ABSTRACT The creep deformation behaviour and its effect on the creep life and rupture ductility are investigated for W-Mo-balanced 9Cr steels at 600 °C to 700 °C. The creep life is described as tr = 1.5/[min (dln/d)], where min and dln/d reflect the creep deformation behaviour in the transient and acceleration creep regions, respectively. The creep life is also correlated with the time to minimum creep rate tm as tr = gtm, where g slightly increases with decreasing stress. The logarithm of creep rate linearly increases with strain in the initial stage of acceleration creep region. This is followed by a decrease in dlnd with strain at high stresses, resulting in ductile failure at large strains, while it is followed by an increase in dln/d with strain at low stresses, resulting in rupture at small strains.

中文翻译：

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蠕变变形行为及其对 W-Mo 平衡 9Cr 钢蠕变寿命和断裂延展性的影响

摘要 研究了 W-Mo 平衡的 9Cr 钢在 600°C 至 700°C 下的蠕变变形行为及其对蠕变寿命和断裂延展性的影响。蠕变寿命被描述为 tr = 1.5/[min (dln/d)]，其中 min 和 dln/d 分别反映了瞬态和加速蠕变区域的蠕变变形行为。蠕变寿命也与达到最小蠕变速率的时间 tm 相关，因为 tr = gtm，其中 g 随着应力的降低而略微增加。在加速蠕变区的初始阶段，蠕变速率的对数随应变线性增加。紧随其后的是高应力应变下 dlnd 减小，导致大应变下的延性破坏，而接着是低应力应变下 dln/d 增加，导致小应变下断裂。