A correlation between creep-fatigue life and tensile hold time for austenitic stainless steels

1994 ◽  
Vol 13 (17) ◽  
pp. 1270-1271 ◽  
Author(s):  
Young Cheol Yoon ◽  
Soo Woo Nam
Keyword(s):  
Fatigue Life ◽  
Stainless Steels ◽  
Hold Time ◽  
Austenitic Stainless Steels ◽  
Tensile Hold ◽  
Creep Fatigue ◽  
Tensile Hold Time

Discussion of Fatigue Data for Austenitic Stainless Steels

2014 ◽  
Author(s):  
Paul Wilhelm ◽  
Paul Steinmann ◽  
Jürgen Rudolph
Keyword(s):  
Fatigue Life ◽  
Stainless Steels ◽  
National Laboratory ◽  
Hold Time ◽  
Argonne National Laboratory ◽  
Austenitic Stainless Steels ◽  
Reduction Factor ◽  
Fatigue Model ◽  
Fatigue Data ◽  
Number Of Cycles

The first results of a detailed fatigue model for austenitic stainless steels in general and for the grades 1.4541 and 1.4550 are presented to describe the effect of the light water reactor (LWR) coolant environments on the fatigue life. The statistical evaluations are based on strain (and load) controlled test series from different institutions. The compiled fatigue data include not only results from America (Keller (1971), Conway (1975), Hale (1977), and Argonne National Laboratory (ANL)(1999–2005)), but also from Europe (Solin (2006), Le Duff (2008–2010), De Baglion (2011, 2012), Huin (2013),…) and Japan (Kanasaki (1997)). The fatigue life is defined as the number of cycles necessary for tensile stress to drop 25 percent from its peak value. Fatigue lives defined by other failure criteria are normalized to the load reduction of 25 percent, before the statistical analysis is performed. The fatigue data are expressed in terms of the Langer equation and the parameter “material variability and data scatter” is quantified. Additionally, fatigue data in air of roughened specimens are compiled and discussed. A reduction factor of 2.5 on number of cycles is derived to cover the maximum allowed surface roughness. Based on the derived best-fit curves, design-curves in air and, in a second step, environmentally assisted fatigue (EAF) curves for LWR environments, which consider temperature, strain rate, dissolved oxygen content, and hold-time effects, will be incorporated in the detailed fatigue model in the future.

scholarly journals Effect of Microstructure on Creep Fatigue Properties for Type 316 Austenitic Stainless Steels

1996 ◽  
Vol 82 (6) ◽  
pp. 538-543 ◽  
Author(s):  
Nobuhiro FUJITA ◽  
Takanori NAKAZAWA ◽  
Hazime KOMATSU ◽  
Hitoshi KAGUCHI ◽  
Hideaki KANEKO ◽  
...  
Keyword(s):  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Fatigue Properties ◽  
Creep Fatigue ◽  
Effect Of Microstructure

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.

Explicit Quantification of the Interaction Between the PWR Environment and Component Surface Finish in Environmental Fatigue Evaluation Methods for Austenitic Stainless Steels

2018 ◽  
Author(s):  
Thomas Métais ◽  
Andrew Morley ◽  
Laurent de Baglion ◽  
David Tice ◽  
Gary L. Stevens ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Strain Rate ◽  
Surface Finish ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Polished Surface ◽  
Small Scale ◽  
Draft Code ◽  
Design Curve ◽  
Wide Range

Additional fatigue rules within the ASME Boiler and Pressure Vessel Code have been developed over the past decade or so, such as those in Code Case N-792-1 [1], which provides an acceptable method to describe the effects of BWR and PWR environments on the fatigue life of components. The incorporation of environmental effects into fatigue calculations is performed via an environmental factor, Fen, and depends on factors such as the temperature, dissolved oxygen and strain rate. In the case of strain rate, lower strain rates (i.e., from slow transients) aggravate the Fen factor which counters the long-held notion that step (fast) transients cause the highest fatigue usage. A wide range of other factors, such as surface finish, can have a deleterious impact on fatigue life, but their impact on fatigue life is typically considered by including transition sub-factors to construct the fatigue design curve from the mean behavior air curve rather than in an explicit way, such as the Fen factor. An extensive amount of testing and evaluation has been conducted and reported in References [2] [3] [4] [5] [6] [7] and [8] that were used to both revise the transition factors and devise the Fen equations contained in Code Case N-792-1. The testing supporting the definition of Fen was performed on small-scale laboratory specimens with a polished surface finish on the basis that the Fen factor is applicable to the design curve without any impact on the transition factors. The work initiated by AREVA in 2005 [4] [5] [6] suggested, in testing of austenitic stainless steels, an interaction between the two aggravating effects of surface finish and PWR environment on fatigue damage. These results have been supported by testing carried out independently in the UK by Rolls-Royce and AMEC Foster Wheeler (now Wood Group) [7], also on austenitic stainless steels. The key finding from these investigations is that the combined detrimental effects of a PWR environment and a rough surface finish are substantially less than the sum of the two individual effects. These results are all the more relevant as most nuclear power plant (NPP) components do not have a polished surface finish. Most NPP component surfaces are either industrially ground or installed as-manufactured. The previous studies concluded that explicit consideration of the combined effects of environment and surface finish could potentially be applicable to a wide range of NPP components and would therefore be of interest to a wider community: EDF has therefore authored a draft Code Case introducing a factor, Fen-threshold, which explicitly quantifies the interaction between PWR environment and surface finish, as well as taking some credit for other conservatisms in the sub-factors that comprise the life transition sub-factor used to build the design fatigue curve . The contents of the draft Code Case were presented last year [9]. Since then, other international organizations have also made progress on these topics and developed their own views. The work performed is applicable to Austenitic Stainless Steels only for the time being. This paper aims therefore to present an update of the draft Code Case based on comments received to-date, and introduces some of the research and discussions which have been ongoing on this topic as part of an international EPRI collaborative group on environmental fatigue issues. It is intended to work towards an international consensus for a final version of the ASME Code Case for Fen-threshold.

Techniques for Fatigue Testing and Extrapolation of Fatigue Life for Austenitic Stainless Steels

1982 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
R Horstman ◽  
KA Peters ◽  
RL Meltzer ◽  
M Bruce Vieth ◽  
MJ Manjoine ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Stainless Steels ◽  
Fatigue Testing ◽  
Austenitic Stainless Steels

Evaluation of Creep-Fatigue Life Using Backscattering of Rayleigh Surface Wave

2005 ◽  
Vol 297-300 ◽  
pp. 415-420 ◽  
Author(s):  
Byeong Soo Lim ◽  
Bum Joon Kim ◽  
Sung Jin Song ◽  
Young H. Kim
Keyword(s):  
Fatigue Life ◽  
Surface Wave ◽  
Fatigue Damage ◽  
Power Plants ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Rayleigh Surface Wave ◽  
P92 Steel ◽  
Creep Fatigue ◽  
Main Steam

The application of nondestructive evaluation to creep-fatigue damage was examined in this paper. Generally, as the hold time of static load increases, the degradation of material becomes more rapid and the creep-fatigue life decreases. Therefore, in the evaluation of creep-fatigue strength and life of high-pressure vessel such as main steam pipe at high temperature is very important in power plants. In this study, the creep-fatigue behavior of P92 steel was evaluated nondestructively by the backscattered ultrasound using the creep-fatigue specimens. The results obtained by Rayleigh surface wave of backscattered ultrasound were compared and analyzed with the experimental parameters. Also, the relation between the SDA (slope of degraded area) and creep-fatigue life was examined. From the result of nondestructive test, we suggest that SDA would be used as the new parameter for the evaluation of creep-fatigue damage. As the degradation increased, the SDA decreased and also the creep-fatigue life decreased.

Influence of Hold Time on Creep-Fatigue Life and Metallurgical Degradation at High Temperature

2006 ◽  
Vol 306-308 ◽  
pp. 1013-1018 ◽  
Author(s):  
Byeong Soo Lim ◽  
Bum Joon Kim
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Life Prediction ◽  
Hold Time ◽  
Creep Damage ◽  
Crack Growth Behavior ◽  
Delta Ferrite ◽  
Austenite Grain ◽  
Creep Fatigue ◽  
The Relationship

This paper investigates the influence of various hold times on creep-fatigue life at 600oC. The relationship between the crack growth behavior and hold time was studied, and a metallurigical investigation to examine the effect of creep was performed. To examine the relationship between creep-fatigue life and microvoids, the fraction of micro-voids/cavity area was analyzed at the crack tip. The crack growth rate of the HAZ was found to be faster than that of base metal while creep-fatigue life was found to be shorter. Finally, it can be stated that the fraction of cavity area, Fca could be utilized for the life prediction under creep-fatigue interaction. As the hold time increased, the creep damage was observed along the prior austenite grain boundaries and inside and boundaries of delta-ferrite.

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