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

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.

Low cycle fatigue behavior of circumferentially notched specimens made of modified 9Cr–1Mo steel at elevated temperature

“…The predefined temperature was applied and fixed at 550 8C for both notched and smooth/un-notched samples. It is worthwhile to mention that the nonlinear isotropic/kinematic hardening and Ramberg-Osgood material models [30,31] have been employed to replicate numerically the cyclic stress-strain behavior of the smooth and notched specimens respectively, more details on the numerical simulation are given in [2]. The Newton-Raphson method was used to solve the nonlinear problem.…”

“…Studies have shown that the total mechanical failures that are caused by fatigue are ranging between 50 and 90 percent [1], which made researchers increasingly concerned about this topic. Most recently, a number of large research studies have been conducted to investigate the fatigue behavior of different materials and geometries, under various loading conditions [2][3][4][5][6][7]. In particular, Abarkan et al [2] studied the Low Cycle Fatigue (LCF) behavior of smooth 316 LN austenitic stainless steel samples at room temperature using several numerical and analytical fatigue methods and they proposed new parameters to correct the inconsistency of some of the better-known low cycle fatigue analytical models used to predict the life to failure of the pressure vessels facilities.…”

A Numerical Analysis on the Cyclic Behavior of 316 FR Stainless Steel and Fatigue Life Prediction

“…Moreover, when using these equations, the accuracy of the stress-strain data is also important for estimating accurate low-cycle fatigue life. Finite Element Analysis (FEA) is one of the most effective tools to use, since it has been shown to be precise and accurate [7,8].…”

“…2021, 11, 28 2 of 7 Materials with good cyclic characteristics are generally required for use in AGRs to withstand severe low cycle fatigue loadings. 316FR Stainless Steel (SS) is identical to 316LN SS [7,8], a low-carbon increased nitrogen grade of austenitic stainless steel that is typically selected for this sort of application due to its extending mechanical, low-cycle fatigue and creep properties at higher temperatures [1].…”

“…Many research investigations have been undertaken in the last few years to examine the durability of 316 SS under low-cycle fatigue at room temperature, in particular [7][8][9], but few studies have been dedicated to low-cycle fatigue at higher temperatures. Hormozi [1], for example, performed thorough experimental and numerical investigations of isothermal and in-phase thermomechanical low cycle fatigue of 316 FR SS with and without hold time.…”