National Research Technological University "Moscow Institute of Steel and Alloys" (Russia):

A. G. Radyuk, radjuk@rambler.ru

A. E. Titlyanov

At the present time in Russia and abroad some experience in the application of gas-thermal coatings (GTC) have been accumulated to improve the metallurgical industry. The chair of Technology and Equipment of Tube Production (TOTP) of the National Research Technological University "Moscow Institute of Steel and Alloys" (NITU "MISIS") investigated the effectiveness of GTC in hot rolling. Considered method of applying GTC using electric arc metallization is the most simple and efficient. The authors have studied possibility of using aluminum to enhance GTC for hot-rolled steel, copper and titanium pieces: reduction of metal loss with the fumes, dross and trimmings, reduction of heat loss peal. Following results were obtained.

Metal loss on waste and dross on slabs of low-alloy steel with an aluminum GTC applied by electric plating, were 2.1-7.8 kg/t. It is less than that for slabs without coating. Expense ratio decreased from 1.195 to 1.152. On steel billets obtained from hot-rolled steel, varietal, coated, carbon-free layer was absent or its thickness was less than that without coating. Aluminum GTC applied to the surface of the slab of low-alloy steel is an effective material for reducing thickness of the rolled-in scale (up to 5 times) and the depth and number of surface cracks on the sheets. The coating on strips along the edges of adjacent wide and narrow sides eliminates appearance of cracks on the surface of overcooled edge zones of plates and align the mechanical properties along their length.

Application of aluminum coating thickness of 150 mcm by electric plating on copper billets is an effective method of protection against fumes and scaling during heating to 900 ^oC and subsequent hot rolling. In the process of hot rolling, Cu-Al diffusion layer is not destroyed and deformed with the substrate. Pre-compaction is caused by hot rolling of billet with aluminum GTC before heating and increases its protective properties.Application of GTC on the aluminum billet of titanium alloy PT-3V reduces heat transfer from the surface of rolls during hot rolling. Application of reflective screens, in which compacted aluminum GTC was used as reflective layer in the area of intermediate rolling group of hot rolling mills showed their high efficiency to keep rolled sheet warm.

1. Borisenok G. V., Vasilyev L. A., Voroshnin L. G. et al. Chemical and heat treatment of metals and alloys. M.: Metallurgiya, 1981. 152 р.

2. Bakalyuk Ya. H., Proskurin E. V. Tubes with metal corrosion-managing coatings. Moscow.: Metallurgiya, 1985. 200 р.

3. Hasui A., Morigaki O. Surfacing and spraying. M.: Mashinostroenie, 1985. 240 р.

4. Polukhin P. I., Klimenko V. М., Polukhin V. P. et al. Rolling of heavy plates. M.: Metallurgiya, 1984. 287 р.

5. Konovalov Y. V. Directory of distributors. Reference book in 2 books. Book 1. Production of hot-rolled sheet and strip. Moscow. Heat. 2008. 640 р.

6. Ryabov V. R. Calorizing steel. M.: Metallurgiya, 1973. 239 р.

7. Polukhin V. P., Titlyanov A. E., Gridnev I. M. et al. Application of protective coatings of aluminum during hot rolling of steels and alloys. Moscow Institute of Steel and Alloys - MISIS. 1982. № 145. P. 39-43.

8. Zinoviev A. V., Kolpashnikov A. I., Polukhin P. I. etc. Forming technology of non-ferrous metals and alloys. A Textbook for Universities. M.: Metallurgiya, 1992. 512 р.

9. Polukhin V. P., Titlyanov A. Е., Gridnev I. M. et al. Theory and technology of the deformation of metals. Researching Proceedings. Moscow Institute of Steel and Alloys - MISIS. M.: Metallurgiya, 1982. № 145. P. 35-39.

10. Khloponin V. N., Titlyanov A. E., Radyuk A. G., Koryshev A. N. The technology of continuous casting and hot rolling of steel sheet. Proceedings of International Conference. Vologda. 4-8 June 1991. No. 1. P. 92-96.

11. USSR Patent 1659153. Titlyanov A. E., Radyuk A. G., Koryshev A. N., Porazhinsky E. L. Buletin of Inventions. 1991. № 24.

12. Titlyanov A. E., Radyuk A. G. Izvestiya Vuzov – Chernaya Metallurgiya (News of High Schools - Ferrous Metallurgy). 1995. № 9. P. 46-48.