Siberian Federal University, Krasnoyarsk, Russia:

V. N. Baranov, Director of Institute of Non-Ferrous Metals and Material Science, Candidate of Technical Sciences, e-mail: vnbar79@mail.ru
B. P. Kulikov, Leading researcher, Doctor of Chemistry Sciences, e-mail: kulikov-boris@yandex.ru
E. G. Partyko, Junior Researcher, e-mail: elforion@mail.ru
A. A. Kosovich, Senior Lecturer, Candidate of Technical Sciences, e-mail: a-herz@mail.ru

Paper presents the laboratory research results about effect of alloying, modifying and fluxing agents, in amount corresponding to consumption standards and used at the RUSAL aluminum smelters, on hydrogen saturation of aluminum melt. In paper the comparison is made between hydrogen measurement results obtained by express analysis of liquid aluminum using an Alu Compact instrument and data of solid aluminum from specialized highly sensitive magnetic mass spectrometer AV-1. As a result of studies, it was found that the maximum of aluminum hydrogen saturation occurs when using powder refining fluxes and alloying agents containing halides of alkali and alkaline earth metals, some of which form crystalline hydrates. It was shown that powder fluxes and alloying agents with flux components contain crystallization and hygroscopic water and, when they are added to melt, increase the concentration of hydrogen in metal by 35-100%. According to the research results, technical solutions are proposed with the aim of reducing the saturation degree of aluminum melt with hydrogen. One of the most effective solutions is to use fused flux lump. The following points were proposed as technical solutions to reduce the saturation degree when alloying, refining, and modifying agents added to melt: make use of fused lump refining and cover-refining fluxes and retreat from powder fluxes; provide incoming control for fluxes and alloying agents containing fluxes; to store fluxes and alloying agents with halides of alkali and alkaline earth metals under conditions that exclude hygroscopic moisture saturation; to increase the consumption of fused refining fluxes by 1.5-2 times during preparation of aluminum-magnesium alloys.
The work was performed within the framework of the state assignment for science of the Federal State Autonomous Educational Institution of Higher Education “Siberian Federal University”, project number FSRZ-2020-0013.

1. Belyaev S. V., Partyko E. G., Kosovich A. A. et al. Analysis of plain aluminium saturation with hydrogen while adding different components. ARPN Journal of Engineering and Applied Sciences. 2018. Vol. 13, No. 9. pp. 3251–3256.
2. Karagadde S., Dutta P. A comparison of time-scales governing the interaction and growth of hydrogen bubbles with a solidifying front. International Communications in Heat and Mass Transfer. 2016. Vol. 79. pp. 16–20.
3. Napalkov V. I., Makhov S. V. The physico-chemical processes behind refining of aluminium and its alloys: Monograph. Moscow, 2015. 576 p.
4. Liu Y., Dai Y., Wang J. et al. Structure of liquid aluminum and hydrogen absorption. Journal of Wuhan University of Technology-Materials Science Edition. 2011. Vol. 26, No. 1. pp. 93–97.
5. Wang H., Fu G., Cheng C. et al. Molecular mechanics and dynamics simulation of hydrogen diffusion in aluminum melt. China Foundry. 2017. Vol. 14, No. 6. pp. 478–484.
6. Mosisa E., Bazhin V. Yu., Savchenkov S. A. Review on nano particle reinforced aluminum metal matrix composites. Research Journal of Applied Sciences. 2016. Vol. 11, No. 5. pp. 188–196.
7. Lunarska E., Chernyaeva O. Effect of precipitates on hydrogen transport and hydrogen embrittlement of aluminum alloys. Materials Science. 2004. Vol. 40, Iss. 3. pp. 399–407.
8. Chernega D. F., Byalik O. M., Ivanchuk D. F., Remizov G. A. Gases in non-ferrous metals and alloys. Moscow : Metallurgiya, 1982. 176 p.
9. Yakimov V. I. Development and implementation of high-performance processes for making castings out of aluminium and magnesium alloys in aircraft building: Doctoral dissertation. Komsomolsk-na-Amure State Technical University. Komsomolsk-on-Amur, 2010. 421 p.
10. Stetsenko V. Yu. Effect of hydrogen and oxygen sorption and desorption on inoculation and solidification of alloys. Litiyo i Metallurgiya. 2010. No. 3. pp. 91–96.
11. Stetsenko V. Yu. On the generation of gas bubbles during solidification of metal and alloy phases. Metallurgiya mashinostroeniya. 2008. No. 3. pp. 28–30.
12. ALU COMPACT II. Available at: https://www.fma.li/alu-tec/wasserstoff#aluc (Accessed: 20.05.2020).
13. Vetyukov M. M., Tsyplakov A. M., Shkolnikov S. N. Electrometallurgy of aluminium and magnesium. Textbook for university students. Moscow : Metallurgiya, 1987. 320 p.
14. Lebedev V. A., Sedykh V. I. Metallurgy of magnesium. Learner’s guide. Yekaterinburg : UGTU-UPI, 2010. 174 p.
15. Hydrogen gas analyzer AV-1. Available at: http://www.spectromass.ru/produktsiya/gazoanalizator-vodoroda-av-1/ (Accessed: 20.05.2020).