Fundamental Properties of Long-term Creep Strength for Ferritic Heat Resistant Steels
Fundamental Properties of Long-term Creep Strength for Ferritic Heat Resistant Steels
复制标题
铁素体耐热钢长期蠕变强度的基本性能
DOI：
10.2355/tetsutohagane1955.77.5_667
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发表时间：
1991
影响因子：
0.3
通讯作者：
C. Tanaka
中科院分区：
文献类型：
--
作者：
K. Kimura;H. Kushima;K. Yagi;C. Tanaka
简介：根据应力-断裂时间曲线呈反S形的特点，利用NRIM蠕变数据表中的大量长期蠕变数据，研究了铁素体耐热钢的长期蠕变强度。观察到应力-断裂时间曲线的反S形不是由强化或变形机制的变化引起的，而是由蠕变强度的降低和由于微观结构变化而接近稳定内应力引起的。在低应力下，蠕变速率-时间曲线的复杂形式，其中有两个最低点的蠕变速率被发现，并归因于反S形的应力-时间断裂曲线。比较不同钢种的持久强度，发现在较低温度和较高应力下，持久寿命相差约4个数量级。然而，在较高的温度和较低的应力下，所有研究的铁素体钢的蠕变断裂强度几乎相同。结果表明，铁素体耐热钢的蠕变强度随显微组织的变化而降低，并接近所有铁素体耐热钢的固有强度值。
Synopsis : In view of inverse sigmoidal form of stress vs. time to rupture curve, long-term creep strength of ferritic heat resistant steels has been investigated using a large number of long-term creep data in the NRIM Creep Data Sheets. It was observed that the inverse sigmoidal form of stress vs. time to rupture curve was caused not by the change in mechanisms of strengthening or deformation, but by the decrease in creep strength and by the approach to steady internal stress due to microstructural change. At lower stresses, the complex form of creep rate vs. time curve which had two minima in creep rate was found and attributed to the inverse sigmoidal form of stress vs. time to rupture curve. Comparing the creep rupture strength for the different kind of steels, the large difference in creep rupture life of about four orders of magnitudes was found at lower temperatures and higher stresses. At higher temperatures and lower stresses, however, the creep rupture strength of all ferritic steels investigated was almost the same. It was concluded that the creep strength of the ferritic heat resistant steels was reduced by the microstructural change and approached to the inherent values which were nearly the same for all ferritic steels investigated.