Claims
- 1. A process for continuously casting thin slabs, comprising the steps of:casting molten metal using an immersion nozzle in a cambered oscillating mold having a mold inlet cross sectional area and a smaller mold outlet cross sectional area while maintaining conditions for the immersion nozzle and the mold so that: FSTFTA>50, where FST=a cross sectional area of a completely solidified slab, and FTA=a cross sectional area of an outlet of the immersion nozzle; supplying casting powder to the molten metal so that a relationship hslag≧hstrand shell, where hslag=a height of a layer of slag proximate an upper surface of the mold, and hstrand shell=a height of a portion of a strand shell in the mold which penetrates the layer of slag proximate the upper surface of the mold, is maintained depending on the oscillating stroke, shape and frequency of mold movement; reducing the strand cross sectional area directly below the mold in a plurality of steps in a cluster roll stand to form a forced convection in a remaining liquid interior of the strand parallel to a continuous strand thickness reduction, so that the strand achieves its final thickness while still having a liquid core at the end of the cluster roll stand; and controlling solidification so that a two-phase zone is present within the strand after achieving the final thickness at an output of the cluster roll stand.
- 2. The process of claim 1, wherein said step of supplying the casting powder includes supplying the casting powder so that a thickness of a layer of casting powder on the slag layer is constant along an entire width of the mold.
- 3. The process of claim 1, including the step of selecting the frequency, stroke, and oscillation mode for the mold movement during casting to achieve a desired output and so that the relationship hslag>hstrand shell is maintained.
- 4. The process of claim 1, wherein said step of casting further comprises the step of configuring the mold so that a strand obtains a residual camber at the mold outlet which is symmetrical to a center axis of the strand and has a thickness of less than 4% of the final thickness of the strand.
- 5. A continuous casting installation for producing thin slabs, comprising:an oscillating rectangular mold having a concave inner contour with a mold inlet having a mold inlet contour and a mold outlet having a mold outlet contour, wherein said mold inlet contour is larger than said mold outlet contour; means for oscillating the mold, the oscillating means being adjustable relative to frequency, stroke and mode of oscillation; an immersion nozzle having a cross sectional area that is less than {fraction (1/50)} of a strand cross sectional area at the outlet of the mold, the immersion nozzle being arranged to project into the rectangular mold; casting powder feed means for supplying powder to the mold as a function of the stroke, mode and frequency of oscillation of the mold so that a height of a slag layer proximate the upper surface of said mold is greater than or equal to a height of a portion of a strand shell which penetrates the slag layer during oscillation of the mold; and a cluster roll stand arranged downstream of the rectangular mold and including two rolls adjustably arranged at a distance from and opposite one another, and a hydraulic arrangement operatively arranged to change the distance between the two rolls in a continuous manner.
- 6. The continuous casting installation according to claim 5, wherein said mold is configured so that a thickness of the mold at said mold inlet is not greater than 120% of a thickness of the strand at said mold outlet.
- 7. The continuous casting installation according to claim 5, wherein two rolls are arranged to have a distance therebetween so that a stirring effect results in a remaining liquid interior of the strand with predetermined strand thickness reduction.
- 8. The continuous casting installation of claim 5, wherein said mold comprises a camber so that a strand has a residual camber at said mold outlet that is not greater than 4% of a strand thickness at said mold outlet.
Priority Claims (1)
Number |
Date |
Country |
Kind |
44 03 049 |
Jan 1994 |
DE |
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Parent Case Info
This application is a Continuation-in-Part of U.S. patent application Ser. No. 08/682,672 filed Jul. 29, 1996, now abandoned, which is a 371 of PCT/DE95/0095 filed Jan. 20, 1995. The disclosure of U.S. patent application Ser. No. 08/682,672 is expressly incorporated herein by reference.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3318363 |
Goss |
May 1967 |
A |
Foreign Referenced Citations (1)
Number |
Date |
Country |
60-87959 |
May 1985 |
JP |
Non-Patent Literature Citations (1)
Entry |
“Giessen und Giesswalzen Duner Brammen Bei Der Mannesmannrohrenwerke Ag” by Ehrenberg et al, Dusseldorf, DE, No. 9/10, May 16, 1989, p. 453-462 by Stahl et al. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08/682672 |
|
US |
Child |
09/167776 |
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US |