摘要
通过添加微合金化元素V和Nb制备新型20Cr Ni MoVNb齿轮钢,研究了V和Nb的加入及热处理工艺对齿轮钢奥氏体晶粒长大趋势、硬度和力学性能的影响。结果表明,20CrNiMoVNb齿轮钢在奥氏体化温度为880～940℃时的晶粒都较为细小,而传统20Cr Ni Mo齿轮钢在相同奥氏体化温度下的晶粒尺寸相对较大,且20Cr Ni MoVNb齿轮钢在奥氏体化处理后的晶内和晶界都可见细小、弥散的Nb(C,N)粒子存在;20Cr Ni Mo和20Cr Ni MoVNb齿轮钢的适宜的奥氏体化温度分别为860℃和900℃;当回火温度为200℃时,20Cr Ni MoVNb齿轮钢的抗拉强度和屈服强度分别为1 368 MPa和1 157 MPa,冲击功为132 J,高于20Cr Ni Mo齿轮钢的力学性能使用要求,这主要与晶粒细化和第二相强化有关。
A new 20CrNiMoVNb gear steel was prepared by adding element V and Nb, and the effects of V, Nb elements and the heat treatment process on the austenite grain growth trend, hardness and mechanical properties of gear steel were investigated. The results show that the grains of 20CrNiMoVNb gear steel in austenitic temperature at 880-940 ℃ are relatively small. However, the grain size of conventional 20CrNiMo gear steel at the same austenite melt temperature is relatively large. In addition, the presence of small, dispersed Nb （C, N） particles in the intragranular and grain boundaries of 20CrNiMoVNb gear steel can be found after austenitizing treatment. The suitable austenitizing temperature of 20CrNiMo and 20CrNiMoVNb gear steels is 860 ℃ and 900 ℃, respectively. When the tempering temperature is 200 ℃, the tensile strength and yield strength of 20CrNiMoVNb gear steel are 1 368 MPa and 1157 MPa, and the impact energy is 132 J, respectively. Which is higher than that of 20CrNiMo gear steel, it is mainly related to grain refinement and second phase strengthening.
作者
丘建雄
廖辉玲
QIU Jianxiong1, LIAO Huiling2(1. Department of Manufacturing Engineering, Huizhou Institute of Technician, Huizhou 516003, China; 2. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510000, China)
出处
《铸造技术》
CAS
2018年第10期2382-2385,2397,共5页
Foundry Technology
基金
省级职能技术基金(粤人社办[2012]419号)
关键词
齿轮钢
奥氏体化
组织
性能
gear steel
austenitizing
microstructure
properties
