微合金镍对轴承钢组织和机械性能的影响

A survey on the effect of microalloyed nickel on the microstructure and mechanical properties of bearing steel

通过组织观察和机械性能分析,研究了轴承钢中镍含量(ωNi=1.1%、2.0%、3.0%、4.0%)对其显微组织及机械性能的影响.显微组织观察结果表明:当镍含量为1.1%时,显微组织为板条马氏体+残留奥氏体+少量碳化物;当镍含量为4.0%时候,显微组织是隐晶马氏体+大量残留奥氏体+少量碳化物.镍含量的增加对组织的影响规律是马氏体板条束变得细小,残留奥氏体的含量逐渐增加.机械性能分析表明,镍的增加提高了材料强硬度和塑、韧性,而残留奥氏体数量的增加消除了部分镍带来的强化效果,高镍含量降低抗拉强度,试验结果表明,镍含量在3.0%的轴承钢综合机械性能最佳.

The effect of nickel content(ωNi=1.1%, 2.0%, 3.0%, 4.0%) in bearing steel on its microstructure and mechanical properties was explored through microstructure observation and mechanical properties analysis. The results of microstructure observation showed: when nickel content was 1.1%, the microstructure was composed of lath martensite +retained austenite +a small amount of carbide. When nickel content was 4.0%, the microstructure was composed of cryptocrystalline martensite +a large amount of retained austenite +a small amount of carbide;The effect of the increase of nickel content on the microstructure followed this law : when the martensite lath bundle became finer, the content of retained austenite gradually increased. The results of mechanical properties analysis showed: the increase of nickel content enhanced the hardness, plasticity and toughness of the material, while the increase of retained austenite offset some strengthening effect caused by nickel;High nickel content reduced tensile strength, and when nickel content was 3%, the overall mechanical properties of bearing steel were the best.