ROLL MANTLE, ROLL BODY AND METHOD OF FORMING SAME

Abstract

A method for manufacturing a roll mantle or roll body for a roll line of a continuous casting apparatus that has a shaft includes casting a metal to form the roll mantle or roll body such that the roll mantle or roll body includes at least one internal channel. The roll mantle or roll body has a first end region, a second end region and a central region between the first end region and the second end region, the central region extending along at least 50% of a length of the roll mantle or roll body, and the internal channel may be formed in the central region. The internal channel may also include a pattern or projection.

Claims

1. A method for manufacturing a roll mantle or roll body for a roll line of a continuous casting apparatus comprising a shaft, the method comprising: casting a metal to form the roll mantle or roll body such that the roll mantle or roll body includes at least one internal channel.

2. The method according to claim 1, wherein casting the roll mantle or roll body comprises casting the roll mantle or roll body in a single piece.

3. The method according to claim 1, wherein casting the roll mantle or roll body comprises casting the roll mantle or roll body from a corrosion resistant material.

4. The method according to claim 1, wherein the roll mantle or roll body has a first end region, a second end region and a central region between said first end region and said second end region, the central region extending along at least 50% of a length of the roll mantle or roll body, and wherein the casting comprises forming the at least one internal channel in the central region.

5. The method according to claim 1, wherein the casting comprises forming the at least one internal channel so that it comprises at least one feature on at least part of an inner surface of the at least one internal channel.

6. The method according to claim 5, wherein the at least one feature comprises a pattern.

7. The method according to claim 5, wherein the at least one feature comprises a projection.

8. The method according to claim 5, wherein the at least one feature is configured to: control a flow of fluid flowing through said at least one internal channel; create turbulence in a fluid flowing through said at least one internal channel; provide an increased contact surface area to facilitate cooling of a said roll mantle or roll body; and/or facilitate mounting of equipment that is to be placed in said at least one internal channel,

9. The method of claim 5, wherein the at least one internal channel has: a uniform or non-uniform cross-section, a uniform or non-uniform cross-sectional area, an extension at a constant or non-constant distance from an outer surface of the roll mantle or roll body, a circular cross-section, a rounded or smooth inside surface, a conical cross-section, and/or a partition wall.

10. The method according to claim 1, including fluidically connecting the at least one internal channel to a coolant line in the shaft.

11. The method according to claim 1, wherein the at least one internal channel has at least one inlet and at least one outlet and a length from the at least one inlet to the at least one outlet, and wherein the at least one channel is formed with a non-uniform cross section along the length.

12. The method according to claim 11, wherein the casting the roll mantle or roll body comprises casting the roll mantle or roll body in a single piece.

13. The method according to claim 11, wherein the at least one internal channel has an internal surface and a pattern cast in the at least one internal surface.

14. The method according to claim 11, wherein the at least one internal channel has an internal surface and a projection cast in the at least one internal surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will hereinafter be further explained by means of non-limiting examples with reference to the appended schematic figures where:

[0046] FIG. 1 is a schematic illustration of a continuous casting system.

[0047] FIG. 2a is a side elevational view, partly in section, of a roll mantle according to an embodiment of the disclosure mounted on a rotatable shaft.

[0048] FIG. 2b is a side elevational view, partly in section, of a roll mantle according to an embodiment of the disclosure mounted on a on a fixed shaft.

[0049] FIG. 2c is a side elevational view, partly in section, of a roll body according to an embodiment of the disclosure mounted on an integrated shaft.

[0050] FIG. 3-5 are perspective views of a roll mantle according to an embodiment of the disclosure.

[0051] FIG. 6 is a perspective view of a roll mantle according to an embodiment of the disclosure that shows the location of internal channel in the roll mantle.

[0052] FIG. 7 is a schematic sectional view of plugs at the end of sand core support openings at one end of a roll mantle according to the present disclosure.

[0053] FIG. 8a-8c illustrate possible configurations of an internal channel in a roll mantle or roll body according to the present disclosure.

DETAILED DESCRIPTION

[0054] It should be noted that the drawings have not been drawn to scale and that the dimensions of certain features have been exaggerated for the sake of clarity.

[0055] FIG. 1 shows a system for performing a continuous casting process in which molten metal 10 is tapped into a ladle 12. After undergoing any ladle treatments, such as alloying and degassing, and arriving at the correct temperature, molten metal 10 from the ladle 12 is transferred via a refractory shroud to a tundish 14. Metal is drained from the tundish 14 into the top of an open-base mold 16. The mold 16 is water-cooled to solidify the molten metal directly in contact with it. In the mold 16, a thin shell of metal next to the mold walls solidifies before the middle section, now called a strand, exits the base of the mold 16 into a cooling chamber 18; the bulk of metal within the walls of the strand is still molten. The strand is supported by closely spaced, water-cooled roll lines 20 which act to support the walls of the strand against the ferrostatic pressure of the still-solidifying liquid within the strand. To increase the rate of solidification, the strand is sprayed with large amounts of water as it passes through the cooling chamber 18. Final solidification of the strand may take place after the strand has exited the cooling chamber 18.

[0056] In the illustrated embodiment the strand exits the mold 16 vertically (or on a near vertical curved path) and as it travels through the cooling chamber 18, the roll lines 20 gradually curve the strand towards the horizontal. (In a vertical casting machine, the strand stays vertical as it passes through the cooling chamber 18).

[0057] After exiting the cooling chamber 18, the strand passes through straightening roll lines (if cast on other than a vertical machine) and withdrawal roll lines. Finally, the strand is cut into predetermined lengths by mechanical shears or by travelling oxyacetylene torches 22 and either taken to a stockpile or the next forming process. In many cases the strand may continue through additional roll lines and other mechanisms which might flatten, roll or extrude the metal into its final shape.

[0058] FIG. 2a shows a roll mantle 24 according to an embodiment of the disclosure. The roll mantle 24 comprises at least one internal channel (not shown in FIG. 2), which roll mantle 24 including its at least one internal channel is produced by casting. The roll mantle may be mounted on a rotatable shaft 26 in a rotationally fixed manner. A roll line 20 of a continuous casting apparatus may for example comprise a common rotatable shaft 26 having an outer diameter and supported by bearings 28, and a plurality of roll mantles 24 fixedly supported on the rotatable shaft 24 for transporting a metal strand along the outer surface 34 thereof, each roll mantle 24 having an inner diameter corresponding to the outer diameter of the rotatable shaft 26.

[0059] FIG. 2b shows an alternative type of roll line design in which a roll mantle 24 according to an embodiment of the disclosure may be arranged to be mounted on a non-rotatable fixed shaft 27 by means of bearings 28, whereby the roll mantle 24 is arranged to be rotatable with respect to the fixed shaft 28.

[0060] FIG. 2c shows a roll body 25 according to an embodiment of the disclosure which comprises an integrated shaft 25a.

[0061] FIGS. 3-5 show a roll mantle 24 comprising a plurality of internal channels 36 that may be used as coolant channels when the roll mantle 24 is in use.

[0062] FIG. 3 is a perspective view of a fully cast roll mantle 24 according to the present disclosure having a length L. The length L of a roll mantle 24 may be 400-800 mm. The outer surface 34 of the roll mantle 24 may be provided with a pattern and/or at least one feature by casting during the manufacture of the roll mantle 24. Such a feature may be used to facilitate the transportation of a metal strand along a roll line 20 or to facilitate the cooling of the metal strand. Preferably, a roller mantle or roller body according to the present disclosure does not comprise any hardfacing, thereby reducing manufacturing time, complexity and cost.

[0063] FIG. 4 shows the roll mantle with a section cut-away so as to show the extension of a plurality of axial internal channels 36 inside the roll mantle 24. In the illustrated embodiment the roll mantle 24 is provided with peripheral bore cooling (also called revolver cooling) and skewed internal channels 36. However, the at least one internal channel of a roll mantle 24 according to the present disclosure may contain one or more internal channels arranged in any axial, non-axial, radial, non-radial, symmetrical, non-symmetrical, regular or irregular manner, as desired. The internal channel inlets 40 and outlets 42 are preferably arranged in the central region CR of the roll mantle 24.

[0064] FIG. 5 shows a cross section of the mid-section of the roll mantle 24. In the illustrated embodiment the roll mantle 24 comprises a plurality of internal channels 36 having a circular cross section which extend mainly in the longitudinal direction of the roll mantle 24. The roll mantle 24 may be mounted on a rotatable shaft 26, whereby the roll mantle 24 is arranged to be supported on the rotatable shaft 26 in a rotationally fixed manner. The rotatable shaft 26 may comprise a coolant line and the internal channels 36 of the roll mantle 34 constitute internal coolant channels arranged to be in fluid communication with the coolant line of the rotatable shaft 26. Coolant, such as water or any other suitable fluid or mixture of fluids, may be fed from the coolant line of the rotatable shaft 26 to the internal channels 36 of the roll mantle 34 at the center of the roll mantle 24 for example, i.e. half way along the roll mantle's length, L or within a central region of the roll mantle.

[0065] The at least one coolant inlet 40 and the at least one coolant outlet 42 of a coolant channel 36 may be in fluid communication with a coolant line of a rotatable shaft 26 via one or more radial or non-radial channels in the rotatable shaft 26. It should however be noted that fluid communication between the coolant inlet 40 of a coolant channel 36 and the coolant line may be provided in any suitable manner.

[0066] FIG. 6 shows a roll mantle 24 according to another embodiment of the disclosure in which the roll mantle 24 comprises a first end region (ER1), a second end region (ER2) and a central region (CR) in between the first end region (ER1) and the second end region (ER2). The roll mantle 24 comprises a plurality of internal channels 36, one of which is shown in FIG. 6. The internal channel 36 has an inlet 40 located in the central region (CR) of the roll mantle 24 and an outlet 42 located in the central region (CR) of the roll mantle 24. The central region (CR) extends along at least 50% of the length (L) of the roll mantle.

[0067] FIG. 6 shows how coolant may be arranged to flow through a roll mantle 24 according to an embodiment of the present disclosure when the roll mantle 24 is in use. Coolant from a coolant line of a rotatable shaft 26 may be made to flow (by means of pumps, valves and fluid distributors for example) into a plurality of fluid inlets 40 that may be arranged around the inner surface of the roll mantle 24 in the central region CR thereof. Coolant then flows along coolant channels 36 in the roll mantle 24 in the direction indicated by the arrows in FIG. 6 and is returned to the coolant line in the rotatable shaft 26 via at least one fluid outlet 42 that may be arranged around the inner surface of the roll mantle 24 in the central region CR thereof.

[0068] FIGS. 3, 4 and 7 show plugs 38 located at one end of the roll mantle 24. These plugs 38 are used to at least partly close, or to seal one or more openings 37 left by a sand core support. A sand core may be used as a mold during the casting of the roll mantle 24 including its at least one internal channel 36. The sand core may need to be supported during the casting. After a roll mantle 24 comprising at least one internal channel 36 has been cast, the sand core is removed and sand core support(s) is/are removed.

[0069] Any suitable plug, stopper, or seal 38 made of any suitable material may be used to close, obstruct or seal one or more openings created by the casting process, such as one or more sand core support openings 37. For example, a fixed or removable plug, stopper or seal may be used to partly obstruct, completely block or seal at least part of an opening. According to an embodiment of the disclosure, a plug, stopper or seal 38 is removable so that a sand core support opening it partly obstructs, completely blocks or seals may be used for inspection or cleaning or accessing the internal channels 36.

[0070] An internal channel 36 may namely be used to contain coolant, to house equipment, to house at least part of a sensor, to contain a fluid that facilitates assembly and/or disassembly of the roll mantle, to contain lubricant, to allow access to the at least one internal channel from the outside of the roll mantle when the roll mantle is supported on the rotatable shaft.

[0071] According to an embodiment of the disclosure, at least part of the inside surface of an internal channel 36 may comprise a pattern (FIG. 8c) and/or at least one feature, such as a projection (FIG. 8b), which is/are produced by casting when the roll mantle 24 is manufactured. The pattern or the at least one feature is arranged to control a flow of fluid flowing through the at least one internal channel, to create turbulence in a fluid flowing through the at least one internal channel, to provide an increased contact surface area to facilitate cooling of the roll mantle, to facilitate mounting of equipment, such as a sensor, inside the at least one internal channel.

[0072] By using casting to manufacture a roll mantle 24 comprising at least one internal channel 36, at least part of an internal channel 36 may be provided with one or more of the following features during casting: a uniform cross section, a non-uniform cross-section (FIG. 8a), a uniform or non-uniform cross-sectional area, an extension at a constant distance from an outer surface of the roll mantle, an extension at a non-constant distance from an outer surface of the roll mantle (FIG. 8a) a circular cross-section, a rounded or smooth inside surface, a conical geometry (FIG. 8a) and/or a partition wall (FIG. 8b).

[0073] A roll mantle 24 including its at least one internal channel 34 according to any of the embodiments of the disclosure is preferably produced by casting in a single piece from a single material, preferably a corrosion resistant material.

[0074] According to an embodiment of the disclosure, the manufacturing method may comprise the step of applying a wear resistant and/or corrosion resistant coating to at least part of the outer surface of the cast roll mantle 24, using any suitable hardfacing method.

[0075] Further modifications of the disclosure within the scope of the claims would be apparent to a skilled person.

[0076] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved roll mantles or roll bodies and methods of making same.

[0077] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0078] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.