Effect of Surface Residual Stress on Hydrogen Embrittlement of Prestressing Steels

1983 ◽  
Vol 18 (2) ◽  
pp. 80-81 ◽  
Author(s):  
M. Elices ◽  
G. Maeder ◽  
V. Sánchez-Gálvez
Keyword(s):  
Residual Stress ◽  
Hydrogen Embrittlement ◽  
Surface Residual Stress ◽  
Effect Of Surface

Effects of Residual Stresses on the High Cycle Fatigue Behavior of Ti-6Al-4V

2010 ◽  
Author(s):  
Yu-Jia Li ◽  
Fu-Zhen Xuan ◽  
Zheng-Dong Wang ◽  
Shan-Tung Tu
Keyword(s):  
Residual Stress ◽  
Fatigue Limit ◽  
Stress Ratio ◽  
Fatigue Behavior ◽  
Fatigue Tests ◽  
X Ray Diffraction ◽  
Surface Residual Stress ◽  
Manufacturing Techniques ◽  
Stress Ratios ◽  
Effect Of Surface

Axial force-controlled fatigue tests are conducted at various stress ratios (R) on Ti-6Al-4V specimens prepared by two different manufacturing techniques (hard turning plus polishing with and without vacuum stress relieve anneal carried out after polishing). Residual stress is measured by using X-ray diffraction. Results indicate that the surface compressive residual stress lead to an increase of fatigue limit at a given life and stress ratio. This effect decreases with increasing stress ratio R. At R = 0.6, the effect of surface residual stress on fatigue limit fades away. In addition, the location of crack initiation shifts from surface to interior when the stress ratio changes from −1 to 0.6.

The Influence of Surface Residual Stress on Fatigue Limit of Titanium

1960 ◽  
Vol 82 (1) ◽  
pp. 76-78 ◽  
Author(s):  
E. C. Reed ◽  
J. A. Viens
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Fatigue Limit ◽  
Experimental Error ◽  
Endurance Limit ◽  
Simple Equation ◽  
Surface Residual Stress ◽  
A Value ◽  
Effect Of Surface

Investigation of the effect of surface residual stress on the endurance limit of 6Al 4V titanium alloy shows that this effect is equal within experimental error to the residual stress divided by a constant. Results can be expressed by a simple equation. A value for the constant has been derived.

scholarly journals Effect of surface residual stress and inclusion size on fatigue failure mode of matrix HSS in very high cycle regime

2010 ◽  
Vol 2 (1) ◽  
pp. 873-882 ◽  
Author(s):  
Yuuji Shimatani ◽  
Kazuaki Shiozawa ◽  
Takehiro Nakada ◽  
Takashi Yoshimoto
Keyword(s):  
Residual Stress ◽  
Failure Mode ◽  
Fatigue Failure ◽  
Inclusion Size ◽  
Surface Residual Stress ◽  
Very High ◽  
Effect Of Surface

Effect of Surface Relaxation on Characteristics of Nanomachined Surface

2011 ◽  
Vol 211-212 ◽  
pp. 742-746
Author(s):  
Yu Lan Tang ◽  
Ya Ting He ◽  
Guo Zhi Liu ◽  
Jing Xiang Fu ◽  
Hong Sun ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Energy ◽  
Mechanical Systems ◽  
Surface Hardness ◽  
Surface Relaxation ◽  
Surface Residual Stress ◽  
Machined Surface ◽  
Micro Electro Mechanical Systems ◽  
Machined Parts ◽  
Effect Of Surface

With the development of Micro-electro-mechanical systems (MEMS) and Nano-electro-mechanical systems (NEMS), dimension of their parts is required to nanometer scale, and the characteristics of machined-surface of nano-scale parts affect strongly its application. Surface relaxation plays an important role to the characteristics of the machined-surface. In this paper, machined-surface of monocrystal copper used as the specimen of surface relaxation, and its surface relaxation process is simulated. The influences of surface relaxation on surface energy, atom array, surface roughness, surfaces hardness and surface residual stress of the monocrystal copper are analyzed. Results show that surface energy and surface hardness decrease due to relaxation; work-hardening can’t be completely eliminated by the relaxation; compression residual stress of the machined surface is changed gradually to tensile stress during the relaxation. These research results are very helpful to the application of nano-machined parts.

Effect of surface elasticity on extensional and torsional stiffnesses of isotropic circular nanorods

2018 ◽  
Vol 24 (6) ◽  
pp. 1613-1629 ◽  
Author(s):  
Prakhar Gupta ◽  
Ajeet Kumar
Keyword(s):  
Residual Stress ◽  
Axial Force ◽  
Surface Elasticity ◽  
Surface Residual Stress ◽  
Molecular Statics ◽  
Stress Components ◽  
Stress Free State ◽  
Tungsten Material ◽  
Analytical Expressions ◽  
Effect Of Surface

We present a continuum formulation to obtain the effects of surface residual stress and surface elastic constants on extensional and torsional stiffnesses of isotropic circular nanorods. Analytical expressions of axial force, twisting moment, and extensional and torsional stiffnesses are obtained. Unlike the case of rectangular nanorods, we show that the stiffnesses of circular nanorods also depend on surface residual stress components. This is attributed to non-zero surface curvature inherent in circular nanorods. We further normalize these expressions and analyze their asymptotic limits in the limit of the nanorod’s radius approaching both zero and infinity, corresponding to surface-dominated and bulk-dominated regimes, respectively. Finally, we use the recently proposed helical Cauchy–Born rule and perform molecular statics calculations to obtain axial force, twisting moment, and stiffnesses of the tungsten nanorod. The tungsten material is selected since its bulk crystal exhibits isotropy in the stress-free state. The results from molecular statics calculations are shown to match the derived continuum formulas accurately.

scholarly journals Effect of Surface Mechanical Treatments on the Microstructure-Property-Performance of Engineering Alloys

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2503 ◽  
Author(s):  
Dharmesh Kumar ◽  
Sridhar Idapalapati ◽  
Wei Wang ◽  
Srikanth Narasimalu
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Mechanical Performance ◽  
Boundary Behavior ◽  
Surface Residual Stress ◽  
Gradient Microstructure ◽  
Engineering Alloys ◽  
Property Performance ◽  
Inducing Surface ◽  
Effect Of Surface

Fatigue is a dominant failure mechanism of several engineering components. One technique for increasing the fatigue life is by inducing surface residual stress to inhibit crack initiation. In this review, a microstructural study under various bulk (such as severe plastic deformation) and surface mechanical treatments is detailed. The effect of individual microstructural feature, residual stress, and strain hardening on mechanical properties and fatigue crack mechanisms are discussed in detail with a focus on nickel-based superalloys. Attention is given to the gradient microstructure and interface boundary behavior for the mechanical performance. It is recommended that hybrid processes, such as shot peening (SP) followed by deep cold rolling (DCR), could enhance fatigue life. The technical and scientific understanding of microstructural features delineated here could be useful for developing materials for fatigue performance.

Surface Stress Concentration Analysis of Shot Peened Aluminium Alloys

2010 ◽  
Vol 449 ◽  
pp. 70-76
Author(s):  
J. Solis-Romero ◽  
J. Oseguera-Peña ◽  
J. Verduzco-Martínez ◽  
J. González-Sánchez
Keyword(s):  
Residual Stress ◽  
Stress Concentration ◽  
Surface Stress ◽  
Aluminium Alloys ◽  
Stress Gradient ◽  
Stress Effect ◽  
Surface Residual Stress ◽  
Closure Stress ◽  
Surface Crack Initiation ◽  
Effect Of Surface

Fatigue limit for surface crack initiation on shot peened Aluminium Alloys resulted to be determined by surface residual stress and stress concentration, according to the magnitude of the applied stress. The effect of surface roughness considered as micro-notches (dents) has been analysed by using the Vallellano and Navarro’s formulation. It was also determined that the stress gradient associated to those dents dominates over the closure stress effect.

scholarly journals Role of Ultrasonic Shot Peening in Environmental Hydrogen Embrittlement Behavior of 7075-T6 Alloy

Hydrogen ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 377-385
Author(s):  
Mahdieh Safyari ◽  
Masoud Moshtaghi
Keyword(s):  
Residual Stress ◽  
Hydrogen Embrittlement ◽  
Fracture Mode ◽  
Shot Peening ◽  
Unit Length ◽  
Surface Residual Stress ◽  
Nitrogen Gas ◽  
Ultrasonic Shot Peening ◽  
Slow Strain Rate Technique

The effect of ultrasonic shot peening on the environmental hydrogen embrittlement behavior of the 7075-T6 aluminum alloy is investigated. The 7075-T6 tensile specimens were treated by ultrasonic shot peening for 50 s. Surface residual stress and the depth of residual stress under the surface were evaluated using an X-ray diffractometer. Then, the specimens were tensile tested in humid air and dry nitrogen gas by the slow strain rate technique. The results showed that the ultrasonic shot-peened specimen has a superior hydrogen embrittlement resistance. Further, the ultrasonic shot peening changes the fracture mode from an intergranular fracture mode to the transgranular one. It was suggested that ultrasonic shot-peening has two effects on hydrogen embrittlement behavior; the distribution of hydrogen inside the surface layer by introducing dislocations/vacancies as hydrogen traps and reducing the normalized amount of hydrogen trapped per unit length of the grain boundary.

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