JPH03133550A - Roll of device to continuously cast sheets directly using molten metal - Google Patents

Abstract

PURPOSE: To reduce the bulging quantity of a roll and to manufacture a cast product having the profile of satisfactory thickness by selecting such materials that the coefficient of expansion of an inside sleeve is made larger than the coefficient of expansion of an outside sleeve at the time of bringing into contact with molten metal. CONSTITUTION: A roll 1 is constituted with a cylindrical inside core 2 and two mutually laminated annular sleeves 3, 4 surrounding the inside core 2. Each of two mutually laminated annular sleeves 3, 4 is manufactured with such materials that the coefficient of thermal expansion of the inside sleeve 3 is made larger than the coefficient of thermal expansion of the outside sleeve 4 in contact with the molten metal. Therefore, at the time of developing large temp. gradient in the two layer sleeves 3, 4 by bringing the outside sleeve into contact with the molten metal, the bulging tendency of two sleeves 3, 4 with the expansion difference of each material of two sleeves 3, 4, particularly, the bulging tendency at the center gap portion between two rolls, are cancelled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to rolls used in apparatus for continuous casting of sheet metal directly from molten metal between two rolls or on a single roll.

As is known in the art, these rolls generally have a cylindrical core surrounded by a sleeve made of copper, with cooling running water, e.g. water, circulating between or through the sleeve and the core. It is cooled down. Therefore, the rolls of this structure bulge outward during casting, so that the profile of the product cast between the two bulged rolls is similar to that of a “dog bone.”
de ch+en)'' shape, ie, the thickness on both sides of the product is greater than the thickness in the center. Such a profile is unsatisfactory.

When casting on a single roll, the bulge of the roll creates an irregular gap between the molten metal feeder and the roll, which may cause the roll to come into contact with the refractory material of the feeder and damage it. become.

OBJECTS OF THE INVENTION The object of the present invention is to provide a roll which eliminates this drawback and makes it possible to obtain cast products with a satisfactory thickness profile.

Means for Solving the Problems In the present invention, the roll has a second sleeve tube that forms a cylindrical laminated double layer together with a first sleeve tube provided around the first sleeve; The material of the second sleeve tube (4) is selected such that the coefficient of expansion of the inner sleeve (3) when in contact with molten metal is greater than the coefficient of expansion of the outer sleeve (4).

The expansion coefficients and corresponding materials described above are such that the dual sleeve of the present invention tends to bulge due to expansion differences between the two materials, especially in the inter-axle gap of the rolls.
selected to offset each other.

For example, the outer sleeve may be made of steel and the inner sleeve made of copper, and the two may be welded together.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the invention will become apparent from the following description, given by way of example and with reference to the accompanying drawings, in which: FIG. However, the present invention is not limited to this example.

The roll 1 shown in the accompanying drawings is used in an apparatus for producing sheet metal by direct continuous casting of molten metal, such as steel, between two similar rolls 1. This device itself is well known and is therefore not shown.

This roll 1 with an axis xx consists of a cylindrical inner core 2 and two annular sleeves 3.4 which surround this inner core 2 and are stacked on top of each other. A cooling passage 5 through which water can circulate is formed inside. Each of the two annular sleeves 3.4 stacked on top of each other is made of a material such that the coefficient of thermal expansion of the inner sleeve 3 is greater than the coefficient of thermal expansion of the outer sleeve 4 in contact with the molten metal.

The two sleeves 3.4 are joined to each other by welding, by filling one on top of the other material, or by electroplating or otherwise.

- By way of example, the inner sleeve 3 is made of copper and the outer sleeve 4 is made of steel. The coefficient of expansion of copper is greater than that of steel. However, the invention is not limited to this example.

The layer thicknesses of the two sleeves 3.4 are adjusted as a function of the expansion coefficient of the selected material.

Therefore, the outer sleeve 4 comes into contact with the molten metal and the above-mentioned two
When large temperature gradients occur in the layer sleeve 3.4, the 2
The differential expansion of the materials of the two sleeves 3.4 counteracts the tendency of the two sleeves 3.4 to bulge, especially in the center gap between the two rolls.

The inner sleeve 3 is preferably made of copper and has a thickness of 5 to 30 mm. The outer sleeve 4 can be made of steel, nickel or chromium and its thickness can be from 1 to 1Q mm.

Example An embodiment of the present invention will be shown below.

Roll: diameter 1,500 mm, width: 800 mm
mm Inner sleeve: Copper, 15 mm thick Outer sleeve: Steel or nickel, 2 mm thick Both sleeves are joined to each other on all sides (the outer sleeve constituted by the lining is mounted on the inner sleeve).

Temperature of the cast steel: 1,450°C Temperature of the inner wall of the inner sleeve: 260°C (equal to the temperature of the cooling water) As a result, the amount of bulge of the roll is 0.3 mm. On the other hand, when the entire sleeve is made of copper, the amount of bulge is approximately 1 mm.

By selecting a material with a better thermal expansion coefficient and better thermal conductivity, such as chromium, as the lining (outer sleeve) material, it would be possible to further reduce the amount of bulge.

The present invention provides cooling passages 5 on the underside of the double sleeves (3, 4).
It will be understood that the cooling passages are not limited to the arrangement, and that the cooling passages can also be formed inside the inner sleeve 3.

Note that the thickness of the copper sleeve described above corresponds to the case where a cooling passage is provided below the sleeve.

It is also appropriate to point out that When the cooling passage is formed inside the inner sleeve, the thickness between the inner sleeve and the core between the cooling passages is maintained at a low temperature and is hardly affected by the expansion difference, so the above-mentioned It will also be appreciated that the thickness is the radial distance between the cooling passage and the inner sleeve/outer sleeve interface.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a roll with a double sleeve according to the invention used in an apparatus for continuous casting of sheet metal. 2 is a partial axial cross-sectional view of the roll of FIG. 1; FIG. (Symbol in the diagram) 1: Low Nope 2. Core, 3: Inner sleeve, 4: Outer sleeve, 5: Cooling passage agent Takashi Koshiba, patent attorney

Claims (3)

[Claims] (1) A cylindrical inner core (2) covered with a first sleeve (3), and a cylindrical inner core (2) formed between the first sleeve (3) and the core or inside the first sleeve (3). in a roll (1) used in an apparatus for direct continuous casting of thin strips of molten metal between two rolls (1) or on a single roll, with cooling passages, together with a first sleeve tube; A second sleeve tube (4) forming a cylindrical double layer stacked on top of each other is provided around the first sleeve, the material of which is a cylindrical double layer which has been in contact with the molten metal. A roll characterized in that the material is selected such that the coefficient of expansion of the inner sleeve (3) is greater than that of the outer sleeve (4). 2. Roll according to claim 1, characterized in that the two sleeves (3, 4) are joined to each other by welding, fitting or electroplating. 3. Roll according to claim 1 or 2, characterized in that the inner sleeve (3) is made of copper and the outer sleeve (4) is made of steel, nickel or chromium.