Strain hardening of armco iron during low-cycle fatigue in gaseous hydrogen

1977 ◽  
Vol 13 (1) ◽  
pp. 4-7 ◽  
Author(s):  
A. N. Romaniv ◽  
V. I. Tkachev
Keyword(s):  
Strain Hardening ◽  
Armco Iron ◽  
Low Cycle Fatigue ◽  
Gaseous Hydrogen ◽  
Cycle Fatigue

Initiation from Low Cycle Fatigue to Gigacycle Fatigue

2014 ◽  
Vol 891-892 ◽  
pp. 1419-1423 ◽  
Author(s):  
Claude Bathias ◽  
Chong Wang
Keyword(s):  
Fatigue Crack ◽  
Grain Boundary ◽  
Armco Iron ◽  
Low Cycle Fatigue ◽  
Point Of View ◽  
Cycle Fatigue ◽  
Physical Point ◽  
Mechanical Aspect

This paper is devoted to the initiation of fatigue crack in Armco iron from low cycle fatigue to gigacycle fatigue. It is shown that the basic mechanisms of initiation are very similar from a physical point of view: PSB and Grain boundary cracking. But the mechanical aspect is specific in LCF and in GCF.

Strain Hardening by High Density SISFs During Low Cycle Fatigue in Ni3(Al,Zr) Single Crystal

1994 ◽  
Vol 364 ◽  
Author(s):  
Yuefeng Gu ◽  
Yi Liu ◽  
Jianting Guo ◽  
Dongliang Lin
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Strain Hardening ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Stacking Faults ◽  
Cyclic Strain ◽  
Cycle Fatigue ◽  
Transmission Electron ◽  
Stress Asymmetry

AbstractStress response and its correlation with dislocation substructures in Ni3(Al,Zr) single crystal fatigued at room temperature have been studied. Cyclic strain hardening was found to be asymmetric and increased with increasing applied cyclic strain. Transmission Electron Microscope (TEM) observation showed that there are a profusion superlattic intrinsic stacking faults (SISFs) in fatigued Ni3(Al,Zr) single crystal samples. The cyclic strain hardening and stress asymmetry are explained by the movement of the SISF.

Low-cycle fatigue of steel 2Kh13 in a medium of gaseous hydrogen

1974 ◽  
Vol 8 (1) ◽  
pp. 102-104
Author(s):  
A. N. Romaniv ◽  
V. I. Tkachev ◽  
R. I. Kripyakevich
Keyword(s):  
Low Cycle Fatigue ◽  
Gaseous Hydrogen ◽  
Cycle Fatigue ◽  
Steel 2Kh13

Continuum damage mechanics-based ductile behavior and fatigue life estimation of low carbon steels: AISI 1020 and AISI 1030

2019 ◽  
Vol 233 (10) ◽  
pp. 2057-2071
Author(s):  
Abhinav Gautam ◽  
Prabir Kumar Sarkar
Keyword(s):  
Fatigue Life ◽  
Strain Hardening ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Strain Curve ◽  
Continuum Damage Mechanics ◽  
Strain Hardening Exponent ◽  
Cycle Fatigue ◽  
Ductile Flow ◽  
Ductile Behavior

This paper presents an experimental estimation of the ductile behavior and low-cycle fatigue life for widely used structural steels AISI 1020 and AISI 1030 based on continuum damage mechanics approach. This method identifies the deterioration in stiffness of a material arising from micromechanisms of formation, growth, and coalescence of microvoids. This helps the characterization of the ductile flow behavior of metals through a damage variable D, evaluated via load–unload cyclic tensile test. The influence of strain hardening exponent, commonly treated as a constant in ductile flow characterization, is also explored in the current investigation. Its determination uses the Hollomon constitutive relation. Estimated D at different strain levels defines the corresponding effective stress. Application of this stress to the strain equivalence theory then enables the prediction of the stress–strain curve. The model-based results closely approximate the experimental stress–strain curve up to the onset of necking. The agreement of experimental results for fatigue life of the materials from low-cycle fatigue tests with damage-based low-cycle fatigue model demonstrates the correctness of the experimental findings. The damage-based model additionally helps in the prediction of microcrack nucleation and crack propagation life separately. Fractographic examinations of test specimen exhibit usually observed morphology of involved failure mechanisms. The present study emphasizes the experimental means of damage-based ductile flow assessment involving strain hardening exponent term and also the low-cycle fatigue life estimation. The significance of varying strain hardening exponent is further expressed in terms of the corresponding damage magnitude. The material data obtained from this study depicts the damage state at different levels of plastic strain that may serve as a useful information for metal-forming process design.

Variation in Mechanical Properties, Microstructures and Fracture Behavior of 304 Stainless Steel During Low-Cycle Fatigue

2010 ◽  
Author(s):  
Duyi Ye ◽  
Yuandong Xu ◽  
Lei Xiao ◽  
Haibo Cha
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Strain Hardening ◽  
Fatigue Damage ◽  
Fracture Behavior ◽  
Damage Mechanics ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Damage Process ◽  
Static Mechanical

A series of experiments, including constant amplitude low-cycle fatigue tests, post-fatigue tension to failure tests, LOP (TEM) observations, and SEM examinations, were performed at room-temperature to investigate the variation of the static mechanical properties, microstructures and fracture behavior of 304 austenitic stainless steel during low-cycle fatigue. The changing characteristics of various static mechanical property parameters, including the strength parameters, stiffness parameter, ductility parameters and strain hardening exponent during fatigue damage process of the stainless steel were obtained experimentally and their micromechanisms were discussed by analyzing both the deformation microstructures and the fracture features of the cyclically pre-deformed specimens. It was shown that the austenite / martensite transformation resulting from the accumulation of cyclic plastic strain was mostly responsible for the variation in the strength, ductility and strain hardening ability of the stainless steel during fatigue damage process. The depletion of the inherent ductility in the material due to fatigue damage evolution led to the ductile-to-brittle transition (DBT) in the fracture modes. Based on the macro- / micro-experiments regarding the exhaustion of the ductility during fatigue damage, the ductility parameter was suggested as a damage indicating parameter for the present stainless steel in further studying the fatigue damage mechanics model as well as the residual fatigue life prediction method.

Effect of T6 Treatment on Low-Cycle Fatigue Properties of Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc Alloy

2014 ◽  
Vol 664 ◽  
pp. 28-33
Author(s):  
Ying Lan ◽  
Li Jia Chen ◽  
Xin Che ◽  
Feng Li
Keyword(s):  
Strain Hardening ◽  
Low Cycle Fatigue ◽  
Aging Treatment ◽  
Cyclic Strain ◽  
Cyclic Stress ◽  
Cyclic Strength ◽  
Fatigue Properties ◽  
Strain Hardening Exponent ◽  
Cycle Fatigue ◽  
Linear Behavior

The low-cycle fatigue behaviors of as-extruded and T6 treated Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloys at room temperature have been investigated under those total-strain amplitudes ranged from 0.3% to 1.0%, and the influence of T6 treatment on the low-cycle fatigue properties of Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy was clarified. The experimental results show that during fatigue deformation, the significant cyclic strain hardening and stable cyclic stress response can be noted for both as-extruded and T6 treated Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloys. The fatigue life of as-extruded Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy at all strain amplitudes is longer than that of the alloy subjected to T6 aging treatment. The relationship between both elastic and plastic strain amplitudes with reversals to failure shows a monotonic linear behavior, and can be described by the Basquin and Coffin-Manson equations, respectively. The T6 treatment can significantly increase the cyclic strain hardening exponent and cyclic strength coefficient of extruded Al-6Zn-2.5Mg-2Cu-0.1Zr-0.1Sc alloy.

Sign in / Sign up

Export Citation Format

Share Document