Solubility of nitrogen in liquid Fe-10Ti and Fe-25Ti alloys

• Autorzy: Hutny A. , Siwka J.
• Języki publikacji: EN

Abstrakty

EN

Purpose: of the study was to determine the physicochemical characteristics of thermodynamic equilibrium in the liquid metal-gas system, where the liquid metal was a liquid Fe-Ti alloy, and the reaction gas was always a mixture of nitrogen and argon with preset chemical composition. Design/methodology/approach: In the experimental studies, the levitation metal melting technique was used, which enabled, on the one hand, the liquid metal-gas thermodynamic system appropriate to the purpose to be fabricated and, on the other hand, precise measurements to be carried out within a wide nitrogen partial pressure range from 0.0005 to 0.070 atm and in the appropriate range of metal temperature variations (1973-2273 K). The solidification of a 1 g-mass sample at a rate higher than 1000 K/s assured the complete nitrogen fixation in the solidified sample compared to the liquid-state sample. Findings: It has been established in the study by experimentally measuring the nitrogen concentration in the liquid Fe-Ti alloy with varying titanium contents under hyperbaric conditions that the solubility of nitrogen in liquid Fe-Ti alloys increases with increasing partial pressure of nitrogen in the gaseous phase, and with increasing liquid metal temperature and titanium content of the metal. Research limitations/implications: The study has found that when the intensive parameters increase above the critical values, the non-metallic phase forming on the levitating metal drop surface is a titanium nitride film, as demonstrated by X-ray analysis. Such samples were eliminated from the characteristics of nitrogen solubility in the homogeneous metallic phase. Practical implications: The collected data on the thermodynamic quantities of the liquid Fe-Ti-N alloy has enriched the autonomous thermodynamic database containing information about liquid alloys of iron with nitrogen, which is being built at Czestochowa University of Technology. Originality/value: The developed formulas seem to be valuable, because - as the relevant literature indicates -the Fe-Ti system has not been examined so far under such extreme thermodynamic conditions.

Słowa kluczowe

EN

titanium; iron alloys; alloy nitrogen; experimental tests; liquid alloy-gaseous phase system equilibrium

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2012
• Tom: Vol. 55, nr 2
• Strony: 265--269
• Opis fizyczny: Bibliogr. 7 poz., rys., tab.

Twórcy

autor

Hutny A.

• Faculty of Materials Processing Technology and Applied Physics, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Częstochowa, Poland

autor

Siwka J.

• Faculty of Materials Processing Technology and Applied Physics, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Częstochowa, Poland

Bibliografia

• [1] J. Foct, Knowledge and ignorance on high nitrogen steels, HNS High Nitrogen Steels, M.O. Speidel, C. Kowanda, M. Diener (Eds.), vdf Hochschuleverlag AG an der ETH Institute of Metallurgy, Zurich, 2003, 9-19.
• [2] A. Hutny, Thermodynamic characterization of molten dual-Fe-V alloy with nitrogen under hyperbaric conditions, Doctoral Dissertation, Czestochowa University of Technology, Częstochowa, 2006 (in Polish).
• [3] Y.K. Rao, H.G. Lee, Rate of nitrogen absorption in molten iron, Part 1, Experimental, Ironmaking and Steelmaking, 12/2 (1985) 209-220.
• [4] X.L. Wu, In situ formation by laser cladding of a TiC composite coating with a gradient distribution, Surface and Coatings Technology 122 (2006) 111-115.
• [5] J. Siwka, Research Project No. 3 P 407 048 04 enitled „Thermodynamic characteristics of liquid chromium-manganese iron alloys with nitrogen under hyperbaric conditions”, Czestochowa University of Technology Report, 1995, unpublished (in Polish).
• [6] L.M. Kaputkina, A.G. Svyazhin, S.P. Yefimenko, J. Siwka, W.W. Kindop, T.I. Morozova, J.S. Fabrin, The structure of a high nitrogen iron alloy produced under an accelerated crystallization, Metallurgy - Metallurgical Engineering News 5 (1995) 146-153 (in Polish).
• [7] J. Siwka, The solubility of nitrogen in liquid iron, chromium and their alloys, and fragments of high-nitrogen steel making by using plasma, Publishing House of Department of Metallurgy and Materials Engineering, Series: Metallurgy 8, Częstochowa, 1999, 1-175 (in Polish).