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应用ΔJ参数和扫描电镜 (SEM)方法 ,研究了 30 9L和 347L不锈钢堆焊层短裂纹的低频疲劳特性。并用da/dN =C(ΔJ) n 计算了裂纹扩展速率和门槛值。发现裂纹扩展行为可分为三个阶段 ,并有三个方程与之对应。经计算得到堆焊态 347L和 30 9L奥氏体不锈钢裂纹扩展门槛值 (ΔJth)分别为 355× 10 - 6 MN/m和 196× 10 - 6 MN/m。SEM断口分析表明 ,三个阶段的短裂纹扩展特性各不相同
The low-frequency fatigue characteristics of short cracks in 30 9L and 347L stainless steel overlay were studied by ΔJ parameter and scanning electron microscope (SEM). The crack propagation rate and threshold were calculated using da / dN = C (ΔJ) n. It is found that the crack propagation behavior can be divided into three phases and three equations correspond to them. The crack propagation thresholds (ΔJth) for the 347L and 3091L austenitic stainless steels deposited at the weld level were calculated to be 355 × 10-6 MN / m and 196 × 10-6 MN / m, respectively. SEM fracture analysis showed that the three stages of the short crack propagation characteristics vary