DE1011257B - Tool, in particular impact tool for hard crushing, with surface armor created by applying wear-resistant material in places - Google Patents

Description

GERMAN

For the production of wear-resistant surfaces that are subject to heavy wear and tear during operation, in particular are subjected to mechanical abrasion, such as. B-. the wear-exposed surfaces of the Beaters, crushing tools, agitators, hot tools and the like are used to an ever increasing extent made use of build-up welding.

Both cast hard alloys and sintered hard metals are used for this purpose Use. For wear-resistant armoring, sintered hard metals are often used, which are mainly based on the Carbides of tungsten, molybdenum, titanium, vanadium etc. in connection with lower-melting ones Auxiliary metals of the iron groups are used.

For the production of grinding wheels and grinding belts, it has been proposed to use a sheet metal support Abrasive grains completely surrounded by metal by welding or soldering or galvanically to raise.

The welding, which is done both with the help of the electric arc and with use the gas fusion welding can be done in such a way that the surfaces to be armored with a layer of the selected material can be covered, with the individual weld beads to achieve a surface that is as smooth as possible are arranged close to one another.

It has also already been proposed that a grid-like network be welded on hard material and by filling the resulting spaces with soft material to create a smooth and wear-resistant surface. Through the skeletal A framework made of hard material is on the one hand a support for such cover layers and on the other hand a Achieved savings in high-quality alloy materials.

The present invention relates to tools, in particular impact tools for hard comminution, with surface armor created by applying wear-resistant material in places, which should above all be resistant to mechanical abrasion.

According to the invention, individual welds are on the surfaces subject to wear approximately round base, for example hump or wart shape, distributed in a point-like arrangement.

As a material for these welds, especially hard alloys come into consideration, which have both can be made by casting and by sintering. Particularly good results have been achieved with sintered hard metals achieved.

Tool, especially striking tool

for hard grinding, with through
surface armor applied in places of wear-resistant material

Applicant:

Gebr. Böhler & Co. Aktiengesellschaft,

Vienna, branch office,
Stuttgart-Untertürkheim, Benzstr. 19th

Claimed priority:
Austria from March 3, 1954

Depending on the intended use and the expected stress and dependency the size of the individual punctiform plots can depend on the size of the tools their base area and their height can be changed.

The arrangement of the applications can also be chosen differently, for example so that the individual rows of points offset from one another or the plots in the form of curves or others geometrical points of view are arranged.

With tools according to the invention, for example with bats for hard comminution, could surprisingly a significant increase in service life compared to tools with common surface armor can be observed under comparable stresses.

With normal surface armoring with hard materials, the applied layer often retains when it cools Hairline cracks, which, in addition to abrasive wear, lead to breakouts when exposed to impact on the tool. This deficiency does not occur in tools according to the invention.

Nevertheless, it is surprising that when there is a wear load, that is, when it is present a destructive effect, which takes place according to the invention compared to conventional surface armor significant enlargements of the areas exposed to the attack do not result in a reduction,

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rather, there is a substantial increase in the resistance of the same.

In the drawing, an armored bat is shown, the impactor with 1 and its point-shaped Plots are denoted by 2. In addition to the areas subject to wear, they are advantageous the edges delimiting these areas are also armored with continuous application layers 3.

For armoring such edges, point-shaped Applications not proven to be suitable. If, therefore, with a heavy wear of the edges must be expected, as is the case, for example, with impacts for hard comminution the advantageous effect of the point-like applications according to the invention only then in full Extent can be achieved if these edges are armored with continuous application layers. By the armouring of the edges may cause damage to those to be protected Avoided areas.

Rackets reinforced according to the invention had an average lifespan that was longer than that Twice the previously known values for the service life under comparable conditions.

Claims (2)

Patent claims: 1. Tool, especially striking tool for hard crushing, with through in places Deposits of wear-resistant material produced surface armor, characterized in that that over the wear-exposed surface individual welds with approximately round base, for example in the shape of a hump or wart, in a point-like arrangement are distributed. 2. Tool according to claim 1, with edges prone to wear *, characterized in that the edges at risk of wear are protected by a continuous coating. Considered publications:
ao German Patent Nos. 718 127, 861 814; Magazine "Autogene Metallverarbeitung", 32 (1940), issues 16 and 17. 1 sheet of drawings