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采用1种自然含氢和5种电化学预充不同含量氢的1Cr17Ni2马氏体-铁素体双相不锈钢CT紧凑拉伸试样进行了室温疲劳裂纹扩展速率实验,并对断裂后的试样断口进行了宏观和SEM分析。结果表明:电化学充氢没有改变试样的稳态疲劳裂纹扩展关系,扩展速率仍符合Paris的幂率关系;随氢含量的增加,疲劳裂纹扩展速率增加;疲劳扩展断口的宏观形貌和微观形貌均与氢含量有关,自然含氢试样的裂纹前沿呈对称的弧形,断口二次裂纹较充氢试样多;随着充氢量的增加,充氢试样裂纹前沿弧线变得越来越平直,断口上二次裂纹越来越少;氢含量较高试样,边缘部位表现为沿晶断裂特征,中心部位及氢含量较低试样断口则为典型的疲劳扩展形貌,可见清晰的疲劳辉纹。
The fatigue crack growth rate of 1Cr17Ni2 martensitic-ferritic dual-phase stainless steel with natural hydrogen and five kinds of electrochemical pre-filled hydrogen with different hydrogen content was tested at room temperature. The fracture specimens Fractures were analyzed macroscopically and SEM. The results show that the steady-state fatigue crack growth does not change with electrochemical hydrogen charging. The rate of expansion still accords with Paris’s power rate relationship. With the increase of hydrogen content, the fatigue crack growth rate increases. The macroscopic morphology and microstructure of the fatigue- Morphology and hydrogen content are related to the crack front of the natural hydrogen-containing specimen was symmetrical arc fracture secondary cracks than the hydrogen-filled specimens; with the charge of hydrogen increased, the crack-front arc of the hydrogen-filled specimen changes More and more flat, less fracture on the second crack; samples with higher hydrogen content, the edge of the performance of the intergranular fracture characteristics, the central part and the lower hydrogen content of the specimen fracture is a typical fatigue expansion Appearance, showing a clear pattern of fatigue.