Nb微合金化对准贝氏体耐磨铸钢组织和性能的影响  

Effect of Nb microalloying on microstructure and properties of quasi-bainitic wear-resistant cast steel

作　　者：张芳[1] 李军平 彭军[1] 郑丽丽 安胜利[1] Zhang Fang;Li Junping;Peng Jun;Zheng Lili;An Shengli(School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,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

出　　处：《金属热处理》2020年第12期205-211,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(51664044,51864041);内蒙古自然科学基金(2018LH05005)。

摘　　要：研究了铌(Nb)微合金化对准贝氏体耐磨铸钢的组织和性能的影响。使用热膨胀测试仪、扫描电镜、拉伸及冲击试验和磨损试验等分析了含铌量不同的低碳(约0.26%)铸钢的组织和力学性能。结果表明,Nb的添加促进了准贝氏体的生长,当Nb含量从0%增加至0.062%时,原始奥氏体晶粒从120.81μm减小至87.65μm,平均晶粒尺寸减小27.4%。同时,Nb的添加降低了钢的磨损率,硬度也有所降低,但冲击吸收能量、侧膨胀值、屈服强度、抗拉强度和断面收缩率均有所提高。当Nb含量为0.024%时,磨损率最低为0.104%,耐磨性能最好,且综合力学性能最好,其硬度为420.4HV0.1,冲击吸收能量为42.6 J,侧膨胀值为67%,屈服强度为826 MPa,抗拉强度为1326 MPa,断面收缩率为7.7%,残留奥氏体含量较高为8.4%。Effect of niobium(Nb)microalloying on the microstructure and properties of quasi-bainite wear-resistant cast steel with low carbon(about 0.26%)and different niobium content was analyzed by means of thermal expansion tester,scanning electron microscope,tensile and impact test and wear test.The results show that the addition of Nb promotes the growth of the quasi-bainite and the prior austenite grains decrease from 120.81μm to 87.65μm when Nb content increases from zero to 0.062%,and the average grain size is reduced by 27.4%.Meanwhile,the addition of Nb caused a decrease in wear rate of the steel,and the hardness is also decreased,but the impact absorbed energy,lateral expansion value,yield strength,tensile strength and reduction of area are all increased.When Nb content is 0.024%,the wear rate reaches the lowest value of 0.104%,and the wear resistance is the best,moreover,the comprehensive mechanical properties are also the best with hardness of 420.4 HV0.1,impact absorbed energy of 42.6 J,side expansion value of 67%,yield strength of 826 MPa,tensile strength of 1326 MPa and percentage reduction of area of 7.7%,while the content of retained austenite is relatively high at 8.4%.

关 键 词：铌微合金化 准贝氏体 耐磨铸钢 组织 力学性能 

分 类 号：TG142.3[一般工业技术—材料科学与工程]