Development of New Design Fatigue Curves in Japan: Proposal of a New Fatigue Evaluation Method

2018 ◽  
Author(s):  
Seiji Asada ◽  
Akihiko Hirano ◽  
Toshiyuki Saito ◽  
Yasukazu Takada ◽  
Hideo Kobayashi
Keyword(s):  
Stainless Steels ◽  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Fatigue Tests ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Stress Effect ◽  
Fatigue Data ◽  
Alloy Steels ◽  
Fatigue Evaluation

In order to develop new design fatigue curves for carbon steels & low-alloy steels and austenitic stainless steels and a new design fatigue evaluation method that are rational and have clear design basis, Design Fatigue Curve (DFC) Phase 1 subcommittee and Phase 2 subcommittee were established in the Atomic Energy Research Committee in the Japan Welding Engineering Society (JWES). The study on design fatigue curves was actively performed in the subcommittees. In the subcommittees, domestic and foreign fatigue data of small test specimens in air were collected and a comprehensive fatigue database (≈6000 data) was constructed and the accurate best-fit curves of carbon steels & low-alloy steels and austenitic stainless steels were developed. Design factors were investigated. Also, a Japanese utility collaborative project performed large scale fatigue tests using austenitic stainless steel piping and low-alloy steel flat plates as well as fatigue tests using small specimens to obtain not only basic data but also fatigue data of mean stress effect, surface finish effect and size effect. Those test results were provided to the subcommittee and utilized the above studies. Based on the above studies, a new fatigue evaluation method has been developed.

Study on Mean Stress Effects for Design Fatigue Curves

2016 ◽  
Author(s):  
Seiji Asada ◽  
Takeshi Ogawa ◽  
Makoto Higuchi ◽  
Hiroshi Kanasaki ◽  
Yasukazu Takada
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Fatigue Curve ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Mean Stress ◽  
Research Committee ◽  
Stress Effects ◽  
Alloy Steels ◽  
Design Factors

In order to develop new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels and a new design fatigue evaluation method that are rational and have a clear design basis, the Design Fatigue Curve (DFC) subcommittee was established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. Mean stress effects for design fatigue curves are to be considered in the development of design fatigue curves. The Modified Goodman approach for mean stress effects is used in the design fatigue curves of the ASME B&PV Code. Tentative design fatigue curves were developed and studies on the effect of mean stress and design factors are on-going. Development of design fatigue curves, effect of mean stress and design factors is needed to establish a new fatigue design evaluation method. The DFC subcommittee has studied correction approaches for mean stress effects and the approaches of modified Goodman, Gerber, Peterson and Smith-Watson-Topper were compared using test data in literature. An appropriate approach for mean stress effects are discussed in this paper.

Proposal of Fatigue Life Equations for Carbon and Low-Alloy Steels and Austenitic Stainless Steels as a Function of Tensile Strength

2013 ◽  
Author(s):  
Hiroshi Kanasaki ◽  
Makoto Higuchi ◽  
Seiji Asada ◽  
Munehiro Yasuda ◽  
Takehiko Sera
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Stainless Steels ◽  
Room Temperature ◽  
Austenitic Stainless Steels ◽  
Low Alloy Steels ◽  
Strength Based ◽  
Fatigue Data ◽  
Current Design ◽  
Alloy Steels

Fatigue life equations for carbon & low-alloy steels and also austenitic stainless steels are proposed as a function of their tensile strength based on large number of fatigue data tested in air at RT to high temperature. The proposed equations give a very good estimation of fatigue life for the steels of varying tensile strength. These results indicate that the current design fatigue curves may be overly conservative at the tensile strength level of 550 MPa for carbon & low-alloy steels. As for austenitic stainless steels, the proposed fatigue life equation is applicable at room temperature to 430 °C and gives more accurate prediction compared to the previously proposed equation which is not function of temperature and tensile strength.

Study on a New Design Fatigue Evaluation Method

2015 ◽  
Author(s):  
Seiji Asada ◽  
Takashi Hirano ◽  
Takehiko Sera
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Design Evaluation ◽  
Low Alloy Steels ◽  
Mean Stress ◽  
Research Committee ◽  
Fatigue Design ◽  
Fatigue Evaluation ◽  
Design Factors

In order to develop new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels and a new design fatigue evaluation method that is rational and has a clear design basis, the Design Fatigue Curve (DFC) subcommittee was established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. Tentative design fatigue curves were developed and studies on the effects of mean stress and design factors are ongoing. Design fatigue curves, including the effects of mean stress and design factors, are needed to establish a new fatigue design evaluation method. This paper describes the study on the new fatigue design evaluation method.

Development of New Design Fatigue Curves in Japan: Discussion of Best Fit Curves Based on Fatigue Test Data With Large Scale Piping

2018 ◽  
Author(s):  
Masaru Bodai ◽  
Yuichi Fukuta ◽  
Seiji Asada ◽  
Kentaro Hayashi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Large Scale ◽  
Fatigue Tests ◽  
Carbon Steels ◽  
Surface Finishing ◽  
Low Alloy Steels ◽  
Fatigue Data ◽  
Alloy Steels ◽  
Best Fit

In order to develop new design fatigue curves for austenitic carbon steels & low alloy steels and stainless steels and a new design fatigue evaluation method that are rational and have clear design basis, Design Fatigue Curve (DFC) Phase 1 subcommittee and Phase 2 subcommittee were established in the Atomic Energy Research Committee in the Japan Welding Engineering Society. The study on design fatigue curves was actively performed in the subcommittees. In the subcommittees, domestic and foreign fatigue data of small test specimens in air were collected and a comprehensive fatigue database was constructed. Using this fatigue database, the accurate best-fit curves of austenitic carbon steels & low alloy steels and stainless steels were developed by applying tensile strength to a parameter of the curve. Regarding design factors on design fatigue curves, data scatter, mean stress correction, surface finishing effect, size effect and variable loading effect were investigated and each design factor was decided to be individually considered on the design fatigue curves. A Japanese utility project performed large scale fatigue tests using austenitic stainless steel piping and carbon and low-alloy steel flat plates as well as fatigue tests using small specimens to obtain not only basic data but also fatigue data of mean stress effect and surface finishing effect. Those test results were provided to the subcommittee and utilized the above studies. In this paper, the large scale fatigue tests using austenitic stainless steel piping and the best-fit curve of austenitic stainless steel are discussed.

Plan and Status of Development of Design Fatigue Curves: Phase 1

2013 ◽  
Author(s):  
Seiji Asada ◽  
Akihiko Hirano ◽  
Masao Itatani ◽  
Munehiro Yasuda ◽  
Takehiko Sera ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Phase 1 ◽  
Austenitic Stainless Steels ◽  
Fatigue Curve ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Energy Research ◽  
Research Committee ◽  
Engineering Society ◽  
Alloy Steels

In order to develop and propose new design fatigue curves for austenitic stainless steels, carbon steels and low alloy steels that are rational and have clear design basis, Design Fatigue Curve (DFC) subcommittee has been established in the Atomic Energy Research Committee in the Japan Welding Engineering Society and the study on design fatigue curves are going on. This paper introduces the plan and status of the activities of the DFC subcommittee.

Environmental Fatigue Evaluation for Interface of Dissimilar Metal Welded Piping

2017 ◽  
Author(s):  
Dae Geon Lee ◽  
Dae Soo Kim ◽  
Kyeong Jin Yang ◽  
Joon Ho Lee ◽  
Seong Cheol Jang
Keyword(s):  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Carbon Steels ◽  
Nuclear Industry ◽  
Low Alloy Steels ◽  
Plant Design ◽  
Dissimilar Metal ◽  
Dissimilar Metal Welding ◽  
Fatigue Evaluation ◽  
Metal Welding

Environmental fatigue evaluation is a key technology to extend Nuclear Power Plant design life. Since USNRC issued the RG 1.207 in 2007, many studies on fatigue evaluation in Light water Reactor coolant environments have been carried out by referencing documents such as NUREG/CR-6909, EPRI-TR-1025823, ASME BPVC Sec. III NB-3600/3200 Code, ASME Code Case, and so on. These documents presented environmental fatigue evaluation methods about each single-metal such as carbon steels, low-alloy steels, nickel-chromium-iron (Ni-Cr-Fe) alloys, and austenitic stainless steels. However, the environmental fatigue evaluation method for interface of dissimilar metal welding is mostly insufficient. Dissimilar metal welding has been widely used in nuclear industry. If environmental fatigue analysis method for dissimilar metal welding is developed, it will facilitate the design of piping for more safety. Therefore, the development of environmental fatigue evaluation for the interface of dissimilar metal welding should be studied. This paper presents environmental fatigue evaluation for the interface of dissimilar metal welded piping. The environmental fatigue evaluation for a dissimilar metal welded piping model was performed based on above documents.

Comparison of Environmental Fatigue Evaluation Methods in LWR Water

2008 ◽  
Author(s):  
Makoto Higuchi
Keyword(s):  
Research Council ◽  
Evaluation Method ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Evaluation Methods ◽  
Fatigue Tests ◽  
Final Report ◽  
The Us ◽  
Fatigue Data ◽  
Fatigue Evaluation

Many studies on the environmental fatigue of structural materials in LWR (Light Water Reactor) water have been carried out over the past 30 years. Early environmental fatigue tests were mainly carried out in Japan in the 1980s, and these results were reported to the ASME in 1988. After that, O. Chopra and W. Shack of ANL (Argonne National Laboratory) also carried out similar fatigue tests and reported that their data corresponded well to Japanese data. In the US, the PVRC (Pressure Vessel Research Council) started the CLEE Committee (Cyclic Life and Environmental Effect, Chair: Sumio Yukawa) for developing the environmental fatigue evaluation method in LWR water under the request from the ASME in 1991. This committee continued for 13 years and closed in 2004 after publishing the final report as WRC (Welding Research Council) Bulletin 487. After 1990 in Japan, the EFD Project (1993–1995) and the EFT Project (1994–2006) were carried out under the collaboration of electric utilities, plant vendors and government. A large number of environmental fatigue data have been generated in these projects, and these were offered to the US through the CLEE Committee. Based on Japanese and US fatigue data, environmental fatigue evaluation methods have been established in both countries that assess the effects of some parameters on fatigue life reduction in LWR water environments. This paper introduces the history of studies on the environmental fatigue in LWR water and the contributions of Sumio Yukawa to these activities. After that, the comparison of three major methods of environmental fatigue evaluation such as PVRC, JSME and MJREG/CR-6909 are reported.

Study on Incorporation of New Design Fatigue Curves and a New Environmental Fatigue Correction Factor for PWR Environment Into the JSME Environmental Fatigue Evaluation Method

2020 ◽  
Author(s):  
Seiji Asada ◽  
Shengde Zhang ◽  
Masahiro Takanashi ◽  
Yuichiro Nomura
Keyword(s):  
Stainless Steel ◽  
Base Metal ◽  
Stainless Steels ◽  
Evaluation Method ◽  
Austenitic Stainless Steels ◽  
Steel Base ◽  
Improved Design ◽  
Fatigue Evaluation ◽  
Cast Stainless Steel ◽  
Metal Weld

Abstract Improved design fatigue curves were developed in the Subcommittee on Design Fatigue Curve in the Atomic Energy Research Committee in the Japan Welding Engineering Society (JWES). Working Group on Design Fatigue Curves (WG DFC) in the JSME has studied the validity and the applicability of the improved design fatigue curves developed in the JWES to incorporate into the JSME Environmental Fatigue Evaluation Method. The authors propose a fatigue analysis method using the design fatigue curves developed in the JWES that are applied revised factors to optimize the environmental fatigue analysis. Also, the Japanese pressurized water reactor (PWR) utility group developed equations of environmental fatigue factors (Fen) for austenitic stainless steel base metal, weld metal and cast stainless steel in PWR environment. The WG DFC has investigated the Fen equations and concluded that the Fen equation of austenitic stainless steel base metal is the most conservative among the three equations and close to NUREG/CR-6909 Rev.1 [24]. The authors propose to use the Fen equation for base metal for austenitic stainless steels for all of the base metal, weld metal and cast stainless steel. In addition, the authors have confirmed that the employment of the proposed Fen equation to the proposed design fatigue curves of austenitic stainless steels accurately predicts the existing environmental fatigue test data of austenitic stainless steels, which were used in the development of the current Fen equation of austenitic stainless steels in PWR environments in the JSME Environmental Fatigue Evaluation Method. Therefore, the proposed Fen equation can be applied to environmental fatigue evaluation for austenitic stainless steels.

Use of NUREG/CR-6909 Environmentally-Assisted Fatigue Rules for a Nuclear Plant License Renewal Application

2011 ◽  
Author(s):  
William F. Weitze ◽  
Matthew C. Walter ◽  
Keith R. Evon
Keyword(s):  
Stainless Steels ◽  
Water Environment ◽  
Austenitic Stainless Steels ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Nuclear Plant ◽  
Lessons Learned ◽  
Low Alloy Steels ◽  
Alloy Steels ◽  
Regulatory Commission

As part of the process of renewing the operating license for an additional 20 years after the original 40-year design life, nuclear plant owners in the United States (US) are required to show that they are managing the effects of aging of systems, structures, and components. US Nuclear Regulatory Commission (NRC) report NUREG-1801, the “Generic Aging Lessons Learned (GALL) Report,” identifies acceptable aging management programs, including programs for fatigue and cyclic operation. This includes fatigue usage analyses that account for reduced fatigue life for components in a reactor water environment. Earlier revisions of the GALL report required plants to perform environmentally-assisted fatigue (EAF) analyses using the rules in reports NUREG/CR-6583 (for carbon and low alloy steels) and NUREG/CR-5704 (for austenitic stainless steels), which were developed in 1998 and 1999, respectively. However, GALL Revision 2, issued in December 2010, requires that the rules in NUREG/CR-6909, issued in 2007, be used for nickel alloy materials, and allows it to be used for carbon, low-alloy and stainless steels as an alternative to those in the previous reports. This paper presents an application of the NUREG/CR-6909 rules, and makes several observations about the differences between using the newer and older rules. The analyses presented were performed for a sample set of boiling water reactor (BWR) locations.

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