SU1547952A1 - Method of preparing charge for melting high-alloyed steels and alloys - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular, to methods for preparing charge materials for smelting. The purpose of the invention is to reduce energy consumption, loss of alloying and ferroalloys and increase the productivity of the process. Alloying elements and ferroalloys are placed in the central zone in the container inside the chips, and heated before briquetting are carried out in an unsealed container, placing it in a furnace with a temperature of 0.75-0.90 melting point of the container material, the temperature zone is 0.3-0.5 chip melting point, while briquetting is performed to a material density in the axial zone of 40-70%. Due to improved heat transfer and intensification of heating, as well as simultaneous heating of alloying materials together with chips, the productivity increases by 70-90% compared to the known method, and energy consumption increases by 20-40%. 1 tab.

Description

The invention relates to ferrous metallurgy, in particular, to methods for preparing charge materials for smelting, and can be carried out at all enterprises that produce steel in electric arc furnaces for shaped casting and blanks for forgings of various purposes.

The purpose of the invention is to reduce energy consumption, loss of alloying and ferroalloys and increase the productivity of the process.

In contrast to the known method, alloying elements and ferroalloys.

placed in the central zone in the container inside the chips and heated before briquetting in a depressurized container, placing it in a furnace with a temperature of 0.75-0.90 of the container materials melting temperature, and being kept at this temperature until the axial zone reaches 0, 3-0.5 chip melting point, and briquetting is carried out to a material density in the axial zone of 40-70%.

The premises of alloying elements and ferroalloys in the central zone CondO

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In the course of subsequent melting of the charge, the loss of alloying and ferroalloys is achieved.

Heating the container in an unsealed state, placing it in a furnace with a temperature of 0.75-0.90 in the melting temperature of the container material is associated with the need to avoid melting the container material while increasing the productivity of the process.

Placing the container in an oven with a temperature below 0.75 of the melting temperature of the container material is impractical because the productivity of the process decreases as a result of its longer heating to the pressing temperature.

Placing the container in an oven with a temperature above 0.90, the melting temperature of the container material may lead to the container melting and breaking upon subsequent pressing.

The holding of the unsealed container in the furnace until the temperature in its axial zone reaches 0.3-0.5 chip melting temperature is ensured by ensuring the best performance during subsequent pressing of the chip.

When the temperature in the axial zone of the container is less than 0.3 of the melting point of the chip material, incomplete removal of moisture, emulsion, oil, and other organic substances is possible. In addition, insufficient heating of the axial zone can lead to a low density in this zone and a subsequent increased carbon loss of the metal during melting. Increasing the temperature in the axial zone of the container to more than 0.5 of the melting point of the chip material leads to an increased energy consumption for heating and a decrease in the productivity of the process.

Example. Made a cylindrical container of art. 3 with a diameter of 76 mm, a height of 200 mm, a wall thickness of 1.5 mm. A hole with a diameter of about 3 mm was drilled in the side of the container to allow gaseous products to exit during heating.

The container was loaded with chips from alloy HN623MKT10B. When the chip was filling half the height of the container, alloying elements and ferroalloys were placed in the axial zone. amount

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five

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five

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and the mass of alloying elements and ferroalloys was determined on the basis of the chemical composition of the chips, taking into account the loss of alloying elements and ferroalloys. Then continued filling the container with chips. After loading the chips, the top cover was welded to the container. The bulk density of the chips in the container was about 38%.

The container was heated in a chamber furnace at 1220 ° C, which was 0.8 melting points of the container material. At this temperature, the container was kept until the melting point XN62B11CTUB alloy was reached in the axial zone.

The briquetting of the container with the raw material 1 was done in a rigid mold at a press with a force of 2.0 MI. The dimensions of the briquettes obtained are 20 mm with a material density in the axial zone of 58%. A total of 20 briquettes were made from HI62VMKTUB chips, the mass of each briquette was about 2 kg.

The manufactured briquettes were melted in an induction furnace followed by the use of vacuum arc remelting. Blades of gas turbine engines and lei were manufactured from the obtained ingot.

Briquetting with a density below 40% leads to the destruction of briquettes during their subsequent transportation to the furnaces. Briquetting with a density of more than 70% is undesirable from the point of view of saving energy costs during pressing.

Tests of the proposed method were carried out at the boundary (experiments-2, 4, 7, 8, 11, and 12), beyond the limits (experiments 1, 5, 6, 9, 10, and 13) and the optimum values of the parameters of the method (experiment 3), to obtain comparative data were carried out similarly to the test of the known method (experiment 14).

The modes of the proposed and known methods and the results of the tests are shown in the table.

Analysis of the data presented in the table shows that the proposed method for preparing the charge improves the process productivity by 70-90%, reduces energy consumption by 20-40%, and reduces the loss of alloying components and ferroalloys.

The use of the proposed method of preparation of the charge for smelting

high-alloy steels and alloys, as compared with the known method, provide a higher productivity of the process; reduction of energy consumption during heating of containers with chips and subsequent briquetting; reducing the loss of dopant components and ferroalloys by placing them in the axial zone of the container.

Claims (1)

Invention Formula The method of preparation of the charge for smelting high-alloy steels and alloys, including the preparation of chips, its crushing, cleaning of oils and shredding into a metal container, heating, briquetting, characterized in that, in order to reduce energy consumption, loss of alloying and ferroalloys and increase the productivity of the process, alloying elements and ferroalloys are placed in the central zone of the container inside the shavings; container placed in a furnace with a temperature of 0.75-0.90 melting temperature of the material of the container, and maintained at this temperature until reaching a temperature in the axial zone of 0.3-0.5 laziness chip material, and the briquetting is carried out until the density of the material in the axial zone other non-metallic impurities, zag- 20 40-70%. 0.98 0.4 0.80 0.2 0,80 0,80 0,80 0,80 0.3 0.5 0.6 0.4 0.80 0.80 0.80 0.4 0.4 0.4 2.2 0.8 shell The destruction of the heated container during transport Great effort during briquetting 2.0 1.6 1.2 1.85 1.85 1.85 1.85 0.75 0.50 0.45 0.50 0.55 0.70 0.80 Big losses on waste of the alloying components and ferroalloys Great effort when briquetting