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本文采用表面裂纹法研究了碳氮共渗、氮化及滚压强化层的疲劳裂纹扩展抗力．与常规的紧凑拉伸试验法相比，前者能灵敏地反映出表面强化层组织及性能的影响，后者却难于实现．试验证实碳氮共渗层中由于残留奥氏体应变诱发马氏体，导致疲劳裂纹扩展抗力提高；滚压强化及渗氮均能提高表面压应力，也使疲劳裂纹扩展抗力明显提高．
In this paper, the surface crack method was used to study the fatigue crack growth resistance of carbonitriding, nitriding and rolling strengthening layer. Compared with the conventional compact tensile test method, the former can sensitively reflect the microstructure and properties of the surface strengthened layer, the latter is difficult to achieve. It was confirmed that the martensite induced by the residual austenite strain in the carbonitrided layer led to the increase of the fatigue crack propagation resistance. Both the rolling strengthening and the nitriding can increase the surface compressive stress and also the fatigue crack propagation resistance obviously increased.