scholarly journals Evaluation of Fatigue Crack Properties on Austenitic Stainless Steel with Artificial Corrosion Pits

2005 ◽  
Vol 54 (12) ◽  
pp. 1262-1267
Author(s):  
Kiyotaka MASAKI ◽  
Yasuo OCHI ◽  
Takashi MATSUMURA
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Austenitic Stainless Steel ◽  
Corrosion Pits

Effect of Hydrogenated Water on Fatigue Crack Growth for Austenitic Stainless Steel in Simulated BWR Water Environment

2004 ◽  
Author(s):  
Li H. Wang
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Cyclic Loading ◽  
Austenitic Stainless Steel ◽  
Fatigue Crack Growth ◽  
Water Chemistry ◽  
Crack Growth ◽  
Growth Stage ◽  
Transgranular Fracture ◽  
Cyclic Loading Condition

Fatigue crack growth rates (FCGR) of sensitized austenitic stainless steel (SS) were measured in simulated BWR water at 288 °C using compact tension specimens under different cyclic loading modes, including saw-tooth, trapezoidal and constant loading pattern. This study tested sensitized SS in normal water chemistry (NWC) and hydrogen water chemistry (HWC) respectively, and attempted to clarify the effect of low electrochemical corrosion potential on the FCGR of sensitized stainless steel. Significant environment effects on FCGR of sensitized stainless steel were observed in both water chemistries when compared with air fatigue curve. The pronounced suppression effect of HWC on crack growth in statically sustained load was not observed in cyclic loading condition. ASME curve doesn’t seem to be conservative and could not bound all the FCGR data tested in this study. In contrast, all of the measured FCGR data were bound by the JSME disposition curve. PLEDGE model proposed by General Electric reasonably predicted the FCGR of sensitized SS in NWC, but underestimated the FCGR in HWC. ANL’s superposition model successfully estimated the FCGR measured in both water chemistries. The fractography exhibited transgranular fracture mode during the crack initiation and growth stage. No differences in the appearance of fracture surface were observed in HWC and NWC. Only in very high DO environments, the sensitized 304 SS exhibited the mixed mode of intergranular and transgranular during growth stage.

Fatigue Crack Growth Properties of a Cryogenic Structural Steel at Liquid Helium Temperature

1996 ◽  
Vol 118 (1) ◽  
pp. 109-113 ◽  
Author(s):  
Shinji Konosu ◽  
Tomohiro Kishiro ◽  
Ogi Ivano ◽  
Yoshihiko Nunoya ◽  
Hideo Nakajima ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Austenitic Stainless Steel ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Liquid Helium ◽  
Liquid Helium Temperature ◽  
Small Scale ◽  
Helium Temperature ◽  
Growth Properties

The structural materials of the coils of superconducting magnets utilized in thermonuclear fusion reactors are used at liquid helium (4.2 K) temperatures and are subjected to repeated thermal stresses and electromagnetic forces. A high strength, high toughness austenitic stainless steel (12Cr-12Ni-10Mn-5Mo-0.2N) has recently been developed for large, thick-walled components used in such environments. This material is non-magnetic even when subjected to processing and, because it is a forging material, it is advantageous as a structural material for large components. In the current research, a large forging of 12Cr-12Ni-10Mn-5Mo-0.2N austenitic stainless steel, was fabricated to a thickness of 250 mm, which is typical of section thicknesses encountered in actual equipment. The tensile fatigue crack growth properties of the forging were examined at liquid helium temperature as function of specimen location across the thickness of the forging. There was virtually no evidence of variation in tensile strength or fatigue crack growth properties attributable to different sampling locations in the thickness direction and no effect of thickness due to the forging or solution treatment associated with large forgings was observed. It has been clarified that there are cases in which small scale yielding (SSY) conditions are not fulfilled when stress ratios are large. ΔJ was introduced in order to achieve unified expression inclusive of these regions and, by expressing crack growth rate accordingly, the following formula was obtained at the second stage (middle range). da/dN = CJ ΔJmJ, CJ = AJ/(ΔJ0)mJ, where, AJ = 1.47 × 10−5 mm/cycle, ΔJ0 = 2.42 × 103N/m.

Influence of texture on the short fatigue crack growth in austenitic stainless steel

2006 ◽  
Vol 42 (4) ◽  
pp. 514-526 ◽  
Author(s):  
V. Mikulich ◽  
C. Blochwitz ◽  
W. Skrotzki ◽  
W. Tirschler
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Austenitic Stainless Steel ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Short Fatigue Crack

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.

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