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

I. O. Leushin, Dr. Eng., Prof., Head of the Dept. of Metallurgical Technologies and Equipment, e-mail: igoleu@yandex.ru
A. N. Grachev, Cand. Eng., Associate Prof., Dept. of Metallurgical Technologies and Equipment, e-mail: alexgra76@mail.ru
L. I. Leushina, Cand. Eng., Associate Prof., Dept. of Metallurgical Technologies and Equipment, e-mail: kafmto@mail.ru

JSC Ruspolymet, Kulebaki, Russia:
A. D. Ryabtsev, Dr. Eng., Prof., Head of the Innovation Center, e-mail: a.ryabtsev@ruspolymet.ru

A. A. Garchenko (JSC Ruspolymet) took part in the work.

The problem of minimizing the amount of head cuttings and increasing the technological yield of stainless steel ingots is considered. The technological scheme of the active ingot production is analyzed, which provides for filling the metal mirror at certain stages of filling the mold with heat-insulating slag-forming and exothermic mixtures. The focus of the authors is the development of an inexpensive exothermic insulation mixture consisting of non-deficient components that does not require restructuring of the existing production and allows achieving an effect comparable to that obtained when using a foreign prototype. Based on the results of the conducted critical analysis, the shortcomings of the imported mixture were identified and a mixture of a new composition was proposed, characterized by an improved ability to heat insulate the area of itswork. Unlike the prototype, coke, CHP ash and chamotte are excluded from the mixture components, but in addition to aluminum-containing material, heat-expanding material, cast graphite and fluorite concentrate, it contains calcined blacksmith scale, potassium or sodium nitrate, or barium, sawdust and alumina cement. The functional purpose and mechanism of operation of each component of the mixture are described in detail. The results of pilot-industrial testing of the mixture in the manufacture of KS 5.3 ingots from steel 12Kh18N10Т siphon pouring into molds are presented, as a result of which the development is recommended for further use in the production of the base enterprise. According to the company's estimates, the use of the developed mixture will reduce the height of the profitable part by 7% without deteriorating the quality of the metal in the main body of the ingot and achieve an economic effect of more than 35 thousand rubles on each ingot.

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