Details

Autor(en) / Beteiligte

• Wang, Zhifang
• Yang, Xiaoguang
• Shi, Duoqi
• Yang, Qinzheng
• Hu, Xiaoan
• Teng, Xuefeng

Titel

Effect of sustained load on fatigue crack growth behavior of FGH96 at elevated temperature

Ist Teil von

• International journal of fatigue, 2023-11, Vol.176, p.107901, Article 107901

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2023

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •The effects of sustained load on fatigue crack growth behavior at elevated temperature were experimental investigated and the influences of temperature and dwell time were discussed;•An extensive concept of “time-dependent damage” which involving all potential influencing mechanism was established, and its evolution with temperature and dwell time was discussed;•A parameter of effective action time of time-dependent damage was proposed to account for that the time-dependent crack extension in a loading cycle increases with dwell time in a decelerated manner;•A two-term crack growth model considering time-dependent damage was proposed and it is confirmed to be applicable to a wide range of temperature and dwell time under dwell fatigue conditions. Accurate prediction of fatigue crack growth behavior is crucial to damage tolerance assessment of turbine disk. Powder nickel-based superalloy is a kind of preferred material of turbine disk. For the purpose of better understanding the characteristics of its crack growth behavior under dwell fatigue conditions at elevated temperature, dwell fatigue crack growth tests of powder nickel-based superalloy FGH96 were conducted with compliance method at three temperatures (600℃, 650℃, 700℃) and multiple dwell time conditions (from 0 s to 60 s). The results show that sustained load can accelerate fatigue crack growth rate of FGH96 significantly at high temperature, and it is more pronounced with higher temperature and prolonged dwell time. At higher ΔK level, the acceleration effect brought by sustained load seems to diminish, this is ascribed to rapid crack growth rate which leads to insufficient time for time-dependent damage occurring at crack tip zone. The effect of temperature on dwell fatigue crack growth rate is more remarkable from 650℃ to 700℃, compared with that from 600℃ to 650℃. The fatigue crack growth resistance of FGH96 is sensitive to sustained load at 700℃, just 1 s dwell loading can produce remarkable acceleration effect on fatigue crack growth rate. The time-dependent crack extension in a loading cycle increases with dwell time in a decelerated manner. Finally, A phenomenological-based crack growth model considering time-dependent damage was proposed, the comparation between the proposed model and the experiment data confirms that it works well for a wide range of temperature and dwell time.