In this study, creep damage in a biaxially creep-damaged Mod.9Cr–1Mo component has been examined via uniaxial miniature creep testing. Using cruciform specimens, biaxial tension creep tests were conducted at principal stress ratios (λ) of $\lambda =0.0$ and 1.0 at 923 K. The principal stress ratio is the ratio of the y-directional principal stress (${\sigma }_y$) to the x-directional principal stress (${\sigma }_x$) in a cruciform specimen ($\lambda ={\sigma }_y/{\sigma }_x$). The equi-biaxial creep test was interrupted at a half lifetime, and two miniature specimens were machined from the damaged cruciform specimen in the x- and y-direction. The applicability of the linear cumulative creep damage rule was assessed using the results of the miniature lifetimes. The linear cumulative creep damage rule gave an unconservative estimate to the remaining life of a biaxially damaged cruciform specimen. Using the hyperbolic constitutive relationship, the unconservative estimate according to the damage accumulation was explained.

在这项研究中，已通过单轴微型蠕变测试检查了双轴蠕变损坏的 Mod.9Cr-1Mo 组件中的蠕变损伤。使用十字形试样，在主应力比 (λ) 下进行双轴拉伸蠕变试验$\lambda =0.0$在 923 K 时为 1.0。主应力比是y方向主应力 (${\sigma }_{是}$) 到x方向的主应力 (${\sigma }_{\times }$) 在十字形标本 ($\lambda ={\sigma }_{是}/{\sigma }_{\times }$）。等双轴蠕变试验在半衰期中断，从损坏的十字形试样沿x和y方向加工两个微型试样。使用微型寿命的结果评估线性累积蠕变损伤规则的适用性。线性累积蠕变损伤规则对双轴损伤十字形试样的剩余寿命给出了不保守的估计。使用双曲本构关系，解释了根据损伤累积的非保守估计。