蠕变极限

本文对大型汽轮机高温铸件用Cr-Mo-V和Cr-Mo两类铸钢的持久强度、蠕变极限、室温断裂韧性、蠕变裂纹扩展速率等主要应用性能进行了比较研究，为合理选材提供了依据。

The vital application properties such as high temperture endurance strength , creep limit , fracture toughness at room temperature , creep crack propagation rate of Cr-Mo-V and Cr-Mo high temperature castings for large steam turbines are comparatively studied , thus providing a cue for reasonable selection of materials .

初始蠕变极限可以表示成稳态蠕变率的函数。

Transient creep limit is a power function of steady state creep strain rate .

预测结果显示约50~120年后，格栅的蠕变极限强度下降到原来的21%~26%。

Prediction results showed after 50 ~ 120 years , the creep limited strength would decrease to 21 ~ 26 % .

岩石应力－应变实验表明，在中等载荷（等于或大于岩石蠕变极限）作用下，岩石蠕变最终可导致破裂；

It has been known from rock deformation experiments that , under moderate load , creep may finally develop into fractures in rocks .

数据处理方法有多种，现采用了一种线性外推的方法来处理数据，得到实验温度下格栅的长周期失效时间和蠕变极限强度数据；

A linear extrapolation method was applied to predict the long-term creep limited strength and the time to ( failure ) at the temperature of experiment .

而以蠕变极限为失效准则的蠕变内应力法与常规的以蠕变试验为基础的等温外推法相比，还具有试验时间短的优点。

It is also shown that under the creep limit failure criterion , the creep internal stress method has the advantage of less test time in comparison with the isothermal extrapolation method based on conventional creep tests .

首先对影响主蒸汽管道运行寿命的因素进行研究，影响主蒸汽管道运行寿命有持久极限、蠕变极限、疲劳极限等内在因素和温度、应力、启停次数和调峰等外在因素；

It is pointed out that the creep limit , the rupture limit , the fatigue limit are internal factor , and that the temperature , the stress , the start-failure rate , the modulation are external factor .

结果表明：应力腐蚀作用使试验材料的蠕变强度、蠕变极限和蠕变模量均减小；

The results indicate that under stress corrosion the creep strength , creep limit and creep modulus of FRP are all lowered .

数据处理部分可对各种试验条件下的数据进行分析并绘制出各种蠕变曲线，进而得到蠕变极限及相应的外推结果。

And in data processing module , the based work of data analyse and creep curves drawing , and the advanced work of creep limit and extrapolate results resolving can be achieved under many kinds of test condition .

介绍了蠕变试验及疲劳试验与岩石破坏过程和普通的单轴压缩破坏过程之间的相关性以及岩石的蠕变极限和疲劳极限的研究结果。

This paper not only introduces the rock failure process under creep trail and fatigue trail . but compares them with the rock failure process under uniaxial compress and gives the study result about rock creep limit and fatigue limit .