Mechanism and Transformation Kinetics of the Alpha → Sigma Phase Transformation in Iron-Vanadium Alloys

Kitchingman, W. J.; Bedford, G. M.

doi:10.1179/030634571790439676

Cited by 12 publications

(4 citation statements)

References 4 publications

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“…The identical appearance of particles without signs of melting indicates that changes in the microhardness of σ-(Fe-V) take place in the solid state: when heated to over ~1200 °C σ-phase transforms into an α-solid solution. According to [13], this transformation takes place at a high rate. In [14] the microhardness of an α-solid solution that is hardened by tempering (an alloy with 40%–50% V at 1300 °C) was 300–400 units.…”

Section: Resultsmentioning

confidence: 99%

Combustion Synthesis of Composition Ferroalloys

2018

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The main objective of this paper is to present results of the research in the development of a specialized self-propagating high-temperature synthesis (SHS) technology for ferroalloy composites, as applied to steelmaking. The problem of creating such a production cycle has been solved by developing a new approach to the practical implementation of self-propagating high-temperature synthesis, as applied to metallurgy. The metallurgical variation of SHS is based on the use of different metallurgic alloys (including waste in the form of dust from ferroalloy production) as basic raw materials in the new process. Here, the process of synthesis by combustion is realized through exothermic exchange reactions. The process produces a composite, based on inorganic compositions with a bond of iron and/or alloy based on iron. It has been shown that in terms of the aggregate state of initial reagents, metallurgical SHS processes are either gasless or gas-absorbing. Combustion regimes significantly differ when realized in practice. To organize the metallurgical SHS process in weakly exothermic systems, different variations of the thermal trimming principle are used. In the present study, self-propagating high-temperature synthesis of ferrovanadium nitride, which is widely used in steel alloying, was investigated. It has been shown that the phase composition of the initial alloy has a profound impact on the regular patterns in ferrovanadium combustion in nitrogen and on the mechanism itself. During the nitriding of σ-(Fe-V), process activation is taking place. The activation is due to the transformation of the intermetallide into an α-solid solution, when the temperature of phase transition is reached (~1200 °C). The composite structure of the products of ferrovanadium is nitriding by the fusion of particles-droplets composed of molten Fe and solid VN.

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Section: Resultsmentioning

confidence: 99%

Combustion Synthesis of Composition Ferroalloys

2018

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“…∼647 o C [10] or ∼650 o C [39]. Theoretical calculations predict quite well the upper temperature limit of the σ-phase for this system [39,40]; however, they fail to predict that the σ-phase loop closes at lower T. Regarding the concentration range, the following values can be found in the literature (in at% V): 31.5 -61 [21], 30-60 [42], 36-60 [3], 37-57 [32,43], ~36 -~56 [44], 40.5 -59.1 [10], 39-54.4 [45]. In some cases only the lower range viz.…”

Section: Fe-vmentioning

confidence: 92%

“…Regarding the concentration range, the following values can be found in the literature (in at% V): 31.5-61, 21 42 36-60, 3 37-57, 32,43 ∼36-∼56, 44 …”

Section: Fe-vmentioning

confidence: 99%

Sigma-Phase in Fe-Cr and Fe-V Alloy Systems and its Physical Properties

Dubiel

Cieślak

2011

Critical Reviews in Solid State and Materials Sciences

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This review addresses the physical properties of the σ -phase in Fe-Cr and Fe-V alloy systems as revealed both with experimental-mostly with the Mössbauer spectroscopy-and theoretical methods. In particular, the following questions relevant to the issue have been addressed: identification of σ and determination of its structural properties, kinetics of α-to-σ and σ -to-α phase transformations, Debye temperature and Fe-partial phonon density of states, Curie temperature and magnetization, hyperfine fields, isomer shifts and electric field gradients.

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“…In the study reported by Kitchingman & Bedford (1970, 1971) the changes in lattice parameters were measured when 3.4 at. % of various transition elements were incorporated in o'-FeV in which equal atomic proportions of Fe and V were always maintained.…”

Section: Addition Of a Third Transition Metalmentioning

confidence: 99%

A sphere-packing model for the prediction of lattice parameters and order in σ phases

Wilson¹,

Spooner²

1973

Acta Cryst Sect A

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A model is presented for the determination of the unit-cell size for ordered and disordered binary o" phases from a geometry assuming spherical atoms. The basis of the calculations is the assumption of an average radius of the atoms occupying each of the five crystallographic sites in the unit cell. The model is then used to predict the changes in lattice parameters produced by fast-neutron irradiation and by the addition of a third element in some ternary a phases. The calculated parameters are compared with experimental results.

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Mechanism and Transformation Kinetics of the Alpha → Sigma Phase Transformation in Iron-Vanadium Alloys

Cited by 12 publications

References 4 publications

Combustion Synthesis of Composition Ferroalloys

Combustion Synthesis of Composition Ferroalloys

Sigma-Phase in Fe-Cr and Fe-V Alloy Systems and its Physical Properties

A sphere-packing model for the prediction of lattice parameters and order in σ phases

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