The Experts below are selected from a list of 34419 Experts worldwide ranked by ideXlab platform
K Lu - One of the best experts on this subject based on the ideXlab platform.
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enhanced tribological performance of a gradient nanostructured interstitial free Steel
Wear, 2018Co-Authors: P F Wang, K LuAbstract:Abstract A gradient nanostructured (GNS) surface layer was fabricated on a commercial interstitial-free (IF) Steel by means of surface mechanical grinding treatment (SMGT). Reciprocating dry sliding tests of the GNS IF Steel in air at room temperature were carried out in comparison with the coarse-grained (CG) Sample. Worn surface morphologies, chemical compositions and worn subsurface microstructures were investigated for both IF Steel Samples. IF Steel with a GNS surface layer exhibits lowered coefficients of friction (COFs) and significantly enhanced wear resistance under high testing loads. The superior tribological performance of the GNS IF Steel Sample is attributed to the finer dynamic recrystallized grains, and the grain coarsening layer that can accommodate large plastic strain and suppress the formation of cracking vortical structure.
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low temperature plasma nitriding of aisi 304 stainless Steel with nano structured surface layer
Zeitschrift Fur Metallkunde, 2003Co-Authors: H W Zhang, Jian Lu, L. Wang, K LuAbstract:A nanostructured surface layer was produced on an AISI 304 stainless Steel plate by means of a surface mechanical attrition treatment (SMAT). Low-temperature plasma nitriding of the SMAT stainless Steel Sample was investigated in comparison with the coarse-grained Sample by using structural analysis (X-ray diffraction, scanning electron microscopy, and transmission electron microscopy) as well as mechanical property measurements. It shows a much thicker nitrided layer is formed on the SMAT Sample relative to that in the coarse-grained counterpart nitrided under the same condition. The nitrided layer in the SMAT Sample is composed of nanostructured austenite expansion and martensite expansion with high supersaturations of nitrogen. The surface hardness and the hardened surface layer thickness, as well as the abrasive and the adhesive wear resistances of the nitrided SMAT Sample are much enhanced relative to the nitrided coarse-grained Sample.
D L Atherton - One of the best experts on this subject based on the ideXlab platform.
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measurement of residual stress in Steel using the magnetic barkhausen noise technique
Ndt & E International, 1998Co-Authors: J Gauthier, Thomas W Krause, D L AthertonAbstract:Surface residual stresses on a structural beam Steel Sample were evaluated using a non-destructive technique based on the measurement of surface magnetic Barkhausen noise (MBN). MBN measurements were performed using a high resolution probe consisting of a small magnetic read head mounted between the poles of a ferrite U-core magnet. Applied stress magnitudes were correlated to MBN energy levels for calibration purposes. MBN energy measurements were done at various locations on the Steel Sample. The magnitude of the residual stress component along the Sample beam axis was evaluated across the width of the beam using these calibration curves. The range of sensitivity of the MBN signal to stress as defined by the calibration curves was limited by the direction of easy magnetization. The effect of stress on the MBN signal was interpreted in terms of the active 180° domain wall population. The validity of the residual stress results was confirmed experimentally using conventional methods: cutting and sectioning and hole drilling. Possible sources of residual stresses and their distribution on the structural Steel specimen are discussed.
M M Attar - One of the best experts on this subject based on the ideXlab platform.
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electrochemical assessing corrosion inhibiting effects of zinc aluminum polyphosphate zapp as a modified zinc phosphate pigment
Electrochimica Acta, 2008Co-Authors: R Naderi, M M AttarAbstract:Abstract Undesirable anti-corrosion performance of zinc phosphate pigment, the classical chromate replacement, has led researchers to take modification into account. Polyphosphate-based anti-corrosion pigments as a result of modification of zinc orthophosphate have been found to function much more efficiently. This study aimed to evaluate performance of Steel Samples immersed in 3.5% NaCl aqueous solution-containing zinc aluminum polyphosphate (ZAPP) pigment extract compared to those involving conventional zinc phosphate (ZP) pigment extract and also no pigment (blank) using electrochemical tests such as electrochemical impedance spectroscopy (EIS) and linear polarization (LP) as well as surface analysis. Impedance spectra and polarization curves revealed two different trends, showing the superiority of ZAPP pigment. Based on the results of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), presence of a precipitated layer on the surface was confirmed when Steel Sample was immersed into the solution-containing ZAPP.
C Stoeberl - One of the best experts on this subject based on the ideXlab platform.
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neutron diffraction investigation of an in plane biaxial fatigued stainless Steel Sample of cruciform geometry
Journal of Physics: Condensed Matter, 2008Co-Authors: Yu V Taran, A M Balagurov, S G Sheverev, J Schreiber, Alexander M Korsunsky, W J J Vorster, H Bomas, C StoeberlAbstract:Fatigue and fracture under multiaxial stresses are among the most important current research topics aimed at ensuring improved reliability of industrial components. An ex situ in-plane biaxial low cycle fatigued Sample of cruciform geometry from austenitic stainless Steel AISI 321 H was investigated on the FSD stress-diffractometer at the IBR-2 pulsed nuclear reactor by using the neutron strain scanner and the uniaxial stress rig. The phase composition of fatigued material was determined and the residual macrostresses and phase microstresses were measured. To the best of our knowledge, no neutron diffraction investigations of materials subjected to biaxial loading have been previously carried out. The first results of the neutron diffraction experiment are presented and discussed.
J Gauthier - One of the best experts on this subject based on the ideXlab platform.
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measurement of residual stress in Steel using the magnetic barkhausen noise technique
Ndt & E International, 1998Co-Authors: J Gauthier, Thomas W Krause, D L AthertonAbstract:Surface residual stresses on a structural beam Steel Sample were evaluated using a non-destructive technique based on the measurement of surface magnetic Barkhausen noise (MBN). MBN measurements were performed using a high resolution probe consisting of a small magnetic read head mounted between the poles of a ferrite U-core magnet. Applied stress magnitudes were correlated to MBN energy levels for calibration purposes. MBN energy measurements were done at various locations on the Steel Sample. The magnitude of the residual stress component along the Sample beam axis was evaluated across the width of the beam using these calibration curves. The range of sensitivity of the MBN signal to stress as defined by the calibration curves was limited by the direction of easy magnetization. The effect of stress on the MBN signal was interpreted in terms of the active 180° domain wall population. The validity of the residual stress results was confirmed experimentally using conventional methods: cutting and sectioning and hole drilling. Possible sources of residual stresses and their distribution on the structural Steel specimen are discussed.