Nizhny Novgorod State Technical University named after R. E. Alekseev:

I. O. Leushin, L. I. Leushina, A. N. Grachev, V. A. Ulyanov

E-mail: lmps@nntu.nnov.ru

Analysis of a generalized technological diagram of investment casting has permitted to single out its major hitch while being implemented within current facilities — manufacturing of multi-layer shell molds. This lengthy, onerous stage consists of a series of operations, such as, for example, assembly of pattern blocks; preparation and application of slurry and the material of sand fill onto the pattern blocks; drying of shell layers; dewaxing; shell firing; etc. That is why the authors’ research focused on solving problems relating to this stage. A task was set to cut energy consumption in firing of shell molds prior to their delivery for steel-melt pouring, which significantly bears on the casting resultant quality. To minimize formation of hard non-metallic inclusions in the casting’s body, as well as oxidation and decarburization of its surface layer, the authors believe expedient to ensure decrease in the shell mold material’s activity. It may be attained by creation of a regenerating atmosphere in the zone of physics-chemical interaction of the mold with the poured metal melt. Implementation of the above measures will ensure decrease in materials consumption, increase in environmental safety of investment casting — a method of producing parts which is competitive globally.

1. Dibrov I. A. Sostoyanie i perspektivnye napravlenia razvitia liteinogo proizvodstva Rossii (State and prospective directions of development of Russian foundry production). Proceedings of the 10^th Congress of Russian Foundrymen. Kazan : “Vertolet” Publishers, 2011. P. 11–15.
2. Ivanov V. N., Kazennov S. A. Litye po vyplavlyaemym modeliam (Casting via molten models). Moscow : “Mashinostroeniye” Publishers, 1984. 408 p.
3. Leushina L. I., Nischenkov A. V., Subbotin A. Yu. Progressivnaya tekhnologia prokalivania obolochkovykh form dlya tochnogo stalnogo litya (Progressive technology for calcination of shell molds for precise steel castings). Liteischik Rossii — Russian Foundryman. 2011. № 2. P. 40–42.
4. RF Patent for Invention №2433013 “Method of manufacturing multi-layer shell investment molds”. Authors: I. O. Leushin, L. I. Leushina, A. V. Ni schenkov, S. B. Smyslov, A. Yu. Subbotin. Published 10.11.2011. Bulletin № 31.
5. Leushina L. I., Nischenkov A. V. Primeneniye otrabotannykh modelnykh kompozitsyii pri provedenii normalizatsii stalnykh otlivok otvetstvennogo naznachenia (Usage of worked model compositions in conducting normalization of heavy-duty steel castings). Liteynye splavy (Casting alloys): Inter-regional collection of scientific papers, devoted to 35^th anniversary of the Chair of electrometallurgy and casting production. Magnitogorsk : “MGTU” Publishers, 2010. P. 129–131.
6. Petrov V. V., Evstigneev A. I., Alaskarov N. I., Chernomas V. V., Odinokov V. I. Treschinostoikost obolochkovykh form (Crack resistance of shell molds). Liteinoye proizvodstvo — Foundry production. 1997. № 7. P. 27–28.
7. Evstigneev A. I., Petrov V. V., Chernyshev E. A. et al. Sovershenstvovaniye tekhnologicheskikh pro tsessov v spetsialnykh vidakh litya (Improvement of technological processes in special casting technologies). Vladivostok : “Dalnauka” Publishers, 2002. 224 p.
8. Evstigneev, A.I., Sapchenco I. G., Tyshkevich V. N., Vasin V. V. Vliyaniye poristosti na prochnost obolochkovykh form po vyplavlyaemym modelyam (Influence of porosity on strength of shell molds for molten models). Izvestia VUZov. Chernaya metallurgiya — News of high schools. Ferrous metallurgy. 1991. № 8. P. 51–53.