Studies on the Adhesion of Oxide Layer Formed on Steel Long-Term Operated at an Elevated Temperature

2015 ◽  
Vol 227 ◽  
pp. 389-392
Author(s):  
Monika Gwoździk
Keyword(s):  
Elevated Temperature ◽  
Friction Coefficient ◽  
Oxide Layer ◽  
Friction Force ◽  
Flue Gas ◽  
Applied Pressure ◽  
Oxide Layers ◽  
Steam Pipeline

The paper contains results of studies into the formation of oxide layers on steel long-term operated at an elevated temperature. The material studied comprised specimens of steel taken from an steam pipeline and on the flue gas side. The oxide layer adhesion tests were carried out on an automated Revetest XPress Plus instrument using a diamond Rockwell indenter. The adhesion of oxide layers, friction force, friction coefficient, scratching depth were determined as well as the force at which the layer was delaminated. It has been found that the oxide layer formed under the influence of applied pressure is more degradation in the areas where are a pores and cracks.

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.

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 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.

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.

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 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.

A Micro-Contact Model for Boundary Lubrication With Lubricant/Surface Physiochemistry

2002 ◽  
Vol 125 (1) ◽  
pp. 8-15 ◽  
Author(s):  
H. Zhang ◽  
L. Chang ◽  
M. N. Webster ◽  
A. Jackson
Keyword(s):  
Plastic Deformation ◽  
Friction Coefficient ◽  
Oxide Layer ◽  
Contact Pressure ◽  
Friction Force ◽  
Boundary Lubrication ◽  
The State ◽  
Surface Generation ◽  
Contact Friction ◽  
Flash Temperature

A model is developed to study the tribological behavior of sliding micro-contacts. It provides a building block to the modeling of tribo-contacts in boundary lubrication. Three contact variables are calculated at the asperity-level by relating them to the state of contact and the state of asperity deformation. These variables include micro-contact friction force, load carrying capacity and flash temperature. The deformation of the contacting asperity is either elastic, elasto-plastic, or fully plastic. Furthermore, the asperity may be covered by the lubricant/additive molecules adsorbed on the surface, protected by a surface oxide layer or other chemical reaction films, or in direct contact with no boundary protection. The possibility of the contact in each of these three states is represented by a corresponding contact probability. A numerical method is developed to determine the contact state and contact variables in the course of an asperity-to-asperity collision. The asperity flash temperature, which governs the kinetics of lubricant/surface adsorption/desorption, is first calculated by integrating the Jaeger equation over the contact area and in time. Then, the probability of contact covered by an adsorbed film is determined using the Volmer adsorption isotherm, and the probability of contact protected by the oxide layer is estimated using a classical wear theory. For elastic/elasto-plastic deformation of the asperity, the friction coefficient is given by the linear combination of the friction coefficients of the three contact states with their contact probabilities as the weighting factors. For fully plastic deformation of the asperity, the contact pressure and friction force become dependent of each other. The shear stress is approximated by a linear function of the contact probabilities, and the contact pressure and friction coefficient then calculated. Meanwhile, the influence of fresh surface generation due to plastic flow on the contact probabilities is also modeled. Insights are provided into the asperity collision through numerical studies of a sample problem. In addition, parametric studies are carried out to analyze the effects of lubricant and surface parameters on the micro-contact severity and its load capacity.

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.

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

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