DE1072343B - - Google Patents

Description

GERMAN

EDITORIAL: DECEMBER 31, 19Ö9

The invention relates to the hot forming of metals, for example forging or deep drawing, and relates to a lubricant used for this purpose and also to a method for Protection and maintenance of the degree of hardness of the tools used for this purpose. Special meaning owns the invention for the production of hollow bodies, the cavity of which has a greater depth, z. ! 5. of cylinders. Husk casings.

The lubricants previously used for this purpose do not tolerate the temperatures that occur here. As a result, glass has been used as a friction reducing agent. This 'jt & £ hear%: T the disadvantage that it tjfld when it cools!' UTver Tjfld. which causes strong mechanical wear and tear and, as a result, has an extremely unfavorable effect on the service life of tools.

In order to avoid these disadvantages, lubricants were used as the lubricating component Contains graphite or mica in flake form. This component causes satisfactory lubrication and withstands the high temperatures that occur during forging or deep drawing. By • This resistance differs from graphite. • ml of mica, for example, to molybdenum • iisulfide. this is also a solid body in the form of leaflets which is suitable for some purposes for lubricating represents, but is completely unsuitable for lubrication during the hot forming of metals. \ veil it »I decompose at the high working temperatures.

The subject matter of the invention is therefore a lubricant for the stated purpose which, in a known manner, has a content of graphite or mica as a lubricating component. Compared to the known lubricants of this type, the lubricant according to the invention differs in that it also contains dispersed carbon and manganese dioxide. The additional use of these two materials means a very significant improvement in that the tools are protected due to processes that still need to be purified Through the simultaneous use of finely divided carbon and mayigandioxide, the lubricant also has the property of a zeining oil. |) a to obtain a good response of the ^r ^ "Lilen> toff to purchase ^ ■" ■ iidung to be brought into feiuverteilter form possible, for example, l <ow oU-r graphite very suitable for this purpose.

The effect can still be improved by adding, according to a further invention, the lubricant and cement a powdery, combustible, porous one.

Lubricants and cementing agents
for tools as well as processes
for protection and maintenance
the degree of hardness of tools
for hot forming of metals

Applicant:

Societe d'Exploitation des Brevets C.L.S., Paris

Representative: Dipl.-Ing. VV. Reinke, patent attorney,
Bensheim-Auerbach, Jahnstr. 11

Claimed priority:
France April 20, 1955

heat insulating oars. However, not mechanically attacking l ^r üllstoff is admixed, for example, pulverulent sawdust, cork powder or straw.

The application of the lubricant can be in the form of a solid body. Be for this purpose the constituents mixed with one another with the aid of a binder, for example dextrin united. However, it can also be used in liquid form by adding the solid components mixed with water. In this way you can get a sprayable suspension in water, which is applied to the surfaces to be lubricated, for example by spraying.

A preferred mixture is given as an example:

Gewiditstcilc

Sawdust 10

Graphite in flake form AO

Soot 23

Manganese dioxide 4

This mixture is mixed with water five other parts, containing about 4 ⁰ Zo dextrin or a similar binder.

The basic idea of the invention is thus once the known lubricants, which as lubricating component graphite or mica removes

Claims (3)

1 hold to improve in a soldier way that in addition to the lubricating effect, cementing is achieved at the same time, which increases the service life of the tools. On the other hand, in connection with this, the Evnndung orders in this process to protect and maintain the degree of hardness of the tools. Reference is made to the drawing to illustrate the practical application of the inventive curative and fermentation agent as well as the implementation of the method according to the invention. Fig. I and Fig. 2 illustrate the deep-drawing of a hollow body according to the hitherto generally used, customary method, showing the tools used: Crfindungsgcmiißcn procedure allows. As can be seen in FIGS. 1 and 2, the conventional method generally requires two successive operations. In the first work step according to FIG. 1, only one preform is forged, namely from a material block 1 of cylindrical or rectangular shape, which is placed in a die 2 and processed by means of a mandrel 3. In the subsequent operation according to FIG. 2, the preform obtained in this way is then driven through a drawing die 5 by means of a mandrel 4. In this second step, the material is drawn out to its final shape. In order to facilitate the first work step, the inner walls of the die 2 and the surface of the mandrel 3 are lubricated with grease or soaps in this common method. Even though lubricants are selected for this whose melting point is as high as possible, the lubricants previously used for this purpose always melt immediately and flow off through an opening 6. which is provided in the testicle of the die for an ejector rod. Since a further part of the lubricant also evaporates as a result of the high temperature, the lubricating effect is very poor. Another difficulty is that the gases emitted when the shaped workpiece is ejected ignite on contact with the air. The. The flames that come out attack the surface of the workpiece and the A tools. These disadvantages are avoided by the invention, as illustrated with the aid of the tool shown in FIG. 3. The lubricant according to the invention can also be properly applied to the die and mandrel when cutting deep hollow bodies. As a result, it is possible to perform the deformation in a single operation. Thus, the tool shown in Fig. 3 is used to manufacture a cylinder 7, the cavity of which has a great depth. Here, too, a block of material is used as the starting body, which is inserted into a die 8. The inside diameter of the die corresponds approximately to the outside diameter of the piece to be manufactured, taking into account the subsequent processing that may be increased. The fonming is done with the help of a mandrel 9. Before the start of the operation, the inner surfaces of the die 8 and the surface of the dome 9 are provided with the lubricant, be it in the form of a mixture with water with the addition of a binder, be it in the form of powder . The guns 10 and 10 'serve this purpose. As already said, the application can also take place in the form of a solid body. So you can improve the provision of the surfaces inii your lubricant by placing a press plate of this lubricant on the block of material to be processed with each forging process or from time to time, so that the lubricant is pressed in through the mandrel 9. The cavity 11 formed at the lower end of the mandrel 9 by the concave shape of the end face serves in a known manner to hold a supply of lubricant, which when the Doriu 9 is pressed down as a thin, lubricating film between the (surface of the dome and the metal 7 In this way the relative separation between the mandrel and the metal is facilitated. This effect is improved by the addition of an organic combustible substance, as already mentioned Surfaces of the die or the mandrel, on the other hand, support the above-mentioned effect. The same applies to the case of deep drawing, in which the combustion gases force their way between the drawn metal and the edge opening of the target iron and thereby promote the lubricating effect Part made of COi are they are not flammable. As a result, those disadvantages cannot arise here which occur in the conventional processes due to the combustion of the flammable gases formed during the decomposition of the lubricant. The effect of the manganese dioxide added according to the invention is based on the fact that during the reaction with the finely divided carbon, which is also added, manganese penetrates freely and by diffusion into the surface of the die and the mandrel. This manganese that has penetrated in this way facilitates the hardening of the die and the dome by means of the carbon. It is essential here that the reaction mentioned, even if it is not particularly exothermic. but at least takes place without heat absorption and thus does not bring about any reduction in temperature of the material to be treated. As the above explanation shows, the lubricant and the method according to the invention bring about good hardening and smoothing of the tool surface. This increases the service life of the tools and improves the surface texture of the molded products. Patent claims: 1. Lubricant and Zemeutierungsmittcl for tools for hot forming of metals, for example for forging or deep drawing, with a content of graphite or mica as lubricating Component, characterized in that it also contains finely divided carbon and manganese dioxide contains. 2. lubricant and ZcmentierungsmitteI according to claim 1, characterized in that it further a powdery !, combustible, porous, heat-insulating and mechanically non-aggressive Filler, for example pre-shaped sawdust. Contains cork or straw powder. 3. Lubricant and cementing agent according to claim 1 and 2, characterized in that it If) parts by weight of powdered sawdust. 60 parts by weight of graphite in leaves. 23 parts by weight Contains soot and 4 parts by weight of manganese dioxide.