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.

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.

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.

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.

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.

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.

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 Defects of Oxide Layers Formed on 10CrMo9-10 Steel Operated for 200,000 Hours at an Elevated Temperature

2016 ◽  
Vol 61 (2) ◽  
pp. 987-992 ◽  
Author(s):  
M. Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Iron Oxides ◽  
Cross Section ◽  
Outer Surface ◽  
Tube Wall ◽  
Wall Surface ◽  
Oxide Layers ◽  
Degree Of Degradation

Abstract The paper contains results of studies into the formation of oxide layers on 10CrMo9-10 (10H2M) steel long-term operated at an elevated temperature (T = 545°C, t = 200,000h). The oxide layer was studied on a surface and a cross-section at the inner and outer surface of the tube wall on the outlet both on the fire and counter-fire side of the tube wall surface. The obtained results of research have shown a higher degree of degradation, both of the steel itself and oxide layers, on the fire side. In addition, it has been shown that on the outside tube wall, apart from iron oxides, there are also deposits composed mainly of Al2SiO5.

Texturing of Magnetite Forming during Long-Term Operation of a Pipeline of 10CrMo9-10 Steel

2013 ◽  
Vol 203-204 ◽  
pp. 121-124 ◽  
Author(s):  
Monika Gwoździk ◽  
Zygmunt Nitkiewicz
Keyword(s):  
Cross Section ◽  
Oxide Surface ◽  
Initial State ◽  
Radiation Beam ◽  
X Ray ◽  
Term Operation ◽  
Magnetite Layer ◽  
Anode Tube

The paper presents results of X-ray measurements of the texture of a magnetite (Fe3O4) layer formed on 10CrMo9-10 steel during 100,000 hours operation at the temperature of 575°C (in a flowing medium environment). The formed oxide layer was ≈140µm thick. Measurements of texturing were performed on the oxide surface and also at the depth of ≈50µm from the surface (1st polishing) and ≈100µm (2nd polishing). X-ray studies were carried out using the radiation of a cobalt anode tube, λCo=0.17902nm, for (311) and (400) Fe3O4 reflections, using a radiation beam collimated to φ=2mm. The study was aimed at determination of correlation between the texturing and the structure on the magnetite layer cross-section. A clear texturing of {111} and {111} type for the magnetite in the initial state and after the second polishing was found. Instead, after the first polishing there was a substantial texturing of {034} and {015} type. A different nature of the texture may result from a diversified morphology of magnetite at various depths (caused inter alia by a differentiated temperature on the tube wall cross-section during the material operation), which is related among other things to the crystallites size. The magnetite structure and texture changes can affect the magnetite porosity and cleavage.

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.

Sign in / Sign up

Export Citation Format

Share Document