scholarly journals Evaluation of high-temperature corrosion on 13CrMo4-5 steel operated in the power industry

2018 ◽  
Vol 4 (21) ◽  
pp. 335-343
Author(s):  
Monika Gwoździk
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
High Temperature Corrosion ◽  
X Ray ◽  
Term Operation ◽  
Scanning Electron

The paper presents results of studies of steel and the oxide layer formed during a long-term operation (t=130,000h) on 13CrMo4-5 steel at an elevated temperature (T=455°C). The oxide layer was studied on a surface and a cross-section at the inner site of the pipe (in the flowing medium – steam side). The paper contains results of studies such as: light microscopy, scanning electron microscopy, X-ray phase analysis.

Analysis of crystallite size changes in a hematite and magnetite formed on steel used in the power idustry

2017 ◽  
Vol 1 (21) ◽  
pp. 65-73
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Cross Section ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula ◽  
Pipe Outlet

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on 10CrMo9-10 steel at an elevated temperature (T = 545° C, t = 200,000 h). This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. The oxide layer was studied on a surface and a cross-section at the outer and inner site on the pipe outlet, at the fire and counter-fire wall of the tube. X-ray studies were carried out on the surface of a tube, then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer.

Long-Term SOFCs Button Cell Testing

2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Gianfranco DiGiuseppe ◽  
Li Sun
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Current Density ◽  
Electrochemical Impedance ◽  
X Ray ◽  
Total Polarization ◽  
Scanning Electron

This paper reports a new study where relatively long-term tests of about a 1000 h are performed on several planar anode-supported solid oxide fuel cells. The cell electrochemical behaviors are studied by using voltage-current density measurement, electrochemical impedance spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The cell total polarization obtained from electrochemical impedance spectroscopy results is shown to be consistent with the area-specific resistance calculated from the voltage-current density curve over the course of the test. In addition, a four-constant phase element model is used to analyze the cell components resistances at different intervals over the lifetime of the test. Scanning electron microscopy and energy-dispersive X-ray spectroscopy are used postmortem to determine if any damages occurred to the cells and to determine if any change in composition occurred to the lanthanum strontium cobalt ferrite cathode. This study shows that the tested cells remain stable with a relatively small increase in the cell total polarization but with no increase in ohmic resistance.

Effects of Ultrasonic Impact Treatment on Performance of Armor Steel Welded Joints

2014 ◽  
Vol 602-605 ◽  
pp. 12-16
Author(s):  
Ge Zhou Li ◽  
Xin Yuan Zhou ◽  
Yong Wang ◽  
Yan Fei Huang ◽  
Wei Zhang
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Scanning Electron Microscopy ◽  
Cross Section ◽  
Steel Weld ◽  
Ultrasonic Impact Treatment ◽  
X Ray ◽  
Armor Steel ◽  
Steel Welds ◽  
Scanning Electron

In this paper, the armor steel welds were treated by ultrasonic impact equipment. The stress, hardness and cross section morphologies of the samples under different impact frequencies were measured by electrolytic polishing machines, X-ray stress analyzer and scanning electron microscopy (SEM). The results show that a clear grain refinement layer is formed on the surface of armored steel weld after ultrasonic impact treatment. Its hardness and residual stress all significantly improve. The ultrasonic impact treatment of different frequencies has greatly affect on ultrasonic impact effect, the higher the frequencies are, the better the ultrasonic impact effects are.

Analysis of Crystallite Size Changes in an Oxide Layer Formed on Steel during Long-Term Operation at an Elevated Temperature

2015 ◽  
Vol 227 ◽  
pp. 381-384
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Computer Software ◽  
Phase Identification ◽  
X Ray ◽  
Term Operation ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Scherrer Formula

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on steel operated for a long time at an elevated temperature. This value was determined by a method based on analysis of the diffraction line profile, according to a Scherrer formula. X-ray studies were carried out on the inner surface of a tube (in a flowing medium environment), then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer. X-ray phase analysis was performed using a SEIFFERT 3003 T/T X-ray diffractometer, with a cobalt tube of λCo = 0.17902 nm wavelength. XRD measurements were performed in the 15÷120° range of angles with an angular step of 0.1° and the exposure time of 4 s. To interpret the results (to determine the 2θ position and the total intensity INet) the diffractograms were described by a Pseudo Voight curve using the Analyze software. A computer software and the PDF4+2009, DHN PDS crystallographic database were used for the phase identification.

Characteristic of Crystallite Sizes and Lattice Deformations Changes in the Oxide Layer Formed on Steel Operated for a Long Time at an Elevated Temperature

2013 ◽  
Vol 203-204 ◽  
pp. 204-207 ◽  
Author(s):  
Monika Gwoździk
Keyword(s):  
Phase Composition ◽  
Elevated Temperature ◽  
Oxide Layer ◽  
Flue Gas ◽  
Phase Identification ◽  
X Ray ◽  
Term Operation ◽  
Long Time ◽  
Crystallite Sizes

The paper presents results of studies on the phase composition, crystallite sizes and lattice deformations of oxide layers formed during a long-term operation on X10CrMoVNb9-1 steel. Test specimens were taken from a live steam pipeline operated at 535°C for 70,000 hours. X-ray studies were carried out on the tube outside surface (on the flue gas side), then the layer’s surface was polished and the diffraction measurements repeated to reveal differences in the originated oxides layer. X-ray phase analysis was performed using a SEIFFERT 3003 T/T X-ray diffractometer, with a cobalt tube of λCo= 0.17902nm wavelength. crystallographic database were used for the phase identification.

Microstructure-Controlled Multilayer PZT Actuators: Effects of Cyclic Actuation on Crystallographic Structure

2005 ◽  
Vol 888 ◽  
Author(s):  
Jens Müller ◽  
Stephanie A. Hooker ◽  
Davor Balzar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electric Fields ◽  
Sintering Temperature ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wall Movement ◽  
Scanning Electron

ABSTRACTIn this study, multilayered PbTixZr1-xO3 (PZT) samples (produced at sintering temperatures in the range of 1175 °C to 1325 °C) were electrically fatigued by long-term exposure (∼106 cycles) to electric fields, and the parameters of initial and remnant polarization were estimated. Changes in the crystallographic microstructure as a function of sintering temperature Ts were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD) to gain insight on fatigue mechanisms and their prevention. Results showed that domain wall movement was facilitated in samples processed at TS less than 1250 °C, and that such samples were more resistant to electrical fatigue.

Elevated temperature erosive wear behavior of superalloy coatings deposited using cold spray technology

2021 ◽  
pp. 146442072110370
Author(s):  
BV Padmini ◽  
Mahantayya Mathapati ◽  
HB Niranjan ◽  
P Sampathkumaran ◽  
S Anand Kumar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elevated Temperature ◽  
Cold Spray ◽  
Vapour Deposition ◽  
Elevated Temperatures ◽  
Thermal Power ◽  
X Ray ◽  
American Society ◽  
Scanning Electron

The boiler tube components in thermal power plants and steam generating systems suffer from erosion and corrosion problems and are even today posturing a grave threat to industries, resulting in forced outages. Unrelenting efforts to decrease the components’ maintenance costs have been made by protecting with coatings. Among the various coating methodologies are thermal spray, chemical vapour deposition (CVD), physical vapour deposition (PVD), etc., in vogue. However, recently, the additive manufacturing-based cold spray technique is gaining interest among material scientists, incorporating high-velocity impacts associated with the low-temperature regime. Nickel-based superalloy Inconel 625 has been chosen and cold sprayed on The American Society of Mechanical Engineers (ASME) T11 and T22 boiler steels. The coated surface is characterized by scanning electron microscopy and energy dispersive X-ray analysis (EDAX), X-ray diffraction, micro-hardness, and elemental X-ray mapping techniques. The solid particle erosion studies have been carried out both at room and an elevated temperature of 700 °C as per American Society for Testing and Materials (ASTM) standard for 30°C and 90 °C impact angles. An optical profilometer has been used to evaluate the erosion volume loss. The results showed that the coated samples exhibit superior erosion resistance than the uncoated samples at both room and elevated temperatures. The erosion data obtained have been substantiated using scanning electron microscopy by analyzing the damage features and correlating with the erosion data.

Selective Laser Sintering of Different Powders of Co-Cr-Mo

2014 ◽  
Vol 802 ◽  
pp. 338-342
Author(s):  
Claudinei dos Santos ◽  
Paula Cipriano da Silva ◽  
Luciane Carvalho de Paula ◽  
Alexandre Fernandes Habibe ◽  
Jefferson Fabrício C. Lins ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Size Distribution ◽  
Cross Section ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

In this work, different commercial Co-Cr-Mo powders were used in selective laser sintering. Commercial powders with particle size distribution between 5 and 50μm were sintered by laser sintering, and characterized. The samples were characterized by X-ray diffraction, indicating Co as the only crystalline phase. Relative density was measured by Archimedes method showing values between 90 and 96% of TD, depending on the powder used. Scanning electron microscopy performed on the cross section of the sintered samples, indicates that the microstructural features are similar, but the surface finish of the samples differ significantly due to the morphology and size distribution of the starting powders used.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

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