DE1783194A1 - PROCESS FOR CONTINUOUS AND SEMI-STRAND CASTING OF METALS - Google Patents

Description

Metallurgichesky zavod imeni V.l. Lenina P 13 374 A Kuibyshev / USSR '1o. Feb. 1976

P 17 83 194.6-24. L / Br

Process for continuous casting and semi-continuous casting

of metals

The invention relates to methods of continuous casting and Semi-continuous casting of metals.

The continuous casting and semi-continuous casting of metals is known to be carried out in such a way that liquid metal from a device that ensures a uniform supply enters a mold, the metal touching its cooled walls, partially solidified and after exiting the mold up to is further cooled to complete solidification. This method g has a number of disadvantages. For example, during the solidification of the shifting strand, when it comes into contact with the mold walls on the strand surface, various types of defects, such as voids and burrs, arise. The inevitable formation of an air gap between the strand surface and the mold causes a reduction in the casting speed, the formation of beads on the surface of the strand and a deterioration in the internal structure of the strand. As a result of the surface defects, machining of the strands is necessary, which not only requires special operations, but also the output of useful

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metal is significantly reduced.

To reduce the friction of the strand on the mold surface is this lubricated. But this has unhealthy working conditions and a corresponding effort for the Applying the lubricant result.

The production of the molds is very expensive because of this

fe made high demands in terms of production quality

w ■. ■. ■. .

and they work perfectly under severe conditions should work.

The invention: is based on the object of specifying a method for continuous and semi-continuous casting of metals, which makes it possible to improve the strand structure, to produce strands with a surface that does not require machining, which ensures better working conditions and no expensive ones with the Molten Metal In Contact ™ requires molds and means to lubricate them.

According to the invention, the strand formation is achieved in that in the continuous and semi-continuous casting of metals The electromagnetic alternating field surrounding liquid metal is excited, which generates forces in the liquid metal flow, which are directed into the interior of the metal flow, a flow apart of the metal and shape it while on the A coolant is passed to the side face of the shaped strand in its solidification zone, ·.

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The essence of the inventive method for strand and Semi-continuous casting of metal consists in the following.

It becomes a surrounding molten metal stream electromagnetic alternating field excited. This field induces in the liquid metal (in the melt) an electromotive alternating force and eddy currents, during the interaction from eddy currents and magnetic fields arise electrodynamic (electromagnetic, mechanical, ponderomotor) forces, ™ the inside of the melt are directed and compress it. The molten metal receives a certain one

Cross-sectional shape with given geometric dimensions,

Induction coil

The shape the melt takes depends on the shape and the geometric dimensions depend on the strength of the magnetic field on the metal surface.

In order to produce a strand having a predetermined shape and predetermined dimensions frequency and current strength are chosen of the solenoid ä! She field-excited generator, providing for a uniform Mghetfeld on the line size and the strand uniformly cooled. The current frequency is chosen so

in

that the eddy currents induced by the shrimp at their surface layers flow, i.e. that a surface effect (skin effect) is created. So for cylindrical strands the Frequency determined by the condition that

^R St * ²

Aä ■ '■ '. ■

60982 3/0 ^ 5-7 * 5 * -4-

- 4 where R _e . - strand radius- in c_m and

You

A ₁ equivalents are the equivalent penetration depth of the current in the metal in cnij.

The electrodynamic forces shape the liquid metal (the melt) and prevent it from flowing apart during of the whole strand making process perfectly.

F die'Seitenflache of the shaped strand, passing a coolant in its solidification zone through which cooled the strand ■ .If wherein it completely solidifies.

For a better understanding of the essence of the invention, the method according to the invention is illustrated using an exemplary embodiment explained in more detail, in which aluminum is cast with the help of a system, as can be seen from the drawing.

k The process of potting aluminum is as follows. First, the frequency of the inductor current is selected. When producing a strand with a diameter of 345 mm, it is 2500 Hz. The casting speed is the same 12o mm / min.

The molten aluminum flows over a channel 2 and an opening 4 of a container 3 on the starting piece 9, the from below into the interior of a so-called electrical

Induction coil

magnetic continuous casting mold 1 forming - used will. Serving as a coolant and consisting of a _. - - · 5—

60 98 2 3 / OW '

Collecting tank Io meets water supplied via a nozzle 11 on the starting piece 9 and cools the molten metal that is on the starting piece 9 and solidify begins.

In the drawing, the solidified part of the melt is indicated by A, the part that has never solidified (liquid) is indicated by B.

That excited by the electromagnetic continuous casting mold electromagnetic field creates forces that cause it to flow apart prevent the liquid part B and shape the strand, which here assumes a cross-sectional shape corresponding to the electrical continuous casting mold.

While increasing the height of the column from molded, partially solidified and accumulated on the earpiece 9 the starting piece is lowered. At the same time, a pan 5 is placed on the surface of the molten metal (part B) put on. The one impinging on the cone 6 of the pan 5 Metal melts on theirs. Floor and flows through the openings 7 evenly distributed over the side walls 8 into the Inside of the electromagnetic continuous casting mold 1.

During the inflow of molten metal, the metal is formed inside the electromagnetic continuous casting mold and solidified _r wherein a column of solid metal corresponds' group which is lowered together with the einfahrstück.

-6-

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There are rollers to keep the stem in its vertical position 13 provided under the electromagnetic continuous casting mold are arranged, and can be moved in the horizontal direction. The solidification takes place when the water hits the directly Side face of the strand. The water coming from the collecting container 1o is through an annular nozzle 11 into the gap between electromagnetic continuous casting mold and strand side face. The nozzle 1t is inside the electromagnetic continuous casting mold 1 arranged concentrically with this and adjustable at a height by means of a spindle which is approximately half the height of the electromagnetic Continuous casting mold corresponds to.

With continuous supply of molten metal inside of the electromagnetic continuous casting mold, a strand is formed in this continuously, which in the case of uninterrupted supply of coolant (water) solidifies and an uninterrupted column of solid metal is created, which with its vertical displacement is cut into parts without interrupting the process »In this way, the continuous casting of steel and its alloys take place. The semi-continuous casting process is used for aluminum, since there are currently no known cutting processes that produce a continuous process Enable process *

The method described was tested in a pilot plant.

The aluminum strands produced in this way were smooth, flawless Surfaces that do not require machining. That The strand structure was fine-grained and dense. The strands became for pressing

609823/0383 ~ ⁷ ~ *

_ 7 -

and forging related. Strength tests on the Strands and the products made from them showed that good plasticity and high strength properties exist are.

609823/0357

Claims (1)

I / u 1o. Feb. 1976 L / Br Claim Process for the continuous casting and semi-continuous casting of Metals, characterized in that an electromagnetic alternating field surrounding the flow of liquid metal is excited, which is in the metal flow Creates forces which are directed into the interior of the metal stream and a rupture of the metal prevent and shape this, taking on the side surface of the shaped metal in its solidification zone Coolant is sliding. 609823/03 - & "^ 3S ^ original inspected