JPS582581B2 - Sliding material with wear and corrosion resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to sliding materials with high wear resistance and corrosion resistance. Conventionally, alloys mainly composed of tungsten carbide and titanium carbide have been used as sliding materials with high hardness and excellent corrosion resistance. I've been

However, tungsten carbide-based materials have become economically expensive, making it difficult to use them as sliding materials for general seal rings, etc., and they have poor wear resistance and corrosion resistance. There were also limits.

On the other hand, those containing titanium carbide as a main component have a drawback of low heat resistance.

The present invention aims to provide a material that eliminates the above-mentioned drawbacks, and the gist thereof is to use 5 to 50 Vol% of one or more of titanium carbide or tungsten carbide, and 25 Vol% of one or more of chromium carbide, molybdenum carbide, or vanadium carbide. % (excluding 0), the balance is 60 to 95 Vol. % of niobium carbide, and 5 to 40 Vol. % of one or more iron group elements is a sliding material having wear and corrosion resistance.

Tests conducted to develop the present invention and their results are shown below.

Table 1 shows various properties of conventionally used alloys mainly composed of tungsten carbide or titanium carbide and hard alloys (1) to (6) mainly composed of niobium carbide.

Among the hard alloys shown in (1) to (6), those (1) to (3) are materials of the present invention, and (4) to (6) are comparative materials.

These various alloys were prepared as shown in Table 1, mixed for 72 hours in a ball mill, and after adding 4 vol% of paraffin as a lubricant, the mass was 1500 kg/cm2.
1300~1450 each after compression molding and preliminary sintering.
Hardness and specific gravity, which indicate the wear resistance of alloys sintered at °C,
Indicates transverse rupture strength.

Table 2 shows the weight changes measured before and after the corrosion resistance test by grinding test pieces of the various alloys mentioned above into shapes of 20 x 20 x 10 mm using a 150# diamond wheel.

-122- When niobium carbide in the present invention contains 5 to 50 Vol% of one or both of titanium carbide or tungsten carbide, a solid solution is formed by sintering, which itself has wear resistance and improves corrosion resistance, but if the content is less than 5 Vol%, Sinterability deteriorates, wear resistance decreases, and if it exceeds 50 Vol%, corrosion resistance deteriorates.

Furthermore, the addition of one or more of chromium carbide, molybdenum carbide, or vanadium carbide is intended to suppress grain growth of the material and further improve wear resistance and corrosion resistance, but as can be seen from Table 1, the amount of these substances should not be too large. Since a decrease in strength is observed in this case, the upper limit is set at 25 Vol%.

The reason for setting the total amount of carbides (combining each carbide listed so far and niobium carbide) to 60 to 95 Vol% is that if it is less than 60 Vol%, wear resistance and corrosion resistance will be insufficient;
%, the binder material becomes insufficient and the alloy strength decreases, making it unusable for practical use.

As mentioned above, the material of the present invention has a somewhat lower transverse rupture strength than cemented carbide, but its hardness is rather high, and the corrosion resistance shown in Table 2 shows that it is H2
It exhibits excellent corrosion resistance to SO4, far exceeding that of cemented carbide.

It also has better heat resistance than materials whose main component is titanium carbide.
The material of the present invention is excellent in both corrosion resistance and is useful as a sliding material such as a seal ring material.

Comparative materials (1) to (6) shown have values equivalent to the materials of the present invention in terms of hardness, transverse rupture strength, and corrosion resistance, but these materials contain Ta and W, which are very easy to form carbides. ,
Since it contains Mo, it has the drawback that abnormal phases such as carbide η phase are easily formed during sintering, making it difficult to obtain a uniform structure, and the manufacturing conditions become strict, so it is not suitable for actual operation.

Claims (1)

[Claims] 1 5-50 Vol% of one or more types of titanium carbide or tungsten carbide, 25 Vol% or less (not including 0) of one or more of chromium carbide, molybdenum carbide, or vanadium carbide, and 60-95 Vol% of one or more types of titanium carbide or tungsten carbide, the balance being niobium carbide.
5 to 40 Vol% of one or more iron group elements to 91%
A sliding material with wear and corrosion resistance consisting of a composition containing: