Abstract: The propertes and microtnicture of high-speed axle steel DZ1 and DZ2 with Ni contents 0. 20% ,0. 80% and 1. 20% are studied by using metalloraphic microscope and SEM etc. The results show that with Ni content increasing from 0. 20% to 1. 20% , the tensile strength and yield strength of the steel increases respectively from 710 MPa to 759 MPa and from 535 MPa to 608 MPa； the impact toughness of steel at 20 ℃ and -40 ℃. impact toughness is inproved, especially at -40 ℃, the transvese impact energy of steel increases from 87 J of 0. 20% Ni contents to 136 J of 1. 20% Ni contents
and the longitudinal impact energy of steel increases from 94 J to 179 J； the temperature of steel's tough-brittle transition decreases from -30℃ to - 100 ℃. The high-speed railway axle steel structure of 3 kinds of composition is Bainite + tempered martensite structure, and the bainite volume increases with the increase of Ni content, and steel microstructure became finer and more uniform after the increase of Ni content.

摘要： 采用金相显微镜(Metallographic)和扫描电镜(SEM)等研究了0.20%、0.80%和1.20%Ni高铁车轴钢DZ1和DZ2性能和组织结构。结果表明,随着Ni含量由0.20%增至1.20%,钢的抗拉强度由710 MPa提高到759 MPa、屈服强度由535 MPa提高到608 MPa;钢的20℃和-40℃冲击韧性均得到提升,特别是-40℃横向冲击韧性从0.20%Ni的87 J提高到1.20%Ni的136 J,-40℃纵向冲击功从94 J提高到179 J;钢的韧脆转变温度由-30℃降低到-100℃;3种成分的高铁车轴钢均可得到贝氏体+回火马氏体组织,贝氏体量随着镍含量的提高而增加,并且镍含量提高后钢的组织更加细小、均匀。

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