RU58405U1 - DEVICE FOR PROTECTING A METAL JET WITH GAS - Google Patents

Abstract

The utility model relates to the field of ferrous metallurgy, and more particularly to continuous casting of steel.

The technical result of the utility model is to reduce the increase in nitrogen in steel, reduce the consumption of protective gas, improve the quality of the metal.

The technical result is achieved in that in a device containing an outlet cup for supplying molten metal, a housing mounted thereon with an annular groove, a casing and a nozzle for supplying gas, a casting pipe, according to the proposal, the annular groove is made in the form of two chambers, while the height of the first chamber equal to 1.7 ÷ 2 of the height of the second chamber connected to the output nozzle, which is conical at an angle of 10 ÷ 15 ° to the axis of the housing, and the width of the groove between the chambers is 1.3 ÷ 1.6 of the width of the output nozzle. The casting pipe is installed below the end of the outlet nozzle at a distance of 3.0 ÷ 6.0 of its width.

Using the proposed device will more reliably protect the metal stream from contact with air, reduce non-metallic inclusions, reduce the increase in nitrogen in steel, improve the quality of the metal.

Description

The utility model relates to the field of ferrous metallurgy, and more particularly to continuous casting of steel.

A device is known for protecting a metal jet with gas, comprising a housing, along the axis of symmetry of which a channel for supplying molten metal is made, a gas pipeline for supplying neutral gas, nozzles located on a circle, the center of which is located on the axis of symmetry of the housing, and communicated by an annular groove from the output section having a cross-section in rectangular shape [1].

The proposed device does not prevent a significant increase in nitrogen in the cast metal even with a high consumption of argon, the high quality of cast billets is not ensured.

The closest in their technical essence and the achieved results to the proposed device is a device for protecting a metal jet with gas, containing a cylindrical body, along the axis of symmetry of which a channel is made, and a gas pipeline for supplying inert gas to an annular groove made in a cylindrical body. The ratio of the diameters of the annular groove, the cylindrical part of the lower protrusion and the upper annular protrusion is (1.05 ÷ 1.07) :( 1.01 ÷ 1.05): 1 [2].

A disadvantage of the known device is that it does not sufficiently protect the metal stream, does not limit the growth of nitrogen in steel as a result of the interaction of the metal stream with atmospheric air, since it does not provide a continuous annular gas stream around the stream of cast steel.

The technical result of the utility model is to reduce the increase in nitrogen in steel, reduce the consumption of protective gas, improve the quality of continuously cast billets.

The technical result is achieved in that in a device containing an outlet cup for supplying molten metal, a housing mounted thereon with an annular groove, a casing and a nozzle for supplying gas, a casting pipe, according to the proposal, the annular groove is made in the form of two chambers, while the height of the first chamber equal to 1.7 ÷ 2 of the height of the second chamber connected to the output nozzle, which is conical at an angle of 10 ÷ 15 ° to the axis of the housing, and the width of the groove between the chambers is 1.3 ÷ 1.6 of the width of the output nozzle. The casting pipe is installed below the end of the outlet nozzle at a distance of 3.0 ÷ 6.0 of its width.

In FIG. The proposed device is shown.

The device comprises an outlet cup 1 for supplying molten metal, a cylindrical body 2 with an annular groove, a casing 3, a nozzle 4 for supplying a protective gas, a filling pipe 5. In a cylindrical body 2, a groove with two different chambers 6 and 7 is made in a plane perpendicular to the axis of symmetry heights. The height of the first chamber 6 is 1.7 ÷ 2 of the height of the second 7, and the width of the groove between them is 1.3 ÷ 1.6 of the width of the output nozzle 8, which is conical at an angle of 10 ÷ 15 ° to the axis of the housing. The casting pipe 5 is located below the end of the output nozzle 8 at a distance of 3.0 ÷ 6.0 of its width.

The device operates as follows.

Prior to casting, the device is fixed to the outlet 1 of the slide gate. Then, a gas pipeline is connected to the pipe 4. In the process of casting steel, a pouring pipe 5 is pressed to the outlet glass 1, argon is fed into the gas pipeline. The gas flow, passing through the chambers 6 and 7, is stabilized and at the exit from the nozzle 8 forms a continuous screen of protective gas. The implementation of the output nozzle 8 is conical, at an angle of 10 ÷ 15 ° to the axis of the housing and the preloading of the casting pipe 5 below the end of the output nozzle 8 at a distance of 3.0 ÷ 6.0

the widths provide a stable gas flow without turbulence, excluding air leakage, the most complete protection of the metal stream.

Tests of the device for protecting a metal stream with gas were carried out on a double-strand continuous casting machine with a mold section of 250 × 1800 mm for steel grades 08Yu, 22Gyu, 10G2FVYu, 17G1SU, IF-type. The smelting mass was 350 tons, the casting speed was 0.8–1.0 m / min.

The device has a cylindrical body, a casing, together they form two chambers, the height of the first is 35 mm, the second is 20 mm, and the width of the groove between them is 2 mm. The output nozzle is 1.5 mm and is made at an angle of 10 ° to the axis of the housing. The filling pipe is located below the end of the outlet nozzle at a distance of 9 mm.

When using the claimed device for protecting a metal stream with gas, the following results were obtained. The increase in nitrogen in steel in the intermediate ladle during casting did not exceed 5 ppm at a specific argon flow rate of 100 ÷ 150 l / min. When casting metal without the claimed device, the maximum increase in nitrogen reached 11 ÷ 20 ppm with a specific argon flow rate of 100 ÷ 150 l / min.

Using the proposed device will more reliably protect the metal stream from contact with air, reduce non-metallic inclusions, reduce the increase in nitrogen in steel, improve the quality of the metal.

Information sources:

1. USSR author's certificate No. 1616767, IPC В 22 D 7/12, 12/30/1990.

2. RF patent No. 2229358, IPC B 22 D 7/12, 05.27.2004.

Claims (1)

A device for protecting a metal stream with gas, comprising an outlet for supplying molten metal, a housing mounted thereon with an annular groove, a casing and a nozzle for supplying protective gas, a casting pipe, characterized in that the annular groove is made in the form of two chambers, the height of the first the chamber is equal to 1.7 ÷ 2 of the height of the second chamber connected to the outlet nozzle, which is conical at an angle of 10 ÷ 15 ° to the axis of the body, the width of the groove between the chambers is 1.3 ÷ 1.6 the width of the outlet nozzle, and the casting pipe on the lower discharge nozzle end at a distance of 3.0 ÷ 6.0 its width.