JP3519152B2 - WC particle-dispersed W-reinforced Ni-based alloy and composite material using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a WC particle-dispersed W-reinforced N
The present invention relates to an i-based alloy and a composite material using the i-based alloy, and particularly to an alloy and a composite material suitable for application to a mechanical member that requires corrosion resistance, wear resistance and strength at the same time.

[0002]

2. Description of the Related Art Conventionally, N such as Ni--Cr--B--Si is used.
The i-based self-fluxing alloy has excellent corrosion resistance and wear resistance, and is widely known as a hardening material for steel surface.

Further, for example, Japanese Patent Laid-Open No. 62-197264 discloses a WC particle-dispersed Ni-based self-fluxing alloy in which WC particles are finely dispersed in the Ni-based self-fluxing alloy.
Since this alloy has excellent corrosion resistance and wear resistance, it is used for machine parts such as barrels of plastic molding machines.

Further, for example, Japanese Patent Publication No. 5-5889 discloses a Mo-Ni-based boride alloy in which a hard layer mainly composed of Mo ₂ NiB ₂ is bonded by a Ni-based bonding phase. Since the alloy has excellent corrosion resistance and wear resistance, it is said to be suitable as a material used in a highly corrosive environment.

Further, for example, Japanese Patent Application Laid-Open No. 6-57360 discloses a corrosion-resistant and wear-resistant Ni-based alloy such as Cr-Mo-W-V-B-Si-Ni, which has excellent corrosion resistance and wear resistance. It is said to be useful as various necessary constituent materials.

[0006]

Among the various conventional alloys mentioned above, Ni-based self-fluxing alloys do not necessarily have sufficient corrosion resistance and wear resistance, and the strength and bending strength of the material are about 0.8 GP.
It is as small as a. For this reason, there is a problem that it cannot be used as a mechanical component to which high stress is applied.

Further, the WC particle-dispersed Ni-based self-fluxing alloy has excellent wear resistance and corrosion resistance because of the uniformly dispersed WC, but the strength of the material is about 0.9 GPa. And small. Therefore, like the Ni-based self-fluxing alloy, there is a problem that it is difficult to use for high-load mechanical parts.

Further, the Mo--Ni type double boride alloy is excellent in corrosion resistance and wear resistance, but the strength and transverse rupture strength of the material are 1.5 GPa, which is low, and is not always sufficient. In addition, the sintering temperature is as high as 1125 to 1225 ° C., and at this temperature, the steel material deteriorates due to the coarsening of the crystal grains of the steel material. is there.

Further, the corrosion-resistant and wear-resistant Ni-based alloy has a problem that it has low hardness and is not always sufficient in wear resistance.

The present invention has been made in view of the above points, and an object thereof is to provide a WC particle-dispersed W-reinforced Ni-based alloy which is excellent in corrosion resistance and wear resistance, and can obtain sufficient strength. And

Another object of the present invention is to provide a composite material using a WC particle-dispersed W-reinforced Ni-based alloy which can be composited by simultaneously performing sintering and joining without deteriorating the steel of the base material. To provide.

[0012]

Means and Actions for Solving the Problems WC of the Present Invention
The particle-dispersed W-reinforced Ni-based alloy is an alloy in which WC particles are dispersed in an amount of 10 to 60% by weight, B is 0.5 to 2.5% by weight, and Si is
Is 0.4 to 3.8% by weight, W is 20 to 35% by weight, and the balance is Ni and inevitable impurities.

The content of each component of the Ni-based alloy is 0.8 to 1.6% by weight for B and 1.0 to 3.2 for Si.
Wt%, W 28-32 wt%, WC particles 20-40
Most preferably it is wt%.

Further, the composite material using the WC particle-dispersed W-reinforced Ni-based alloy of the present invention is characterized in that the Ni-based alloy having the above-mentioned chemical composition is joined with steel to form a composite.

The reasons for limiting the components of the Ni-based alloy of the present invention are as follows. B: 0.5 to 2.5 wt% (hereinafter simply referred to as%) B lowers the sintering temperature of the present alloy and forms borides with Ni and W to enhance the wear resistance of the alloy. Used for. If the B content is large or small, the transverse rupture strength is lowered, so 0.5 to 2.5%, preferably 0.7 to
2.2%. Si: 0 to 3.8% Si is used together with B to lower the sintering temperature of the present alloy. Therefore, when sintering and joining the steel material, it is effective to metallurgically bond the steel material without deteriorating the steel material. In this alloy, the sintering temperature decreases as the amount of Si increases, but when it exceeds 3.3%, the sintering temperature rises and the strength tends to decrease. Densification is hindered and the strength is rapidly reduced, so the upper limit is made 3.8%.

Here, the reason why densification is prevented is 3.8.
%, The amount of Si that does not form a solid solution with Ni remains, and unsintered S
It is considered that this is because i remains. Therefore, the Si content is 0 to 3.8%, preferably 0.4 to 3.4%. W: 20-35% W forms fine borides with B, and significantly increases the wear resistance and strength of the alloy. The W content exhibits the above effect from 20%, and if it exceeds 35%, the transverse rupture strength is lowered and the sintering temperature is increased, which is not preferable. Therefore, the W content is 2
0 to 35%, preferably 25 to 33%. WC: 10 to 60% WC is finely dispersed in the alloy and enhances the wear resistance of the alloy. Also, the dispersion of WC enhances the transverse rupture strength by dispersion strengthening the alloy. If the WC content is less than 10%, the above effect cannot be obtained, and if it exceeds 60%, a large number of micropores are generated in the alloy, resulting in poor sintering and deterioration of the transverse rupture strength.
Therefore, the WC content is 10 to 60%, preferably 1
0 to 50%.

Among the B, Si, W and WC contents, B: 0.8 to 1.6% and Si: 1.0 show the best corrosion resistance, wear resistance and strength. ~ 3.2%,
W: 28 to 32%, WC: 20 to 40%.

The Ni-based alloy of the present invention comprises B, Si, W and N.
The i and WC powders, or alloy powders containing two or more of these elements are blended in a predetermined amount, and the powder is crushed and mixed by a rotary ball mill or the like, and molded and sintered. Sintering may be performed in vacuum or in a reducing gas, or may be performed by another method such as hot isostatic pressing.
Although the sintering temperature varies depending on the alloy composition, it is 1030 to
It is carried out at 1170 ° C. When the temperature is low, the densification is not completely performed and the transverse rupture strength is lowered, and when the temperature is too high,
Not only does the grain size become coarse and the transverse rupture strength decreases, but it also deteriorates the steel material when it is combined with the steel material simultaneously with sintering.

Next, the production of the composite material of the present invention, which is composited by metallic bonding of the Ni-based alloy and the steel material, will be described.

When a plate-shaped steel material and the Ni-base alloy of the present invention are compounded, if the Ni-base alloy is sintered in direct contact with the compact, the compact is sintered due to the appearance of a liquid phase. At the same time, the steel material and the Ni-based alloy are joined to form a composite.

When the Ni-based alloy of the present invention is joined to the outer diameter portion of a cylindrical steel material to form a composite, the Ni-based alloy compact is sintered in consideration of shrinkage during sintering. Due to the appearance of the liquid phase in the final process, the steel material and the Ni-based alloy are composited.

The steel materials used for compounding with the Ni-based alloy of the present invention will be described.

The expansion coefficient of the Ni-based alloy of the present invention is 9 to 1
1 × 10 ⁻⁶ / ° C. (20 to 700 ° C.), which is 13
It is similar to% Cr steel. Considering the residual stress of the joint surface after compounding, as the steel material, SUS420J2, SU
Stainless steel such as S440C and SUS430 is preferable. If the Ni-based alloy compact has a simple shape, S25
Composite with carbon steel such as C is possible.

As a method for compounding the Ni-based alloy and the steel material of the present invention, alloy powder having the same composition as the Ni-based alloy is previously produced by a water atomizing method or a gas atomizing method, and the alloy powder is used. It is also possible by thermal spraying, remelting or overlaying.

[0025]

EXAMPLES The present invention will be further described below with reference to examples.

Example In producing the Ni-based alloy of the present invention, alloy powders of Sample Nos. 1 to 5 having the mixing ratios of the raw material powders shown in Table 1 were mixed and mixed and pulverized in ethyl alcohol by a rotary ball mill. The mixed alloy powder was then dried, press molded and sintered in vacuum.

[0027]

[Table 1] Table 2 shows the sintering temperatures of Sample Nos. 1 to 5 of the alloys of the present invention. The sintering time is 10 minutes in each case. Various performance tests such as hardness, specific wear amount, corrosion resistance, and transverse rupture strength were conducted. The results of these tests are shown in Table 2.

The conditions of various performance tests are as follows. (1) Wear test tester: Ogoshi rapid wear tester Test conditions: Friction speed 2.0 m / sec Friction distance 600 m Final load 18.6 kgf Mating material SKD11 (HRC58) (2) Corrosion test Corrosion liquid 20% hydrochloric acid solution ( 22 ℃) Immersion time 5 hours (3) Bending test method JIS H5501 Three-point bending bending test Dimension of test piece 4 × 8 × 24 mm, grinding

[0029]

[Table 2] The alloy of the present invention and four conventional alloys as comparative examples were compared for sintering temperature, corrosion loss, specific wear amount, hardness and transverse rupture strength.
The results are shown in Table 3.

[0030]

[Table 3] As can be seen from Table 3, the alloy of the present invention is superior to the conventional alloy in corrosion resistance and wear resistance, and exhibits high transverse rupture strength.

Reference Example 1 A reference example in which a disc-shaped compact of a Ni-based alloy and a steel material were compounded simultaneously with sintering is shown below.

The target component of the Ni-based alloy is 2.
The raw material powders were blended so as to be 2% B, 3.5% Si, 25% W, and the balance Ni, and pulverized and mixed in ethyl alcohol by a rotary ball mill for 48 hours. Then, it was dried and press-molded to prepare a disk-shaped molded body having the shape shown in FIG. The size of this compact is 10 mm thick and 40 mm in diameter.
mm, the density was about 50%.

This disk-shaped compact was placed on a steel material SUS420J2 as shown in FIG. 1 (b) and sintered at 1030 ° C. for 10 minutes in vacuum to form a composite.
The sintered body shrank to a thickness of 7 mm and a diameter of 34 mm.

When the cross section of the contact surface between the SUS420J2 material and the sintered body shown in FIG. 1 (c) was polished and then observed with an optical microscope, it was confirmed that both were strongly metal-bonded. A liquid phase is generated in this bond by sintering, and SUS42
It is thought that this was done by getting wet with the 0J2 material.
In this way, the composite material that is sintered and compounded is machined,
The product was finished to a predetermined size and used as a member for a plastic molding machine.

Reference Example 2 A reference example in which a steel material is sintered and compounded on the outer diameter of a cylinder of a Ni-based alloy is shown below.

The target component of the Ni-based alloy is 1.
The raw material powders were blended so that 0% B, 2.0% Si, 20% W and the balance Ni were obtained, and the mixture was pulverized and mixed in ethyl alcohol by a rotary ball mill for 48 hours. Then, it was dried and molded by a rubber press, and the molded body was processed into the cylindrical shape shown in FIG. The dimensions of this molded body are an outer diameter of 56 mm,
The inner diameter was 27 mm, the height was 48 mm, and the density was about 50%.

As shown in FIG. 2 (b), a round bar of SUS440C material was inserted and set in the center of this cylindrical molded body,
Sintering and compounding were performed in vacuum at 1080 ° C. for 10 minutes. The outer diameter of the SUS440C round bar was φ23.0 mm in consideration of the sintering shrinkage of the molded body.

As shown in FIG. 2 (c), the cylindrical molded body shrinks due to sintering and compounding, and its dimension is an outer diameter φ4.
Shrinked to 5 mm and height 40 mm. According to the observation with an optical microscope, the round bar steel material and the sintered body are strongly metal-bonded to each other due to the liquid phase generation in the molded body. After sintering and compounding, the composite material was machined to a predetermined size and used as a screw member for a plastic molding machine.

[0039]

As described above, according to the present invention, an alloy material having corrosion resistance, wear resistance, and high strength, which is suitable for a machine part under high load, was obtained. Moreover, since the alloy of the present invention has a relatively low sintering temperature, it can be compounded with a steel material simultaneously with sintering, which is advantageous in terms of efficient production and cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a method of manufacturing a composite material in which a disc-shaped compact of a Ni-based alloy and a steel material are compounded simultaneously with sintering.

FIG. 2 is a diagram illustrating a method of manufacturing a composite material in which a disk-shaped compact of a Ni-based alloy and a round bar steel material are compounded simultaneously with sintering.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Minoru Umehara               2068 Ooka, Numazu City, Shizuoka Prefecture Toshiba Machine Co., Ltd.               Ceremony Company Numazu Office                (56) References JP-A-48-58059 (JP, A)                 JP 62-177144 (JP, A)                 JP 62-197264 (JP, A)                 JP-A-4-337047 (JP, A)                 JP-A-5-214479 (JP, A)                 JP-A-4-56745 (JP, A)                 JP-A-2-185942 (JP, A)                 Japanese Patent Laid-Open No. 2-15140 (JP, A)                 Japanese Patent Laid-Open No. 2-156037 (JP, A)                 Japanese Patent Sho 56-30181 (JP, B2)

Claims (6)

(57) [Claims] 1. An alloy in which 10 to 60% by weight of WC particles are dispersed, 0.5 to 2.5% by weight of B and 0.4 to 3.4 of Si.
% Of W, 20 to 35% by weight of W, balance Ni and inevitable impurities, WC particle-dispersed W-reinforced Ni-based alloy. 2. The WC particle-dispersed W-reinforced Ni-based alloy according to claim 1, wherein the content of B is 0.8 to 1.6% by weight. 3. The WC particle-dispersed W-reinforced Ni-based alloy according to claim 1, wherein the Si content is 1.0 to 3.2% by weight. 4. The WC particle-dispersed W-reinforced Ni-based alloy according to claim 1, wherein the W content is 28 to 32% by weight. 5. The WC particle-dispersed W-reinforced Ni-based alloy according to claim 1, 2, 3 or 4, wherein the amount of the WC particles dispersed is 20 to 40% by weight. 6. The WC according to claim 1, 2, 3, 4 or 5.
A composite material using a WC particle-dispersed W-reinforced Ni-based alloy, characterized in that a particle-dispersed W-reinforced Ni-based alloy and steel are joined together.