FI91134C - Roll for device for continuous casting - Google Patents

Abstract

This cylinder (1) is covered by a combination of two metal sleeves (3, 4) forming two superposed cylindrical layers and chosen from materials such that the inner sleeve (3) has a coefficient of expansion greater than that of the outer sleeve (4) in contact with the molten metal; the differential thermal expansion experienced by the two sleeves (3, 4) during casting of the molten metal prevents the cylinder (1) from bulging and, consequently, guarantees the production of cast products having a satisfactory thickness profile. Application to the continuous casting of molten steel. <IMAGE>

Description

i 91134

Roller for continuous casting equipment

The object of the present invention is a roll for a continuous casting apparatus in which thin strips of molten metal are cast directly on a roll of two rolls with a single roll comprising a cylindrical core embedded in a first shell and cooling channels which are in the silence or vigilance of the nucleus.

As is known, ndma rolls contain a cylindrical core which is corrugated in a jacket, usually made of copper, and are cooled by circulating a coolant such as water in channels in the jacket or jacket of the jacket and core. In fact, it has been found that the rolls produced in such a way bulge out during casting, so that the products cast in the stems of the two rolls rolled in such a way have a "dog bone" -shaped profile. The thickness of such products at the edges is greater than their thickness at the mid-20 line and they are therefore unsatisfactory.

In the case of single casting on a roll, the bulging of the roll makes the choice of roll and molten metal feeder uneven. The roller may therefore come into contact with and damage the fire-resistant feeder.

The object of the invention is to provide rolls which make it possible to eliminate this disadvantage and thus to provide castings with a satisfactory profile thickness.

These bales are achieved by a roll according to the invention, characterized in that the roll casts a second sheath arranged around the first sheath, which together with the first sheath forms two patchy cylindrical layers, the materials of which are chosen so that the inner sheath is larger. coefficient of lampd expansion than the outer sheath in contact with the molten metal.

2

The coefficients of lamp expansion and thus the corresponding materials are chosen so that the difference in expansion between the two materials eliminates the tendency of the double sheath thus produced to bulge, especially at the level of the 5-roll state of the two rolls.

The inner sheath may be made of copper, for example, while the outer sheath is made of steel and these sheaths are soldered together.

Preferred embodiments of the roll 10 according to the invention appear from the appended claims 2-3.

Other features and advantages of the invention will be apparent from the following description, taken in conjunction with the accompanying drawings, which illustrate a non-limiting embodiment by way of example.

Figure 1 is a perspective view of a roll covering a double jacket according to the invention for a continuous casting machine for thin metal strips.

Figure 2 is an axial partial section of the roll of Figure 1.

The roll 1 shown in the drawings is intended for a continuous casting device for molten metal such as steel, by means of which thin strips of metal are cast in the coils of two similar rolls 1. Such a device is well known and therefore not shown.

The roll 1, the axis of which is XX, consists of an inner core 2 and two patchy annular sheaths 3 and 4 which surround an inner core 2 into which cooling channels have been made in which water can circulate. The materials of the superimposed layers 3 and 4 are selected such that the inner sheath 3 has a higher coefficient of lampd expansion than the outer sheath 4 in contact with the molten metal.

The two sheaths 3 and 4 are joined together, for example by welding, the second material

II

91134 3 Coat the electrolyte back with a coating. Without limitation, the inner sheath 3 is made of copper and the outer sheath is made of steel, while copper actually has a higher lamp coefficient than steel.

The thicknesses of layers 3 and 4 are obtained on the basis of the lamp expansion coefficients of the selected materials.

When the double jacket 3, 4 is subjected to a large lamp state gradient as the molten metal contacts the outer jacket 4, the different expansion of the material of the two materials 10 of layers 3 and 4 eliminates the tendency of the double jacket to bulge, especially at the level of the two rolls.

The inner sheath is preferably made of copper and is 5 to 30 mm thick. The outer sheath can be made of te-15, nickel or chrome and is 1 to 10 mm thick.

For example: - roll: diameter 1,500 mm, width 800 mm - inner casing: copper, thickness 15 mm 20 - outer casing: steel or nlkkelid; thickness 2 mm - the sheaths are soldered to each other over their entire surface (the outer sheath consists of a coating coated on the inner sheath) - cast steel lamp space 1,450 ° - inner 25 sheath inner wall temperature: 60 ° C (approximately the same as the cooling water lamp space).

the result: the bulge of the roll is 0.3 mm while if the roll were made entirely of copper, the bulge would be about 1 mm.

30 It would be possible to further reduce the bulge in the beam by choosing a material with a lower coefficient of lamp expansion and better thermal conductivity, such as chromium, as the bale layer (outer shell).

Finally, it should be noted that the invention is not limited to an arrangement in which the cooling channels 5 are below the 4 double sheaths (3, 4), but these channels can also be drilled into the inner shell.

It is expedient to note that the thickness of the above-mentioned sheath made of copper corresponds to 5 cases in which the cooling channels are made under this sheath. If the ducts are made in the inner jacket, the thickness in question is the rainy distance between these ducts and the inner / outer jacket interface, in this case the thickness dividing between the ducts and the core remains at a low temperature and Silia has only a waxy effect on the different lamp expansion.

II

Claims (3)

A roller for a continuous casting device, in which device thin strips of narrow metal are cast directly between two rollers (1) or on a roller comprising a cylindrical core (2) coated with a first sheath (3) and cooling ducts (5) between mante (3) and the core (2) or in mante (3), characterized in that the roller comprises a second jacket (4) arranged around the top mante (3) which together with the top mante ( 3) forms two superposed cylindrical layers, the material of which is so selected that the inner manifold (3) has a larger coefficient of thermal expansion of the surface three manifolds (4) which are in contact with the molten metal. 2. A roller according to claim 1, characterized in that said two rolls (3, 4) are interconnected with each other, e.g. welding, by pressing one material onto the other or by electrolytic coating. 3. A roller according to claim 1 or 2, characterized in that the inner manifold (3) is made of copper and the outer manifold (4) of steel, nickel or chrome. II