钒对Cr12Mo模具钢渗氮层及其摩擦学行为的影响

在Cr12Mo和Cr12MoV模具钢表面进行气体渗氮处理,对比分析了V对Cr12Mo模具钢渗氮层显微结构及其摩擦学行为的影响。结果表明,气体渗氮后两种模具钢的表面均制备出深度约120 μm的渗氮层,由表及里依次为渗氮层、扩散层和基体;V提高了模具钢的耐磨性,Cr12MoV表现出较好的耐磨效果;相比V对模具钢基体和扩散层硬度的提升而言,V对渗氮层最大硬度值附近区域的硬度提升幅度更为明显;V对两种模具钢渗氮层耐磨性的影响并不明显,但V的主要贡献在于促进了渗氮时N的有效渗入,大大提高了渗氮层与扩散层间的界面结合力,避免了渗氮层与扩散层间的开裂,促使磨损机制由疲劳磨损转变为黏着磨损,进一步提高了渗氮层的服役寿命。

Effect of vanadium on nitrided layer of Cr12Mo die steel and its tribological behavior

Cr12Mo and Cr12MoV die steels were gas nitrided, and then the effect of V on microstructure and tribological behavior of Cr12Mo die steel was compared and analyzed. The results show that after gas nitriding, a nitrided layer with a depth of about 120 μm is prepared on the surface of both the two die steels, and the nitriding layer, diffusion layer and matrix are successively from the surface to the inside. The V improves the wear resistance of die steel, and the Cr12MoV steel shows better anti-wear effect. Compared with that on the increase of the hardness of the die steel matrix and the diffusion layer, the effect of V on the increase of the hardness of the zone near the maximum hardness value of the nitriding layer is more obvious. The effect of V on wear resistance of the nitrided layer of the two die steels is not obvious, but the main contribution of V is to promote the effective infiltration of N during nitriding, greatly improve the interface bonding force between the nitrided layer and the diffusion layer, avoid the cracking between the nitriding layer and the diffusion layer, and promote the change of the wear mechanism from fatigue wear to adhesive wear, and the service life of the nitrided layer is further improved.