Influence of Variable Amplitude Fatigue Loading on AISI 304L Stainless Steel

2013 ◽  
Author(s):  
Anne-Lise Gloanec ◽  
Aqmal Syafiq Anis ◽  
Stéphan Courtin
Keyword(s):  
Stainless Steel ◽  
Low Cycle Fatigue ◽  
Fatigue Crack Initiation ◽  
Constant Strain Rate ◽  
Total Strain ◽  
Complex Signal ◽  
304L Stainless Steel ◽  
Total Strain Amplitude ◽  
Aisi 304L ◽  
Variable Amplitude

The aim of this work was to study the influence of variable amplitude loading on the fatigue crack initiation and propagation. Low Cycle Fatigue (LCF) tests are conducted, on an AISI type 304L austenitic stainless steel, at different total-strain-amplitudes, in laboratory air at room temperature and with a constant strain rate of 3.10−3 s−1. Two types of signal were used: a conventional signal and a complex signal. The first one was triangular in shape with a negative strain ratio (Rε = −1). The second one is still triangular in shape with Rε = −1, but between the maximum of the total-strain (εmax = +0.6%) and the minimum (εmin = −0.6%), several cycles with a smaller total-strain-amplitude are introduced (with values ranged from 0% to +/− 0.3%). From these tests, several conclusions can be drawn on Cyclic Stress Strain (CSS) behaviour, fatigue life and fracture characteristics.

Fatigue Behaviour of a Stainless Steel Based on Energy Measurements

2009 ◽  
Vol 417-418 ◽  
pp. 333-336 ◽  
Author(s):  
Bruno Atzori ◽  
Giovanni Meneghetti ◽  
Mauro Ricotta
Keyword(s):  
Stainless Steel ◽  
Unit Volume ◽  
Low Cycle Fatigue ◽  
Mechanical Energy ◽  
Hysteresis Loops ◽  
Infrared Camera ◽  
Fatigue Behaviour ◽  
304L Stainless Steel ◽  
Aisi 304L ◽  
Static Test

In this paper the low cycle fatigue behaviour of an AISI 304L stainless steel is analysed on the basis of energy concepts. In particular during the fatigue tests different forms of energy in a unit volume of material per cycle involved in the fatigue process were measured: the mechanical energy expended was evaluated from the area of the hysteresis loops, while the energy released as heat by the specimen to the surroundings was estimated from surface temperature measurements by means of an infrared camera. By subtracting the mechanical input energy and that released as heat, the energy stored in a unit volume of material at fracture was calculated for each tested specimen. The mean value obtained from different specimens is in agreement with the energy absorbed by the material in a static test.

Effect of solution annealing on low cycle fatigue of 304L stainless steel

2021 ◽  
pp. 141807
Author(s):  
Miroslav Šmíd ◽  
Ivo Kuběna ◽  
Michal Jambor ◽  
Stanislava Fintová
Keyword(s):  
Stainless Steel ◽  
Low Cycle Fatigue ◽  
304L Stainless Steel ◽  
Cycle Fatigue ◽  
Solution Annealing

Development of Laser Cleaning for Metallic Equipment

2018 ◽  
Author(s):  
L. Carvalho ◽  
W. Pacquentin ◽  
M. Tabarant ◽  
J. Lambert ◽  
A. Semerok ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser Scanning ◽  
Surface Defects ◽  
Complex Geometry ◽  
Laser Cleaning ◽  
304L Stainless Steel ◽  
Primary Coolant ◽  
Aisi 304L ◽  
Weight Percentage ◽  
Aisi 304L Stainless Steel

Laser cleaning study was performed on prepared samples using a nanosecond pulsed ytterbium fiber laser. To prepare samples, AISI 304L stainless steel samples were oxidized and implemented with non-radioactive contaminants in a controlled manner. In order to validate the cleaning process for metallic equipment polluted in nuclear installations, two types of contamination with europium (Eu) and with cobalt (Co) were studied. Eu was used as a simulator-product resulting from uranium fission, while Co — as an activation-product of nickel, which is a composing element of a primary coolant system of a reactor. The oxide layers have suffered laser scanning which was followed by the furnace treatment to obtain thicknesses in the range of 100 nm to 1 μm depending on the oxidation parameters [1] with a mean weight percentage of 1% of Eu and 1 % of Co in the volume of the oxide layer. Glow Discharge Optical Emission (GD-OES) and Mass Spectrometry (GD-MS) analyses have been performed to assess the efficiency of the cleaning treatment and to follow the distribution of residual contamination with a detection limit of 0.1mg/kg of Eu and Co. Decontamination rates up to 95.5 % were obtained. One of the identified reasons for this limitation is that the radionuclides are trapped in surface defects like micro cracks [2, 3]. Therefore, cleaning treatments have been applied on surface defects with controlled geometry and a micrometric aperture obtained by laser engraving and juxtaposition of polished sheets of AISI 304L stainless steel. The goal of this study is surface decontamination without either welding or inducing penetration of contamination into the cracks. GD-MS analysis and Scanning Electron Microscopy (SEM) were performed to analyze the efficiency of the treatment and the diffusion of contaminants in this complex geometry.

scholarly journals High-Strength Reinforcing Steel Bars: Low Cycle Fatigue Behavior Using RGB Methodology

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jorge E. Egger ◽  
Fabian R. Rojas ◽  
Leonardo M. Massone
Keyword(s):  
Fatigue Life ◽  
Strain Amplitude ◽  
Low Cycle Fatigue ◽  
High Strength ◽  
Image Correlation ◽  
Total Strain ◽  
Total Strain Amplitude ◽  
Reinforcing Steel ◽  
Cycle Fatigue ◽  
Steel Bars

AbstractLow cycle fatigue life of high-strength reinforcing steel bars (ASTM A706 Grade 80), using photogrammetry by RGB methodology is evaluated. Fatigue tests are performed on specimens under constant axial displacement with total strain amplitudes ranging from 0.01 to 0.05. The experimental observations indicate that buckling of high-strength reinforcing bars results in a damaging degradation of their fatigue life performance as the slenderness ratio increases, including an early rebar failure as the total strain amplitude increases since it achieves the plastic range faster. In addition to this, the results show that the ratio of the ultimate tensile strength to yield strength satisfies the minimum of 1.25 specified in ASTM A706 for reinforcement. On the other hand, the RGB methodology indicates that the axial strains measured by photogrammetry provide more accurate data since the registered results by the traditional experimental setup do not detect second-order effects, such as slippage or lengthening of the specimens within the clamps. Moreover, the RGB filter is faster than digital image correlation (DIC) because the RGB methodology requires a fewer computational cost than DIC algorithms. The RGB methodology allows to reduce the total strain amplitude up to 45% compared to the results obtained by the traditional setup. Finally, models relating total strain amplitude with half-cycles to failure and total strain amplitude with total energy dissipated for multiple slenderness ratios (L/d of 5, 10, and 15) are obtained.

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