scholarly journals Effects of ultrasonic surface rolling process on tribological behavior of 4Cr13 stainless steel

Author(s):  
Xiaoshuang Luo ◽  
Shengpeng Zhan ◽  
Dan Jia ◽  
Jiesong Tu ◽  
Yinhua Li ◽  
...  

Abstract Ultrasonic surface rolling (USR) process is a novel surface strengthening technique based on the tool head's high-frequency impact on the workpiece. USR can cause severe plastic deformation on the superficial surface of metal material, and greatly improving the mechanical properties of the material. This paper elucidates the effects of USR passes on the surface roughness, sample height, microstructure, microhardness, residual stress, and tribological properties of 4Cr13 stainless steel. The results revealed that multiple USR treatments refined the near-surface layer grain of the sample. Compared with untreated sample, USR treatments significantly improved the surface roughness and microhardness of the samples. Obvious compressive residual stress and plastic deformed with a maximum value of about -723 MPa and a depth of about 229 μm were also introduced into the sample surface. Under a dry friction environment, the samples that underwent the USR treatments exhibited significantly enhanced wear resistance, and six rolling passes were found to be the most suitable treatment.

2014 ◽  
Vol 802 ◽  
pp. 334-337
Author(s):  
C.L. Santos ◽  
G. Vasconcelos ◽  
H.S. Oliveira ◽  
L.G. Oliveira ◽  
J.F. Azevedo ◽  
...  

This study shows the influence of the temperature in the Direct Forming Laser process (DFL) of 316L stainless steel metal powder. Results shows that an increasing in the sample surface temperature can improve the laser beam absorption in the DFL process. A pre-heating in the substrate and in the powder contributed to decrease the time to reach the melting point and to improve the surface roughness. This effect was investigated with constant lasers parameters (scanning speed and intensity) and a heating in the samples in the temperature range of 20oto 200oC. It was possible to evaluate the DFL process and to optimize the quality of the sample surface roughness. These results will benefit the knowledge of the DFL technology that can be applied in the development of turbine blades.


2014 ◽  
Vol 996 ◽  
pp. 8-13 ◽  
Author(s):  
Alexander J.G. Lunt ◽  
Alexander M. Korsunsky

Titanium aluminide (TiAl) is a lightweight intermetallic compound with a range of exceptional mid-to-high temperature mechanical properties. These characteristics have the potential to deliver significant weight savings in aero engine components. However, the relatively low ductility of TiAl requires improved understanding of the relationship between manufacturing processes and residual stresses in order to expand the use of such components in service. Previous studies have suggested that stress determination at high spatial resolution is necessary to achieve better insight. The present paper reports progress beyond the current state-of-the-art towards the identification of the near-surface intragranular residual stress state in cast and ground TiAl at a resolution better than 5μm. The semi-destructive ring-core drilling method using Focused Ion Beam (FIB) and Digital Image Correlation (DIC) was used for in-plane residual stress estimation in ten grains at the sample surface. The nature of the locally observed strain reliefs suggests that tensile residual stresses may have been induced in some grains by the unidirectional grinding process applied to the surface.


1997 ◽  
Vol 30 (4) ◽  
pp. 449-455 ◽  
Author(s):  
S. Spooner ◽  
X.-L. Wang

Near-surface measurement of residual strain and stress with neutron scattering complements and extends the surface residual stress measurements by X-ray diffraction. However, neutron diffraction measurements near surfaces are sensitive to scattering volume alignment, neutron beam wavelength spread and beam collimation and, unless properly understood, can give large fictitious strains. An analytic calculation and a numerical computation of neutron diffraction peak shifts due to partial burial of the sampling volume have been made and are compared with experimental measurement. Peak shifts in a strain-free nickel sample were determined for conditions where the sample surface is displaced so that the scattering gage volume is partially buried in the sample. The analytic and numerically computed peak shifts take into account the beam collimation, neutron source size, monochromator crystal mosaic spread and the collection of diffracted intensity with a linear position-sensitive counter.


2014 ◽  
Vol 606 ◽  
pp. 91-94
Author(s):  
Ondřej Kovářík ◽  
Petr Haušild ◽  
Zdenek Pala ◽  
Pavel Sachr ◽  
Vadim Davydov

The effect of grit-blasting on the development of residual stress field during the surface treatment of the cold rolled mild steel was characterized by means of neutron diffraction, nanohardness measurement and electron back-scatter diffraction. The neutron diffraction revealed strong residual compressive stress with the maximum value (about-100 MPa) situated just under the sample surface of the grit-blasted sample. The deformation profiles obtained by the nanoindentation and electron back-scatter diffraction (band slope signal) revealed the strain hardening after grit blasting up to depth of approximately 100 μm.


2018 ◽  
Vol 22 (3) ◽  
pp. 728-742
Author(s):  
Mehran Kamali Andani ◽  
Habib Daneshmanesh ◽  
Seyed Ahmad Jenabali Jahromi

In this study, a metal/polymer tri-layer composite was produced by direct adhesion (without adhesive), and mechanical locks were created using the warm rolling process. The effect of the process parameters including preheating temperature, rolling speed, thickness reduction, surface roughness, and the orientation of the surface scratches on the bond strength between layers was investigated. The results indicated that the suitable polymer fluidity and penetration, to provide stronger mechanical locks and higher bond strengths, could be achieved at an optimum preheating temperature and a rolling speed of 240°C and 36 r/min, respectively. In addition, the most appropriate surface pretreatment was obtained in the wire brush in the rolling direction mode with the surface roughness of 0.65 µm, so that the failure mechanism in this case was cohesive and the optimum thickness reduction was achieved at 40%. Furthermore, the mechanical properties of the sandwich sheet with highest bonding strength were evaluated.


2020 ◽  
Vol 29 (12) ◽  
pp. 8060-8069
Author(s):  
Wojciech J. Nowak

AbstractIn the present work, the influence of surface roughness on oxidation kinetics of AISI 316Ti stainless steel and its consequences in term of oxidation resistance were investigated. Namely, the effect of surface roughness on oxidation resistance was evaluated during different types of cyclic oxidation tests at 900 and 1000 °C. The obtained results revealed that alloy possessing higher surface roughness showed longer lifetime compared to that with lower surface roughness. It was also found that more severe cyclic conditions suppressed the positive effect of surface roughness on sample’s lifetime. The better oxidation resistance of rougher alloy was correlated with suppressed formation of Fe-rich nodules on ground surfaces and explained by the combined effect of introduced defects in the near-surface region and possible increase in residual stresses caused by mechanical surface preparation.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
J. J. Liou ◽  
T. I. El-Wardany

The kinematics of the deep rolling tool, contact stress, and induced residual stress in the near-surface material of a flat Ti-6Al-4V alloy plate are numerically investigated. The deep rolling tool is under multiaxis nonlinear motion in the process. Unlike available deep rolling simulations in the open literature, the roller motion investigated in this study includes penetrative and slightly translational motions. A three-dimensional finite element model with dynamic explicit technique is developed to simulate the instantaneous complex roller motions during the deep rolling process. The initial motion of the rollers followed by the penetration motion to apply the load and perform the deep rolling process, the load releasing, and material recovery steps is sequentially simulated. This model is able to capture the transient characteristics of the kinematics on the roller and contacts between the roller and the plate due to variations of roller motion. The predictions show that the magnitude of roller reaction force in the penetration direction starts to decrease with time when the roller motion changes to the deep rolling step and the residual stress distributions in the near-surface material after the material recovery step varies considerably along the roller path.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1408
Author(s):  
Yu-Hsuan Chung ◽  
Tai-Cheng Chen ◽  
Hung-Bin Lee ◽  
Leu-Wen Tsay

The effects of micro-shot peening on the rotating bending fatigue resistance of AISI 304 stainless steel (SS) were investigated in this study. The strain-hardening, surface roughness and induced residual stress were inspected and correlated with fatigue strength. Micro-shot peening caused intense strain-hardening, phase transformation and residual stress but was also accompanied by a minor increase in surface roughness. A nanograined structure, which was advantageous to fatigue resistance, was observed in the severe shot-peened layer. The absence of microcracks, minor increase in surface roughness, nanograined structure and induced high compressive residual stress in the shot-peened layer were responsible for the improved fatigue strength of AISI 304 SS.


2014 ◽  
Vol 966-967 ◽  
pp. 406-424
Author(s):  
Joe J. Liou ◽  
Tahany I. El-Wardany

Deep rolling process is a mechanical surface treatment that provides several advantages, such as low friction on the interface between the tool and workpiece in the process, controlled profile of induced compressive residual stress to enhance the HCF and LCF strength, enhancement of the stability of the near-surface structure at high temperature, and improvement of surface finish after the process. This paper investigates the deep rolling process under lubricated condition for a complex deep rolling path. A three-dimensional finite element model incorporating the strain hardening and strain rate effects on the material responses is developed to sequentially simulate the continuous multi-axis roller motion in the process. This model can capture the horizontal and normal forces acting on the roller so that a time-varying apparent coefficient of friction can be obtained. In addition, due to the complex roller path, the model also predicts a complex residual stress distribution in the near-surface material.


Author(s):  
S Anand Kumar ◽  
R Sundar ◽  
S Ganesh Sundara Raman ◽  
R Gnanamoorthy ◽  
R Kaul ◽  
...  

This paper deals with the effects of laser peening on fretting wear behaviour of a nickel-based superalloy, alloy 718, fretted against two different counterbody materials (alumina and SAE 52100 steel). Laser peening was carried out on alloy 718. Microstructural characterization of laser peened surface was done by electron back-scattered diffraction and transmission electron microscopy. Surface roughness, nanoindentation hardness, and residual stress of both laser peened and unpeened samples were determined. Fretting wear tests were conducted on unpeened and laser peened samples using two different counterbody materials (alumina and SAE 52100 steel balls). The results show that nanocrystallites formed in the surface and near-surface regions and compressive residual stress were induced after laser peening. Hardness increased due to grain refinement at the surface and near-surface regions. There was no significant change in the surface roughness. The laser peened sample exhibited lower tangential force coefficient values compared to unpeened samples at all loads, which may be attributed to higher hardness. Samples fretted against alumina counterbody exhibited higher tangential force coefficient compared to samples fretted against steel counterbody. Owing to increased surface hardness and higher compressive residual stress, laser peened samples exhibited lower fretting wear damage compared to unpeened samples. Due to tribochemical reactions, the wear volume of unpeened and laser peened samples fretted against alumina counterbody was higher than that of the samples fretted against steel counterbody.


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