Neutron Determination of Residual Stress in a Nitrided Notched Part

2005 ◽  
Vol 490-491 ◽  
pp. 251-256 ◽  
Author(s):  
Agnès Fabre ◽  
Laurent Barrallier
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Thermomechanical Treatment ◽  
Gear Tooth ◽  
Stress Profile ◽  
Residual Stress Profile ◽  
Improve Fatigue

Nitriding is an hardening thermomechanical treatment generally used to improve fatigue life of steel parts, like gear for example. Another effect of this treatment is generating superficial stress, influenced by nitriding conditions, composition of steel and geometry of the part. This work deals with the effect of shape on the residual stress profile obtain after nitriding on a gear tooth. The residual stress profile was determined using neutrons diffraction technique.

scholarly journals Influence of residual stress profile and surface microstructure on fatigue life of a 15-5PH

2018 ◽  
Vol 213 ◽  
pp. 623-629 ◽  
Author(s):  
F. Valiorgue ◽  
V. Zmelty ◽  
M. Dumas ◽  
V. Chomienne ◽  
C. Verdu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Surface Microstructure ◽  
Stress Profile ◽  
Residual Stress Profile

Peripheral milling-induced residual stress and its effect on tensile–tensile fatigue life of aeronautic titanium alloy Ti–6Al–4V

2019 ◽  
Vol 123 (1260) ◽  
pp. 212-229 ◽  
Author(s):  
Dong Yang ◽  
Xiao Xiao ◽  
Yulei Liu ◽  
Jing Sun
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Fatigue Life ◽  
Surface Energy ◽  
Compressive Residual Stress ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Stress Profile ◽  
Peripheral Milling ◽  
Residual Stress Profile

ABSTRACTThe special application environment puts forward the higher requirement of reliability of parts made from titanium alloy Ti–6Al–4V, which is closely related to the machining-induced residual stress. For the fact of the non-linear distribution of residual stress beneath the machined surface, distribution of peripheral milling-induced residual stress and its effect on fatigue performance of titanium alloy Ti–6Al–4V are still confusing. In the present study, residual stress profile induced by peripheral milling of Ti–6Al–4V is first studied. And then, energy criteria are proposed to characterise the whole state of the residual stress field. Finally, the effects of residual stress profile and surface energy on tensile–tensile fatigue performance of titanium alloy Ti–6Al–4V are discussed. The conclusions were drawn that the variation trend of surface residual stress (σr,Sur), maximum compressive residual stress (σC,ax), location (hr0) and response depth (hry) of residual stress profile with cutting parameters showed a similar pattern for both measure directions those parallel (σ1) and perpendicular (σ3) to the cutting direction. Cutting speed and feed rate have a main effect on surface residual stress, and the depth of cut has little effect on all the four key factors of residual stress profile. With the increase of cutting speed and feed rate, machining-induced surface energy tends to become larger. But increasing the depth of cut caused the strain energy stored in unit time to decrease. Furthermore, the effect of depth of cut on surface energy was weakened when the value of cutting depth becomes larger. Both the surface compressive residual stress and the maximum compressive residual stress are beneficial for prolonging the fatigue life, while large value of machining-induced surface energy leads to a decrease of fatigue life. Analysis of variance result shows that maximum residual compressive stress has a greater impact on fatigue life than other residual stress factors.

Effects of process combinations of milling, grinding, and polishing on the surface integrity and fatigue life of GH4169 components

2019 ◽  
Vol 234 (3) ◽  
pp. 538-548
Author(s):  
Fang Quan ◽  
Zhitong Chen ◽  
Qiantong Li ◽  
Shimin Gao
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Boron Nitride ◽  
Compressive Residual Stress ◽  
High Cycle Fatigue ◽  
Cubic Boron Nitride ◽  
Stress Profile ◽  
Cycle Fatigue ◽  
Squeezing Effect ◽  
Residual Stress Profile

The nickel-based superalloy GH4169 is widely applied in the aviation industry due to its outstanding mechanical properties. However, many blades of GH4169 are still produced by milling and manual polishing, which is costly and unreliable. In this article, GH4169 superalloy components manufactured with combination processes of milling, grinding, and polishing were comparatively studied involving surface integrity and fatigue performance. Test results indicate that the final polishing is the most dominant process that influences the high-cycle fatigue life of GH4169 components. Samples produced via cubic boron nitride grinding and numerical control polishing with a diamond-rubber wheel exhibit fatigue limits of 150 MPa higher than the milled and manually polished samples. Cubic boron nitride grinding induces a considerable compressive residual stress profile with a magnitude of -930 MPa and a depth of 200 μm. Milling induces a typical “hook” residual stress profile with 318 MPa at the surface. Polishing affects the machined surface by two ways, the removal effect and the squeezing effect. The squeezing effect induces a shallow compressive residual stress with approximately −1000 MPa, therefore improves the surface condition. However, inevitable omissions, scratches, texture disorders, and knock marks in hand-polishing are the main causes of the unstable high-cycle fatigue life of hand-polished components.

scholarly journals Cross-Sectional Mapping of Residual Stresses by Measuring the Surface Contour After a Cut

2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Superposition Principle ◽  
New Method ◽  
Contour Method ◽  
Stress Profile ◽  
Relaxation Methods ◽  
Cross Sectional ◽  
Residual Stress Profile

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.

Study of Effect of Repetition Rate on Laser Shock Peening Using Finite Element Modeling

2020 ◽  
Author(s):  
Sai Kosaraju ◽  
Xin Zhao
Keyword(s):  
Shock Wave ◽  
Residual Stress ◽  
Finite Element ◽  
Shock Waves ◽  
Repetition Rate ◽  
High Repetition Rate ◽  
Stress Profile ◽  
Surface Residual Stress ◽  
Residual Stress Profile ◽  
High Repetition

Abstract A two-dimensional finite element model is developed to simulate the interaction between metal samples and laser-induced shock waves. Multiple laser impacts are applied at each location to increase plastically affected depth and compressive stress. The in-depth and surface residual stress profiles are analyzed at various repetition rates and spot sizes. It is found that the residual stress is not sensitive to repetition rate until it reaches a very high level. At extremely high repetition rate (100 MHz), the delay between two shock waves is even shorter than their duration, and there will be shock wave superposition. It is revealed that the interaction of metal with shock wave is significantly different, leading to a different residual stress profile. Stronger residual stress with deeper distribution will be obtained comparing with lower repetition rate cases. The effect of repetition rate at different spot sizes is also studied. It is found that with larger laser spot, the peak compressive residual stress decreases but the distribution is deeper at extremely high repetition rates.

scholarly journals Impact of grinding wheel specification on surface integrity and residual stress when grinding Inconel 718

2020 ◽  
pp. 095440542096120
Author(s):  
David Curtis ◽  
Holger Krain ◽  
Andrew Winder ◽  
Donka Novovic
Keyword(s):  
Residual Stress ◽  
Inconel 718 ◽  
Cubic Boron Nitride ◽  
Grinding Wheel ◽  
Stress Profile ◽  
Standard Equipment ◽  
Residual Stress Profile ◽  
Grinding Parameters ◽  
Stress Formation

The grinding process is often maligned by grinding burn; which refers to many unwanted effects, including residual stress formation. This paper presents an overview of the role of grinding wheel technologies in the surface response and residual stress formation of thin section Inconel 718. Using production standard equipment, conventional abrasive vitrified, and super abrasive electroplated wheel technologies were evaluated in initial comparative trials. Results revealed the dominant residual stress profiles, which manifested as measurable distortion and the thermo-mechanical impact of grinding, such as softening. Following this, a parametric study was carried out using cubic boron nitride super abrasive electroplated wheels to investigate the interaction of grinding parameters on the generated output. It was shown that at increased grinding aggressions, tensile stress regimes increased resulting in increased distortion magnitudes. The study highlights the importance of assessing residual stress formation when manipulating both wheel technologies and grinding parameters. It is envisaged that with additional assessment, a route to an engineered residual stress profile might be achieved.

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