Ultra-Long Life Fatigue Behavior of Welded Joints with Shot Blast Treatment

2013 ◽  
Vol 275-277 ◽  
pp. 179-183 ◽  
Author(s):  
Chao He ◽  
Yong Jie Liu ◽  
Qing Yuan Wang
Keyword(s):  
Fatigue Strength ◽  
Welded Joints ◽  
Shot Peening ◽  
High Cycle Fatigue ◽  
Base Material ◽  
Ambient Air ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Base Steel ◽  
Long Life

In order to investigate the ultra-long life fatigue properties of welded joints, ultrasonic fatigue tests of base material and welded joints were carried out using Q345q steel in ambient air at room temperature with a stress ratio R=-1. The results showed that the fatigue strength of specimens with welded joints dropped about 60% compared with that of base steel. To improve the fatigue properties of welded joints, two groups of specimens were treated by shot peening with different degrees which produced different compressive residual stresses on samples. It was found that the shot peening treatment could improve the fatigue strength of welded joints obviously. The fatigue fracture surface was analyzed by scanning electron microscopy. The fractography showed that there were two kinds of crack initiation mechanism in the Q345q base steel, crack inition from defects on the surface for high cycle fatigue failure and in the interior of the sample in very high cycle fatigue range. However, almost all cracks of welded joints initiated from defects caused by welding process. The failure of welded joints usually happened at the section of welded toes in the area of fusion or geometric discontinuity.

scholarly journals High Cycle Fatigue Properties of Shot Peening Treated FPDI in Long Life Region.

1999 ◽  
Vol 65 (638) ◽  
pp. 2086-2091 ◽  
Author(s):  
Yasuo OCHI ◽  
Takeshi SEKINO ◽  
Shohei OKAZAKI ◽  
Takashi MATSUMURA
Keyword(s):  
Shot Peening ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Long Life

The Effects of Specimen Size on the Very High Cycle Fatigue Properties of FV520B-I

2015 ◽  
Author(s):  
Ming Zhang ◽  
Weiqiang Wang ◽  
Aiju Li
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Specimen Size ◽  
Fatigue Properties ◽  
Test Results ◽  
Cycle Fatigue ◽  
Very High Cycle Fatigue ◽  
Heat Effects ◽  
Very High

The authors researched the effects of specimen size on the very high cycle fatigue properties of FV520B-I through ultrasonic fatigue testing. The test results showed that the very high cycle fatigue mechanism was not changed and the fatigue properties declined as the specimen size increased. The S-N curve moved downward and the fatigue life decreased under the same stress level maybe due to the heat effects of large specimens in tests. The fatigue strength and the fatigue life were predicted by relevant models. The prediction of fatigue strength was close to test result, and the prediction of fatigue life was less effective compared with the previous prediction of small size specimen test results.

scholarly journals Influence of Zirconia Shot Peening Treatment on High-Cycle Fatigue Properties of Ti-6Al-4V

2016 ◽  
Vol 65 (9) ◽  
pp. 679-686 ◽  
Author(s):  
Kiyotaka MASAKI ◽  
Yuki YONAKUNI ◽  
Noriyuki HISAMORI ◽  
Yuichiro SUGA ◽  
Yuji KOBAYASHI ◽  
...  
Keyword(s):  
Shot Peening ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue

312 High Cycle Fatigue Property of Shot peening Treated ADI in Long Life Fatigue

2001 ◽  
Vol 2001 (0) ◽  
pp. 251-252
Author(s):  
Takusaburo Hosoya ◽  
Takeshi Sekino ◽  
Kiyotaka Masaki ◽  
Takashi Matsumura ◽  
Yasuo Ochi
Keyword(s):  
Shot Peening ◽  
High Cycle Fatigue ◽  
Fatigue Property ◽  
Cycle Fatigue ◽  
Long Life

scholarly journals Effect of Carburizing and Nitriding on Fatigue Properties of 18Cr2Ni4WA Steel in Very High Cycle Fatigue Regime

2021 ◽  
Vol 45 (3) ◽  
pp. 207-215
Author(s):  
Zhenduo Sun ◽  
Dongbo Hou ◽  
Wei Li
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Internal Defect ◽  
Surface Fatigue ◽  
Very High Cycle Fatigue ◽  
The Relationship ◽  
Very High

The work aims to study the influence of carburizing and nitriding on fatigue properties of 18Cr2Ni4WA high strength steel in very high cycle fatigue regime. Very high cycle fatigue tests were carried out on 18Cr2Ni4WA Steel after carburizing and nitriding respectively. The micro morphology of fatigue fracture was observed by scanning electron microscope, the failure mode and failure mechanism were discussed. The relationship between fatigue life and defect size, FGA size, fish eye size of fracture was analyzed. The characteristic size of defects is evaluated by Gumbel, Weibull and GEV distribution functions, and a modified Akiniwa fatigue life prediction model considering the relationship between FGA size and inclusion size was established. The results showed that, nitriding and carburizing treatment improve the surface fatigue limit of the steel. The fatigue life decreases with the increase of internal defect size and FGA size. After carburizing and nitriding treatment, the internal fatigue strength of the specimen decreases slightly. When the failure probability is 99%, the internal defect sizes of nitrided specimens calculated by Weibull, Gumbel and GEV distributions are 141.5 μm, 148.4 μm and 211.7 μm respectively. The calculated internal defect sizes of carburized specimens are 47 μm, 67.8 μm and 40 μm respectively. Compared with the experimental data, the fatigue strength predicted by GEV is the most appropriate. carburizing and nitriding treatment can improve the surface fatigue strength of 18Cr2Ni4WA steel, but slightly reduce the internal fatigue strength. The prediction result of the new model is conservative when the failure probability is 99%, which is suitable for engineering application.

scholarly journals Influence of Shot Peening Treatment on High-Cycle Fatigue Properties of Degassing Processed AC4CH Aluminum Alloy

2005 ◽  
Vol 54 (12) ◽  
pp. 1255-1261 ◽  
Author(s):  
Kiyotaka MASAKI ◽  
Youhei KUMAGAI ◽  
Yasuo OCHI ◽  
Takashi MATSUMURA ◽  
Tatsuhiko HAMAGUCHI
Keyword(s):  
Aluminum Alloy ◽  
Shot Peening ◽  
High Cycle Fatigue ◽  
Fatigue Properties ◽  
Cycle Fatigue
Sign in / Sign up

Export Citation Format

Share Document