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

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

Structure studies of porous oxide layers formed on 13CrMo4-5 steels long-term operated in the power industry

The paper contains results of studies on the formation of oxide layers on 13CrMo4-5 steel long-term operated at an elevated temperature. The material studied comprised specimens of 13CrMo4-5 steel operated at the temperature of 455oC during 130,000 hours (steel 1) and 540oC during 120,000 hours (steel 2). The oxide layer was studied on a surface and a cross-section at the outer surface of the tube wall. The paper contains results of studies of porosity in the oxide layer. The oxide layer formed on the studied steel 1 is ~146 μm thick, while on the steel 2 ~248 μm. It has been found that steel 2 has higher porosity

Evaluation of the surface condition of steel used for surgical instruments by means of atomic forces microscope (AFM)

Prezentowana praca przedstawia wyniki badań stanu powierzchni stali X39Cr13 z gatunku stali stopowych odpornych na korozję stosowanych na narzędzia chirurgiczne. Badaną stal poddano obróbce cieplnej (hartowanie + odpuszczanie) oraz powierzchniowej (azotowanie jarzeniowe). Po zastosowanych obróbkach powierzchnię próbek analizowano za pomocą mikroskopu sił atomowych (AFM).Przeprowadzone badania pozwoliły na ocenę wpływu różnych wariantów obróbek na stan powierzchni poprzez parametr chropowatości.The paper presents results of surface condition examinations of X39Cr13 steel from the group of corrosion-resisting alloy steels used for surgical instruments. The tested steel was subject to heat (quenching + tempering) and surface (plasma nitriding) treatment. After the treatments applied the specimens surface was analysed by means of atomic forces microscope (AFM).The examinations carried out allowed evaluating the effect of various treatments’ variants on the surface condition through the roughness

Analysis of crystallite size changes in an oxide layer formed on steel used in the power industry

The paper presents results of studies on the crystallite sizes of oxide layer formed during a long-term operation on steel at an elevated temperature. 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 inner site on the pipe inlet, at the fire and counter-fire wall of the tube. 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 by the use of a SEIFERT 3003 T/T X-ray diffractometer, with a cobalt source of λ_{Co}=0.17902 nm wavelength. X-ray diffraction measurements were performed in the 20÷120° range of angles with an angular step of 0.1°. To interpret the results the diffractograms were described by a pseudo Voigt curve using the Analyze software. A computer software and the DHN PDS, PDF4+2009 crystallographic database were used for the phase identification. The results showed that the crystallite sizes have an effect on the properties of the oxide. It has been shown that the outer oxide layer having larger crystallites, is more porous and thus more brittle

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

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

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

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

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

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

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

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