SU893392A1 - Apparatus for introducing metal into continuous casting mould - Google Patents

Description

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The invention relates to metallurgy, namely to the continuous casting of metals and alloys.

The closest in technical essence to the present invention is a device for metal casting, containing a refractory glass with a passage channel and slotted outlet openings in the wall, made at a distance of 0.2-0.5 of the diameter of the conductive channel to the axis of the glass. This makes it possible to reduce to a certain extent the intensity of the melt flows in the crystallizer and to somewhat improve the quality of the cast ingots fl.

However, due to the fact that the slotted channels are made at a distance of 0.20, 5 of the diameter of the conductive channel to the axis of the glass, part of the metal stream from the intermittent bucket, which has the highest kinetic energy, enters the liquid phase of the workpiece, i.e. the intensity of the circulation flows is not reduced to the required value. In some cases, this leads to erosion of the ingot envelope and deteriorates it. macrostructure. In addition, this slot arrangement directs the bulk of the flow.

the melt in the lower part of the ingot and, to a lesser extent, turned to the surface of the metal covered with the slag-forming mixture. At the same time, there is a lack of physical heat in the meniscus, which complicates the normal operation of the slag-forming mixture and impairs the surface quality of the ingots. In addition, moving relative to

10 high-speed holes, the metal of the central portion of the jet from the tundish blurs the slit hole, resulting in unstable casting conditions.

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The purpose of the invention is to improve the quality of the ingots due to a significant decrease in the circulation flows of the liquid metal in the mold, increasing the efficiency of the slag-forming mixture and stabilizing the casting conditions.

This goal is achieved by the fact that in the device for the supply of metals to the crystallizer, containing

25 refractory cup with a conductive channel and slotted outlet openings in the wall; the outlet openings are made in the form of three slits, the large axes of whose output sections intersect at one point so that

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of these axes are parallel to the axis of the glass, and the other two intersect at an angle of 150-170 and form an angle of 105iS with the first axis.

These signs, which ensure a higher quality of the cast ingots, are determined on the basis of hydraulic modeling of the process of casting steel on the GNSS through submersible glasses with different positions of slotted holes, parallel, angled to each other, and with mutual intersection of the slots at different angles. In the process of modeling using high-speed filming, the dynamics of the propagation of streams of tinted modeling fluid were recorded. Evaluated the direction and speed of flow. The erosion of the ingot shell due to its melting by the flows of superheated steel was simulated by the process of dissolving the modeling substance by the liquid flows entering the crystallizer model.

The results obtained allow to establish that the highest flow rates at the exit from the holes (up to 240 mm / s) are obtained when pouring through the glass with the arrangement of the slit holes in a plane parallel to the axis of the glass, and the smallest (up to 160 mm / s) - when casting a glass with a hole in the form of three slits, the large axes of the output sections of which intersect at one point at certain angles. In the latter case, the minimum blurring effect of the jet on the ingot shell is also noted. Moreover, the most favorable results were obtained on a glass in which the major axes of the cross sections of the outlet openings intersect each other so that one axis is parallel to the axis of the glass and the other two intersect at an angle of 150-170 and form an angle of 105-95 ° with the first axis. When casting through this glass, the casting process is stable, the speed varies slightly with time and provides effective heating of the slag-forming mixture without burr meniscus.

The obtained results can probably be explained by the fact that the presence of intersecting in different planes t x at certain angles of the slots makes it possible to disperse the flow to the greatest degree and thereby reduce its kinetic energy and turbulence. In addition, intersecting gaps, obviously. The mutual positive influence of the dispersed parts of the flow is ensured, as a result of which we obtain a more laminar flow at the outlet from the holes with a lower initial velocity. When two slots intersect at an angle of ISO-ITO, they form in the upper part of the slit located parallel to the axis of the glass.

the protrusion cuts to some extent the flow and serves as a kind of stabilizer. When two slots intersect at an angle of 180, we do not observe the stabilization effect, and the flow velocity field has changed over time over wider limits. With a decrease in the angle of intersection of the slots of less than 150, a slight increase in the flow at the outlet of the holes was noted. In addition, the lower limit of the intersection angle of the slots is limited by the length of the glass, and the generally accepted size of the part of the glass that is immersed in molten steel during casting.

Figure 1 shows the proposed device, a General view; Fig.2 section aa on fig.1.

The device consists of a refractory cup 1 for the supply of metal below the meniscus level in the mold. The glass has an outlet opening2 consisting of three slotted channels with large axes of output sections that intersect at one point so that one of these axes is parallel to the axis of the glass and the other two intersect at an angle of 150-170 ° and form an angle of 105-95 ° with the first axis.

The device works as follows.

Liquid steel from the tundish enters the conductive channel 3 of the cup and exits from it through the slit openings under the meniscus in the mold. The arrangement of the slit holes so that their large axes of the input sections intersect at one point and one axis is parallel to the axis of the glass, and the other two intersect at an angle of 150170, significantly reduces the intensity of circulation of the flows, increases the efficiency of the slag-forming mixture, stabilizes the casting process and increases the resistance of the glass. All this improves the quality of ingots.

Claims (1)

1. USSR author's certificate No. 582619, cl. In Я2 О 11/00, 1975.