Swiss Aluminium Ltd.

Raoul Sautebin

Jean-Claude Weber

Carlo Alborghetti

A device for contactless, vertically downwards continuous casting of metals in an electromagnetic alternating field, has an inductor and an electrically conductive, non-ferromagnetic screen that tapers downwards and features at a vertical distance 9 from this screen an electrically conductive, non-ferromagnetic counter screen that tapers upwards, the distance 9 between the said screen and counter screen being at least 2 mm, at most equal of the height of the inductor and in a continuous process which employs this device the circulation of the melt in the molten head of the ingot is reduced at least in the steady-state phase of casting. The process is particularly suitable for continuous casting aluminum alloys having a magnesium content of at least 2%.

Device and process for the continuous casting of metals

The cooling of a continuously cast ingot of metal as it emerges from the mold is carried out by applying coolant directly to the ingot surface. In order to reduce the amount of curvature at the foot of the ingot due to too rapid cooling, a substance which releases a gas as a product of decomposition on striking the hot ingot surface is added to the coolant at least during the initial phase of casting. This gas forms an insulating film on the ingot surface thus reducing the rate of heat extraction. Particularly suitable for this purpose are substances which produce carbon dioxide or nitrogen as decomposition product.

Process for cooling in ingot during continuous casting

A continuously cast strand or ingot of metal is cooled as it emerges from the mold by applying a coolant directly to the surface of the strand. In order to prevent distortion at the foot of the ingot due to too abrupt cooling, polymers of molecular weight 10.sup.4 -10.sup.8 are added to the coolant at least during the initial phase of casting. By the addition of polymers to the coolant the kinetics of formation and discharge of vapor bubbles as the coolant strikes the ingot surface are significantly altered due to the reduction in the surface tension of the coolant; as a result of this an insulating film of coolant vapor forms on the surface of the ingot thus reducing the heat flow from the ingot.

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Sierre, Switzerland

Raoul Sautebin