EVRAZ Nizhniy Tagil Iron & Steel Works (EVRAZ NTMK) (Nizhniy Tagil, Russia):

Kushnarev A. V., Cand. Eng., Managing Director, e-mail: director@ntmk.ru

Due to the increasing requirements on the metallurgical quality of the railroad wheels, JSC “EVRAZ NTMK” has developed a steel plant revamping and improvement program which offers transition to a principaly new technological level including the converter method of liquid steel manufacturing followed by secondary metallurgy, vacuum degassing and continuous casting. The main concept of the new technology can be formulated as follows: production of clean steel semiproduct (free of phosphorus, silphur, gases and non-ferrous imputities); secondary metallurgy providing minimum gas pickup in steel and low non-metallic inclusions; continuous casting of steel into billets as the base for quality improvement of finished product and higher yield. The technology of wheel steel production in basic oxygen converters via duplex process is described and required chemical composition of vanadium iron and semiproduct is presented. Development of secodary metallurgical treatment of wheel steel is described and mechanical properties of wheel steel (such as tensile strength, relative elongation and contraction, hardness and impact toughness) are observed for the cases of aluminum and aluminum-free deoxidation and compared with standard data. Desulphurizing route is presented and modification of non-metallic inclusions by silicocalcium processing and without it are comparatively analyzed. The histogram of hydrogen distribution in wheel steel displayed hydrogen content after vacuum degassing.

1. Smirnov L. A., Deryabin Yu. A., Nosov S. K. Konverternyy peredel vanadievogo chuguna (Converter production stage of vanadium cast iron). Ekaterinburg : Middle Urals Book Publishing House, 2001. 528 p.
2. Kushnarev A. V., Kirichkov A. A., Petrenko A. A., Savelev M. V., Remigo S. A. Sovershenstvovanie tekhnologii obrabotki metalla na ustanovke desulfuratsii v usloviyakh Otkrytogo Aktsionernogo Obshchestva «NTMK» (Improvement of metal processing technology on desulphurization unit in the conditions of “Nizhniy Tagil Iron and Steel Works” JSC). X Mezhdunarodnyy simpozium po desulfuratsii chuguna i stali (The X International Symposium on desulphuration of cast iron and steel). Lisbon, 2011. pp. 55–62.
3. Kushnarev A. V., Smirnov L. A., Mukhatdinov N. Kh., Babenko A. A., Danilin Yu. A., Vinogradov S. V., Chelpan S. M., Mukhranov N. V., Levchuk V. V., Shekhovtsov E. V., Remigo S. A., Krivykh L. Yu. Osvoenie tekhnologii vyplavki stali iz uglerodistogo poluprodukta v konverterakh s kombinirovannoy produvkoy (Mastering of technology of steel smelting from carbonaceous semi-finished product in combined blowing converters). Trudy X Mezhdunarodnogo kongressa staleplavilshchikov, Magnitogorsk, 13–17 oktyabrya, 2008 (Proceedings of the X International congress of steel makers, Magnitogorsk, October 13–17, 2008). Moscow, 2009. pp. 130–132.
4. Kushnarev A. V., Ilin V. I., Shekhovtsov E. V., Fedorov L. K., Minaeva L. V. Stal — Steel in Translation. 2003. No. 6. pp. 14–16.
5. GOST 10791-2004. Kolesa tselnokatanye. Tekhnicheskie usloviya (State Standard 10791-2004. Solid-rolled wheels. Technical requirements). Introduced: 2005–07–01. Moscow : Publishing House of Standards, 2006.
6. GOST 1778-70. Stal. Metallograficheskie metody opredeleniya nemetallicheskikh vklyucheniy (State standard 1778-70. Steel. Metallographic methods of definition of non-metallic inclusions). Introduced: 1972–01–01. Moscow : Publishing House of Standards, 2011.