Time- and cycle-dependent crack propagation in Haynes 282

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• 作者：Jonas Saarimä ; ki^a ; ^{jonas.saarimaki@liu.se" class="auth_mail" title="E-mail the corresponding author} ; Johan J. Moverare^a ; Magnus Hö ; rnqvist Colliander^b ; ^c
• 关键词：Nickel based superalloys ; Fatigue ; Fracture ; Mechanical characterisation ; Electron microscopy
• 刊名：Materials Science & Engineering A
• 出版年：2016
• 出版时间：21 March 2016
• 年：2016
• 卷：658
• 期：Complete
• 页码：463-471
• 全文大小：2871 K

文摘

Haynes 282 is a promising superalloy candidate for several high-temperature applications in both aero and land-based gas turbine engines. To study the crack growth behaviour under time-dependent conditions relevant to such applications, a test program was carried out at room temperature up to 700 °C with conditions ranging from pure cyclic to sustained tensile loading. At 650 °C and high stress intensity factors the crack growth was fully time-dependent for dwell-times of 90 s and longer. At lower stress intensities, the behaviour was mainly controlled by the cyclic loading, even under dwell conditions. The behaviour under dwell-fatigue conditions was well described by a liner superposition model. The main crack growth occurred transgranularly at room temperature and there was a transition in cracking behaviour from cycle dependent transgranular growth to time-dependent intergranular propagation at $\sim 45\mathrm{MPa}\sqrt{\mathrm{m}}$ for the high temperature tests. No effect of cyclic frequency could be observed at room temperature, and at lower frequencies the crack growth rate increased with temperature.