12Cr 강에 대한 저주기 피로수명 평가

In this study the life assessment of low cycle fatigue for 12Cr steel at high temperature arc described. Secondly, comparisons between predicted lives and experimental lives are made for the several sample life prediction models. Two minute hold lime in either tension or compression reduce the number of cycles to failure by about a factor of two. Twenty minute hold time in compression lead to shorter lives than 2 minute hold time in compression. Experiments showed that life predictions from cIassical phenomenological models have limitations. More low cycle fatigue experiments should be pursued to gain understanding of the physical damage mechanisms and to allow the development of physically-based models which can enhance the accuracy of the predictions of components. From a design point-of-view, life prediction has been judged acceptable for these particular loading conditions but extrapolations to thermo-mechanical fatigue loading, for example, require more sophisticated models including physical damage mechanisms.