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.

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

2019 ◽  
Author(s):  
Masaru Bodai ◽  
Yuichi Fukuta ◽  
Seiji Asada ◽  
Kentaro Hayashi
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Austenitic Stainless Steel ◽  
Crack Growth ◽  
Large Scale ◽  
Fatigue Tests ◽  
Surface Finishing ◽  
Mean Stress ◽  
Best Fit ◽  
Steel Piping

Abstract 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. 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 carbon steels & low alloy steels and austenitic 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 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 the last PVP Conference, the large scale fatigue tests using austenitic stainless steel piping were discussed for the best-fit curve of austenitic stainless steel (PVP2018-84436). In this paper, further studies are performed based on fatigue crack growth of the large scale fatigue tests using austenitic stainless steel piping. From the obtained crack growth data of the tested piping, the number of cycles at 3-mm-deep crack depth and through-wall crack of piping compares with the best-fit curve developed by the DFC1 subcommittee with considering the confidence lower bounds to survey the fatigue life of piping, and size effect for fatigue lives is discussed. The relations between the fatigue crack growths and the number of cycles and the aspect ratios are surveyed including mean stress effect.

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.

The Oxidational Wear of High-Chromium Ferritic Steel on Austenitic Stainless Steel

1985 ◽  
Vol 107 (2) ◽  
pp. 172-179 ◽  
Author(s):  
C. B. Allen ◽  
T. F. J. Quinn ◽  
J. L. Sullivan
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Ferritic Steel ◽  
Elevated Temperatures ◽  
Frictional Heating ◽  
Surface Model ◽  
Low Alloy Steels ◽  
High Chromium ◽  
Mild Wear ◽  
Alloy Steels

Experiments are described in which high-chromium ferritic steel pins were slid, without lubrication, against austenitic stainless steel disks, under loads varying from 7 to 95N and speeds varying from 0.23 to 3.3 ms−1. Although no external heating was supplied, all the worn surfaces were oxidized, as also was the wear debris, indicating that some form of mild wear always occurred under these conditions. Measurements were made, using a special tilt correction facility on the Scanning Electron Microscope, of the thicknesses of the oxide formed both on the pin and the disk surfaces, due to the evolution of frictional heating at the interface. The division of heat at the interface was also deduced from thermocouple measurements. These measurements, combined with the surface model used as the basis for the Oxidational Wear Theory, are shown to give rise to independent estimates of the contact temperature (Tc), the number of contacts beneath the pin at any instant (N), and the radius (a) of each of those contacts, that are consistent with those obtained in earlier published experiments involving the mild wear of low-alloy steels. In these earlier experiments, the validity of the estimates of N, Tc and “a,” depended upon the validity of the choice of Arrhenius Constant used in the Oxidational Wear Theory. The correlation between the two sets of estimates is discussed. Suggestions are made for further work to validate the Oxidational Theory of the mild wear of these industrially-important materials, particularly at elevated temperatures.

UNIFLUX VCM 125

Alloy Digest ◽  
1978 ◽  
Vol 27 (1) ◽  
Keyword(s):  
Carbon Dioxide ◽  
Fracture Toughness ◽  
Weld Metal ◽  
Heat Treating ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Electrode Wire ◽  
Molybdenum Steel ◽  
Alloy Steels ◽  
Welding Electrode

Abstract UNIFLUX VCM 125 is a continuous flux-cored welding electrode (wire) that is used to deposit 1 1/4% chromium-1/2% molybdenum steel for which it was developed. Welding is protected by a shielding atmosphere of 100% carbon dioxide. This electrode also may be used to weld other low-alloy steels and carbon steels; however, the weld metal may differ somewhat from 1 1/4% chromium-1/2% molybdenum because of weld-metal dilution. When Uniflux VCM 125 is used to weld 1 1/4% chromium-1/2% molybdenum steel, it provides 95,000 psi tensile strength at 70 F and 24 foot-pounds Charpy V-notch impact at 40 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-340. Producer or source: Unicore Inc., United Nuclear Corporation.

UNIFLUX V90

Alloy Digest ◽  
1979 ◽  
Vol 28 (2) ◽  
Keyword(s):  
Carbon Dioxide ◽  
High Strength ◽  
Heat Treating ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Nickel Steel ◽  
Steel Weld Metal ◽  
Alloy Steels ◽  
Temperature Impact ◽  
Welding Electrode

Abstract UNIFLUX V90 is a continuous flux-cored welding electrode (wire) developed to weld high-strength low-alloy steels, but it may be used to weld other low-alloy steels and carbon steels. It is used to deposit typically 2.40% nickel steel weld metal with good low-temperature impact properties. Welding is protected by a shielding atmosphere of either 75% argon-25% carbon dioxide or 100% carbon dioxide. Uniflux V90 is used widely in shipbuilding and other fabricating industries. It provides around 88,000 psi tensile strength and around 26 food-pounds Charpy V-notch impact at 60 F. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as heat treating, machining, and joining. Filing Code: SA-355. Producer or source: Unicore Inc., United Nuclear Corporation.

scholarly journals Influence of Activated Fluxes on the Bead Shape of A-TIG Welds on Carbon and Low-Alloy Steels in Comparison with Stainless Steel AISI 304L

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 530
Author(s):  
Jerzy Niagaj
Keyword(s):  
Stainless Steel ◽  
Penetration Depth ◽  
High Strength ◽  
Tig Welding ◽  
Low Alloy Steels ◽  
Aisi 304L ◽  
A Tig Welding ◽  
Alloy Steels ◽  
Steel Aisi ◽  
Stainless Steel Aisi

The article presents results of comparative A-TIG welding tests involving selected unalloyed and fine-grained steels, as well as high-strength steel WELDOX 1300 and austenitic stainless steel AISI 304L. The tests involved the use of single ingredient activated fluxes (Cr2O3, TiO2, SiO2, Fe2O3, NaF, and AlF3). In cases of carbon and low-alloy steels, the tests revealed that the greatest increase in penetration depth was observed in the steels which had been well deoxidized and purified during their production in steelworks. The tests revealed that among the activated fluxes, the TiO2 and SiO2 oxides always led to an increase in penetration depth during A-TIG welding, regardless of the type and grade of steel. The degree of the aforesaid increase was restricted within the range of 30% to more than 200%.

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.

AK STEEL 409 Ni

Alloy Digest ◽  
2021 ◽  
Vol 70 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Physical Properties ◽  
Cost Effective ◽  
Heat Treating ◽  
Low Alloy Steels ◽  
Service Temperature ◽  
Alloy Steels ◽  
Cost Effective Alternative ◽  
Maximum Service Temperature

Abstract AK Steel 409 Ni is a 11% chromium ferritic stainless steel microalloyed with titanium and nickel. It provides excellent weldability, toughness, and fabricating characteristics superior to those of type 409 stainless steel in thicknesses over 3.05 mm (0.120 in.). This alloy is a cost effective alternative to mild steels and low-alloy steels that also provides superior corrosion and/or oxidation resistance. The recommended maximum service temperature of AK Steel 409 Ni is 730 °C (1350 °F). This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as heat treating and joining. Filing Code: SS-1336. Producer or source: AK Steel Corporation.

Sign in / Sign up

Export Citation Format

Share Document