SU1216216A1 - Method of alloying steel - Google Patents

Description

 one

The invention relates to ferrous metallurgy and can be used in the smelting of carbon and alloyed steels in electric arc furnaces.

The aim of the invention is to increase the productivity of the smelting unit, reduce the contamination of steel with non-metallic inclusions, and reduce the consumption of margaceous-containing ferroalloys,

Manganese-containing slags, in which the ratio of silica to cyr-jMe of manganese and calcium oxides and emenket — from 8 to 155–1.9, are close to the tactical composition in the SiOj – CaO – MnQ system, and therefore have a low melting point; 1240-125Г / С The use of such materials accelerates the formation of the refining shpak and reduces the duration of both the refining period and the strip as a whole.

An increase or decrease in this ratio leads to a significant increase in the melting temperature of manganese-containing slags, which in turn makes it difficult to form refining slags.

The activity coefficient of manganese oxide in sour yupaks is substantial but lower than in the main ones. At 1600 C, the MpO activity coefficient in basic slags is 5.0 times higher than in acid slags, respectively, 1i, 25 and 0.25.

However, in basic slags, the activity ratio of manganese oxide depends on the basicity of the slag, the ratio of CaO / SiO, which is confirmed; the price for the experimental melts using manganese-containing slags, in which the silica-to-ic ratio is 1.5-1 ,9,

As a manganese-containing donkeys, waste slags of ferroalloy production of the following chemical composition can be used,%: Sug 48-52, MpO 17-20, CaO 10-15, AlgOg 8, up to 5 and FeO up to 0.3. The manganese content in these packs is high enough to provide an increase in the manganese content in the metal when these materials are used as one of the components to form the refining slags.

162162

Manganese; Drester Ets e slags specified composition, in a mixture with lime must be introduced into the electric arc furnace immediately after removal of the oxidizer; of this slag. This restriction is caused by the need to form a sufficiently liquid homogeneous refining slag in the furnace furnace without increasing the duration of the period.

And 5 refining.

Example. In a 100 t electric arc furnace, steel types 10-45 are melted. The melting and oxidation period are carried out in the usual way.

SS After downloading the oxidative slag, the metaplus is deacidified with lump ferrous sulfatema and then slag-forming materials are set: 1000 kg manganese-containing .1 pack and 1500 kg of lime,

20 In the process of smelting slag-to-slurry mixture into the furnace, 1.0-2.0 kg / ton of coke powder is set, which contributes to accelerated recovery of manganese and iron oxides from slag. After the molten slag-forming and metal sampling, the slag is deoxidized with coke and ferrosilicon powders. The use of manganese-containing slag accelerates the formation of the refining donkey and creates a shortening of the refining period by 3-5 minutes. The final adjustment of the manganese smelting is carried out by manganese-containing ferroalloys: taking into account the reduced manganese of the KZ slag.

In tab. 1 shows data on the effect of the composition of the used manganese-containing slags, in particular, the SiO./CaO + MpO ratio, on the technical-ecological

,,. The nominal melting indices according to the claimed method with the ratio between manganese-containing slag and lime equal to 1.:2.2.

As c-pedals from the above data, the low melting point of manganese-containing slags, in which the ratio of SiO / CaO + MpO components is 155-1.9, provides faster slag-forming and it is 5Q without the use of fluorspar.

The priming of manganese-containing slags with an optimal composition ensures the rapid and complete reduction of oxides of 1 gh mangans and the corresponding 35 increase in manganese content in steel.

Table 2 shows data on the effect of the composition of the slag-forming mixture.

35

3

in particular, the relationship between manganese-containing slag and lime, on the technical and economic indicators of smelting.

As follows from the above data, the optimum ratio between manganese-containing slags and lime is in the range of 1.5-3.0. This ratio provides a shorter refining interval.

 the period (mainly due to the rapid formation of refining slag, Table 2), effective desulfurization of the metal, as well as a decrease in the consumption of manganese ferroalloys due to the reduction of manganese from the slag.

The economic effect from the implementation of the 10 method will be more than 500 thousand rubles.

Table 1

table 2

Claims (1)

METHOD OF STEEL ALLOYING, including the use of ferroalloy production joints and the final adjustment of the chemical composition of ferroalloys, characterized in that, in order to increase the productivity of the melting unit, reduce steel contamination by non-metallic inclusions and reduce the consumption of manganese-containing ferroalloys, they are introduced into the arc furnace immediately after removal of the oxidizing slag slag with a ratio of silica to the sum of oxides of manganese and calcium equal to 1.5-1.9, in a mixture with lime in a ratio of 1: (1.5-3.0).