The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C
Effects of the stress ratio on the very high cycle fatigue behaviors of 9%Cr turbine steel have been investigated at 630 °C. The experimental results show that the S–N curve has a continuous downward trend and has no fatigue limit with the increasing in the cycles at 630 °C. Meanwhile, according to...
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2020-08-01
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doaj-57f4873bcb754181ac0867582b87c77e2020-11-25T01:58:45ZengMDPI AGMaterials1996-19442020-08-01133444344410.3390/ma13163444The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °CQuanyi Wang0Yao Chen1Yongjie Liu2Chong Wang3Lang Li4Chao He5Xiufang Gong6Tianjian Wang7Wei Zhang8Qingyuan Wang9Hong Zhang10School of Aeronautics and Astronautics, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaState Key Laboratory of Long-Life High Temperature Materials, DongFang Turbine Co., Ltd., Deyang 618000, ChinaState Key Laboratory of Long-Life High Temperature Materials, DongFang Turbine Co., Ltd., Deyang 618000, ChinaDongFang Boiler Group Co., Ltd., Zigong 643001, ChinaSchool of Aeronautics and Astronautics, Sichuan University, Chengdu 610065, ChinaFailure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan Province, College of Architecture and Environment, Sichuan University, Chengdu 610065, ChinaEffects of the stress ratio on the very high cycle fatigue behaviors of 9%Cr turbine steel have been investigated at 630 °C. The experimental results show that the S–N curve has a continuous downward trend and has no fatigue limit with the increasing in the cycles at 630 °C. Meanwhile, according to the analysis of microstructure, there are two failure modes that were observed at different stress ratios (R = −1 and 0.1), including surface crack failure and internal crack failure, respectively. Besides, the theoretical threshold value of the crack growth is compared with the calculated value of the fracture surface. To decrease the difference between the threshold value of internal crack initiation and the corresponding theoretical value, a new model for the crack growth threshold of the interior-induced fracture at different stress ratios is proposed and discussed.https://www.mdpi.com/1996-1944/13/16/34449%Cr turbine steelvery high cycle fatiguestress intensity factorstress ratiohigh temperature |
| collection |
DOAJ |
| language |
English |
| format |
Article |
| sources |
DOAJ |
| author |
Quanyi Wang Yao Chen Yongjie Liu Chong Wang Lang Li Chao He Xiufang Gong Tianjian Wang Wei Zhang Qingyuan Wang Hong Zhang |
| spellingShingle |
Quanyi Wang Yao Chen Yongjie Liu Chong Wang Lang Li Chao He Xiufang Gong Tianjian Wang Wei Zhang Qingyuan Wang Hong Zhang The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C Materials 9%Cr turbine steel very high cycle fatigue stress intensity factor stress ratio high temperature |
| author_facet |
Quanyi Wang Yao Chen Yongjie Liu Chong Wang Lang Li Chao He Xiufang Gong Tianjian Wang Wei Zhang Qingyuan Wang Hong Zhang |
| author_sort |
Quanyi Wang |
| title |
The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C |
| title_short |
The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C |
| title_full |
The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C |
| title_fullStr |
The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C |
| title_full_unstemmed |
The Effect of Stress Ratios on the Very High Cycle Fatigue Behavior of 9%Cr Turbine Steel at 630 °C |
| title_sort |
effect of stress ratios on the very high cycle fatigue behavior of 9%cr turbine steel at 630 °c |
| publisher |
MDPI AG |
| series |
Materials |
| issn |
1996-1944 |
| publishDate |
2020-08-01 |
| description |
Effects of the stress ratio on the very high cycle fatigue behaviors of 9%Cr turbine steel have been investigated at 630 °C. The experimental results show that the S–N curve has a continuous downward trend and has no fatigue limit with the increasing in the cycles at 630 °C. Meanwhile, according to the analysis of microstructure, there are two failure modes that were observed at different stress ratios (R = −1 and 0.1), including surface crack failure and internal crack failure, respectively. Besides, the theoretical threshold value of the crack growth is compared with the calculated value of the fracture surface. To decrease the difference between the threshold value of internal crack initiation and the corresponding theoretical value, a new model for the crack growth threshold of the interior-induced fracture at different stress ratios is proposed and discussed. |
| topic |
9%Cr turbine steel very high cycle fatigue stress intensity factor stress ratio high temperature |
| url |
https://www.mdpi.com/1996-1944/13/16/3444 |
| work_keys_str_mv |
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