添加稀土的20MnCrNi2Mo耐磨铸钢的组织与性能  

Microstructure and properties of 20MnCrNi2Mo wear resistant cast steel with addition of rare earth

作　　者：侯敬超[1] 计云萍[1] 靳晓燕[1] 金自力[1] 任慧平[1,2] 

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]内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室,内蒙古包头014010

出　　处：《金属热处理》2015年第10期18-21,共4页Heat Treatment of Metals

基　　金：国家自然科学基金(51261018);内蒙古自然科学基金(2012MS0805);内蒙古科技大学创新基金(2011NCL037)

摘　　要：针对添加镧、铈混合稀土的20Mn Cr Ni2Mo耐磨铸钢,采用扫描电镜、透射电镜、洛氏硬度计、电子万能试验机和电子式摆锤冲击试验机进行组织观察和和力学性能测定,并分析试验钢显微组织和力学性能的关系。结果表明:添加镧、铈混合稀土的20Mn Cr Ni2Mo耐磨铸钢铸态组织为粒状贝氏体,且存在较高密度位错;稀土含量为0.0092%的20Mn Cr Ni2Mo耐磨铸钢硬度达到32.11 HRC,抗拉强度为1128.48 MPa,冲击吸收能量(-40℃)为9.887 J。高密度位错能提高试验钢的硬度,但不利于塑性的改善;贝氏体组织中的(M/A)岛对于硬度和强度的提高有利,但会降低韧性;添加稀土元素使夹杂物变质,有助于改善韧性。The microstructure and mechanical properties of 20 Mn Cr Ni2 Mo wear resistant cast steel alloyed with rare earth La and Ce were investigated by means of scanning electron microscope,transmission electron microscope,Rockwell hardometer,electronic universal testing machine and electronic pendulum impact testing machine. Then the relationship between microstructure and mechanical properties of the tested steel was analyzed. The results show that the microstructure of 20 Mn Cr Ni2 Mo wear resistant cast steel is granular bainite with high density dislocation. The hardness of 20 Mn Cr Ni2 Mo wear resistant cast steel alloyed with 0. 0092% RE is 32. 11 HRC. The tensile strength and impact absorbtion energy（- 40 ℃） are 1128. 48 MPa and 9. 887 J respectively. The high-density dislocation can improve the hardness of the tested steel,but can decrease the plasticity. The（ M / A） islands in bainite may increase the hardness and tensile strength,but decrease the toughness of the steel. The rare earth elements in the tested steel can modify the inclusions and then improve the toughness of the steel.

关 键 词：20MnCrNi2Mo耐磨铸钢 镧铈混合稀土 粒状贝氏体 抗拉强度 冲击性能 

分 类 号：TG142.72[一般工业技术—材料科学与工程]