scholarly journals Evaluation of Surface Integrity in 18CrNiMo7-6 Steel after Multiple Abrasive Waterjet Peening Process

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 844
Author(s):  
Yun Zou ◽  
Yafeng Xu ◽  
Jingkai Li ◽  
Shuhao Liu ◽  
Dong Wang ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Surface Properties ◽  
Compressive Residual Stress ◽  
Abrasive Waterjet ◽  
X Ray Diffraction ◽  
Surface Residual Stresses ◽  
3D Surface Topography ◽  
Insight Into ◽  
Strengthening Method

Abrasive waterjet peening (AWJP) as an important surface strengthening method can effectively improve surface properties. In this study, after multiple AWJP, the distribution of compressive residual stress and roughness on the surface of 18CrNiMo7-6 steel has been evaluated by an X-ray diffraction (XRD) method and a 3D surface topography system, respectively. Compared with the single AWJP, multiple AWJP can obviously increase the surface residual stresses (−1024 MPa to −1455 MPa) and the depth of maximum compressive residual stress (100 μm to 120 μm), as well as make the stress distribution more uniform. In terms of the surface roughness, multiple AWJP influences its uniform distribution and reduces the surface roughness (Sa = 0.69 μm), compared with a single AWJP (Sa = 2.96 μm), due to the smaller shot balls and a uniform deformation during multiple AWJP. In addition, we have studied the effects of multiple AWJP on the hardness of the surface layer. The results show that multiple AWJP increases the hardness by up to 15.9%, compared to the single AWJP. These studies provide useful insight into improving the surface properties of 18CrNiMo7-6 steel by multiple AWJP.

Characterization on Surface Properties of Ti–6Al–4V After Multiple Shot Peening Treatments

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Lechun Xie ◽  
Yan Wen ◽  
Liqiang Wang ◽  
Chuanhai Jiang ◽  
Vincent Ji
Keyword(s):  
Surface Roughness ◽  
Stress Distribution ◽  
Surface Properties ◽  
Shot Peening ◽  
Diffraction Method ◽  
Domain Size ◽  
Treatment Method ◽  
X Ray Diffraction ◽  
Obvious Effect ◽  
Surface Residual Stresses

As an important surface treatment method, shot peening (SP) can improve the surface properties effectively. In this work, after multiple SP treatments, the uniformity of the residual stress distribution and the domain size distribution on the surface of Ti–6Al–4 V have been investigated via an X-ray diffraction method. Compared with traditional SP treatments, the multiple SP can increase the surface residual stresses and make the stress distribution more uniform. In terms of the domain size, the multiple SP treatments mainly influence its uniform distribution, and there is no obvious effect to the values, which is due to the saturation status of SP process. In addition, the effects of multiple SP on the surface roughness and hardness have been studied. The results show that the multiple SP can reduce the surface roughness and increase the hardness in a certain extent comparing with the effect of traditional SP, which are ascribed to the smaller shot balls and the more homogeneous deformation during the process of multiple SP. Therefore, an appropriate multiple SP can improve the surface properties of Ti–6Al–4 V effectively.

scholarly journals Precision of the Residual Stress determined by X-ray Diffraction: Summery and Limits

2019 ◽  
Author(s):  
Eckehard Mueller
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Round Robin ◽  
Surface Treatments ◽  
X Ray Diffraction ◽  
Measurement Standard ◽  
Passenger Cars ◽  
Round Robin Test ◽  
X Ray ◽  
Mechanical Surface

Today components specially for passenger cars are weight optimized. Often it is done by mechanical surface treatments. Therefore, the amount of compressive residual stress induced by the treatment must be known. The measurement is very often done by x-ray diffraction. But how precise can you determine (and not directly measured) the amount? A big question is the calibration of the equipment. A specimen must be designed and calibrated by round robin test, because no measurement standard is available.

Effect of the Type of Grinding Wheel on the Surface Characteristics of a Titanium Alloy with Internal Coolant Supply

2019 ◽  
Vol 825 ◽  
pp. 92-98
Author(s):  
Nakatsuka Nagatoshi ◽  
Sumito Toyokawa ◽  
Atsushi Kusakabe ◽  
Shinya Nakatsukasa ◽  
Hiroyuki Sasahara
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Silicon Carbide ◽  
Titanium Alloy ◽  
Aluminum Oxide ◽  
Compressive Residual Stress ◽  
Surface Characteristics ◽  
Grinding Wheel

The objective of this paper is to clarify the effect of grinding surface characteristics in the grinding of a titanium alloy with a coolant supply from the inner side of the grinding wheel. In this paper, we selected a white aluminum oxide (WA) vitrified bonded grinding wheel and a green silicon carbide (GC) vitrified bonded grinding wheel, and compared their grinding characteristics. As a result, in the case of the GC vitrified bonded grinding wheel, the surface roughness decreased by about 54% and the compressive residual stress increased by about 128%.

A Study on the Fatigue Characteristics of Al6061-T651 by Shot Peening Velocity

2006 ◽  
Vol 326-328 ◽  
pp. 1093-1096 ◽  
Author(s):  
Won Jo Park ◽  
Sun Chul Huh ◽  
Sung Ho Park
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Fatigue Life ◽  
Shot Peening ◽  
High Speed ◽  
Compressive Residual Stress ◽  
Velocity Increase ◽  
Fatigue Characteristics ◽  
Height Increase ◽  
Small Steel

Small steel ball is utilized in Shot peening process. Called “shot ball” are shot in high speed on the surface of metal. When the shot ball hit the surface, it makes plastic deformation and bounce off, that increase the fatigue life by compressive residual stress on surface. In this study, the results of observation on the tensile strength, hardness, surface roughness, compressive residual stress and fatigue life of a shot peened Al6061-T651 were obtained. Experimental results show that arc height increase tremendously by shot velocity. Also, it shows that surface roughness, hardness, compressive residual stress and fatigue life increase as shot velocity increase.

scholarly journals Strategy of Residual Stress Determination on Selective Laser Melted Al Alloy Using XRD

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 451 ◽  
Author(s):  
Yujiong Chen ◽  
Hua Sun ◽  
Zechen Li ◽  
Yi Wu ◽  
Yakai Xiao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Residual Stresses ◽  
High Surface ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
Scanning Strategy ◽  
Surface Distribution ◽  
Finished Surface ◽  
Microstructural Morphology

Selective laser melting (SLM) is known to generate large and anisotropic residual stresses in the samples. Accurate measurement of residual stresses on SLM-produced samples is essential for understanding the residual stress build-up mechanism during SLM, while a dramatic fluctuation can be observed in the residual stress values reported in the literature. On the basis of studying the influence of surface roughness on residual stress measured using X-ray diffraction (XRD), we propose a procedure coupling XRD technique with pretreatment consisting of mechanical polishing and chemical etching. The results highlight that residual stresses measured using XRD on as-built SLM-produced samples with high surface roughness are significantly lower than those measured on samples with finished surface, which is due to the stress relaxation on the spiked surface of as-built samples. Surface distribution of residual stresses and the effect of scanning strategy were systematically investigated for SLM-produced AlSi10Mg samples. Microstructural morphology was observed at the interface between sample and building platform and was linked to the surface distribution of residual stresses. This procedure can help us accurately measure the residual stresses in SLM-produced samples and thus better understand its build-up mechanism during the SLM process.

Influence of Surface Roughness on the Quality of Data Obtained by Pseudo-Grazing Incidence X-Ray Diffraction

2006 ◽  
Vol 514-516 ◽  
pp. 1618-1622 ◽  
Author(s):  
Maria José Marques ◽  
J.C.P. Pina ◽  
A. Morão Dias
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Stress Gradient ◽  
Roughness Parameter ◽  
Diffraction Method ◽  
Grazing Incidence ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
Residual Surface Stress ◽  
X Ray

The conventional Bragg diffraction geometry, normally used to characterize the residual surface stress state, it is not suitable to evaluate surface treated materials and thin films. The X-ray path lengths through a surface layer or thin film are too short to produce adequate diffraction intensities in relation to the bulk or the substrate. Another limitation of the conventional technique appears when a residual stress gradient is present in the irradiated surface. The technique only enables the evaluation of the mean value of this gradient. In these cases, a recently proposed Pseudo-Grazing Incident X-ray Diffraction method would be better applicable. In this study, the Pseudo-Grazing Incidence X-ray Diffraction is applied to characterize the residual stress depth profiles of several AISI 4140 samples, which were prepared, by mechanical polishing and grinding, in order to present different surface roughness parameters, Ra. The experimental results lead to the conclusion that the surface roughness limits the application of the Pseudo-Grazing Incidence methodology to a minimum X-ray incident angle. This angle is the one that enables a mean X-ray penetration depth with the same order of magnitude of the sample surface roughness parameter, Ra.

Characteristics of Residual Stress in P92 Steel Welds

2007 ◽  
Vol 26-28 ◽  
pp. 1175-1180
Author(s):  
Keun Bong Yoo ◽  
Hyun Sun Choi ◽  
Eui Hyun Kim ◽  
Jae Hoon Kim
Keyword(s):  
Residual Stress ◽  
Compressive Residual Stress ◽  
Diffraction Method ◽  
Welding Residual Stress ◽  
Distribution Characteristics ◽  
X Ray Diffraction ◽  
P92 Steel ◽  
X Ray ◽  
Steel Welds ◽  
Directional Difference

Welding residual stress has important influence on the performance of engineering components. In this paper, the residual stress and FWHM were measured by X-ray diffraction method to investigate characteristics for P92 steel welds. The aim of the study is to estimate the residual stress and FWHM distribution characteristics. A compressive residual stress distributed as a function of depth has a different pattern in welds and base metal. A large tensile residual stress occurs welds and near the HAZ, but approaches gradually zero as away from the welding center. Residual stress and FWHM undergo rapid relaxation after PWHT. Also, FWHM is a scalar quantity without any directional difference and is proportional to hardness on the whole.

Modification of Microstrucure and Residual Stress on Friction Welding Surface of Titanium Alloy by Water-Jet Cavitation Peening

2011 ◽  
Vol 317-319 ◽  
pp. 429-435 ◽  
Author(s):  
Dong Ying Ju ◽  
Xin Mao Fu ◽  
Shun Na ◽  
Bing Han ◽  
Xiao Hu Deng
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Welded Joints ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Water Jet ◽  
X Ray Diffraction ◽  
X Ray ◽  
Welding Surface ◽  
Scanning Electron

Water jet cavitation peening is applied to improve the strength and mechanical properties of the friction-welded joints of titanium alloys. Scanning electron microscopy observations of the microstructure of the welded joints and welded area before/after water jet cavitation peening confirm slip dislocation at the microstructure near the surface of the specimens. The residual stress on the surface of the welded joint is measured by X-ray diffraction. The results indicate the effect of peening time on the strength of compressive residual stress.

Determination of Surface Residual Stresses in Machined Ceramics Using Indentation Fracture

1996 ◽  
Vol 118 (4) ◽  
pp. 483-489 ◽  
Author(s):  
Y. Ahn ◽  
S. Chandrasekar ◽  
T. N. Farris
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Soda Lime Glass ◽  
X Ray Diffraction ◽  
Reliable Technique ◽  
X Ray ◽  
Indentation Technique ◽  
Vickers Indenter ◽  
Surface Residual Stresses ◽  
Zn Ferrite

Machining produces surface residual stresses which significantly influence the strength and wear resistance of ceramic components. As new methods are developed for machining ceramics, a quick and reliable technique for measurement of residual stresses would be valuable in assessing the viability of these methods from a residual stress perspective. The residual stresses on ground and polished (i.e. machined) surfaces of soda-lime glass, Ni-Zn ferrite, and silicon nitride have been measured using an indentation technique with a Vickers indenter. In this technique, the surface extent of the median/radial cracks produced by the Vickers indenter in machined and in annealed ceramics are measured. These are then combined with a fracture mechanics analysis to estimate the surface residual stresses produced by machining. In order to determine the validity of the indentation technique for estimating machining residual stresses, these stresses were also measured using an X-ray diffraction and a deflection method. The residual stress values determined using the indentation technique in the machined ceramics were found to be reasonably close to those obtained from the X-ray diffraction and deflection methods. Since the indentation technique is relatively simple and easily applied, it offers a promising method for evaluating surface residual stresses in machined ceramics.

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