SU994567A1 - Charge for alloying steel - Google Patents

Description

This invention relates to metallurgy, in particular, to the production of vanadium-containing steels for castings and ingots.

Typically, ferrovanadium or other vanadium ferroalloys (master alloys) are used to alloy steel with vanadium. These materials are expensive and scarce, resulting in a significant oh4y increase in the value of steel produced and therefore are of little use when used for mass purposes.

In addition, when using ferrovanadium and vanadium masterpieces, the extraction of vanadium from ore to steel is significantly reduced. When using ferrovanadium, 39.5% of vanadium reaches steel, and when using vanadium master alloys, 47.6% of Wangshi.

A known exothermic mixture for steel alloying (charge) on the basis of vanadium-containing slag, containing in its composition, besides it, silicon, carbon, nitrogen-containing substance, and kg. This pos-. It is possible to increase the extraction of vanadium from steel into steel to 52.8% and to reduce

the cost of its alloying of the van | (itG1.,

However, the field of application of this alloying material is limited, since the presence of the nitrogen-containing substance in the exothermic mixture implies its use for the doping of nitrogen-containing steels, and calcium leads to a certain increase in its cost and deficiency.

The closest to the technical essence and the achieved result to the invention is the charge for steel alloying Vanghia, containing vanadium slag, aluminum, silicon, and oxide.

Such an exothermic mixture for vanadium alloying and steel refining makes it possible to use all the advantages of the previous one (exothermic mixture of steel alloying) and has a wider range of application, i.e. practically can be used for doping

25 ngshey any brands with no restrictions 2.

However, due to the use of a crush, which is introduced in the form of expensive and scarce strong glass (or metallic calcium), it is over-consumed and the cost of alloying steel with vanadium, as well as an increase in its cost price losses associated with the melting of the deoxidizing agent of slag-forming additives and the dissociation of calcium carbonite, also leads to higher costs and waste of materials. The purpose of the invention is to reduce the cost of steel and increase efficiency of production. The goal is achieved by the fact that silicon carbide, silicon dioxide, alumina oxide, sodium oxide, fluorine-containing material are additionally introduced into the mixture for doping with vanadium, containing vanadium aluminum, aluminum, silicon, calcium oxide, and .%: Aluminum, and silicon (in cyNcvse) 15 - 35 Calcium oxide 0.4-5.0 Silicon carbide. 3.0-12.0 Silicon dioxide 0.4-5.0 Oxide aluminum 5.0-14.0 Sodium oxide 0.4-3.0 Fluorine-containing material 0.2-0.5 Vanadium slag Else Aluminum, silicon, oxide calcium, 1sarbid silicon, silica, alumina, sodium oxide, fluorine are used. slag electrothermal production silumin. The ratio of charge components for doping is determined from the following considerations. The amount of reducing agents (aluminum, silicon, silicon carbide) was determined from the conditions of complete reduction of vanadium, iron, manganese from converter vanadium slag, steel deoxidation and heat generation due to the heat of exothermic reactions, which is necessary for fast formation of a fluid-active active slag, and heat loss compensation. . The content of reducing agents less than the lower limit does not provide the specified conditions, and more than the upper limit does not contribute to the improvement of process performance. In addition, the introduction of silicon carbide into the mixture, which is a strong reducing agent, increases the deoxidizing ability of aluminum and silicon and makes it possible to exclude expensive and scarce calcium from the composition. Slag-forming additives: alumina, calcium oxide, fluorine-containing materials, sodium oxide, at this ratio, contribute to the production of slag with low fusibility values of the liquidus temperature. and in z.kost that. significantly intensifies diffusion processes of interaction between slag and metal. Alumina, sodium oxide, fluorine-oxide materials are fluxing additives, their content below the lower limit does not contribute to a noticeable decrease in the viscosity and liquidus temperature formed after the slag mixture, and a higher decrease in the viscosity of the slag. Calcium oxide 0.4–5.0% contributes to the increase in the basicity of slag. When its content is more than 5%, the cost of heat for melting the charge increases. At the same time, the content of silicon dioxide in the batch up to 5% does not complicate the process of reducing vanadium, iron, manganese, and slag melting. This circumstance makes it possible to use less deficient slag-forming and charge materials in the composition of the charge. The most fully described advantages are manifested when using as a component of the slag charge of electrothermal production of silumin (production waste), which contains the necessary ingredients in order to achieve the goal. To determine the feasibility of the manufacturability of the proposed mixture for steel alloying, it is carried out industrial tests using the compositions shown in the table. The 35FL steel is melted in an electric arc furnace with a capacity of 5 tons. The mixture for alloying steel is introduced into the recovery period of melting in the form of a mechanical mixture of vanadium converter slag according to TU 14-11-178-79, having a chemical composition, wt.%: Pioxy Vanadium 13-26 Silicon Dioxide 12 - 26 Iron General 28-42 Calcium Oxide Up to 1.5 Magnesium Oxide 1.0-6.0 Manganese Oxide 5-13 Chromium Oxide1.0-5.0 Aluminum Oxide 0.6-1.8 . Metal inclusion 4.0-25.0 and slag of electrothermal production of silumin according to TU 48-01-13-75, with the following chemical composition, May.% S / Aluminum, and silicon. . (total) 30-60 Aluminum oxide 10-28 Silicon dioxide Up to 5.0 Silicon carbide 6 - le Calcium oxide Up to 5.0

Sodium oxide O, 8-6, 6 Fluoro0.4-1.0

When used for doping all three compositions listed in the table, the required vanadium content in steel is obtained, 12% at a high degree of its reduction from converter slag. According to the mechanical properties of the smelted steel meets the requirements of the mill.

The feasibility of using the proposed mixture is confirmed by the fact that the cost of doping with nanium and 1 ton of steel (calculated data, the basic content of vanadium is 0.10%) is, rub:

using ferrovanadi 7, 33 using an exothermic mixture for doping vanadium and refining steel

for the prototype. 6.27

using

the proposed charge

for alloying steel 5.26

In addition, the use of slag electrothermal production silumin poz. It can save scarce fragments (aluminum, silicocalcium, or metallic calcium), and form recycled materials. from the “moves that contain these elements /. :

S Thus, the use, proposed) of the charge as an alloying material leads to a decrease in the stress of 1 ton of steel by 1.01 rubles. and savings of materials. Yri volume

0. Steel production 30 thousand tons of eco-. The effect is 30300 rubles.

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Claims (2)

1. A mixture for alloying steel with vanadium, containing vanadium ish aluminum, silicon, calcium oxide, characterized in that, in order to reduce the cost price of a hundred and increase production efficiency, carbide, silicon, silicon dioxide, oxide, oxide are additionally introduced into it sodium, fluorine-containing material with a trace of the ratio of components, wt.%: Alkminium and silicon (in total) 15 - 35 Calcium Oxide 0.4-5.0 Silicon Carbide 3.0-12.0 JJfByoKKCb Silicon 0.4-5.0 Aluminum oxide 5.0-14.0 Sodium oxide. 0.4-3.0 Fluorine-containing material. 0.2-0.5 Vanadium shpak. The rest 2. The mixture according to claim 1, about t and h and the fact that. Papaum, silicon, calcium oxide, silicon carbide silicon dioxide, aluminum oxide, sodium oxide, fluorine introduced in the form of slag electrothermal production silumin. Sources of infmacin taken into account during the examination 1. Authors certificate of the USSR 697572, cl. C 21 C 5/52, 1979. 2. USSR author's certificate number 54682, cl. C 21 C 5/52, 1977 ..