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在动力、航空及化工等高温机械中,一些重要零部件往往也会含有裂纹或类似裂纹的缺陷,即使其所承受的交变载荷远低于由常规方法所求得的疲劳极限,也可能由于裂纹的扩展而导致灾难性的事故。因此,研究裂纹在高温疲劳条件下的扩展规律是十分重要的,它乃是对传统疲劳试验和分析方法的一个重要发展和补充。本文拟就高温疲劳裂纹亚临界扩展的控制参量、影响因素及测试技术等方面的研究现状作介绍。一高温疲劳裂纹亚临界扩展的控制参量在高温下,对受应力控制的疲劳,目前主要采用应力强度因子的幅度△K作为裂纹扩展速率的控制参
In high-temperature machinery such as power, aviation and chemical industry, some important parts often contain defects such as cracks or similar cracks. Even if the alternating load they bear is far lower than the fatigue limit obtained by conventional methods, it may be due to Crack expansion leads to catastrophic accident. Therefore, it is very important to study the crack propagation under high-temperature fatigue conditions, which is an important development and supplement to traditional fatigue testing and analysis methods. This paper intends to introduce the research status of control parameters, influencing factors and testing techniques of subcritical expansion of high temperature fatigue crack. A Control Parameter of Sub-critical Expansion of High-temperature Fatigue Crack At the high temperature, under the stress-controlled fatigue, the magnitude of stress intensity factor is mainly used as the control parameter of crack propagation rate