DE1108385B - Hot rolled ingot produced by casting - Google Patents

Description

GERMAN

PATENT OFFICE

M / *

ti ^ r

U4215VI / 31C

REGISTRATION DATE: NOVEMBER 16, 1956

NOTICE
THE REGISTRATION
ANDOUTPUTE
EDITORIAL: JUNE 8, 1961

The invention relates to the special shape of the end of the casting head made of killed steel or other metal cast billets for the purpose of reducing the amount of hot rolling involved Overlap.

Overlap is understood to be an uneven stretching of the which occurs during rolling Material, whereby its outer parts are pulled past the inner parts. The club ends This gives them a funnel-like or bag-like appearance and must be scrapped.

A related experiment on a calmed steel block with a transverse dimension of 410 mm at the coarse end delivered the following result:

After sawing off the casting head, a short bolt was placed in the center of the exposed surface screwed in steel quality that differs from the block material. After hot rolling in the duo-block mill for a square dimension of 80 mm, the funnel formed at the end of the billet was about 1.1 to 1.2 m, correspondingly about 55 kg or about 5% of the usable block weight. The lowest point of the The funnel was fixed by means of the upper end of the bolt screwed in beforehand. By Further experiments have found that the piece containing the funnel at the end of the billet is so The longer it turns out, the larger the initial transverse dimension of the block and, in contrast, the smaller the final transverse dimension of the stick is.

With those used today, from the thermal point of view from the point of view of more or less effective casting hoods, refilling takes place during the solidification shrinkage, which leads to an often flat U-shaped sinking of the casting surface of the Blockes leads. As a result, their appearance comes closer and closer to that of the experiments described above used very flat block surfaces. When these blocks are rolled, there is therefore an overlap on, d. h., the flawless material located under the casting head part, in particular on the The outside of the block is pulled past the part of the middle section that is prone to voids and segregation and falls off as scrap when the billet is cut and sawed. This will increase the yield less favorable on billets from the blocks, d. i.e. more material is cut off at the end of the billet, than corresponds to the pouring head part of the original block.

It is the object of the invention to overcome this disadvantage, which is more or less common to all rolled blocks Execution regardless of the type of pouring head used, largely eliminated. The Erfin-Through Hot rolled ingot produced by casting

Applicant:

Uddeholms Aktiebolag, Uddeholm (Sweden)

Representative: Dipl.-Ing. E. Jourdan, patent attorney, Frankfurt / M., Kronberger Str. 46

Claimed priority: Sweden from December 1, 1955

Carl Kristian Werner, Vikmanshyttan (Sweden), has been named as the inventor

manure is characterized in that the block in the upper part 2, but below the pouring head 1 and the segregation, with a conicity of an average of 20 to 55 ° inclined to the block axis Areas is drawn in to one fifth to half of its largest diameter, which is preferably is provided at the transition between the upper section 2 and the lower remaining block 3.

Many of the known block designs have due to the design of the mold head tapered areas at the top ends. They differ from the block according to the invention but basically in that the pouring head coincides with the tapered part. Which tapering part of the block according to the invention is located below the pouring head and is free of Cavities and segregations.

It has become known a mold shape in which the block is at the top below the Casting head and slightly tapered at the lower end to the bottom of the mold. This mold is used for production very long and narrow blocks, preferably made of copper, for making wire, which makes the preparatory rolling before wire drawing is to be simplified. The bevel angle on the tapered ends is opposite to the length to width ratio of these blocks the bevel angle according to the invention is very small and is expressly used to facilitate the Introduction of the blocks between the rollers.

109 610/363

The invention is illustrated by the exemplary embodiments shown schematically in the figures explained. It shows

1 shows a cross section of a rolling block according to the invention,

Fig. 2 is a cross section of another billet according to the invention.

The rolling blocks according to the invention have a casting head 1, an upper section 2 and the lower, remaining block 3.

A rolling test with a block according to the invention with a transverse dimension of 410 mm led to the following Result: After cutting off the casting head flat and forming a tapered part with inclined surfaces less than 30 ° and tapering to 270 mm transverse dimension, d. H. so by about a third, after rolling to a square dimension of 80 mm, an overlap of only 2%, d. H. an improvement in the yield of 3% compared to the above-mentioned experiment was achieved.

The tapered part can be made in various ways, e.g. B. through appropriate training the mold or by using one or more mold parts above or in the main mold are arranged. It can also be connected to an in or the casting head part arranged on the mold can be obtained, for example by using a collapsible or demountable template. This connection part can be made of fire-resistant or consist of completely or partially combustible material.

In order to best counteract the overlap, the tapered part of the block body should be from Be completely free of cavities and impermissible segregation. However, the invention extends also in the case in which the blowholes or the undesired segregation to a small extent the tapered part of the block are present. In this case, however, the possible yield will be decreased.

Claims (1)

PATENT CLAIM: Hot rolled block produced by casting, especially made of killed steel, characterized in that the block in the upper section (2) below the casting head (1) with surfaces inclined on average 20 to 55 ° relative to the block axis to a fifth to half of its largest, preferably at the transition between the upper part (2) and the lower, remaining block (3) existing transverse dimension is drawn in tapering towards the pouring head (1). Considered publications:
German Patent No. 706 908;
U.S. Patent Nos. 2,030,199, 2,097,658. 1 sheet of drawings © 109 610/363 5.61