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.

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.

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.

Evaluation of High-Temperature Corrosion on 16Mo3 Steel Long-Term Operated at an Elevated Temperature

2015 ◽  
Vol 227 ◽  
pp. 397-400
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Tube Wall ◽  
Computer Software ◽  
Optical Microscope ◽  
Composition Analysis ◽  
Phase Identification ◽  
Oxide Layers ◽  
X Ray

The paper contains results of studies on the formation of oxide layers on steel long-term operated at an elevated temperature. The oxide layer was studied on a surface and a cross-section at the inner surface of the tube wall. Thorough examinations of the oxide layer carried out on the inside surface of tube wall comprised:microscopic examinations of the oxide layer were performed using an Olympus GX41 optical microscope,thickness measurements of formed oxide layers,chemical composition analysis of deposits/oxides using a Joel JSM-6610LV scanning electron microscope (SEM) working with an Oxford EDS electron microprobe X-ray analyser,X-ray (XRD) measurements; the layer was subject to measurements using a Seifert 3003T/T X-ray diffractometer and the radiation originating from a tube with a cobalt anode (λCo=0.17902 nm). X-ray studies were performed, comprising measurements in a symmetric Bragg-Brentano geometry (XRD). 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 the diffractograms were described by a Pseudo Voight curve using the Analyze software. DHN PDS and PDF4+2009 computer software and crystallographic database were used for the phase identification.

scholarly journals Changes of crystallite sizes in the oxide layer forming during long-term operation of 10CrMo9-10 steel

2017 ◽  
Vol 3 (20) ◽  
pp. 289-296
Author(s):  
Monika Gwoździk
Keyword(s):  
Oxide Layer ◽  
Tube Wall ◽  
X Ray Diffraction ◽  
Oxide Layers ◽  
X Ray ◽  
Term Operation ◽  
Long Time ◽  
Crystallite Sizes ◽  
Scherrer Formula

The paper contains results of the studies on X-ray diffraction analysis XRD (studying the phase composition, crystallite sizes) of oxide layers on 10CrMo9-10 steel, operated for a long time at an elevated temperature (T = 525°C, t = 200,000 h). The oxide layer was studied on a surface and a cross-section at the outer on the inlet both on the fire and counter-fire side of the tube wall surface. X-ray studies were carried out on the outer surface of a tube, and then the layer surface was polished down and the diffraction measurements were performed again to determine crystallite size in oxide layers. Based on the width and the position of the main coat and substrate reflections, the size of the crystallites was determined using the Scherrer formula.

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 and Lattice Deformations Changes in an Oxide Layer on P91 Steel / Analiza Zmian Wielkosci Krystalitów I Odkształcen Sieciowych W Warstwie Tlenków Na Stali P91

2013 ◽  
Vol 58 (1) ◽  
pp. 31-34 ◽  
Author(s):  
M. Gwozdzik ◽  
Z. Nitkiewicz
Keyword(s):  
Oxide Layer ◽  
Diffraction Line ◽  
P91 Steel ◽  
Oxide Layers ◽  
X Ray ◽  
Term Operation ◽  
Relaxation Of Stresses ◽  
Inner Surface ◽  
Long Time ◽  
Crystallite Sizes

The paper contains results of studies on X-ray diffraction analysis XRD (studying the phase composition, crystallite sizes and lattice deformations) of oxide layers on P91 steel, operated for a long time at an elevated temperature (T = 535°C, t = 70,000 h). X-ray studies were carried out on the inner surface of a tube, and then the layer surface was polished down to 3.5 μm and the diffraction measurements were performed again to determine individual oxide layers. It has been found that a three-zone oxide layer is formed as a result of long-term operation of P91 steel at the temperature of 535°C. Hematite occurs on the inner surface of the tube. Then magnetite appears below hematite. Going deeper into the layer there is a spinel, i.e. a mixture of magnetite and chromite. A visible decay of total intensity for Fe2O3 is observed already at the polishing depth of 3.5 μm. In the case of Fe3O4 and FeCr2O4 an increase in total intensity is observed already from 7 μm, what manifests in narrowing the diffraction line and hence in increasing the crystallites size and in the relaxation of stresses in this oxide layer. The broadening of a diffraction line caused by a small size of crystallites is expressed by the Scherrer relationship. Instead, the β2 broadening resulting from lattice distortions (relaxation of stresses) was determined from the Taylor relationship.

scholarly journals The Effect of Long-Term Impact of Elevated Temperature on Changes in Microstructure and Mechanical Properties of HR3C Steel

2016 ◽  
Vol 61 (2) ◽  
pp. 761-766 ◽  
Author(s):  
A. Zieliński ◽  
M. Sroka ◽  
A. Hernas ◽  
M. Kremzer
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Microstructure And Mechanical Properties ◽  
Transmission Electron ◽  
Quantitative Identification ◽  
Working Parameters ◽  
Long Term Impact

Abstract The HR3C is a new steel for pressure components used in the construction of boilers with supercritical working parameters. In the HR3C steel, due to adding Nb and N, the compounds such as MX, CrNbN and M23C6 precipitate during service at elevated temperature, resulting in changes in mechanical properties. This paper presents the results of microstructure investigations after ageing at 650, 700 and 750 °C for 5,000 h. The microstructure investigations were carried out using scanning and transmission electron microscopy. The qualitative and quantitative identification of the existing precipitates was carried out using X-ray analysis of phase composition. The effect elevated temperature on microstructure and mechanical properties of the examined steel was described.

Effect of N2 Flow Rate on Structure and Morphology of (Ti,Cr)N Thin Films Deposited by Unbalanced Magnetron Co-Sputtering

2012 ◽  
Vol 488-489 ◽  
pp. 432-436
Author(s):  
Chutima Paksunchai ◽  
Somyod Denchitcharoen ◽  
Surasing Chaiyakun ◽  
Pichet Limsuwan
Keyword(s):  
Thin Films ◽  
Flow Rate ◽  
Columnar Structure ◽  
Root Mean Square Roughness ◽  
Cross Sectional ◽  
X Ray ◽  
Force Microscopy ◽  
Unbalanced Magnetron ◽  
Crystallite Sizes ◽  
Scherrer Formula

The (Ti,Cr)N thin films were deposited with various N2 flow rates on silicon wafers by reactive unbalanced magnetron co-sputtering without heating and biasing substrates. The effects of N2 flow rate on the structure and morphologies of the films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM) and energy dispersive x-ray spectroscopy (EDS). The results revealed that the (Ti,Cr)N thin films formed solid solutions with the fcc structure. The crystallite sizes calculated from Scherrer formula are about 13 nm. The root-mean-square roughness (Rrms) and the thickness (Tth) of the films were slightly decreased with the increase in N2 flow rate. The cross-sectional morphology showed columnar structure corresponding to zone 2. In addition, the N atomic concentration was also increased with the increase in N2 flow rate.

X-ray diffraction analysis of stacking and twin faults in f.c.c. metals: a revision and allowance for texture and non-uniform fault probabilities

2000 ◽  
Vol 33 (2) ◽  
pp. 296-306 ◽  
Author(s):  
L. Velterop ◽  
R. Delhez ◽  
Th. H. de Keijser ◽  
E. J. Mittemeijer ◽  
D. Reefman
Keyword(s):  
Diffraction Analysis ◽  
Line Profile ◽  
Intensity Distribution ◽  
Original Description ◽  
Powder Pattern ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Line Profile ◽  
Crystallite Sizes ◽  
Diffraction Peaks

A revision is presented of the original description by Warren [X-ray Diffraction, (1969), pp. 275–298. Massachusetts: Addison-Wesley] of the intensity distribution of powder-pattern reflections from f.c.c. metal samples containing stacking and twin faults. The assumptions (in many cases unrealistic) that fault probabilities need to be very small and equal for all fault planes and that the crystallites in the sample have to be randomly oriented have been removed. To elucidate the theory, a number of examples are given, showing how stacking and twin faults change the shape and position of diffraction peaks. It is seen that significant errors may arise from Warren's assumptions, especially in the peak maximum shift. Furthermore, it is explained how to describe powder-pattern reflections from textured specimens and specimens with non-uniform fault probabilities. Finally, it is discussed how stacking- and twin-fault probabilities (and crystallite sizes) can be determined from diffraction line-profile measurements.

scholarly journals Electrochemical and physical characterization of Ni-Cu-Fe alloy for chlor-alkali hydrogen cathodes

2003 ◽  
Vol 28 (2) ◽  
pp. 21-28 ◽  
Author(s):  
M. J. Giz ◽  
M. C. Marengo ◽  
E. A. Ticianelli ◽  
E. R. Gonzalez
Keyword(s):  
Low Ph ◽  
Physical Characterization ◽  
Energy Dispersive Analysis ◽  
Positive Aspect ◽  
X Ray ◽  
Term Operation ◽  
Different Temperatures ◽  
X Ray Absorption

This work describes the development of an alternative acetate bath for the electrochemical codeposition of Ni-Cu-Fe electrodes at low pH that is stable for several weeks and produces electrodes with good performance for chlor-alkali electrolysis. Physical characterization of the electrode surface was made using X ray absorption spectroscopy (XAS), scanning electron microscopy (SEM) and energy dispersive analysis (EDX). The evaluation of the material as electrocatalyst for the hydrogen evolution reaction (her) was carried out in brine solution (160 g L-1 NaCl + 150 g L-1 NaOH) at different temperatures through steady-state polarization curves. The Ni-Cu-Fe electrodes obtained with this bath have shown low overpotentials for the her, around 0.150 V at 353 K, and good stability under continuous long-term operation for 260 hours. One positive aspect of this cathode is that the polarization behavior of the material shows only one Tafel slope over the temperature range of 298 - 353 K.

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