Impact of Cooling Character on Structure and CTE of Cast Invar Alloy Made From Secondary Raw Materials
Abstract
Metallography analysis of invar alloys made from secondary raw materials and crystallized with different cooling rates has been carried out. The study has demonstrated that velocity of crystallization has an impact on the dispersity of graphite. The higher velocity of cooling, the more dispersive graphite is. The volume percentage of graphite in alloy, crystallized with high cooling rate, is lower than compared with low cooling rate. Crystallization with low cooling rate leads to the reduction of the amount of carbon into g-phase. The coefficient of thermal expansion is basically depends on the amount of carbon into g-phase.
Keywords: invar, alloying, carbon,
References
[1] M. Shiga, “Invar alloys,” Current Opinion in Solid State and Materials Science, vol. 1, no. 3, pp. 340–348, 1996.
[2] G. V. Shcherbedinskii and Yu. L. Rodionov, “Multifunctional alloys with a regulated complex of hardly compatible mechanical and physicochemical properties,” Russian Metallurgy (Metally), pp. 554–563, 2001.
[3] A. S. Zhilin, S. V. Grachev, N. A. Popov, S. B. Mikhailov, V. V. Tokarev, and S. M. Nikiforova, “Features of structure formation in super-invar alloys additionally doped with carbon, Higher Educational Institutions News,” Oil and Gas, pp. 91–94, 2014.
[4] S. V. Grachev, M. A. Filippov, V. I. Chermenskii et al., “Thermal properties and structure of cast carbon-containing invar and superinvar alloys after two-stage annealing,” Metal Science and Heat Treatment, vol. 55, no. 3-4, pp. 124–128, 2013.