National University of Science and Technology "Moscow Institute of Steel and Alloys" (MISiS), Moscow, Russia:

V. A. Trusov, Doctor of Engineering Science, Professor, prof.trusov@mail.ru

M. B. Zinkevich, Post-graduate

The paper describes the method of transition of cooling agent in the units for accelerated cooling of rolled sections. Experimental unit for thermal strengthening of reinforced sections has been developed; it allowed to achieve preset heating temperature and is equipped by the feeder of rolled semiproduct (pinch roll unit) and control-measuring devices for monitoring of variations of hydrodynamic parameters in cooling unit and final temperature of accelerated cooling. The ratio of heat exchange has been determined for different speed and different temperature of accelerated cooling of rolled sections. The effect of hydrodynamic parameters of a colling unit on forming the structure and mechanical properties of rolled sections is analyzed. Possibility of obtaining stabilized structure of rolled sections (inside one melt) has been established experimentally, recommendations for improvement of production technology for periodic sections of A600C strength grade from low-carbon steel are given. Usage of such cooling units in production of thermally strengthened reinforced sections from weldable steels allows to rise productivity and achieve the required mechanical properties (including A600C). Recommended temperature of finishing deformation is equal to 800 ºC and corresponds to dual-phase area.

1. Kugushin A. A., Uzlov I. G., Kalmykov V. V. et al. Vysokoprochnaya armaturnaya stal (High-strength reinforcing bar steel). Moscow : Metallurgiya, 1986. 272 p.

2. Gubinskiy V. I., Minaev A. N., Goncharov Yu. V. Umenshenie okalinoobrazovaniya pri proizvodstve prokata (Decreasing of scale formation during rolled metal production). Kiev : Tekhnika, 1981. 135 p.

3. Landau L. D., Lifshits E. M. Gidrodinamika – pyatoe izdanie (Hydrodynamics – fifth edition). Moscow, 2003. 736 p.

4. Trusov V. A., Zinkevich M. B. Teoreticheskoe i eksperimentalnoe issledovanie uskorennogo okhlazhdeniya sortovogo prokata s prinuditelnym vrashcheniem okhladitelya (Theoretical and experimental researching of the accelerated cooling of bar with the forced turning of coolering agent). Nowe technologie w metalurgii i inzynierii materialowej. XII Miedzynarodowa konferencja naukowa – Czestochowa : Politechnica Czestochowska. 2011. S. 366–372.