DE1608131B1 - Sintered carbide hard alloy - Google Patents

Description

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The invention relates to a sintered carbide hard It has now been found that the previously occupied with 25 to 75% titanium carbide and 25 to 75%. carbide hard alloys did not have sufficient fineness austenitic or through transformation and / or resistance to external wear through pulverför precipitation intermetallic phases hardenable, moderate or granular foreign materials, such as metal powder, Steel. 5 porcelain bodies, cement, sand, etc. It

So-called hard carbide alloys are known, and it is therefore the object of the present invention to provide carbide diaphragms Powder-metallurgical methods are used to propose alloys that provide sufficient and up to 75% carbide, finely divided in a steel wear resistance against external wear Base compound included as a binder. From the known powdery or granular foreign materials on hard metals these carbide hardnesses differ.

Alloys in that the binder, which was surprisingly found in hard that these metals consists of iron, cobalt or nickel, hard condition is met when you are in a sintered bar. In this way it is possible to machine the sintered carbide hard alloy, consisting of 25 to 75% semi-finished titanium in the non-hardened state to finished size carbide and 25 to 75% steel, an austenitic or and then through a suitable 15 by transformation and / or precipitation to harden inter heat treatment. The metallic phases hardenable steel can be selected and this advantage of good machinability of the semi-finished product with the 1.2 to 15% manganese in addition to other elements takes advantage of high hardness, which can be up to 75 RC .

associate. Since an alloy with 25 to 75% carbide there are hard carbide alloys known that proportion not produced by smelting metallurgy 20 in addition to titanium carbide in the specified amount carbide austenitic or by transformation and / or alloying is carried out the known powder metallurgical route. divorce hardenable steel base material contain and

Hard carbide alloys usually contain titanium and steels such as those that contain manganese in the specified carbide as a carbide component, which can contain up to an amount. However, it was not to be expected that a certain proportion of hardenable steels alloyed with manganese could also be replaced by another carbide than steel. Above all, austenitic base masses for carbide hard alloys are used as binders, which are effective in this way or, through conversion and / or separation, to protect against external wear by means of powdery steels or steels that can be hardened by flanging. The austenitic foreign materials, such as those found in pressed and sometimes martensitic steels, in addition to shapes for all powdery or granular products, have the advantage of hardenability as well as the favorable 30 metallic or ceramic type, mixing blades, properties, corrosion and heat-resistant to press rollers for Grinding wheels, sandblasting nozzles. This means that hard carbide alloys with a grinding ball and similar parts occur, would behave such steel base material for objects with advantage. So has z. 35 about 70 RC during pressing (profiling) are required to have immersion of abrasive resistance as a Karbidhartlegierung with use, which in addition to good wear properties of a steel matrix without manganese at a hardness of resistance and heat resistance and a good corro-. discs are the same despite their comparative hardness

When producing the well-known carbide hard alloy tool life like a steel with 1.9% manganese and a

It has now been found that difficulties have a hardness of about 63 RC. A hard carbide alloy with

arise when the alloys in a poorer the addition of manganese according to the invention to their

Can be sintered vacuum as 10 ~ ^{s Torr.} In addition to the 40 steel base mass, on the other hand, there is a

Formation of porous surface layers due to 5 times longer service life.

In addition, there are two significant advantages in obtaining the sintered compacts by producing carbide hard alloys with hard hydrocarbons, carbon monoxide or the like, which contain 1.2 to 15% manganese. Since the generation of a high vacuum with a 45 holds, which surprisingly and by no means foreseeable negative pressure above 10 ~ ² Torr increases the cost of production. These exist in the first place, in numerous attempts have already been made to use a vacuum from 5 · 10 ^-1 Torr sintering to a worse vacuum. So it is z. B. NEN, without any unfamiliar by evaporation, to avoid evaporation in the standing porous edge zone showed in the sintering. Surface zones and the resulting porosity 50 On the other hand, it is also possible to sinter through compacts with one of the edge zones the titanium carbide to chromium carbide with a diameter of more than 60 mm up to the core to a more or less saturated mixed carbide.

to tie. This measure enabled carbide- The increase in the wear resistance of counter-

hard alloys in a worse, z. B. in stands a'.is the composite according to the invention

a technical vacuum without the formation of carbide hard alloy in connection with those mentioned

Evaporation resulting from porous edge zones.

be sintered, but it resulted from unexplained production, especially during sintering,

The carbide hard alloy according to the invention provides for reasons that compacts with a diameter "of

no more than about 60 mm to the core through a step that is caused by the well-known carbide hard

sintered. 60 alloys could not be reached so far.

The well-known sintered steel-bonded carbide The following examples give an excerpt

hard alloys are used in particular as materials of the alloy material claimed according to the invention

used for hot or cold work tools, the reichs.

are exposed to high wear. A high example 1
Hardness of 65 used for wear-resistant objects

However, the material alone is not enough. Relevant for ^Eme carbide hard alloy nut

the wear resistance is rather the resistance 33% TiC and

of the material against abrasion. 67% steel, consisting of

Claims (1)

3 4 8% Ni, 13% Cr, 9% Co, 5.75% Mo, 5% Mo, 2.75% Ti, 0.7% Ti, 1.60% Al, 0.7% Al, 5 0.70% Nb, 0.5% Cu, 0.01% B, 0.02% B, 1.95% Mn, 1.5% Mn, remainder Fe ₅
Remainder Fe, io has one due to the precipitation of intermetallic phases stands as an example of a steel base mass that can be transformed and hardened. The hardship in the deterrent Separation of intermetallic phases (nickel martensites) th (austenitic) state was achieved with 35 to 38 RC curable steel base material having a hardness in the lösungsge- and after a löstündigen annealing at 790 ⁰ C and Annealed condition 45 to 49 RC and after hardening followed by a 16-hour hold at 650 ° C A hardness of 64 15 54 to 56 RC was measured for 6 to 8 hours at 480 ° C. to 66 RC . Example 5
Example 2. The alloy with
An alloy with ₃₀ ^ _{tic and} 33% TiC and ^ao 70% steel with 67% steel, consisting of 1.25% C, 0.90% C, 12.5% Mn, 0.12% V, remainder Fe, Re'st Fe ^'25 ^ ^at due to their high manganese content in particular which after quenching a purely austenitic one is an example of a purely martensitic steel matrix. It is therefore not magnetizable, mass which, hardened from 810 ° C in OeI and, depending on the need, tempered at 150 to 350 ° C in terms of agile toughness, this so-called manganese austenite has an inherent hardness that is significantly more favorable in terms of its wear resistance, depending on the tempering temperature of 65 up to 71 RC as the nickel austenite according to Example 4, as can be shown. it is present in stainless steels, for example. the Example 3 Hardness of this alloy was 45 to 48 RC ge measure up. An alloy with The production of the inventively combined 33 ° / TiC and ^{35 se z} t t ^s Karbidhartlegierung carried out by a known 67 ° / steel consisting of powder metallurgy. The individual components 12 ⁰ I C 'will have a grain size of about 2 to 5 microns Ground 1 * 5 ° / Mo, pressed into shaped bodies and then g'o 0 / ° M _n 'sintered. After sintering, the parts are Finished balance Fe ^'4 ° ti§ ^ma ß followed by a Depending on the quality, suitable heat treatment stands out as an example of a martensitic, ie through hardening.
Conversion of hardenable steel matrix that is still has a certain retained austenite content. This alloy claim: tion reaches its maximum hardness after a 45 horror of 1040 ° C in OeI. Despite the retained austenite sintered carbide hard alloy with a high content, a hardness of 70 to 72 RC is achieved. wear resistance, especially friction and erosion τ, ■ · ι / ι wear resistance, consisting of 25 to 75% Example * titanium carbide and 25 to 75% steel, thereby The alloy with ₅ o marked that the austenitic 30% TiC and or by conversion and / or precipitation 70% steel, consisting of intermetallic phases hardenable steel 1.2 to 15% 38% Ni, contains manganese.