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采用Ｘ射线衍射仪及光学显微镜分析了Ｗ１８Ｃｒ４Ｖ高速钢离子氮碳共渗层的相结构，采用连续加载压入法研究了共渗层脆性。研究结果表明：在渗氮气氛中引入ＣＨ４进行离子氮碳共渗时，碳的渗入可抑制渗层中γ′Ｆｅ４Ｎ相的形成；渗层中γ′Ｆｅ４Ｎ相的减少，降低了ε与γ′相混合时的脆性。另一方面ＣＨ４的引入增加了碳化物相，会使脆性增加，综合效果取决于Ｖ（Ｎ２）／Ｖ（Ｈ２）值及ＣＨ４加入量。选择比例适当的Ｎ２、Ｈ２、ＣＨ４气氛，可使共渗层脆性较单纯渗氮小；当Ｖ（Ｎ２）∶Ｖ（Ｈ２）为３∶１时，随ＣＨ４量的增加，渗层深度增加至一定峰值之后下降。
The phase structure of ion nitrocarburizing layer of W18Cr4V high speed steel was analyzed by X-ray diffractometer and optical microscope. The brittleness of co-permeation layer was studied by continuous loading and pressing method. The results show that the infiltration of carbon can inhibit the formation of γ’Fe4N phase in the infiltrated layer when introducing CH4 into nitriding atmosphere. The decrease of γ’Fe4N phase in the infiltrated layer reduces ε and γ ’phase when the brittleness. On the other hand, the introduction of CH4 increases the carbide phase and increases the brittleness. The combined effect depends on the value of V (N2) / V (H2) and the amount of CH4 added. When the V (N2): V (H2) is 3:1, the depth of the diffusion layer increases with the increase of the amount of CH4 to Decreased after a certain peak.