Prediction of Creep Rupture Time and Strain of Steam Pipe Accounting for Material Damage and Grain Boundary Sliding

재료손상과 입계 미끄럼을 고려한 증기배관의 크리프 파단수명 및 변형률 예측

Several methods have been developed to predict the creep rupture time of the steam pipes in thermal power plant. However, existing creep life prediction methods give very conservative value at operating stress of power plant and creep rupture strain cannot be well estimated. Therefore, in this study, creep rupture time and strain prediction method accounting for material damage and grain boundary sliding is newly proposed and compared with the existing experimental data. The creep damage evolves by continuous cavity nucleation and constrained cavity growth. The results showed good correlation between the theoretically predicted creep rupture time and the experimental data. And creep rupture strain may be well estimated by using the proposed method.