Determination of Thermal Diffusivity and Its Temperature Dependence of Fe&lt;sub&gt;1−&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;O Scale at High Temperature by Electrical-Optical Hybrid Pulse-Heating Method

Yang, Yongrong; Watanabe, Hirokazu; Akoshima, Megumi; Hayashi, Miyuki; Susa, Masahiro; Tanei, Hiroshi; Okada, Hideya; Endo, Rie

doi:10.2355/isijinternational.isijint-2019-635

Cited by 3 publications

(1 citation statement)

References 21 publications

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“…There have been a few reports regarding the thermal diffusivity and conductivity of FeO scale provided by oxidation of iron. [2][3][4][5] For Fe 3 O 4 , there are some extant data only for sintered samples. 6,7) However, the authors' previous experience says that sintered FeO is not an alternative to FeO scale.…”

Section: Introductionmentioning

confidence: 99%

Thermal Diffusivity and Conductivity of Fe3O4 Scale Provided by Oxidation of Iron

Akoshima¹,

Endo

Ueda

et al. 2022

ISIJ Int.

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The thermal diffusivity and conductivity of Fe 3 O 4 scale have been determined with the laser flash method. Fe 3 O 4 scale was provided by oxidation of iron plates at 823 K in Ar containing 0.84%H 2 and 15.6%H 2 O. The scale was characterized by scanning electron microscopy and X-ray diffraction analysis for high temperature use to identify the phase of the scale. The thermal diffusivity and conductivity derived for the Fe 3 O 4 scale decrease from 1.1 × 10 − 6 m 2 s − 1 to 4.1 × 10 − 7 m 2 s − 1 and from 3.5 Wm − 1 K − 1 to 1.7 Wm − 1 K − 1 , respectively, with increasing temperature from room temperature to 676 K. The effective thermal conductivity of iron oxide scale with Fe 3 O 4 has been evaluated assuming that Fe 3 O 4 occupies 30% of the total scale thickness, suggesting the impact of the presence of Fe 3 O 4 is about ten percent. KEY WORDS: iron oxide scale; Fe 3 O 4 ; thermal diffusivity; thermal conductivity; effective thermal conductivity; laser flash method.

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Section: Introductionmentioning

confidence: 99%

Thermal Diffusivity and Conductivity of Fe3O4 Scale Provided by Oxidation of Iron

Akoshima¹,

Endo

Ueda

et al. 2022

ISIJ Int.

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Data Sets Formation on the Physical Properties of Oxide Scale Components for Theoretical Assessment of Efficiency Parameters of Laser Cleaning of Carbon Steels and Related Processes

Devoino,

Gorbunov,

Lapkovsky

et al. 2024

Nauka teh.

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There is a need in machine-building industries nowadays to automate technologies, in particular, laser ones, to remove surface oxide layers – mill scale, rust – from steel products/pieces in order to improve the energy effectiveness of processing. Herewith, a theoretical assessment method for the intensity of heating of the oxide layer and the phase transition in it can be used to optimize laser cleaning (LC) of the steel surface. To realize this, it is possible to use some calculation and modeling procedures that require, as a first step, the data collection and verification on the temperature-dependent properties of iron-containing condensed phases, as possible components contained, in particular, in scale, which is typically widespread into various metal products. In this regard, the formation of database for characteristics of oxide scale components by the way of selection of information on thermophysical (including optical) properties of the components mentioned and of steel base, which are required for a reliable calculation of the thermal efficiency parameters of the technology for laser cleaning of carbon steels, as well as such actively developed related technologies as laser cutting, drilling, coating remelting, etc., was chosen as the task of our research. An analytical overview of published experimental data made it possible to systematize information on a number of transport and other physical properties of iron-containing components at ambient pressure, including thermal conductivity (k) and diffusivity (a), density ρ, irradiation absorptance and integral emissivity in the temperature range from T ≈ 298 K to the melting temperatures of oxide and metal phases and above them. At the same time, a preliminary thermochemical estimation shows (on the calculated data) the existence of such thermodynamically stable forms of the condensed phase in the heating spot of scale layers during its LC at the melting point and above it, as Fe3O4, FeO, and Fe, which is consistent with known experimental data. Comparison of the values of a calculated by us (using the published values of k, ρ and molar heat capacity and using extrapolation in the high-temperature region) for the types of scale components under consideration with a set of experimental values of this parameter in current literature revealed the presence of differences for both oxide and metal phases. These new values make it possible to fill in a gap in the temperature range T = 1600–1800 K that existed in the data on the thermal diffusivity. The value of a = (0.83–0.92)·10–6 m2/s was also calculated for liquid iron oxide for the T ≈ 1800 K, which was not measured experimentally, that, obviously, prevented modeling of not only laser surface processing, melting and cleaning of steels, but also calculations in the field of metallurgical and other technologies, which are characterized by the presence of iron oxide melts during heating.

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Density Determination for Oxide Scale Formed on Steel Plate Considering Non-stoichiometry of Fe1-xO

et al. 2021

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Density of oxide scale formed on steel is essential to derive thermal conductivity, which is used for the process simulation for cooling of steel plate in hot-rolling of steelmaking. Thus, the aim of this research was to propose the density determination method for the oxide scale. The samples used were prepared by the high-temperature oxidation of iron plate, consisting of 96% Fe 1-x O and 4%Fe 3 O 4 , and there were voids in the Fe 1-x O layer. The density was determined by four methods based on (1) thickness and mass of oxide scale, (2) the mass balance in the sample, (3) volume balance in the sample, and (4) single crystal density and volume of voids. All of the methods considered the non-stoichiometry of Fe 1-x O because the perfect FeO has a much larger density. The density of the oxide scale was firstly determined by assuming that the oxide scale consisted only of Fe 1-x O. The methods (1) and (2) did not show reasonable density and reproducibility. The results by methods (3) and ( 4) showed reasonable values with good reproducibility. The density was then determined again by methods (3) and ( 4), taking into account the presence of Fe 3 O 4 . It is also discussed the effect of density revision on the thermal diffusivity/conductivity determination of the oxide scale.

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Determination of Thermal Diffusivity and Its Temperature Dependence of Fe<sub>1−<i>x</i></sub>O Scale at High Temperature by Electrical-Optical Hybrid Pulse-Heating Method

Cited by 3 publications

References 21 publications

Thermal Diffusivity and Conductivity of Fe<sub>3</sub>O<sub>4</sub> Scale Provided by Oxidation of Iron

Thermal Diffusivity and Conductivity of Fe<sub>3</sub>O<sub>4</sub> Scale Provided by Oxidation of Iron

Data Sets Formation on the Physical Properties of Oxide Scale Components for Theoretical Assessment of Efficiency Parameters of Laser Cleaning of Carbon Steels and Related Processes

Density Determination for Oxide Scale Formed on Steel Plate Considering Non-stoichiometry of Fe<sub>1-x</sub>O

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