Low Cycle Fatigue Behavior of 316LN Stainless Steel Alloyed with Varying Nitrogen Content. Part II: Fatigue Life and Fracture Behavior

2014 ◽  
Vol 45 (11) ◽  
pp. 5057-5067 ◽  
Author(s):  
G. V. Prasad Reddy ◽  
R. Sandhya ◽  
S. Sankaran ◽  
M. D. Mathew
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Nitrogen Content ◽  
Fracture Behavior ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
316Ln Stainless Steel ◽  
Content Part

Effects of Surface Finish and Loading Conditions on the Low Cycle Fatigue Behavior of Austenitic Stainless Steel in PWR Environment: Comparison of LCF Test Results With NUREG/CR-6909 Life Estimations

2008 ◽  
Author(s):  
Jean Alain Le Duff ◽  
Andre´ Lefranc¸ois ◽  
Jean Philippe Vernot
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Austenitic Stainless Steel ◽  
Environmental Effects ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Complex Signal ◽  
Loading Conditions ◽  
Test Results ◽  
Cycle Fatigue

During mid 2006, ANL issued a NUREG/CR-6909 [2] report that is now applicable in The US for evaluations of PWR environmental effects in the fatigue analysis of new reactor components. In order to assess the conservativeness of the application of this NUREG report, low cycle fatigue (LCF) tests were performed by AREVA NP on austenitic stainless steel specimens in a PWR environment. The selected material exhibits in an air environment a fatigue behavior consistent with the ANL reference “air” mean curve. Tests were performed for two various loading conditions: for fully reverse triangular signal (for comparison purpose with tests performed by other laboratories with same loading conditions) and complex signal, simulating strain variation for actual typical PWR thermal transients. Two surface finish conditions were tested: polished and ground. The paper presents on one side the comparison of environmental penalty factors (Fen = Nair,RT/Nwater) as observed experimentally with the ANL formulation (considering the strain integral method for complex loading), and, on the other hand, the actual fatigue life of the specimen with the fatigue life predicted through the NUREG/CR-6909 application. Low Cycle Fatigue test results obtained on austenitic stainless steel specimens in PWR environment with triangle waveforms at constant low strain rates gives Fen penalty factors close to those estimated using the ANL formulation (NUREG report 6909). On the contrary, it was observed that constant amplitude LCF test results obtained under complex signal reproducing an actual sequence of a cold and hot thermal shock exhibits significantly lower environmental effects when compared to the Fen penalty factor estimated on the basis of the ANL formulations. It appears that the application of the NUREG/CR-6909 [2] in conjunction with the Fen model proposed by ANL for austenitic stainless steel provides excessive margins whereas the current ASME approach seems sufficient to cover significant environmental effect for components.

Low-Cycle Fatigue Properties of Steels and Their Weld Metals

1989 ◽  
Vol 111 (4) ◽  
pp. 431-437 ◽  
Author(s):  
Y. Z. Itoh ◽  
H. Kashiwaya
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Weld Metal ◽  
Arc Welding ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Steel Weld ◽  
Cycle Fatigue ◽  
Weld Metals ◽  
Metal Arc Welding

Completely reversed, strain-controlled, low-cycle fatigue behavior at room temperature is investigated for steels and their weld metals. Weld metal specimens were taken from multi-pass weld metal deposited by shield metal arc welding (SMAW) and gas metal arc welding (GMAW), such that their gage length consisted entirely of the weld metal. Results indicate that there is a trend toward reduction in the low-cycle fatigue life of weld metals as compared with the base metals. In low carbon steel weld metals, the tendency described above is explained in terms of local plastic strain concentration by lack of uniformity of the multi-pass weld metals. The weld metals do not have the same mechanical properties anywhere as confirmed by hardness distribution, and the fatigue crack grows preferentially through the temper softened region in the multi-pass welds. In Type 308 stainless steel weld metals, the ductility reduction causes reductions in low-cycle fatigue life. This study leads to the conclusion that fairly accurate estimates of the low-cycle fatigue life of weld metals can be obtained using Manson’s universal slope method. However, life estimates of the Type 304 stainless steel is difficult due to a lack of ductility caused by a deformation-induced martensitic transformation.

Low Cycle Fatigue Behavior of 429EM Ferritic Stainless Steel at Elevated Temperatures

2004 ◽  
Vol 261-263 ◽  
pp. 1135-1140 ◽  
Author(s):  
Keum Oh Lee ◽  
Sam Son Yoon ◽  
Soon Bok Lee ◽  
Bum Shin Kim
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Fatigue Life ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cyclic Hardening ◽  
Dynamic Strain ◽  
Temperature Structure ◽  
Cycle Fatigue

In recent, ferritic stainless steels are widely used in high temperature structure because of their high resistance in thermal fatigue and low prices. Tensile and low cycle fatigue(LCF) tests on 429EM stainless steel were performed at several temperatures from room temperature to 600°C. Elastic modulus, yield stress and ultimate tensile strength(UTS) decreased with increasing temperature. Considerable cyclic hardening occurred at 200°C and 400°C. 475°C embrittlement observed could not explain this phenomenon but dynamic strain aging(DSA) observed from 200°C to 500°C could explain the hardening mechanism at 200°C and 400°C. And it was observed that plastic strain energy density(PSED) was useful to predict fatigue life when large cyclic hardening occurred. Fatigue life using PSED over elastic modulus could be well predicted within 2X scatter band at various temperatures.

scholarly journals Numerical and Analytical Analysis of the Low Cycle Fatigue Behavior of Notched and Un-Notched 316 L (N) Austenitic Stainless-Steel Samples at Ambient and Elevated Temperatures

2021 ◽  
Vol 3 (1) ◽  
pp. 25
Author(s):  
Ikram Abarkan ◽  
Abdellatif Khamlichi ◽  
Rabee Shamass
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Corrosion Properties ◽  
Notched Specimens ◽  
Different Temperatures ◽  
New Equation

Smooth and notched mechanical components made of metals frequently experience repeated cyclic loads at different temperatures. Thus, low cycle fatigue (LCF) is considered the dominant failure mode for these components. Stainless steel (SS) is the most widely selected material by engineers owing to its outstanding mechanical and LCF and anti-corrosion properties. Moreover, a reliable estimation of the fatigue life is essential in order to preserve people’s safety in industries. In the present study, an evaluation of some of the commonly known low cycle fatigue life methodologies are performed for notched and un-notched samples made of 316L (N) SS at ambient and higher temperatures. For the notched samples, the elastic–plastic strains were firstly determined and then the fatigue lives were estimated for constant nominal strain amplitudes, varying from ±0.4% to ±0.8%. A comparison between the calculated fatigue lives and those obtained experimentally from the literature was made. Overall, some of the widely used fatigue life prediction methods for smooth specimens have resulted in unsafe estimations for applied strain amplitudes ranging from ±0.3% to ±1.0%, and those of the notched specimens were generally found to give strongly conservative predictions. To overcome this problem, attempts were made to suggest new parameters that can precisely assess the lifetimes of smooth samples, and a new equation was suggested for notched samples under both room and high temperatures.

Numerical and Analytical Studies of Low Cycle Fatigue Behavior of 316 LN Austenitic Stainless Steel

2020 ◽  
Author(s):  
Ikram Abarkan ◽  
Rabee Shamass ◽  
Zineb Achegaf ◽  
Abdellatif Khamlichi
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Austenitic Stainless Steel ◽  
Shear Strain ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Maximum Shear Strain ◽  
Conservative Estimation ◽  
316 Ln Ss

Abstract Mechanical components are frequently subjected to severe cyclic pressure and/or temperature loadings. Therefore, numerical and analytical low cycle fatigue methods become widely used in the field of engineering to estimate the design fatigue lives. The primary aim of this work is to evaluate the accuracy of the most commonly used numerical and analytical low cycle fatigue life methods for specimens made of 316 LN austenitic stainless steel and subjected to fully reversed uniaxial tension-compression loading, in the room temperature condition. It was found that both Maximum shear strain and Brown-Miller criterions result in a very conservative estimation for uniaxially loaded specimens, however, Maximum shear strain criteria provides better results compared to the Brown-Miller criteria. The total strain energy density approach was also used, and both the Masing and non-Masing analysis were adopted in this study. It is found that the Masing model provides conservative fatigue lives, and non-Masing model results in a more realistic fatigue life prediction for 316 LN stainless steel for both low and high strain amplitude. The fatigue design curves obtained from the commonly used analytical low cycle fatigue equations were reexamined for 316 LN SS. The obtained design curves from Langer model and its modified versions are non-conservative for this type of material. Consequently, the authors suggest new optimized parameters to fit the given test data. The obtained curve using the currently suggested parameters is in better agreement with the experimental data for 316 LN SS.

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