钇基稀土对51CrV4弹簧钢组织性能的影响

Effects of Y-based rear earth (RE) on microstructure and properties of 51CrV4 spring steel

摘要: 设计了添加钇基稀土的51CrV4弹簧钢，并借助于单向拉伸试验机，扫描电子显微镜（SEM）以及室温冲击试验机对比分析了钇基稀土对51CrV4弹簧钢组织性能的影响.结果表明，2种弹簧钢的强度和硬度均随回火温度的上升而逐渐下降，而断面收缩率逐渐上升；钇基稀土能明显提高弹簧钢的强度和硬度，尤其是屈服强度，归因于钇基稀土能抑制弹簧钢板条组织特征的形成以及碳化物析出；钇基稀土与弹簧钢中氧、硫形成了细小、均匀分布的稀土氧硫复合夹杂物，可明显改善弹簧钢的冲击韧性.

Abstract: the 51CrV4 spring steel modified by Y-based rare earth (RE) was designed. The effect of Y-base RE on microstructure and properties of the steel was comparative studied using uniaxial tensile testing machine, scanning electron microscopy (SEM) and room temperature impact testing. The results show that the strength and hardness of the spring steel decreased gradually with the increase of tempering temperature, but the contraction of area can be increased. The strength, especially for yield strength can be obviously improved, which attributed to the Y-based RE can inhibit the formation of carbide during tempering. The REOS compound inclusions formed by the reaction between RE and oxygen, sulfur in spring steel, which can significantly improve the impact toughness of spring steel.