DE10256751A1 - Mold for a continuous casting machine, to cast steel strands, has copper or copper alloy plates for the mold walls, with a deeper strip section with a roughened surface to reduce heat loss - Google Patents

Abstract

The continuous casting mold, for casting steel strands, has a casting cross section defined by plates of copper or a copper alloy at the wide sides (1) and/or the narrow sides. A structured surface is formed at the hot side as a protection against wear and heat, at least at the height of the molten metal level, to reduce the heat loss and wall copper temperature in the molten bath (4), and prevent the formation of scores in the cast strand. The side plates give a deeper strip mold section (5) at the molten bath level. The structured surface is formed by ball blasting to give a deeper roughness (9) with a minimum depth of 20 mu and a maximum of 200 mu. The structured section starts at least 50 mm below the upper edge (6) of the mold and ends at a maximum of 250 mm from the upper edge

Description

The invention relates to a continuous casting mold for to water of strands made of metal, in particular steel materials, the casting cross-section is limited by plates made of copper or copper alloys Form broad side plates and / or narrow side plates, wherein one at least in the area of the bathroom mirror on the hot side against wear and heat formed surface is provided.

Such a continuous casting mold is from, for example EP 1 099 496 A1 known. There, in order to reduce the heat dissipation in their bath level area, the heat flow between the strand shell that forms and the inner surface of the mold is throttled by a higher thermal resistance. This measure counteracts the risk of cracks in the strand shell. The higher heat transfer resistance is generated by a macro texture in the mold inner surface.

A similar design is from the EP 0 228 335 B1 known that proposes an application of about 100 to 200 mm, which should consist of a coating of a heat-resistant material with a lower thermal conductivity.

All of these suggestions is together, the problem of the higher temperature stresses occurring in the bathroom mirror area to solve. Particularly in the case of thin slab continuous casting plants casting speeds targeted up to 10 m / min. As the casting speed increases the mold life due to the increasing temperature stress from. In addition to the measures mentioned above, the copper plates to increase the mold life on the working side (hot side ) e.g. coated with nickel. The high temperature load caused however also cracks in the nickel coating and the coating flakes off. Coatings with oxides, carbides or other materials have not been successful either. In addition, such a surface structure critical in the adjustment range of the narrow side plates, as these the narrow side plate adjustment is changed and scoring in Adjustment range of the mold and thus to surface defects on the casting strand to lead can.

The invention has for its object a Reduction of heat dissipation or a reduction in the copper temperature in the bath level area the hot side of the mold plate without having to adjust the narrow side plates to marks and surface defects on the casting line leads.

The object is achieved according to the invention solved, that at least in the broadside panels in the bathroom mirror area deepened, stripe-shaped Mold section is provided, and through the recessed surface a blasting process has a greater roughness depth receives. This causes a reduction in heat dissipation or a reduction the copper temperature. Through the deeper, blasted area there is no contact between the narrow side plate and the irradiated Area. present, which causes scoring when adjusting the narrow side be avoided.

This can still improve can be achieved as a shot peening process is applied.

After the further invention begins the recessed mold section at least 50 mm from the upper edge of the mold and ends a maximum of 250 mm from the upper edge of the mold.

The blasted mold section has a depth of 0.05 to 0.3 mm. An adjustment of the narrow side plates is also possible without scoring across the non-blasted surface (mold hot side) to create..

It is also advantageous that the deepening has corner radii in the upper and lower area.

Another essential measure is that the roughness of the blasted mold section is at least 20 µm and a maximum of 200 µm.

An exemplary embodiment is shown in the drawing, this in more detail below explained becomes.

Show it:

1 a front view of the broad side plate and

2 a vertical section AA through the recessed, strip-shaped mold section.

The drawing shows, for example, a CSP continuous casting mold with a broad side plate 1 that in the middle area 2 a funnel 3 has. to a dip tube in the middle 2 to be able to introduce. The broadside plate 1 consists of copper or a copper alloy. In the bathroom mirror area 4 is a deeper, strip-shaped mold section 5 applied by shot peening. These areas are hatched twice.

The recessed mold section 5 starts at least approx. 50 mm from the upper edge of the mold 6 and ends at a maximum of approx. 250 mm from the upper edge of the mold 6 ,

According to 2 is in the recessed mold section 5 the blasting, preferably applied by shot peening, the recess 7 is between 0.05 and 0.3 mm. In the upper and lower recess area 7a and 7b are corner radii 8th provided with adapted sizes.

The roughness 9 of the recessed mold section 5 is a minimum of 20 µm and a maximum of 200 µm.

1

Broadside plate

2

mid-range

3

funnel

4

bath level

5

Kokillenabschnitt

6

chill mold

7

deepening

7a

depression area

7b

depression area

8th

Corner radii

9

roughness

Claims (6)

Continuous casting mold for casting strands of metal, in particular of steel materials, the casting cross section of which is limited by plates made of copper or copper alloys, the broad side plates ( 1 ) and / or narrow side plates, one at least in the area of the bathroom mirror ( 4 ) arranged on the hot side, formed against wear and heat, characterized in that at least in the broad side plates ( 1 ) in the bathroom mirror area ( 4 ) a recessed, strip-shaped mold section ( 5 ) is provided and the recessed surface is given a greater roughness depth by a blasting process. continuous casting according to claim 1, characterized in that as a blasting method a shot peening process is used. Continuous casting mold according to one of claims 1 or 2, characterized in that the recessed mold section ( 5 ) at least 50 mm from the upper edge of the mold ( 6 ) begins and a maximum of 250 mm from the upper edge of the mold ( 6 ) ends. Continuous casting mold according to one of claims 1 to 3, characterized in that the blasted mold section ( 5 ) has a depth of 0.05 to 0.3 mm. Continuous casting mold according to one of claims 5 or 6, characterized in that the recess ( 7 ) in the upper and lower area ( 7a ; 7b ) Corner radii ( 8th ) having. Continuous casting mold according to one of claims 1 to 5, characterized in that the roughness ( 9 ) of the blasted mold section ( 5 ) is a minimum of 20 µm and a maximum of 200 µm.