Gorkovsky Automotive Plant (GAZ), Nizhny Novgorod, Russia

A. N. Timofeev, Engineer

Nizhny Novgorod State Technical University named after R. E. Alekseev, Nizhny Novgorod, Russia

I. O. Leushin, Doctor of Engineering Sciences, Professor, Head of the Chair of Casting and Metallurgical Processes and Technologies,  lmps@nntu.nnov.ru

Yu. A. Zinovyev, Candidate of Engineering Sciences, Assistant Professor, Chair of Casting and Metallurgical Processes and Technologies

The combined influence of complex modifier and micro-addition of boron on the properties of castings of high-strength iron was researched, especially, their influence on toughness values in the area of working negative temperatures. The paper presents solving of the announced problem applying to cast billets of valves and fittings as well as components for railroads. These products are manufactured at GAZ metallurgical production facilities and intended for operation in the Far North conditions at working temperatures about - 80 ºC. During experimental examinations, technological restrictions for content of silicon, manganese and phosphorus in cold-resistant iron were determined. The samples were taken from 24 pilot melts, and these samples have been cooled and tested for impact strength in accordance with GOST 9454-78 standard. Cast iron microstructure was investigated for boron content in the range between 0.003 % and 0.01 %. The optimal amount of injected boron located within the 0.005 - 0.007 % was established; it allowed, using flexibility and versatility of the technical scheme of in-mold inoculation, to solve the problem of ensuring the necessary level of cold resistance of castings of high-strength iron. It was also shown that micro-additions of boron have effect on size and distribution of graphite inclusions.

1. Shebatinov M. P., Abramenko Yu. E., Bekh N. I. Vysokoprochnyi chugun v avtomobilestroenii (High-strength cast iron in the automotive industry). Moscow : Mashinostroenie, 1988. 216 p.

2. D. N. Khudokormov, V. M. Korolev, S. M. Lekakh, I. Yu. Saponko. (High-strength cast iron). Patent USSR, No. 773121 C22 C37/10. Declarant and patentee : Belorus National Technical University, No. 2738219/22-02. Asserted 21.03.79. Published 23.10.80. Bulletin No. 39.

3. G. I. Silman, V. V. Kamynin, S. A. Kharitonenko. Chugun, sposob ego polucheniya i sposob termicheskoy obrabotki otlivok iz nego (Cast iron, its obtaining method and method of obtaining of the thermal treatment of the cast iron`s foundaries). Patent RF, No. 2267542 C22 C37/10. Declarant and patentee : Bryansk State Engineering and Technological Academy, No. 2004122139/02. Asserted 19.07.04. Published 10.01.06. Bulletin No. 3.

4. Yu. A. Shchepochkina. Chugun (Cast iron). Patent RF, No. 2313603 C22 C37/10. Declarant and patentee : Yu. A. Shchepochkina. No. 2006113333/02. Asserted 19.04.06. Published 27.12.07. Bulletin No. 45.

5. Aleksandrov N. N. et al. Liteynoe proizvodstvo – Foundry. Technologies and Equipment. 1981. No. 1. pp. 4-5.

6. Sherman A. D., Zhukov A. A. Chugun : spravochnoe izdanie (Cast iron : reference book). Moscow : Metallurgiya, 1991. 576 p.

7. Yakovlev M. I., Petrov E. S., Andreev A. D. Liteynoe proizvodstvo – Foundry. Technologies and Equipment. 2001. No. 3. pp. 6-7.

8. Anikeev V. V. Liteynoe proizvodstvo – Foundry. Technologies and Equipment. 2010. No. 4. pp. 6-10.

9. Mikhaylovskiy V. M., Korolev S. P., Konstantinovich O. A. Liteynoe proizvodstvo – Foundry. Technologies and Equipment. 2008. No. 3. pp. 4-6.

10. Lyakishev N. P., Pliner Yu. L., Lappo S. I. Borsoderzhashchie stali i splavy (Boron-containing steels and alloys). Moscow : Metallurgiya, 1986. 192 p.

11. Gulyaev A. P. Metallovedenie (Physical metallurgy). Moscow : Metallurgiya, 1986. 544 p.

12. Timofeev A. M., Leushin I. O., Zinovev Yu. A. Povyshenie fiziko-mekhanicheskikh svoystv vysokoprochnogo chuguna posredstvom mikrolegirovaniya borom (Increasing of the physical and mechanical properties of the high-strength cast iron by boron microalloying).Materialy X syezda liteyshchikov Rossii (Materials of the X congress of Russian foundry workers). Kazan : Vertolet, 2011. pp. 153-155.

13. Girshovich N. G. Spravochnik po chugunnomu lityu (Reference book on the cast-iron founding). Leningrad : Mashinostroenie, 1978. 758 p.

14. V. I. Krestyanov, E. A. Vestfalskiy, S. S. Bakuma, E. V. Stepantsov. Chugun (Cast iron). Patent RF, No. 2138578 C22 C37/10. Declarant and patentee : "Association of metallurgists and investors" LLC No. 98122904/02. Asserted 18.12.98. Published 20.02.03. Bulletin No. 5.