离子氮碳共渗与离子渗氮复合处理对45钢组织与性能的影响

Effects of Complex Treatment of Plasma Nitrocarburizing and Plasma Nitriding on Microstructure and Properties of 45 Steel

为进一步提高渗层厚度及渗层性能,对45钢进行离子氮碳共渗与离子渗氮复合处理。采用扫描电镜、X射线衍射仪、显微硬度计和光学显微镜对渗层厚度、物相组成、截面与表面硬度、渗层脆性进行了分析。结果表明,复合处理可使45钢获得比单一离子渗氮或离子氮碳共渗更快的渗速、更优的性能。相同的处理时间下,复合处理渗层厚度比单一离子渗氮或离子氮碳共渗大幅度增加,有效硬化层比单一离子渗氮增加约35μm,提高约1倍,同时渗层脆性显著降低。物相分析表明复合处理后化合物层中ε相和γ'相的相对含量发生了变化,即ε相增多,而γ′相减少。

To further enhance the compound layer thickness and its properties, a complex treatment of plasma nitrocarburizing and nitriding was carried out for 45 steel. The thickness, phase constituents, cross-sectional and surface microhardness, and frangibility of the nitrided layer were investigated by means of scanning electron microscopy （SEM）, X-ray diffraction （XRD）, microhardness tester and optical microscope （OM）. The results show that higher efficiency and better properties are obtained after the complex treatment for 45 steel. The nitrided layer thickness is increased significantly, and the effective hardening layer increased above 35 μm, nearly doubled. Meanwhile, the frangibility of the nitrided layer is decreased notably. The relative amount of ε phase in the compound layer is increased, but that ofγ′ is reduced.