JPS58135750A - Continuous steel casting apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting apparatus for metal products, particularly copper alloys.

It is well known to continuously cast metals, especially copper alloys, by means of an apparatus (FIG. 1) consisting of a crucible 11) containing it in a molten state. This crucible (11) includes a casting orifice opening into a graphite die (2), which is e.g. rectangular in cross-section and has e.g. a cooling element (3) in which a cooling fluid circulates.
). The molten metal is sequentially cooled in the die (2) by said element (3) and discharged in the form of a ribbon.

The operating speed of such a device depends on the ability to cool the assembly mounted by the die (2) and element (3). ribbon(
4) may be discharged only when it exhibits sufficient resistance, in other words when it is sufficiently cooled.

Two types of dies (Figures 2 and 3) are commonly used. The first type of die consists of two graphite half-shells (21) machined to form passageways (22) for the metal ribbon.
-21). These two half dies (21
) are held between the cooling elements (3) and secured to each other by connecting rods or assembly means (5).

This solution requires expensive machining steps on the die.

The second type (FIG. 3) currently in use consists of two plates (23) separated by a separating element (24) to form a metal passageway (22). The assembly thus constructed is held between two cooling elements (3) which are connected together by a connecting rod (5).

This solution is more advantageous than the previous one. This is because there is no need to machine a die with a relatively complex shape from graphite.

The working speed of this device is the die channel (22) and the
(3), the surface of the die (21
), (23) and the surfaces of the cooling element (3) are important to have as good contact as possible.

Unfortunately, the elements (23) or (21) of this die tend to curve (FIG. 4), which is caused primarily by expansion as a result of temperature gradients inside the graphite element.

As a result of this curved shape, the key! (23) Or,
(21)'' comes to form a void (6) away from the element (3). This void (6) reduces to a considerable extent the efficiency of heat exchange and thus the working speed of the device.

One solution already proposed is to form the elements (23), (21) with a curvature opposite to that shown in the fourth diagram. Once used, these elements should be flat to element (3). Now, apart from the fact that this solution is extremely difficult due to its complex shape and therefore the delicate machining of the die element (23), this solution does not give the expected effect.

It is well known to fix the lug 1 (23) to the element (3) by gluing or better by screwing. Although the latter solution is more effective than gluing, it has significant disadvantages. This is because the graphite element must be machined with screw holes and must be made thicker so that it is not brittle.

Furthermore, the element must be drilled with a passage for the threaded connecting rod, making assembly and disassembly also much more complex and time-consuming.

Another problem associated with continuous casting is power collection. For this purpose, according to a die having a cross section corresponding to FIG. 6A,
A product is obtained with a cross-section corresponding to FIG. 6B (in which the concavity of the central part is shown greatly enlarged).

When the portions (42), (42) are concave in the center of this cross section, both ends (41), (41) of the ribbon (4)
) corresponds to the shape of the die, which results from the temperature difference between the ends and center of the ribbon. This indentation effect is partially reinforced in a cumulative manner.

This is because graphite dies have the worst heat exchange characteristics towards the center as a result of relatively weak contact with the cooling element and deformation of the die elements (see Figure 4).

The object of the present invention is to improve these disadvantages and to create a continuous casting die, in particular for casting copper alloys, which can produce ribbons of perfectly regular thickness at high casting rates. It can be cast at high speed.

To this end, the invention relates to a continuous casting apparatus, which apparatus includes means for generating a bending moment that presses the parts of the die against the corresponding surfaces of the cooling element, and in particular below the neutral plane across the die. It is characterized in that it includes means for exerting a compressive action and, by reaction, pressing the elements constituting the die over the entire accessible surface onto the cooling element.

By transversely prestressing the parts of the continuous casting die, the backs of these die parts are aligned and in full contact with the cooling element, thereby ensuring effective cooling by the cooling element of the die.

According to another feature of the invention, the contact surface of the cooling element is concavely curved.

By forming the cooling element in this slightly curved shape, the contact between the parts of the die and the cooling element is further improved and the concave shape of the ribbon is compensated for.

This solution does not pose any special problems. This is because the parts that wear are those that make up the die, and the cooling elements do not undergo any wear.

Now, the elements of the die are always formed by flat elements, which tend to bend under lateral forces.

According to a feature of the invention, the concave surface of the cooling element is formed by a collection of small surface elements separated by concave portions that are susceptible to bending under lateral forces.

According to another feature of the invention, the concave surface of the cooling element is formed by a collection of surface elements separated by recessed portions forming channels for the heat exchange fluid.

The distribution of force within the flat elements that make up the die is improved by applying pressure at three points.

This solution also has the advantage of simplifying the production of cooling elements. This is because the three-point contact surfaces are all flat surfaces.

The invention will now be explained in more detail with reference to the accompanying drawings.

According to FIG. 7, the device according to the invention, shown in a sectional view at the level of the die, consists of a cooling element (3), which is pressed against a part (23) of the die, and which is pressed against the part (23) of the die.
) are themselves separated by isolation elements (24) to define dies of e.g. rectangular cross-section. The device includes compression means (25), capable of exerting a bending moment, which acts on the edges of the parts of the die, such that each part of the die (
With respect to the plane (26) containing the neutral line of 23), a compressive force F is exerted on the side opposite the cooling element (3).

Figure 8 shows the effect of the compression means (25) on the part (232) of the die.

The resultant force F of the compressive forces acting on the end face portion (232) opposite the cooling element (3) with respect to the plane containing the neutral line (26) presses the part (23) against the cooling V element (3). .

The distance d between the neutral line and the direction of the resultant force F acts on the part (23) and makes it possible to calculate the moment M=FXd that can bend this part (23) as shown in FIG.

Since the cooling element (3) is resisting the curve C de of the part (23) (Fig. 1θ), the force f1 distributed at a distance di from each isolation point fi (24), which is the starting point, is as follows: It is.

M = ΣMl or FXd = ΣflXdi Now, this calculation shows that the force fl (or its reaction) decreases as dl increases and there is a central zone where no force acts.

Figure 11 shows how a bending moment is created by applying a force F1 to the end of the die part (23) located beyond the isolation element (24).

According to FIG. 12A, a better distribution of forces and thus parts (
A first solution for pressing 23) more favorably against the cooling element presents a complete die with a concavely curved element (31).

Another solution with a different distribution of forces is shown in Figures 13 and 14.
As shown in FIG.

According to FIG. 13, the cooling element (3°1)
'), which has a supporting surface for the isolation element (24)
It has a transverse zone (31) pressing onto the part (23) to the right, a central zone (33) and an intermediate cavity (32).

In these conditions, the force fi (or reaction force) acts only in the central zone (33), which
) and (3”), but the zone (
31), (33), and (31), no contact is possible.

The cavity (32) contains a heat transfer fluid such as hydrogen or helium or mercury.1. F” can be done.

Figure 14 is a variant of Figure 13 in which the cooling element (3'') has a concave contact surface.
4), (34) at both ends and in the center, and a cavity (35) filled with a heat transfer fluid (hydrogen, helium, mercury).

This solution combines the benefits of pressure zones and concave surfaces.

FIG. 15 shows a particularly advantageous embodiment.

Thus, the cooling element (3”) consists of three straight sections (37)
, (38), (37).

When the parts (2'3) exhibit a continuous curved shape under compressive force, the voids (39) are formed into polygons (37), (38), and (3).
7) and the continuously curved part (23).

As mentioned above, these cavities (39) may contain a heat transfer fluid.

This last solution is particularly advantageous in its preparation and use. Its manufacturing method is simple. This is because it is sufficient to create a space in (3''') with p polygonal cross sections (the number of segments is not limited to 3).

The efficiency of this solution is very high as a result of the combination of the pressure zone and the conical shape of the cavity.

It should be noted that the force exerted by the cooling element on the concave surface of the die part will cause the ribbon to take on a concave shape, but the ribbon is usually concave to compensate.Generally and as a variation of FIG. ) The bending moment caused by the compressive force acting on the outside of the die part (2
1), (23) and the corresponding surface of the element (3) over the isolation element (4), which may be obtained by exerting a traction force by the connecting rod (5).

The continuous casting apparatus, a part of which is shown in FIGS. 16 and 17, consists of a cooling element (3), which has a curved surface (3") against which the die part (23) rests. 3”) may be flat in some cases.

The die part (23) is subjected to means (25°) in which a bending moment is generated in the part to press it against the surface (3'') (FIG. 17).

These means (25'') exert a distributed force f oblique to the direction of the surface (311), ie with a component directed towards the surface (311).

These forces exerted by the means (25')
and distributed over the entire surface of the die part (23).

According to FIG. 18, the reaction RE of the small goo part element (100) to the cooling element (3) can be calculated,
can be described as a function of the force F experienced as a result of a distributed force f applied to the end surface (231). C=Thickness of die part (23),! - Width of the die part (23), U - Length of the die part element, S = surface where the Gui part element is pressed against the cooling element, F = resultant force of the distributed force fi, then s = t! xu, F=fixeJ R is the radius of curvature of the cooling element (3) and die part (23).

α is the angle formed by the key *(100) of the die part (23) at the center of curvature (α-1)...
... (1) The two forces F produce a vertical reaction force RE, and R
El=Fα・・・・・・・・・・・・
...(2).=Total=V FIG. 19 shows another embodiment. Die parts (23)
is held inside the corresponding cooling element (3), and the element (
3) has a lateral portion (312) which includes a die part (23).
) defines a recess for accommodating the. The lower surface of die part (23) may be curved, as indicated by reference numeral (232), or flat, as indicated by reference numeral (232).

Means (25) are shown in line on both sides of FIG. 19, and a bending moment is applied to the die part (23) due to a lateral force distributed over substantially the entire lateral surface (231) of the die part (23). effect.

According to another embodiment, not shown, the means for generating a bending moment cooperates with at least a portion of the layer to a particular depth to elongate this layer, thereby causing more bending in the die part therein. This is a means by which components can be introduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a known device for continuously casting copper alloys; FIG. 2 is a sectional view of a first type of continuous casting die;
Fig. 3 is a cross-sectional view of another form of continuous casting die according to the prior art; Fig. 4 is an illustration of deformation of elements constituting the die under the influence of thermal stress; and Fig. 5 is a conversely curved FIGS. 6A and 6B are a theoretical cross-sectional view of a product formed by continuous casting and a cross-sectional view of an actually obtained product, and the deformation is exaggerated. Figure 7 is a route map of two forms of this device, one on the right and one on the left, Figures 8, 9, and 10 are explanatory diagrams of Figure 7, and Figure 11 is a bending diagram. 12A and 12B show another embodiment of the invention; FIG. 13 is a route diagram of another variant of the invention; FIGS. Two embodiments of the modification according to FIG. 13 are shown, FIG. 16 is a route diagram of the upper half of the modification of a part of the continuous casting apparatus, and FIG. 17 is similar to FIG. Figure 18 shows that the first
5 and 16, and FIG. 19 is a schematic representation of another variant. In the figure (3), (3”), (3″’”), (3”)
is a cooling element, (21), (23) are die parts, (24)
is an isolation element, (25), (25') is a compression means, (26
) is the neutral line, (32), (35), (39) are blank spaces, (
100) is a die component element.

Claims (1)

[Claims] 1. An apparatus for continuous casting of metals such as the same alloy, comprising a graphite casting die held between cooling elements (3),
This die has at least two parts (21°22.23.
24), characterized in that it comprises means for generating bending moments in these die parts (21, 23) in order to press them against the corresponding surfaces of the cooling element (3). Continuous casting equipment. 2. The device that generates the bending moment is a part (21),
(23) and across the zone (232) of these lateral parts opposite the contact surface with the cooling element with respect to the neutral plane of the part (23) to compress each part (21) of the die. ), (23) against the contact surface (233) of the corresponding cooling element (3). 3. Claim 2, characterized in that the contact surface of the cooling element (3) with respect to the die part (23) is concave.
Continuous casting equipment as described in section. 4. The cooling element (3"'), (3"') is the die part (23
3. Continuous casting device according to claim 2, characterized in that it has lateral pressure zones (31), (34) and central pressure zones (33), (36) for the continuous casting. 5. Pressure zone (31), (34), (33), (36)
5. Continuous casting apparatus according to claim 4, characterized in that the continuous casting apparatus is separated by a cavity (32), (25) containing a heat transfer fluid. 6. Continuous casting device according to any one of claims 1 to 4, characterized in that the concave pressure surface of the element (3") has a polygonal cross section. 7. Isolation element Continuous casting apparatus according to claim 1, characterized in that it includes means for exerting a compressive force on the die part outside of (24). 8. The means for generating a bending moment at the die/cooling element boundary 9. Continuous casting device according to claim 1, characterized in that the means are for introducing into the layer of the die part (23) located in the vicinity of the surface a component that stretches this layer. Moment generating means (25'') apply a force (25'') to the two side faces (232) of the die part (23) with a component directed in the direction of the support surface (311) of the corresponding cooling element (3). The continuous casting apparatus according to claim 1, characterized in that it is a means for acting F). 10. Continuous casting device according to claim 1, characterized in that the support surface (311) is curved or flat. 11. Continuous casting apparatus, characterized in that the die part (23) is held in a cavity formed in the cooling element (3).