Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/12—Accessories for subsequent treating or working cast stock in situ
  • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
  • B22D11/1245—Accessories for subsequent treating or working cast stock in situ for cooling using specific cooling agents

Definitions

• the invention relates to a method for casting a strand, in particular made of aluminum or an aluminum alloy, through a casting mold while cooling the strand formed by means of water containing carbon dioxide.
• the thermal stresses that occur as a result of this temperature shock are greater than the tensile strength of the cast strand and lead to permanent deformation in the form of a convex curvature of the strand foot and, if the tensile strength is exceeded, to cracks in the strand.
• the strand In order to obtain a cast strand with a flat foot, the strand must not be cooled too much during the start-up process.
• DE-AS 12 93 956 deals with a method for cooling continuously cast thin strips, plates or the like, in which a water-air mixture is produced in the mold in an ejector-like manner and before being discharged for direct cooling, i.e. cooling by directly applying the coolant to the thin tape or the like. itself, for indirect cooling, i.e. cooling via the webs of the mold is used.
• the bottom depth and / or the temperature of the cast thin strip is controlled by varying the amount of air and / or water. Since the water-air mixture is sprayed as a mist, especially during direct cooling, targeted control of the cooling is not possible.
• a further embodiment of the above-mentioned method can be found in DE-OS 24 08 285.
• a water-air mixture is also used to cool the casting strand emerging from the mold. First, cooling water flows under pressure in water chambers or channels of the mold and cools the work surfaces of the mold room. Then it emerges from the mold and cools the cast strip directly. As a result of different cross sections of the coolant outlet openings and additional air gaps, air from the latter is drawn in according to the principle of a water jet pump effect. However, this air remains with little influence on the cooling capacity in the cooling water.
• controlling the cooling is also likely to be very problematic here, since, for example, significantly more air is drawn in when the addition of cooling water is increased, but this does not necessarily result in a better effect of the cooling, but rather only an increased atomization of the air-water mixture .
• the rate of heat dissipation is increased by reducing the amount of gas mixed with the coolant.
• the main disadvantage of this method lies in its complexity, which in particular that for solving the Ga
• the mixing and control equipment required in the coolant Control of the cooling also remains dependent on the solubility of the gas in the liquid coolant, which is determined by various different parameters which also depend, inter alia, on the changing conditions during the entire casting process.
• the inventor has set itself the goal of developing a method of the type mentioned above which overcomes these disadvantages and by means of which in particular precise control of the cooling process is possible both with regard to the phase of indirect and direct cooling.
• the water-carbon dioxide mixture initially has such a solution ratio that the thermal shock between the indirect cooling emanating from the mold and that or the like when lowering a start-up floor or the like. direct cooling is as low as possible.
• this solution ratio is also the highest necessary value of the concentration of carbon dioxide in water, the lowering of which by adding water is not difficult, while a reduction in the amount of carbon dioxide with the same amount of water is accompanied by the imponderability of the amount of actually dissolved carbon dioxide.
• a carbon dioxide-water mixture of a certain concentration or the like before starting up in a tank. ready and then add additional water to it during the start-up process. It is also possible to continuously prepare carbon dioxide and water as a coolant in a mixing device and to continuously increase the water content.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)

Applications Claiming Priority (6)

Publications (2)

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ID=27191042

Family Applications (1)

Country Status (3)

Cited By (3)

Family Cites Families (1)

• 1984
  • 1984-05-10 EP EP84810226A patent/EP0127577A3/fr not_active Withdrawn
  • 1984-05-16 AU AU28088/84A patent/AU2808884A/en not_active Abandoned
  • 1984-05-24 FR FR8408166A patent/FR2546429A1/fr active Pending

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