scholarly journals Fatigue Crack Growth Curve for Austenitic Stainless Steels in PWR Environment

2003 ◽  
Vol 2003 (0) ◽  
pp. 917-918
Author(s):  
Yuichiro Nomura ◽  
Kazuya Tsutsumi ◽  
Hiroshi Kanasaki ◽  
Morihito Nakano ◽  
Kazuhiro Jotaki ◽  
...  
Author(s):  
Yuichiro Nomura ◽  
Kazuya Tsutsumi ◽  
Hiroshi Kanasaki ◽  
Naoki Chigusa ◽  
Kazuhiro Jotaki ◽  
...  

Although reference fatigue crack growth curves for austenitic stainless steels in air environments and boiling water reactor (BWR) environments were prescribed in JSME S NA1-2002, similar curves for pressurized water reactors (PWR) were not prescribed. In order to propose the reference curve in PWR environment, fatigue tests of austenitic stainless steels in simulated PWR primary water environment were carried out. According to the procedure to determine the reference fatigue crack growth curve of BWR, which of PWR is proposed. The reference fatigue crack growth curve in PWR environment have been determines as a function of stress intensity factor range, Temperature, load rising time and stress ratio.


Author(s):  
Yuichiro Nomura ◽  
Katsumi Sakaguchi ◽  
Hiroshi Kanasaki ◽  
Shigeki Suzuki

Reference fatigue crack growth rate curves for austenitic stainless steels in pressurized water reactors (PWR) environments were prescribed in JSME S NA1-2004(1) in Japan. The reference fatigue crack growth curve in PWR environment had been determined as a function of stress intensity factor range, temperature, load rising time and stress ratio. In order to confirm the applicability of the reference fatigue crack growth rate curve under high stress ratio, low rising time and low stress intensity range, fatigue crack propagation tests of austenitic stainless steels 316, 316 weld metal, 304 and 304 weld metal were carried out. It is concluded that the reference fatigue crack growth curve in PWR environment is applicable to predict fatigue crack growth rate of this study test conditions.


Author(s):  
Masao Itatani ◽  
Takuya Ogawa ◽  
Chihiro Narazaki ◽  
Toshiyuki Saito

The Rules on Fitness-for-Service for Nuclear Power Plants of the Japan Society of Mechanical Engineers (JSME Code) has the reference fatigue crack growth curve for austenitic stainless steels in BWR environment. This reference curve was determined as the upper bound of crack growth data excluding the outlier data. However, the other reference curves for fatigue crack growth rate such as austenitic stainless steels and ferritic steels in air environment and ferritic steels in water environment in the ASME Boiler and Pressure Vessel Code, Section XI and the JSME Code, austenitic stainless steels in PWR environment in the JSME Code and Ni-base alloys in PWR environment in the JSME Code Case are determined based on the 95% upper confidential limit by statistic data treatment. In the present study, the fatigue crack growth data of austenitic stainless steels in BWR environment were re-evaluated statistically. It was found that the current reference curve almost coincides with 95% upper confidential limit of fatigue crack growth data in the Paris region. Consequently, the current reference fatigue crack growth curve for austenitic stainless steels in BWR environment in the JSME Code can be regarded to stand on the same technical bases with other reference fatigue crack growth curves. Furthermore, the authors proposed to extend applicable upper bound of load rising time tr from 1000 s to 32000 s.


1999 ◽  
Vol 65 (634) ◽  
pp. 1343-1348 ◽  
Author(s):  
Hisashi HIRUKAWA ◽  
Saburo MATSUOKA ◽  
Etsuo TAKEUCHI ◽  
Takahito OMURA ◽  
Koji YAMAGUCHI ◽  
...  

Author(s):  
Masayuki Kamaya ◽  
Takao Nakamura

Incorporation of the flaw tolerance concept in plant design and maintenance is discussed in order to consider the reduction in fatigue life due to the high-temperature water environment of class 1 components of NPPs. The flaw tolerance concept has been included in Section XI of the ASME BPVC. The structural factor (safety factor) for the flaw evaluation is considered in the stress, whereas it was considered in the design fatigue curve in Section III of the ASME BPVC. In order to apply the flaw tolerance concept to plant design and maintenance, it is necessary to assume the crack initiation and growth behavior. In this study, first, crack initiation and growth behavior during fatigue tests was reviewed and a relationship between the crack growth and fatigue life was quantified. Then, the safety factor was considered in the crack growth curve. It was shown that the crack size could be correlated to the usage factor and the flaw tolerance concept was reasonably considered in the plant maintenance by using the proposed virtual fatigue crack growth curve.


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