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.

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.

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.

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.

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 Characterization Of Oxide Layers Formed On 13CrMo4-5 Steel Operated For A Long Time At An Elevated Temperature

2015 ◽  
Vol 60 (3) ◽  
pp. 1783-1788 ◽  
Author(s):  
M. Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Oxide Layer ◽  
Steel Substrate ◽  
Scratch Test ◽  
Scanning Microscope ◽  
Oxide Layers ◽  
Optical Scanning ◽  
Long Time ◽  
2D And 3D

Abstract The paper contains results of studies into the formation of oxide layers on 13CrMo4-5 (15HM) steel long-term operated at an elevated temperature. The oxide layer was studied on a surface and a cross-section at the inner and outer surface of the tube wall. The 13CrMo4-5 steel operated at the temperature of 470°C during 190,000 hours was investigated. X-ray structural examinations (XRD) were carried out, microscope observation s using an optical, scanning microscope were performed. The native material chemical composition was analysed by means of emission spark spectroscopy, while that of oxide layers on a scanning microscope (EDS). The studies on the topography of the oxide layers comprised studies on the roughness plane, which were carried out using a AFM microscope designed for 2D and 3D studies on the surface. Mechanical properties of the oxide layer – steel (substrate) were characterised on the basis of scratch test. The adhesion of oxide layers, friction force, friction coefficient, scratching depth were determined as well as the force at which the layer was delaminated.

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.

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.

Steam Oxidation of TP 347H FG in Power Plants

2006 ◽  
Vol 522-523 ◽  
pp. 181-188 ◽  
Author(s):  
A.N. Hansson ◽  
Melanie Montgomery
Keyword(s):  
Oxide Layer ◽  
Kinetic Data ◽  
Power Plants ◽  
Oxidation Behaviour ◽  
Oxidation Time ◽  
Steam Oxidation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Supercritical Steam Conditions

The long term oxidation behaviour of TP 347H FG at ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal-fired power plant. The steamside oxide layer was investigated with scanning electron microscopy and energy dispersive X-ray diffraction in order to reveal the effect of oxidation time and temperature on the microstructure. A double layered oxide formed during steam oxidation. The morphology of the inner Cr-containing layer was influenced by the oxidation temperature. At temperatures below approx. 585oC, it consisted of regions of Fe-Ni-Cr spinel surrounded by Fe-Cr oxide. At higher temperatures almost the entire inner oxide layer was composed of Fe-Cr oxide. Possible mechanisms for the oxide growth are discussed and it is suggested that faster Cr transport within the alloy at higher temperatures explains the change in morphology. This hypothesis is supported by thermodynamic calculations and kinetic data. The thickness of the inner oxide layer did not change significantly with oxidation time and temperature for exposures less than 30000 h; however after 57554 h the thickness had increased significantly at the lowest temperatures.

scholarly journals Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

2020 ◽  
Vol 9 (1) ◽  
pp. 998-1008
Author(s):  
Guo Li ◽  
Zheng Zhuang ◽  
Yajun Lv ◽  
Kejin Wang ◽  
David Hui
Keyword(s):  
Cement Hydration ◽  
Mercury Intrusion Porosimetry ◽  
Hardened Concrete ◽  
Optimal Dosage ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Carbonation Depth ◽  
X Ray ◽  
Chloride Resistance

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

Sign in / Sign up

Export Citation Format

Share Document