Effects of Strong Carbide-Forming Elements on Low Temperature Salt-Bath Chromizing

2011 ◽  
Vol 214 ◽  
pp. 646-650 ◽  
Author(s):  
Jin Ling Ye ◽  
Feng Ye
Keyword(s):  
Low Temperature ◽  
Layer Thickness ◽  
Plasma Nitriding ◽  
White Layer ◽  
Salt Bath ◽  
Chromium Concentration ◽  
X Ray Diffraction ◽  
White Layer Thickness ◽  
X Ray ◽  
Scanning Electron

The microstructure, phase structure, white layer thickness and chromium concentration, microhardness of the chromized layer of T10 steel and 3Cr2W8V steel by low temperature salt-bath chromizing with plasma nitriding are contrasted. The chromizing process is investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD). Results show that the strong carbide-forming elements (Cr, W, V) obstruct the diffusion of chromium and carbon, the white layer thickness and microhardness, surface chromium concentration of the chromized layer are reduced. A chromized layer of T10 steel with average 7.3μm in thickness, 84.47% in surface chromium concentration and 1300HV-1400HV in microhardness is formed on the substrate by chromizing at 610°C for 6h, as compared to the chromized layer of 3Cr2W8V steel with average 3.3μm in thickness, 74.27% in surface chromium concentration and 1200HV-1300HV in microhardness.

Effects of Plasma Nitriding on Low Temperature Salt-Bath Chromizing of W18Cr4V Steel

2011 ◽  
Vol 213 ◽  
pp. 543-547
Author(s):  
Jin Ling Ye ◽  
Feng Ye
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Plasma Nitriding ◽  
Xrd Analysis ◽  
Salt Bath ◽  
Chromium Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Effects of plasma nitriding on low temperature salt-bath chromizing of W18Cr4V steel is studied .The chromizing process is investigated by means of optical microscopy(OM), scanning electron microscopy(SEM), X-ray diffraction (XRD). Results show that the specimens are chromized successfully by low temperature salt-bath subjected to plasma nitriding. A chromized layer with average 3.3μm in thickness and 1200HV-1300HV in microhardness is formed on the substrate by chromizing at 610°C for 6h. XRD analysis show that the chromized layer is composed of Cr23C6, CrN, Cr/Fe, (Cr, Fe)7C3 , (Cr, Fe)2N and the surface chromium concentration reaches 77.67%.

Magnesium Nitrate as Additive for Synthesis of Mg(OH)2 Nanoparticles

2012 ◽  
Vol 198-199 ◽  
pp. 99-102
Author(s):  
Qing Gang Kong ◽  
Hai Yan Qian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Magnesium Nitrate ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size And Morphology ◽  
Scanning Electron

Magnesium nitrate was used as additive for synthesis of Mg(OH)2 (MH) nanoparticles at low temperature (70°C). Mg(OH)2 nanoparticles have platelet-like structure and approximately 40-60nm in thicknesses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase. The supersaturation degree of solution effects the size and morphology of MH nanoparticles.

SiO2ZrO2 Thin Films as Low Temperature NO2 and O3 Sensors

2015 ◽  
Vol 1088 ◽  
pp. 81-85 ◽  
Author(s):  
T.N. Myasoedova ◽  
Victor V. Petrov ◽  
Nina K. Plugotarenko ◽  
Dmitriy V. Sergeenko ◽  
Galina Yalovega ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Operating Temperatures ◽  
Scanning Electron

Thin SiO2ZrO2films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO2in the SiO2matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO2and O3impurity in air at lower operating temperatures in the range of 30-60°C.

Properties of Boride Layer on Boridesae 1035 Steel by Molten Salt

2013 ◽  
Vol 467 ◽  
pp. 116-121 ◽  
Author(s):  
Alaeddine Kaouka ◽  
Omar Allaoui ◽  
Mourad Keddam
Keyword(s):  
Layer Thickness ◽  
Steel Substrate ◽  
Kinetic Studies ◽  
Salt Bath ◽  
Boride Layer ◽  
Process Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Parabolic Relationship ◽  
Borided Steel

Properties of borided SAE 1035 steel have been investigated during boriding treatment, which was carried out in slurry salt bath at temperature range from1073 to 1273K for 2, 4 and 8 h. The presence of both FeB and Fe2B phases formed on the surface of steel substrate was confirmed by X-ray diffraction. Scanning electron microscopy (SEM) and optical microscopy examinations showed that boride layers have saw-tooth and columnar morphology. It has been shown that the thickness of boride layers increased when the time and temperature process increased, its value ranged from 20 to 387 μm. The hardness value of the boride layer was about 1760±200 HV0.1, while the hardness of un-borided steel was about 225±20 HV0.1. The kinetic studies showed a parabolic relationship between layer thickness and process time. Depending on temperature and layer thickness.

Corrosion Behavior of Fe-12Cr-2Mo Stainless Steel in Na2SO4-50%NaCl with Flowing Ar-20%O2 Environments at High Temperature

2015 ◽  
Vol 1107 ◽  
pp. 727-732
Author(s):  
Muhamad Izhar Sahri ◽  
Norinsan Kamil Othman ◽  
Abdul Razak Daud ◽  
Azman Jalar
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
High Temperature ◽  
Chromium Concentration ◽  
Oxide Scales ◽  
X Ray Diffraction ◽  
Salt Mixture ◽  
Cross Sectional ◽  
X Ray ◽  
Scanning Electron

The behavior of Fe-12Cr-2Mo stainless steel exposed isothermally in tube furnace at 700°C for 10 h had been studied in different environments; of mixed environment (Ar-20%O2 with coated Na2SO4-50%NaCl salts), molten salt (Na2SO4-50%NaCl) and dry oxygen (Ar-20%O2) atmospheres. The exposed samples were characterized by using optical microscopy (OM), scanning electron microscope (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD). The results indicated that, sample exposed in mixed environments undergoes highest corrosion rate compared with other samples. The main phase exists in all samples generally were iron-rich oxides which non-protective and thick. Conversely, EDX analysis on cross-sectional samples revealed the Cr-enrichment developed underneath the iron-rich oxide scales as the chromium concentration increases towards near the substrate. In presence of salt mixture, the oxide scales undergo spallation, however there is no crack observed. The catastrophic corrosion sample was occurred in combined environment due to the oxidation induced by the chloridation and sulfidation phenomena as well.

Effect of Doping Cation Valencies on Low Temperature Performance of LiFePO4/C

2011 ◽  
Vol 391-392 ◽  
pp. 935-939
Author(s):  
Ning Li ◽  
Bo Rong Wu ◽  
Chuan Xiong Zhou ◽  
Yong Huan Ren ◽  
Chun Wei Yang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Low Temperature ◽  
Metal Ions ◽  
Electrode Polarization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Temperature Performance ◽  
The One ◽  
Scanning Electron

The doped and undoped LiFePO4/C samples are prepared by two-step solid-state reaction. The X Ray Diffraction (XRD) results indicate that metal ions are successfully doped in LiFePO4 without any unexpected phase. The Scanning Electron Microscope (SEM) shows that the particle morphologies of samples are near-spherical with about 200-300nm size which can be observed in all samples. The electrochemical tests indicate that doping oversize ions will increase electrode polarization. The limitation of the Li+ migration is intensified by doping metal ions with high valence. LiFePO4/C samples doped with Mn2+ and Ti4+behave better at low temperature, especially the one doped with Ti4+. Battery with this Ti4+doped material can yield 77mAhg-1 when discharge at -20°C and 0.5C, about 26mAhg-1 higher than the undoped one.

Substrate Effect on Well-Aligned ZnO Nanorods Growth Using a Low Temperature Solution Method

2015 ◽  
Vol 1109 ◽  
pp. 491-494
Author(s):  
J. Rouhi ◽  
M.H. Mamat ◽  
Kevin Alvin Eswar ◽  
F.S. Husairi ◽  
Salman A.H. Alrokayan ◽  
...  
Keyword(s):  
Low Temperature ◽  
Solution Method ◽  
Zno Nanorods ◽  
Substrate Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Radio Frequency Sputtering ◽  
Temperature Solution ◽  
Scanning Electron ◽  
Seed Layers

The effect of various substrates on the morphology of ZnO nanorods synthesized by a low temperature solution method has been investigated. ZnO seed layers on the substrates were prepared by radio-frequency sputtering. ZnO nanorods have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM. FESEM results showed that hexagon-shaped ZnO nanorods with a diameter in the range of 30 nm to 80 nm and a length of about 1 μm were formed. The sharp (0002) peak in the XRD spectra indicates that the synthesized nanorods are single crystalline, grown along the [0001] direction. These findings have shown that the morphology of ZnO nanorods strongly depend on the substrate.

scholarly journals Anticorrosion Properties of the Low-Temperature Glow Plasma Nitriding Layer on AISI 904L Austenitic Stainless Steel in Hydrofluoric Acid Obtained at Various NH3 Pressures

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1156 ◽  
Author(s):  
Wei Shi ◽  
Jiaxu Wang ◽  
Ruyi Jiang ◽  
Song Xiang
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Plasma Nitriding ◽  
Corrosion Performance ◽  
X Ray Diffraction ◽  
Kelvin Probe ◽  
X Ray ◽  
Glow Plasma ◽  
Anticorrosion Properties

A low-temperature (400 °C) glow plasma nitriding layer on AISI 904L austenitic stainless steel was obtained at various NH3 pressures and studied using electrochemical method, X-ray diffraction, and scanning Kelvin probe. The pressure of NH3 dominated the microstructure of the nitriding layer. The saturation degree of γN controlled corrosion performance and microhardness. Insufficient NH3 pressure (<100 Pa) resulted in discontinuous nitride caking coverage, whereas excessive NH3 pressure (>100 Pa) facilitated the transformation of the nitriding layer to harmful nitrides (CrN) due to a localized overheating effect caused by the over-sputtering current.

LOW TEMPERATURE HYDROTHERMAL SYNTHESIS OF BISMUTH SODIUM TITANATE NANOPOWDERS

2005 ◽  
Vol 04 (04) ◽  
pp. 637-641 ◽  
Author(s):  
PUSIT POOKMANEE ◽  
SUKON PHANICHPHANT
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Sodium Titanate ◽  
Bismuth Sodium Titanate ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
X Ray ◽  
Calcination Step ◽  
Bismuth Sodium ◽  
Scanning Electron

Nanopowders bismuth sodium titanate ( Bi 0.5 Na 0.5 TiO 3, BNT ) were synthesized by the hydrothermal route at low temperature in the range of 150-200°C with different holding periods of 5-20 h. Bismuth nitrate, sodium nitrate and titanium (IV) isopropoxide were used as the starting materials. The phase structure was examined using X-ray diffraction (XRD). The morphology of the formed nanopowders was investigated by scanning electron microscopy (SEM). Rhombohedral BNT nanopowders was obtained without calcination step. The spherical nanopowders were agglomerated. The average sizes of particle size were about 50-200 nm.

The Effect of Low-Temperature Glow Discharge Nitriding of Duplex Stainless Steel on Absorption and Desorption of Hydrogen

2011 ◽  
Vol 183 ◽  
pp. 71-80 ◽  
Author(s):  
Bartosz Gołębiowski ◽  
Tadeusz Zakroczymski ◽  
Wiesław Świątnicki
Keyword(s):  
Electron Microscopy ◽  
Stainless Steel ◽  
Low Temperature ◽  
Glow Discharge ◽  
Hydrogen Absorption ◽  
Nitrided Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Absorption Of Hydrogen

The effect of the nitrided layers produced on ferritic-austenitic stainless steel to hydrogen absorption and desorption was studied. The layers were formed during low-temperature glow discharge nitriding process. The microstructure of steel after nitriding and cathodic hydrogen charging was investigated by means of X-ray diffraction and by scanning electron microscopy (SEM). One of the objectives was to determine the quantity of hydrogen absorbed by the steel samples with and without the nitrided layer. To determine the quantity of the diffusible and trapped hydrogen, the electrochemical permeation and desorption methods were used. The influence of the nitrided layer on the entry, absorption and desorption of hydrogen was determined. The results revealed that the nitrided layer hinders absorption of hydrogen into and desorption of hydrogen from the membrane.

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