Abstract From experimental creep rates of high temperature alloys, it is found they can be classified into three types: with creep rate decreasing only, with creep rate deceasing firstly but accelerating after a certain time, and with creep rate increasing slowly but accelerating after a certain time. These three typical creep types can be characterized in a unified form, by dividing creep process into two creep stages distinguished by the critical creep time. Before the critical time, the first stage has decreasing or slowly increasing creep rate only, after the critical time, the second stage also has accelerating creep rate besides the previous creep rate. A new generalized creep constitutive relationship with creep time and four stress-dependent parameters has then been proposed. The stress-dependent parameters can be interpolated from test results under various stress levels. It is found that the interpolation functions should be expressed in different styles according to the stress level distinguished by a critical creep stress. The critical creep stress can be determined just by the glass strain variation under various stress levels. More meaningfully, critical creep stress corresponds to the cross point in the bi-linear model of creep failure life in fact. It is also found there is a non-creep stress below which creep deformation can be neglected.

中文翻译：

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一种新的高温合金蠕变本构关系

摘要 从高温合金的实验蠕变速率中发现，它们可分为三种类型：蠕变速率仅降低、蠕变速率先降低但经过一定时间后加速、蠕变速率缓慢增加但经过一定时间后加速。时间。这三种典型的蠕变类型可以以统一的形式表征，将蠕变过程划分为以临界蠕变时间区分的两个蠕变阶段。在临界时间之前，第一阶段只有降低或缓慢增加的蠕变速率，在临界时间之后，第二阶段除了先前的蠕变速率外，还有加速的蠕变速率。然后提出了一种具有蠕变时间和四个应力相关参数的新的广义蠕变本构关系。应力相关参数可以从各种应力水平下的测试结果中插入。发现插值函数应根据临界蠕变应力区分的应力水平以不同的方式表示。临界蠕变应力可以仅通过不同应力水平下的玻璃应变变化来确定。更有意义的是，临界蠕变应力实际上对应于蠕变失效寿命双线性模型中的交叉点。还发现存在非蠕变应力，低于该应力可以忽略蠕变变形。临界蠕变应力可以仅通过不同应力水平下的玻璃应变变化来确定。更有意义的是，临界蠕变应力实际上对应于蠕变失效寿命双线性模型中的交叉点。还发现存在非蠕变应力，低于该应力可以忽略蠕变变形。临界蠕变应力可以仅通过不同应力水平下的玻璃应变变化来确定。更有意义的是，临界蠕变应力实际上对应于蠕变失效寿命双线性模型中的交叉点。还发现存在非蠕变应力，低于该应力可以忽略蠕变变形。