改良9Cr-1Mo鋼溶接材の供用中クリープ余寿命予測

抄録

This paper has applied the new in-situ remaining creep life prediction methods previously proposed by the present author to the weld joint of modified 9Cr-1Mo steel. The methods used in the present study were based on two types of the modified theta method and the combination of the modified theta and modified omega methods and were applied to creep deformation data during creep tests made at different applied stress levels at 823 and 923 K in air. Remaining creep lives were predicted by the proposed three methods at arbitrary time in the continuous measurement of deformation during the creep tests. The results show that the combination of the modified theta and modified omega methods gives the most accurate prediction of creep rupture time at the two levels of test temperature for different applied stress levels. These results were found the same as the modified 9Cr-1Mo base material.