Fatigue crack growth resistance of the austenitic stainless steel Alloy 709 at elevated temperatures
Fatigue crack growth resistance of the austenitic stainless steel Alloy 709 at elevated temperatures
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DOI：
10.1016/j.jmrt.2020.09.050
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
Suyang Yu;Jin Yan;Hangyue Li;R. Ding;Amrita Lall;A. Rabiei;P. Bowen
中科院分区：
文献类型：
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作者：
Suyang Yu;Jin Yan;Hangyue Li;R. Ding;Amrita Lall;A. Rabiei;P. Bowen
在550、650和750 °C的温度下，在空气和真空中评估了奥氏体不锈钢合金709的抗疲劳裂纹扩展性。测试在0.25 Hz的频率和0.1的应力比下进行。线弹性应力强度因子范围（ΔK）已被用来衡量疲劳裂纹扩展阻力。一个温和的有害影响的空气在高温下对疲劳裂纹扩展的识别和讨论。条纹穿晶疲劳被认为是所有测试条件下的失效机制。条纹的形成和相互作用的裂纹增长与滑移痕迹进一步研究使用原位测试（在扫描电子显微镜），连同透射电子显微镜进行的样品提取的聚焦离子束铣削垂直断裂面。最后，提出了一个分析模型来预测709合金在空气中的疲劳裂纹扩展。
Fatigue crack growth resistance of an austenitic stainless steel Alloy 709 has been evaluated at temperatures of 550, 650 and 750 °C in air and vacuum. Tests were conducted at a frequency of 0.25 Hz and a stress ratio of 0.1. The linear elastic stress intensity factor range (ΔK) has been used to characterise fatigue crack growth resistance. A modest detrimental effect of air at elevated temperatures on fatigue crack growth is identified and discussed. Striated transgranular fatigue is found to be the failure mechanism for all test conditions. The formation of striations and the interaction of crack growth with slip traces are further investigated using in-situ testing (within a scanning electron microscope), together with transmission electron microscopy carried out on samples extracted by focused ion-beam milling perpendicular to fracture surfaces. Finally, an analytical model is proposed to predict fatigue crack growth in air for Alloy 709.