JPS5837377B2 - wear resistant alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is characterized in that most of the carbide or nitride crystals in the alloy are ultrafine grains of 1μ or less.
The present invention relates to a Ni-based wear-resistant alloy.

Generally, WC-Ni alloys are used for molds and the like because they have a certain degree of hardness and strength as cemented carbide and can be made non-magnetic.

However, it has the drawbacks of poor sinterability and high carbon content, which tends to result in coarse grains.

Therefore, even in the same group, the grain size varies,
Even in the healthy phase range, not only the hardness but also the strength varied, and the properties as an alloy were unstable.

Furthermore, compared to known WC-Co alloys, it is inferior in both strength and hardness, making it unsuitable as a wear-resistant alloy for dies, plugs, and the like.

Figure 1 shows WC-15Ni (average grain size of carbides in the alloy: 1.
5μ), and FIG. 2 is a photograph showing the structure of WC-15Ni (average grain size of carbides in the alloy: 35μ), which has become coarse grained even under the same group or manufacturing conditions.

As is clear from Figures 1 and 2, the conventional WC-Ni
Alloys have variations in grain size, hardness, and strength in their structures.

Also, TiC-Ni system, Cr3C2-Ni system, WC-Co
Regarding grain control, research is being conducted on grain suppressants.
No research has been conducted on grain suppressors for WC-Ni alloys, and currently no WC-Ni alloys having an ultrafine grain structure of 1 μm or less have been found.

In view of the above circumstances, the present invention was devised to improve this, and by making most of the carbide or nitride crystals in the WC-Ni alloy into ultrafine grains of 1μ or less, The object of the present invention is to provide a material that has excellent wear resistance and has less variation in hardness and strength.

The inventors of the present invention have repeatedly conducted research on adding various carbides to WC-Ni alloys for the above purpose, and have found that VC has the most effect of suppressing WC grains, and have arrived at the present invention. be.

That is, the present invention uses 3 to 30 w% of Ni as the binding metal.
containing 2 to 8 W% of VC (V as L) of this bond metal.
tl. 6 to 6.5 w%) with the remainder being WC, and 3 to 6.5 w% as a bonding metal.
30w% N! containing 2 to 8 w% of V of this bond metal.
In a wear-resistant alloy containing C (1.6 to 6.5 w% as V) and the remainder being WC, the WC is 1:1.
Wear resistance characterized by containing carbides and/or nitrides of transition metals in the following proportions, and containing iron group metals other than Ni in substitutions with the Ni in a proportion of 1:1 or less. It is an alloy.

However, the reason why VC is added to the WC-Ni wear-resistant alloy of the present invention is that, as mentioned above, we have obtained the knowledge that it has a grain suppressing effect on WC, and the addition ratio is determined by adjusting the addition ratio of VC to the bonding metal. The reason for setting it at 2 to 8% is that as a result of research, less than 2% of the binding metal does not have sufficient effect.
Furthermore, it has been found that when the content exceeds 8%, VC becomes noticeable in the tissue and the effect is weakened.

In addition, in the invention described in claim 2, WC and 1
: Transition metal carbide and/or in the form of substitution at a ratio of 1 or less
The reason why we decided to include iron group metals other than Ni in the form of substituting with Ni at a ratio of 1:1 or less is that
This is because even if transition metal carbides, nitrides, and iron group metals other than Ni are included in the alloy within the above range, the same effect as the invention described in claim 1 can be obtained. .

The WC-Ni-based wear-resistant alloy of the present invention having the above-mentioned structure is produced by adding a small amount of VC to the WC-Ni-based alloy, so that most of the carbides in the alloy have a force exceeding μ or less. It becomes a fine-grained alloy that has high hardness and strength for this type of alloy, and has excellent wear resistance.

Therefore, it can be applied to applications that require excellent wear resistance such as dies and plugs, for which WC-Ni alloys have not been used in the past, as well as applications such as molds, making them suitable for industrial use. There is a lot to contribute.

Next, examples will be given to supplement the explanation of the present invention and also to show the effects.

Example 1 WC with an average particle size of 0.5μ and N with an average particle size of 0.3μ
i and VC with an average particle size of 1.5μ are blended to have the composition shown in Table 1 below, and thoroughly mixed in a ball mill.
After molding the powder with a compacting force of t/i, it was vacuum sintered at a temperature of 1500°C, and was further subjected to hot hydrostatic treatment at 1350°CXIOOO air.

The hardness and transverse rupture strength of this product were as shown in Table 2.

Example 2 WC, TaC, TiC and T with an average particle size of 0.5μ
iN, Ni and Co with an average particle size of 0.3μ, and VC with an average particle size of 1.5μ are blended so as to have the composition shown in Table 3 below, and thoroughly mixed in a ball mill to produce 1t/CI1l.
After molding the powder using a hot mold, vacuum sintering was performed at a temperature of 1500°C, and a hot still water beading process was performed using 1350'CX1,000 air beads.

The hardness and transverse rupture strength of this product were as shown in Table 4.

Claims (1)

[Claims] 1 Contains 3 to 30 w% of Ni as a binding metal, and contains 2 to 8 w% of VC (V is 16 to 6.5 w%) of this binding metal.
%), with the remainder being WC. 2 Contains 3 to 30 w% Ni as a binding metal, and 2 to 8 W% of VC (V is 16 to 6.5 w) of this binding metal.
%), and the remainder is WC, which contains transition metal oxides and/or nitrides in substitution for the WC at a ratio of 1:1 or less, and 1:1 or less with the Ni. A wear-resistant alloy characterized by containing an iron group metal other than Ni in a substituted proportion.