Technical Basis of Fatigue Crack Growth Threshold for Stainless Steel in Air Environment for ASME Code Section XI

2017 ◽  
Author(s):  
Kunio Hasegawa ◽  
Saburo Usami
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Threshold Values ◽  
Asme Code ◽  
American Society ◽  
Growth Threshold

The fatigue crack growth threshold is an important characteristic of crack growth assessment for the integrity of structural components. However, threshold values for austenitic stainless steels in air environment are not well provided in many fitness-for-service (FFS) codes, although extensive amount of fatigue crack growth tests data has been published. This paper focuses on fatigue crack growth threshold values for austenitic stainless steel in air environment at room and high temperatures. The paper introduces the current fatigue crack growth rates provided by the ASME (American Society of Mechanical Engineers) Code Section XI and summarizes the available test data of fatigue crack growth thresholds based on the literature survey. The paper then discusses the applicability of the existing fatigue crack growth thresholds for stainless steels and proposes a new relation as a function of the stress ratio for use by the ASME Code Section XI.

Development of Fatigue Crack Growth Thresholds for Austenitic Stainless Steels Exposed to Air Environment for ASME Code Section XI

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Kunio Hasegawa ◽  
Saburo Usami
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Stress Ratio ◽  
Austenitic Stainless Steels ◽  
Stress Intensity Factor Range ◽  
Asme Code ◽  
American Society ◽  
Growth Experiments

Fatigue crack growth thresholds ΔKth define stress intensity factor range below which cracks will not grow. The thresholds ΔKth are useful in industries to determine durability lifetime. Although massive fatigue crack growth experiments for stainless steels in air environment had been reported, the thresholds ΔKth are not codified at the American Society of Mechanical Engineers (ASME) Code Section XI, as well as other fitness-for-service (FFS) codes and standards. Based on the investigation of a few FFS codes and review of literature survey of experimental data, the thresholds ΔKth exposed to air environment have been developed for the ASME Code Section XI. A guidance of the thresholds ΔKth for austenitic stainless steels in air at room and high temperatures can be developed as a function of stress ratio R.

Analysis of Environmental Fatigue Crack Growth Behavior of Type 347 Stainless Steels Under Simulated PWR Water Conditions

2017 ◽  
Author(s):  
Seokmin Hong ◽  
Ki-Deuk Min ◽  
Soon-Hyeok Jeon ◽  
Bong-Sang Lee
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Stainless Steels ◽  
Growth Behavior ◽  
Crack Growth Behavior ◽  
Fatigue Crack Growth Behavior ◽  
Water Conditions ◽  
Asme Code

In this study, the fatigue crack growth behavior of Type 347 stainless steel (SS) used in pressurizer surge line in Korea Standard Nuclear Power Plant was analyzed. Environmental fatigue crack growth rates (FCGRs) were evaluated using pre-cracked compact tension (CT) specimens under the various simulated PWR water conditions; different levels of dissolved oxygen (DO) and loading frequencies. FCGRs of 347SSs were accelerated under PWR water conditions. When DO levels increased and frequency decreased, FCGR of 347SS increased. Under the more corrosive environment at crack tip, FCGRs were accelerated more. FCGRs of 347SSs under PWR water condition were compared with reference FCGR curves of stainless steel in ASME code section XI, ASME Code Case N-809, and JSME based on FCGR data of 304SS and 316SS. In this study, FCGRs of 347SS were slightly faster than reference curves in JSME under PWR environment but slower than that in JSME under BWR environment. Compared to reference FCGR curve in ASME Code Case N-809, FCGRs of 347 stainless steels are similar or slightly higher.

Effect of Stress Ratio on Fatigue Crack Growth Threshold for Austenitic Stainless Steels in Air Environment

2017 ◽  
Vol 741 ◽  
pp. 88-93 ◽  
Author(s):  
Kunio Hasegawa ◽  
Saburo Usami
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Test Data ◽  
Stainless Steels ◽  
Stress Ratio ◽  
Austenitic Stainless Steels ◽  
R Ratio ◽  
Growth Assessment ◽  
Growth Threshold

The fatigue crack growth threshold ΔKth is an important characteristic of crack growth assessment for the integrity of structural components. However, the accurate threshold ΔKth values for austenitic stainless steels in air environment are lacking in many fitness-for-service (FFS) codes, although fatigue crack growth tests have been performed and many test data had been published. This paper focuses on fatigue crack growth threshold ΔKth values for austentic stainless steel in air environment. The paper introduces the current ΔKth values provided by four major FFS codes and summarizes the available test data based on the literature survey. The paper then discusses the applicability of the existing ΔKth for stainless steels and proposes a new relation as a function of the stress ratio (the R ratio) for use by FFS codes.

scholarly journals High Resistance of Fatigue Crack Growth for Austenitic Stainless Steels Containing Nitrogen.

1999 ◽  
Vol 65 (634) ◽  
pp. 1343-1348 ◽  
Author(s):  
Hisashi HIRUKAWA ◽  
Saburo MATSUOKA ◽  
Etsuo TAKEUCHI ◽  
Takahito OMURA ◽  
Koji YAMAGUCHI ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
High Resistance ◽  
Stainless Steels ◽  
Austenitic Stainless Steels

Fatigue Crack Growth Curve for Austenitic Stainless Steels in PWR Environment

2004 ◽  
Author(s):  
Yuichiro Nomura ◽  
Kazuya Tsutsumi ◽  
Hiroshi Kanasaki ◽  
Naoki Chigusa ◽  
Kazuhiro Jotaki ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Curve ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Stress Intensity Factor Range ◽  
Reference Curve ◽  
Pressurized Water ◽  
Crack Growth Curve

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.

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