A simulation method for microscopic creep damage at grain boundaries in the fine-grain heat-affected zone of low-alloy steel welds involving high energy piping was proposed on the basis of the combination of elastic-c...A simulation method for microscopic creep damage at grain boundaries in the fine-grain heat-affected zone of low-alloy steel welds involving high energy piping was proposed on the basis of the combination of elastic-creep FEM (finite element method) analysis and random fracture resistance modeling of the materials. The procedure to determine the initiation and growth-driving forces of small defects were briefly described. Then, a simulation procedure combining the stress distribution from elastic-creep FEM and the random fracture resistance model was proposed, and Ms procedure was applied to the simulation of the microscopic damage progress in a welded joint model test and in actual power piping. The results in terms of the simulated number density of small defects throughout the wall thickness were in good agreement with the observed results.展开更多
Creep-fatigue test was carried out using smooth round bar specimens of Type 304 stainless steel. Cavities and small cracks on the cross-section of the specimen were carefully observed by a scanning laser microscope. ...Creep-fatigue test was carried out using smooth round bar specimens of Type 304 stainless steel. Cavities and small cracks on the cross-section of the specimen were carefully observed by a scanning laser microscope. Moreover, direct current electrical potential method (DC-EPM) was applied in order to evaluate non-destructively the distribution of internal cracks. The distribution evaluated by DC-EPM agrees well with the actual one. (Edited author abstract) 9 Refs.展开更多
文摘A simulation method for microscopic creep damage at grain boundaries in the fine-grain heat-affected zone of low-alloy steel welds involving high energy piping was proposed on the basis of the combination of elastic-creep FEM (finite element method) analysis and random fracture resistance modeling of the materials. The procedure to determine the initiation and growth-driving forces of small defects were briefly described. Then, a simulation procedure combining the stress distribution from elastic-creep FEM and the random fracture resistance model was proposed, and Ms procedure was applied to the simulation of the microscopic damage progress in a welded joint model test and in actual power piping. The results in terms of the simulated number density of small defects throughout the wall thickness were in good agreement with the observed results.
文摘Creep-fatigue test was carried out using smooth round bar specimens of Type 304 stainless steel. Cavities and small cracks on the cross-section of the specimen were carefully observed by a scanning laser microscope. Moreover, direct current electrical potential method (DC-EPM) was applied in order to evaluate non-destructively the distribution of internal cracks. The distribution evaluated by DC-EPM agrees well with the actual one. (Edited author abstract) 9 Refs.
