DSC curves of the experiment steels were measured by NETZSCH STA 449C differential scanning calorimeter.The solidification mode of the steel was researched.The effects of lanthanum-cerium mischmetal on the solidification process were analyzed and the mechanism of the rare earth was discussed.The results show that the solidification mode of 20MnCrNi2Mo low alloy wear-resistant cast steel is as follows:L→L+δ→L+δ+γ→L+γ→γ.The 0.0327%lanthanum-cerium mischmetal doesn’t change the solidification mode of 20MnCrNi2Mo cast steel.However,it reduces the liquidus temperature and increases the solidus temperature,so the crystallization interval is dramatically narrowed down.The lanthanum-cerium mischmetal also greatly increases the onset and end temperature of the peritectic transformation,which governs the reduction of the crystallization interval.The study can provide the theoretical and experimental basis for the effective utilization of lanthanum-cerium mischmetal in low alloy wear-resistant cast steel.

关 键 词：镧铈混合稀土 20MnCrNi2Mo铸钢 凝固模式 结晶区间 

分 类 号：TG142.72[一般工业技术—材料科学与工程]