JSC Ural Steel, Novotroitsk, Russia:
G. A. Kunitsyn, Dr. Eng., Technical Director, e-mail: g.kunitsyn@uralsteel.com
M. S. Kuznetsov, Cand. Eng., Head of department, e-mail: m.kuznetsov@uralsteel.com

Novotroitsk Branch of NUST MISIS, Novotroitsk, Russia:
A. N. Shapovalov, Cand. Eng., Associate Professor, Head of the Dept. of Metallurgical Technologies and Equipment, e-mail: alshapo@misis.ru

NPP Tekhnologiya, Chelyabinsk, Russia:
I. V. Bakin, Head of Innovation, Modernization and Technical Development Department, e-mail: igor.npp.bakin@gmail.com

Ladle treatment of steel with calcium-containing flux-cored wires is an integral part of modern production technology. However, using only silicocalcium and aluminum, steelmakers are not always able to change the morphology of non-metallic inclusions (NI) in the right direction and create conditions for their removal from the liquid metal. The results of a pilot-industrial experiment on the production of steel with increased requirements for non-metallic inclusions are presented. During the experiment, instead of a standard wire with SС40 grade silicocalcium, a flux-cored wire with complex modifiers was used. Complex microcrystalline modifiers contained, in addition to calcium, such alkaline earth metals as barium and strontium. It has been established that the replacement of silicocalcium with experimental variants of modifiers provided a decrease in the maximum score for brittle silicates in the sheet metal (according to GOST 1778) from 4.0 to 1.5–2.5. The maximum contamination of sheet metal with non-deforming silicates decreased from 4.0 points according to the standard technology to 3.0–3.5 points when using experimental microcrystalline modifiers. Improvement of the basic physical properties of sheet metal was the result of the reducing the contamination of steel with non-metallic inclusions with experimental modifiers. Thus, the replacement of silicocalcium with experimental modifiers provided an increase in the strength properties of rolled sheets both in static tensile tests and in dynamic impact bending tests at low temperatures. The indicated influence was observed for all variants of experimental modifiers consumption. At the same time, with an increase in the consumption of modifiers, the positive effect on the mechanical properties of steel, as a rule, increased.
V. A. Golubtsov, I. V. Ryabchikov, A. A. Tokarev, V. V. Novokreshchenov, A. O. Ovodov took part in the work.

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