PREDICTION OF CREEP-RUPTURE TIME AND STRAIN OF STEAM PIPE ACCOUNTING FOR MATERIAL DAMAGE AND GRAIN BOUNDARY SLIDING

摘要

Several methods have been developed to predict the creep-rupture time of steam pipes in thermal power plants. However, current creep-rupture time prediction methods give very conservative results from operating stresses under high temperature, and thus creep rupture strain cannot be well estimated. Taking into account damage and grain boundary sliding in addition to continuous cavity nucleation and constrained cavity growth, we have developed a method predicting the time and strain at creep-rupture. Our results show that creep-rupture times are close to experimental data. Also, the creep-rupture strain may be well estimated by using the proposed method.