Engineering & Technologies, 2016, 9(5), 671-685 ~ ~ ~ УДК 669.1.017 Improvement of the Properties of Gray Cast Iron by Silicon Dioxide and Carbon Nanostructures Victor V. Kondratyev*, Nikolay A. Ivanov, Andrey E. Balanovskiy, Nikolay N. Ivanchik and Antonina I. Karlina Irkutsk National Research Technical University 83 Lermontova, Irkutsk, 664074, Russia Received 09.04.2016, received in revised form 28.05.2016, accepted 20.06.2016 Increasing requirements in terms of performance in modern industry forced to use materials that can operate at higher loads. <...> For metallurgical industry production increasingly require the casting of gray cast iron (GI) high marks. <...> Improving the properties of cast iron and steel is achieved only through the effective doping and modifi cation, allowing to eliminate defects, to grind grain. <...> Currently, the industry uses over 500 existing types of modifi ers, most of them are multicomponent. <...> Very often the main component of additives is silicon – effective graphitizer and deoxidizer. <...> Additives remaining components serve to enhance the effect of modifi cation, increase “survivability” of modifi ers, and to change the shape of inclusions of graphite in the iron. <...> At present, the highly competitive component requires an effi ciency modifi ers, considering the economic component. <...> For this purpose, this paper investigated the effect of nano-additives with high chemical reactivity of carbon and silicon. <...> Cast iron modifi cation process made by three different formulations of modifi ers, including: - Composition 1 – Replaced 50 % of standard metallurgical graphite particulate graphitic carbon with a content of 0.20 % by weight. carbon multiwalled nanotubes. <...> Smelting of gray iron took place in standard <...>