DE1257334B - Lubricant plate template for pressing carbon steel blocks out of extrusion presses - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

ClOm

German class: 23 c -1/04

Number: 1 257 334

File number: H 42518IV c / 23 c

Filing date: May 5, 1961

Open date: December 28, 1967

It is used in the extrusion of metals and steel in ingot form from the transducer of metal extrusion known, between the contact surfaces of material and tools, in particular between Die, punch and the block end faces, the lubricant in the form of a melting point Insert plate or other shaped body. Such cylinders are also designed as hollow cylinders Lubricant molded body known, which surround the block surface area.

Molded lubricant bodies of this type, in particular plate templates, are often made of glass or glass-containing Mixtures made. Independent of these glass-containing lubricants will also be Borax, molybdenum sulfide, graphite and other substances are used without adding glass.

Have experience in pressing steel blocks, especially carbon steel blocks On the one hand, it has been shown that a more or less pronounced decarburization of the surfaces during the pressing out of the strand occurs. When glass is used as a lubricant, this carbon loss remains fully received. No carburization is achieved. The use of non-glass Lubricants has also not given satisfactory results because they generate gas that causes efflorescence on the surfaces. Further experiments have shown that although a carbonization of the surface, which is desirable per se, is caused by graphite, but that with it a sufficient lubricating effect cannot be achieved.

On the other hand, one is when pressing carbon steel blocks with the help of known glass lubricants Dependent on having expensive fluoric acid baths ready to remove the profiles from the adhering To free the glass layer or by additional straightening or stretching work, the glass layer from the profile to blow up.

Since graphite, which in itself allows a certain desirable carburization of the surfaces of the metal block, seemed suitable as a lubricant for carbon steels, attempts were made to apply a graphite paste to the block surface. However, this only happened with the result that there was no sufficient lubricating effect. Other known lubricants based on graphite - including those with colloidal graphite - in connection with a binder made of oils and fats or sugar and oil or sawdust, oil and soot have not proven themselves for pressing carbon steel blocks because these binder additives coke or lubricant plate template for pressing out
of carbon steel blocks
from extrusion

Applicant:

Hydraulics G. mb H.,
Duisburg, Mülheimer Str. 72

Named as inventor:
Hermann Prött, Duisburg

burn. As a result, the lubricity is lost. For carbon steels, these are lubricants therefore not suitable.

In another known lubricant template, in which glass is bound in water glass, there is the Disadvantage that for the production of carbon steels there is insufficient carburization and none

r . Lubricating effect are guaranteed up to the highest temperature areas.

The invention shows a way of providing a plate template for lubrication when extruding steel blocks from the receiver of a metal extrusion press for the production of extruded parts To create carbon steel that has both a sufficient carburization of the extruded material and thus enables an excellent surface quality and at the same time achieves a very good lubricating effect, whereby the lubricant is stable even at the relatively high temperatures in the The lubricant is effective and does not coke or burn during the extrusion process.

According to the invention, the plate template consists of a mixture that is produced by pressing, which is known per se and drying a suspension of colloidal graphite in water glass of approximately equal parts has been.

Thus, the problem with extrusion or tube pressing when using one under the influence of Block heat melting plate template with a binder, which because of its liquid property in the cold state is excellent as a binder and that on the other hand after pressing and drying has a thermal insulation property similar to that of glass, solved in the best possible way. By choosing suitable substances bound in the suspension, which can easily between

709 710/537

Claims (1)

Die, block face and punch are to be brought in and optimal lubricity up to the area ensure the highest temperatures and the surface of carbon steels with a desired Carburization provided without coking or burning exist compared to the known bonded lubricants have several advantages. So that the lubricant additives do not coke or burn, the colloidal graphite is kept airtight in water glass in the plate template according to the invention. As a result of this measure, no coking or burning now occurs. Since this water glass is a poor conductor of heat, it not only protects the graphite, but also the substances that come into contact with it, e.g. B. the metallic walls of the tools, against undesirably high temperature absorption. The water glass has a thermal insulation effect comparable to that of glass. It thus serves as an insulation in contrast to binders that contain oils, fats, sugar or sawdust or the like. In the case of the latter, there is a high degree of heat transfer capability, as a result of which the lubricating effect steadily decreases with increasing temperatures and which ceases completely at the beginning of coking or burning. The layer of residual lubricant adhering to the profiles produced after pressing out can be removed with simple, inexpensive means, e.g. B. by brushing or sandblasting to remove. In some cases it is even desirable that the slightly graphite skin of the residual lubricant layer is not removed. Overall, however, this is due to the use of the lubricant template according to the invention, the treatment of the finished product easier and cheaper. The following are examples of lubricants plate templates are given according to the invention, without that they should be limited to the specified composition of. example 1
The plate template has the following composition: Volume percentage ⁴ -> Water glass 45 Colloidal graphite 55 The suspension is prepared by mixing at room temperature, in a semi-viscous state dried and the mixture pressed into molds under low pressure conditions. Afterward the final drying of the plate template takes place. This plate template is used to lubricate an alloy carbon steel with a Carbon content of 0.10%. The pressing temperature is in the range from 1100 to 1200 ° C, and the exit speed of the strand is about 4 to 6 m / s. Example 2 Volume percentage Water glass 45 Colloidal graphite 55 The plate template is produced by drying and pressing in the same way as under Example 1 described, with the difference that the finished shaped template then again is immersed in water glass. As in general in the production of extruded steel profiles, in particular from Carbon steel, decarburizations occur, these losses are equally due to the invention Lubricant plate template replaced again, d. i.e. practically nothing of carbon is lost, and beyond this level of carburization required, there is an additional carburization of 3 ° / o achieved. This applies to example 1. In Example 2, the additional carburization is 1.5 to 2%. Claim: Lubricant plate template for extruding carbon steel blocks from extrusion presses, consisting of a mixture containing colloidal graphite, characterized in that that the mixture by pressing and drying, known per se, a suspension of graphite in water glass of approximately the same Share has been received. Considered publications:
German publication no.1000770, 1,062,663, 1,089,936, 1102 351, 1,065 122;
French patent specification No. 1111626, 1038 836;
British Patent No. 797 365. 709 710/537 12.67 © Bundesdruckerei Berlin