Determination of Polymorphic Transformation Temperature for Alloy VT8

Abstract:

The temperature of polymorphic transformation (Tpt) has been determined for accurate composition of two-phase titanium alloy which has been marked like VT8 through different ways: the method of trial quench and with the help of dilatometric and differential thermal analyzes. The close values of Tpt have been received. Herewith the phase composition has been estimated qualitatively and quantitatively for the hardened samples of alloy VT8 using optical and scanning electron microscopes and the chemical composition with the help of the micro X-ray spectral analysis. The influence of the quenching temperature on the hardness has been investigated. Also, the hardness of the individual structural components and alloy VT8 as a whole unit has been measured. Hardness curves are based depending of the quenching temperature; the results are displayed in tabular and graphical form. The coefficient k has been found for the calculation of allotropic transformation temperature for this alloy using the known temperature of hardening and quantity of preserved α-phase of hardened structure. The album of the microstructures after quench with different temperatures has been created, this album will allow to reduce the duration of preliminary works for finding specific temperature of polymorphic transformation in production conditions for each new batch of alloy VT8 with another chemical composition (but within the vintage), knowledge of which is necessary for setting the temperature regime of treatment.

• Periodical: Materials Science Forum (Volume 946)
• Pages: 42-46
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.946.42
• Online since: February 2019
• Authors: Nikita A. Zavartsev*, Nadezhda T. Kareva
• Keywords: Composition of Hardened Titanium Alloys, Microhardness, Quench, Temperature of Polymorphic Transformation, Titanium Alloys, VT8

References

[1] V.N. Moiseev, A Titan in Russia. Metal Science and Heat Treatment, 8 (2005) 23-29.

[2] B.B. Chechulin, S.S. Ushkov, I.N. Razuvaeva, V.N. Goldfayn, Titanium alloys in mechanical engineering. Leningrad: Mechanical engineering, (1977).

[3] M.A. Smirnov, V.M. Schastlivtsev, L.G. Zhuravlev, Basics of heat treatment of steel. Ekaterinburg: UrO RAN, (1999).

[4] S.P. Belov, M.Ya. Brun, S.G. Glazunov et al., Titanium alloys. Metallurgy of titanium and its alloys, Metallurgiya, (1992).

[5] M. Beckert, H. Klemm, Handbuch der metallographichen, Atzverfahren, (1988).

[6] I.A. Illarionov, Use of thermal analysis methods to determine the temperature of polymorphic transformation in a high-alloy titanium-based alloy based on the β phase, Ekaterinburg, Uralskogo universiteta, Ch.2 (2015) 266-268.

[7] RU Patent 2498280 (2012).

[8] E.A. Borisova, G.A. Bochvar, M.Y. Brun et al., Metallography of titanium alloys: The handbook, Moscow: Metallurgiya, (1980).

[9] B.A. Kolachev, V.I. Elagin, V.A. Livanov, Metal Science and Heat Treatment of Non-Ferrous Metals and Alloys: The textbook for Universities, Moscow: MISA, (2005).

[10] I.N. Bronshteyn, K.A. Semendyaev, Handbook of Mathematics for Engineers and Students VTUZOV. Moscow: Science, the main edition of physical and mathematical literature, (1986).

[11] A.D. Makkvillen, M.K. Makkvillen, Titanium, Moscow, Metallurgizdat, (1958).

[12] E.K. Molchanova, Atlas of state diagrams of titanium alloys. Moscow, Mashinostroenie, (1964).