DE1037661B - Steel mill mold for standing casting - Google Patents

Description

It is known that steel mill blocks produced in static casting, especially those with a round cross-section, tend to show longitudinal cracks. Blocks, regardless of their cross-section, are primarily at risk. made of low carbon steels. These longitudinal cracks are generally accepted attributed to a shrinkage of the block at a point in time at which the relatively thin solidified outer layer has not yet reached such a great thickness and thus mechanical strength that they withstand these shrinkage stresses and the ferrostatic pressure of the still liquid interior of the block could. It is known that these shrinkage stresses and thus shrinkage cracks to a certain extent Counteract the extent by regulating the casting speed. They are also available for steel that is prone to cracking Instead of round blocks those have been used that have a square or polygonal cross-section because with these block shapes the tendency to longitudinal cracks is lower. There are already Mold shapes have been proposed which are provided with a wave-shaped inner wall, for example in such a way that thirty-two edges were provided for an internal diameter of the mold of 450 mm, which are connected to one another by slightly curved surfaces, so that a corrugated inner wall of the mold arises. All these measures, in particular those resulting from the corrugation, in the axial direction running recesses can cause longitudinal cracks to appear on the blocks produced not to prevent.

It is proposed for the continuous casting of light metals, in particular aluminum and aluminum alloy been to provide the continuous casting mold with longitudinal grooves with the aim of being on the surface of the Casting cold welds that occur in particular perpendicular to the axis of the cast bar, as well as exudations to avoid. A hint on how to avoid longitudinal cracks, as they are when casting from Steel occur, can not be deduced from this previously known proposal.

For the static casting of steel it has now been found that the formation of longitudinal cracks is practical Can be completely prevented if the inner wall of the mold runs in the axial direction, tight has adjacent grooves. These grooves are easiest to make directly during manufacture attached to the mold itself, namely by having the casting core of the mold on the outside corresponding grooves is provided, which are then depicted on the inner wall of the finished mold. Based on a block diameter of 450 mm, the grooves should have a distance of about 5 mm from groove tip to groove tip and a deep steel mill mold for stationary casting

Applicant: Deutsche Edelstahlwerke

Aktiengesellschaft, Krefeld, Oberschlesienstr. 16

Dr. Roman Schustek, Krefeld, has been named as the inventor

also have about 5 mm. Of course, it is also possible to use slightly larger or smaller ones Observe depths and distances. Such closely spaced grooves that run in the axial direction, can be used for round, square and polygonal molds will. In the case of square or polygonal molds, where the block cracks are predominantly on the rounded ones If edges occur, it is generally sufficient to use the closely spaced grooves in the area of the provided rounded edges.

In Fig. 1, the upper part of a round mold is shown in vertical section. The inner wall reveals the closely spaced grooves 1.

In Fig. 2 the shape of the grooves is indicated, whereby, based on a block diameter of 450 mm, the groove depth 2 and the groove spacing 3 are each about 5 mm. As it appears to be for success the measure according to the invention only to a relatively strong roughening of the inner When the mold wall arrives, it goes without saying that this must be strictly adhered to for routes 2 and 3 specified dimensions are not decisive. In the case of comparatively small mold diameters, it is advisable to to provide narrower grooves than with comparatively large diameters. The depth 2 can also be chosen larger than the distance 3 and vice versa. It doesn't matter whether the is acute-angled or whether a certain rounding is provided at the tips and the bottom of the groove will.

When using the molds according to the Erfindt can even those steels that are particularly vulnerable ^r # longitudinal cracking are properly sealed and that without it especially sorgf * tig ankommjr to an ^e compliance with the casting speed, the

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Claims (2)

Creasing is only superficially transferred to the cast block, so that by using such molds there is in no way the disadvantage that material would have to be removed before rolling or forging in order to remove the creasing, for example, when the blocks are machined is the case with the known corrugated molds. If the material allows it, it is of course also possible to roll out or forge the block cast in a mold according to the invention directly without machining it beforehand. Pate ν τ λ ν s ρ η (■ c η ε: 1. Steel mill mold with recesses in the axial direction on the inner surface for static casting, marked by grooves which, based on a block diameter of 450 mm, have a distance of Groove tip to groove tip of about 5 mm and a groove depth of also about 5 mm. 2. Steel mill mold according to claim 1, characterized in that the grooves at four or polygonal shape is limited to the area of the rounded edges. Considered publications: German Patent Nos. 685 746, 649 492, 810175; U.S. Patents Nos. 2,018,762, 2,071,906, 221947; German interpretation document E 4841 VI / 31c; Stahl and Eisen, 1952, pp. 872 to 875; Schwarzmaier, Stranggießen, 1957, p. 138. 1 sheet of drawings 809 59W496 8.