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Metallurgical quality evaluation of the wind turbine main shaft 42CrMo4 steel: microscopic and Mössbauer studies

Siemiątkowski Z., Gzik-Szumiata M., Szumiata T., Rucki M., Martynowski R.

Nukleonika

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2017

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Vol. 62, No. 2

171--176

EN

In this paper, the results of the complex examination of the 42CrMo4 steel samples are presented. The samples were taken from the metallurgical forging prepared for the production of the wind turbine main shaft. The samples underwent Mössbauer spectroscopic analysis, as well as the measurement of its mechanical characteristics such as hardness and strength are analysed. Conversion electron Mössbauer spectrometry confirmed phase purity and isotropy of the investigated 42CrMo4 steel. The method provided accurate results, proving Mössbauer spectrometry to be an effective tool for the wind turbine main shaft analysis.

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Iron-containing phases in metallurgical and coke dusts as well as in bog iron ore

Szumiata T., Rachwał M., Magiera T., Brzózka K., Gzik-Szumiata M., Gawroński M., Górka B., Kyzioł-Komosińska J.

Nukleonika

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2017

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Vol. 62, No. 2

187--195

EN

Several samples of dusts from steel and coke plants (collected mostly with electro filters) were subjected to the investigation of content of mineral phases in their particles. Additionally, sample of bog iron ore and metallurgical slurry was studied. Next, the magnetic susceptibility of all the samples was determined, and investigations of iron-containing phases were performed using transmission Mössbauer spectrometry. The values of mass-specific magnetic susceptibility  varied in a wide range: from 59 to above 7000 × 10−8 m3kg−1. The low values are determined for bog iron ore, metallurgical slurry, and coke dusts. The extremely high  was obtained for metallurgical dusts. The Mössbauer spectra and X-ray diffraction patterns point to the presence of the following phases containing iron: hematite and oxidized magnetite (in coke and metallurgical dusts as well as metallurgical slurry), traces of magnetite fi ne grains fraction (in metallurgical dusts), amorphous glassy silicates with paramagnetic Fe3+ and Fe2+ ions, traces of pyrrhotite (in coke dusts), α-Fe and nonstoichiometric wüstite (in metallurgical slurry), as well as ferrihydrite nanoparticles (in bog iron ore). For individual samples of metallurgical dusts, the relative contributions of Fe2+/3+ ions in octahedral B sites and Fe2+ ions in tetrahedral A sites in magnetite spinel structure differs considerably.

3

Subsurface structure and magnetic parameters of Fe-Mo-Cu-B metallic glass

Miglierini M., Hasiak M., Bujdoš M.

Nukleonika

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2015

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Vol. 60, No. 1

115--119

EN

Subsurface properties of 57Fe81Mo9Cu1B9 metallic glass were studied by conversion electron and conversion X-ray Mössbauer spectrometry. They were applied to both surfaces of the ribbons. Deviations in structural surface features are exhibited via different contents of crystalline phases, which were identifi ed as bcc-Fe and magnetite. The presence of small ferromagnetic particles was also suggested from magnetic measurements. An infl uence of irradiation with 130-keV N+ ions on surface properties of the as-quenched alloy is also discussed.

4

Iron-containing phases in fly ashes from different combustion systems

Szumiata T., Gzik-Szumiata M, Brzózka K., Górka B., Gawroński M., Świetlik R., Trojanowska M.

Nukleonika

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2015

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Vol. 60, No. 1

151--154

EN

The investigations of iron-containing phases existing in fly ashes were performed using transmission Mössbauer spectrometry. The examined samples of fly ashes were collected from different coal combustion systems, that is, stoker-fired boiler in municipal heating plant and pulverized coal boiler in power plant. Several phases are identifi ed in the samples: iron oxides, paramagnetic aluminosilicate glass with Fe3+ ions and Al2O4- -type spinel with Fe2+ ions. It was pointed out that proportions of contents of phases strongly depend not only on the combustion temperature but also on the way of ash collection.

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Chemical, magnetic and Mössbauer effect analysis of road dust from expressway

Szumiata T., Gawroński M., Górka B., Brzózka K., Świetlik R., Trojanowska M., Strzelecka M.

Nukleonika

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2013

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Vol. 58, No. 1

109-112

EN

Environmental dusts of urban and industrial origin are one of the most important factors responsible for air and soil pollution - mainly because of heavy metals content. In this work a dust collected from the acoustic barriers of E-77 expressway (Poland) has been investigated. Chemical analysis was performed by means of atomic absorption spectrometer with flame atomization (F-AAS). Fe, Al and Zn metals dominate in the investigated road dusts. Mossbauer spectra collected at room temperature enabled the identification of several iron-containing phases in the dust. Some traces of hematite and magnetite have been found as well as alfa-Fe phase in ferromagnetic state. A significant component could be interpreted as pure iron in paramagnetic state. The dominating doublet in the spectrum of high quadrupole splitting could correspond to iron carbonates. Complementary measurements of low-field AC magnetic susceptibility confirmed a different metal content in the road dust samples collected from different altitudes of acoustic barriers.

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Modelling of thermomagnetic curves obtained with Mössbauer spectrometry for two-phase nanocrystalline alloys

Szumiata T., Gzik-Szumiata M., Brzózka K.

Materials Science Poland

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2007

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Vol. 25, No. 2

559--564

EN

Thermomagnetic curves obtained with Mössbauer spectrometry for two-phase nanocrystalline alloys have been analyzed theoretically. The main goal was to understand a slope jump in the temperature dependence of the hyperfine field for crystalline phase of higher Curie temperature at the Curie point of the amorphous phase. We propose a simple model introducing an effective exchange integral for one phase depending on mean spin value in the other phase. We also consider a strong spin polarization of the amorphous phase by penetrating field originating from nanocrystallites. Results of numerical calculations within the mean field approximation (MFA) reproduce qualitatively the experimental curves for nanocrystalline FINEMET and Fe-Nb-B alloys.