JSC Ural Steel, Novotroitsk, Russia:
V. V. Lazeev, Chief Specialist of the Directorate for Innovations, e-mail: v.lazeev@uralsteel.com
K. S. Skokov, Chief Specialist on Casting and Electric Steelmaking Production
D. V. Nizhelsky, Head of New Products Department
L. G. Evsina, Chief Specialist in Metallurgy
O. P. Pudovkina, Engineer of the 1^st Category

I. V. Kovalko and N. G. Karkhanina took part in the metallographic studies.

The results of mastering the technology of production of high-strength cast iron with sphericalnodular graphite in a 6-ton electric arc furnace of the Ural Steel foundry for manufacture of castings are presented. A special lining scheme has been developed, as well as a scheme for placing modifiers in cast iron ladles with a capacity of 2 and 3 tons. To assess the effectiveness of modifying cast iron, the work was carried out in 4 stages under different conditions of placing the materials in the bucket. Molded products with a wall thickness from 15 to 300 mm were cast. The structure and mechanical properties of the castings obtained meet the requirements of GOST 7293–85.

1. Lekakh S. N., Bestuzhev N. I. Ladle furnace processing of high-quality cast irons in mechanical engineering. Minsk: Navuka i tekhnika, 1992. 269 p.
2. Psyrkov N. V. Special high-strength cast iron with nodular graphite as a new construction material. Mekhanika mashin, mekhanizmov i materialov. 2012. No. 3. pp. 213–218.
3. Bekh N. I., Aleksandrov N. N., Nuraliev F. А. High-strength cast iron now and in the future. Liteinoe proizvodstvo. 2018. No. 5. pp. 2–5.
4. Iskhakov А. F. et al. Ferroalloys, modifiers, ligatures: reference book in 2 volumes. Chelyabinsk: Tsitsero, 2009. 259 p.
5. Bublikov V. B., Berchuk D. N. Increasing the degree of modification of high-strength cast iron. Metallurgiya mashinostroeniya. 2006. No. 5. pp. 31–35.
6. Sertucha J. Chunky graphite in low and high silicon spheroidal graphite cast irons–occurrence, control and effect on mechanical properties. Materials. 2020. No. 13. pp. 55–60.
7. Chaikin V. А., Boldyrev D. А., Chaikina N. V. Features of graphitizing modification of highstrength cast iron with mixed modifiers in the conditions of JSC AVTOVAZ. Vestnik Magnitogorskogo gosudarstvennogo tekhnicheskogo universiteta imeni G. I. Nosova. 2007. No. 4. pp. 53, 54.
8. Boldyrev D. А. Investigation of the complex effect of technological parameters of modification of structural cast iron on the indicators of their structure and properties. Proceedings of the Nizhny Novgorod State Technical University named after R. E. Alekseev. 2010. No. 4. pp. 226–239.
9. GOST 7293–85. Spheroidal graphite iron for castings. Grades. Introduced: 01.01.1987.
10. Kovalevich Е. V. Environmentally friendly technology for production of nodular cast iron. Liteinoe proizvodstvo. 2010. No. 12. pp. 82–85.
11. Doroshenko V. S. About simple solutions for production of high-strength cast iron. Metallurgiya mashinostroeniya. 2021. No. 1. pp. 5–10.
12. GOST 1497–84. Metals. Methods of tension test. Introduced: 01.01.1986.
13. GOST 9454–78. Metals. Method for testing the impact strength at low, room and high temperature. Introduced: 01.01.1979.
14. GOST 9012–59. Metals. Method of Brinell hardness measurement. Introduced: 01.01.1960.
15. GOST 3443–87. Cast iron castings with graphite of different form. Method of structure determination. Introduced: 01.07.1988.
16. Nakayama H. Effect of amount of chunky graphite on mechanical properties of spheroidalgraphite cast iron. Materials. 2018. Vol. 59. pp. 412–419.
17. Melnikov А. P., Karpenko М. I., Khomets U. S. Study of the influence of microalloying and modifying elements on the structure and properties of pearlitic cast irons. Lityo i metallurgiya. 2010. No. 57. pp. 86–88.