JP2011235410A - Cutting tool made from wc-based cemented carbide and cutting tool made from surface coating wc-based cemented carbide which exhibit excellent chipping resistance in cutting work of heat resistant alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting tool which exhibits an excellent chipping resistance for a long period of use in a rolling cutting work of heat resistant alloy such as Ni-based alloy, Co-based alloy, and the like.SOLUTION: In the cutting tool formed with WC-based cemented carbide, the content of Co as a binding phase component is 4 to 12 mass%. In the binding phase, 3-20 mass% of solid Re is soluble. On a surface of a WC particle of a hard phase, a diffusion thin layer of Re is formed. The diffusion thin layer is formed throughout an area of depth of 1-10% in terms of a particle diameter from the surface of the WC particle. The content of the solid soluble Re in this area is 0.2-7 mass%. As components of the cemented carbide, VC, CrC, TiC, TaC and NbC are included as required. Otherwise, a hard coating layer is deposited on the surface of the cutting tool.

Description

  The present invention relates to a cutting tool made of a WC-based cemented carbide (hereinafter referred to as a WC-based cemented carbide tool) that exhibits excellent fracture resistance over long-term use in cutting of heat-resistant alloys such as Ni-based alloys and Co-based alloys. And a surface-coated WC-based cemented carbide cutting tool (hereinafter referred to as a coated WC-based cemented carbide tool).

Conventionally, as a cutting tool having excellent wear resistance, for example, a WC-based cemented carbide containing Co as a binder phase forming component and the remainder consisting of WC and inevitable impurities, or VC, Cr ₃ C _2. WC based cemented carbide tools are known which are made of WC based cemented carbide containing at least one selected from TiC, TaC and NbC. In order to further improve the tool characteristics, Re is used as an alloy component. Furthermore, a WC-based carbide tool containing the same has also been developed.
For example, in patent document 1, after mixing and heat-processing powders, such as W, C, and Re, as raw material powder, it mixes with Co powder etc., obtains a compacting body, and sinters after that, It is described that a WC-based cemented carbide tool (referred to as a conventional cemented carbide tool 1) is manufactured. In the conventional cemented carbide tool 1, as shown in FIG. 2, the entire interior of the WC particles constituting the hard phase is covered. It is known that about 0.1 to 3 wt% of Re is dissolved in a substantially uniform manner, and by providing such a structure, excellent toughness is exhibited.
Patent Document 2 discloses that a WC-based cemented carbide tool is produced by solid-phase sintering a WC-based cemented carbide containing 25 wt% or more of Re in the binder phase. As shown in FIG. 3, it is known that a base carbide tool (conventional carbide tool 2) is improved in high-temperature hardness because a high melting point Re component exists in the binder phase.

JP 2004-263251 A JP-T-2006-513119

In recent years, the performance of cutting machines has been dramatically improved, while on the other hand, there are strong demands for labor saving and energy saving in cutting, and further high efficiency and low cost, and there is also a demand for generalization of cutting tools. However, for example, when the conventional carbide tools 1 and 2 shown in Patent Documents 1 and 2 are used in cutting under normal conditions, no particular problem occurs.
However, especially when this is used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys that have low thermal conductivity and high cutting edges during cutting, the tool life is shortened. Becomes prominent.
That is, for example, in the conventional carbide tool 1, although Re is uniformly dissolved in the WC particles, the toughness of the WC particles themselves is improved, but on the other hand, the thermal conductivity of the WC particles is significantly reduced. For this reason, the cutting edge portion is likely to be overheated. As a result, there is a problem that thermoplastic deformation is likely to occur and uneven wear is likely to occur.
Further, in the conventional cemented carbide tool 2, since a large amount of Re is present in the binder phase, the high-temperature hardness of the binder phase is improved, whereas the adhesion strength between the hard phase WC particles and the binder phase is reduced, When Re is excessively present, the toughness of the binder phase itself is lowered, which causes a problem that chipping and defects are likely to occur.

  Therefore, the present inventors, from the above viewpoint, exhibit excellent fracture resistance and heat plastic deformation even when used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys, As a result of earnest research on a WC-based carbide tool that exhibits excellent cutting performance over a long period of use, the following knowledge was obtained.

Usually, a sintered body made of a WC-based cemented carbide is manufactured together with a WC powder and a Co powder having a specific average particle size, as needed, a VC powder, a Cr ₃ C ₂ powder, a TiC powder, a TaC powder, and an NbC. The raw material powder in which the powder is mixed in a predetermined ratio is mixed and molded in a wet ball mill, and the green compact is then sintered at a predetermined temperature for a predetermined time.

In the above-described ordinary method for producing a WC-based cemented carbide sintered body, the present inventors have added Re powder so as to have a predetermined average particle size and a predetermined content ratio in addition to Co powder as a binder phase forming component. Is added and blended to prepare a raw material powder, which is subjected to liquid phase sintering at a temperature within the range of 1380 to 1500 ° C., and is further subjected to hot isostatic pressing in a predetermined pressurized atmosphere ( HIP) Then, while maintaining the pressure, by slowly cooling to at least 1150 ° C. at a cooling rate of 1 ° C./min or less, a thin Re diffusion layer is formed on the surface of the WC particles constituting the hard phase. I found what I could do.
Here, the diffusion thin layer of Re is a layer of Re having a solid solution Re content of 0.2 to 7% by mass from the surface of the WC particle to a depth region of 1 to 10% of the particle diameter of the WC particle. In the region other than the diffusion thin layer of Re, that is, the inner side of the WC particle, the average solid solution Re content is less than 0.2% by mass.
Then, cutting is performed using a WC-based cemented carbide tool (hereinafter referred to as a cemented carbide tool of the present invention) manufactured from a WC-based cemented carbide having a sintered structure in which the Re diffusion thin layer is formed on the surface of the WC particles. As a result, in cutting of heat-resistant alloys such as Ni-based alloys and Co-based alloys with high heat generation, overheating of the cutting edge portion is suppressed, and excellent fracture resistance and heat-resistant plastic deformation are exhibited. As a result, it has been found that excellent cutting performance is exhibited over a long period of use without occurrence of chipping, uneven wear and the like.

This invention has been made based on the above findings,
"(1) In a WC-based cemented carbide cutting tool having a tool base of a WC-based cemented carbide containing Co as a binder phase component and the balance being WC as a hard phase component and inevitable impurities,
The content of Co as a binder phase component is 4 to 12% by mass, and Re is dissolved in the binder phase, and the average Re content in the binder phase is 3 to 20% by mass, A WC-based cemented carbide cutting tool characterized in that a thin Re diffusion layer is formed on the surface of the WC particles constituting the hard phase.
(2) The Re diffusion thin layer is formed from the surface of the WC particle to a depth region of 1 to 10% of the particle size of the WC particle, and the solid solution Re content in the depth region is 0. 2-7 mass%, on the other hand, on the inner side of the WC particles, the solute Re content is less than 0.2 mass%. Cutting tools.
(3) The WC-based cemented carbide cutting tool base further includes one or more selected from VC, Cr ₃ C ₂ , TiC, TaC, and NbC in a total amount of 0.1 to 2% by mass. The WC-based cemented carbide cutting tool according to (1) or (2), wherein the WC-based cemented carbide cutting tool is contained.
(4) A surface-coated WC-based cemented carbide cutting tool formed by vapor-depositing a hard coating layer on the surface of the WC-based cemented carbide cutting tool according to any one of (1) to (3). "
It has the characteristics.

The WC-based carbide tool of the present invention will be described in detail below.
The WC-based cemented carbide tool of the present invention is blended with Re powder in addition to WC powder and Co powder, and further, VC powder, Cr ₃ C ₂ powder, TiC powder, TaC powder, and NbC powder as required. After mixing the raw material powder blended so as to be a ratio in a wet ball mill and press-molding it into a predetermined shape, this compacted body is subjected to a predetermined pressure within a range of 1380 to 1500 ° C. in a vacuum of 1 to 15 Pa. Liquid phase sintering at a temperature of, and then, for example, hot isostatic pressing (HIP) molding in a pressurized atmosphere introduced Ar gas to 3-15 MPa, for example, while maintaining the atmospheric pressure, It can be produced by slow cooling at least to 1150 ° C. at a cooling rate of 1 ° C./min or less.
Here, as the sintering condition, the atmosphere was set to 1-15 Pa in vacuum because it prevented the decarbonization of the WC and the oxidation of the binder phase, and it was in the range of 1380-1500 ° C. The reason why liquid-phase sintering at a temperature is determined is that Re is uniformly dissolved in the binder phase.
Furthermore, as the cooling conditions after HIP, the reason why the cooling was performed at a temperature of at least 1150 ° C. at a cooling rate of 1 ° C./min or less is because Re is forcibly dissolved on the surface of the WC grains.
The WC-based carbide tool of the present invention produced in the above manufacturing process has 3 to 20% by mass of Re dissolved in the binder phase, and from the surface of the WC particle, the particle size of the WC particle A Re diffusion thin layer having a solid solution Re content of 0.2 to 7% by mass is formed over a depth region of 1 to 10%, and the inside of the diffusion thin layer, that is, the inner side of the WC particles. Then, the solid solution Re content is less than 0.2% by mass.
In the WC-based cemented carbide tool of the present invention in which such a structure is formed, since Re is present only on the surface of the WC particle, the thermal conductivity of the WC particle is not greatly reduced, Since Re is dissolved in the solid phase, the high-temperature hardness of the binder phase is improved, and the adhesion strength between the WC particles and the binder phase is enhanced by the diffusion thin layer formed on the WC surface.

  If the Co component constituting the binder phase in the WC-based cemented carbide tool of the present invention is less than 4% by mass, the WC-based cemented carbide will not be sufficiently densified, while the binder phase content is 12%. If the mass% is exceeded, the hardness of the WC-based cemented carbide decreases, and the wear resistance tends to decrease in the cutting of heat-resistant alloys such as Ni-based alloys and Co-based alloys. The content ratio of the binder phase in the cemented carbide sintered body was determined to be 4 to 12% by mass.

  In the present invention, the Re powder blended together with the WC powder and the Co powder is mostly dissolved (3 to 20% by mass) in Co constituting the binder phase, and part of the powder is diffused into the surface area of the WC particles. A thin layer is formed, but if the Re content (Re / (Co + Re)) dissolved in Co is less than 3% by mass, the effect of improving the adhesion between the WC grains and the binder phase and the effect of improving the hardness of the binder phase are obtained. On the other hand, if the content of Re dissolved in Co (Re / (Co + Re)) exceeds 20% by mass, the toughness of the binder phase is remarkably reduced, and defects are easily generated. The Re content (Re / (Co + Re)) to be dissolved is determined to be 3 to 20% by mass.

Further, in the present invention, a Re diffusion thin layer is formed on the surface of the WC particle, and the diffusion thin layer is formed over a depth region of 1 to 10% of the particle size of the WC particle, and in the depth region. The solute Re content is 0.2 to 7% by mass. However, when the solute Re content in the depth region of 1 to 10% of the particle size of the WC particles is less than 0.2% by mass, the WC particles However, when the solid solution Re content exceeds 7% by mass, the thermal conductivity of the WC particles is remarkably reduced, and the cutting edge is likely to be overheated. As a result, since thermoplastic deformation is likely to occur, the content of solid solution Re in the diffusion thin layer, that is, a depth region of 1 to 10% of the particle diameter of the WC particles is determined to be 0.2 to 7% by mass.
In addition, when “the depth region of 1 to 10% of the particle diameter of the WC particles” is defined by another expression, the WC particles observed with a scanning electron microscope (SEM) are approximated to a circle of the same area. When the diameter of WC is the WC grain size, it is a depth region of 1 to 10% of the WC grain size from the surface of the WC grain.

The WC-based cemented carbide tool of the present invention can contain one or more components selected from VC, Cr ₃ C ₂ , TiC, TaC, and NbC.
One or more components selected from VC, Cr ₃ C ₂ , TiC, TaC, and NbC all have an action of suppressing grain growth of WC during sintering, but the total content thereof If it is less than 0.1% by mass, the effect of suppressing grain growth is small. On the other hand, if it exceeds 2% by mass, a composite carbide phase is precipitated and the hardness tends to decrease. Therefore, VC, Cr ₃ C ₂ The content of one or more components selected from TiC, TaC, and NbC was determined to be 0.1 to 2% by mass in total.

In addition, the WC-based cemented carbide tool of the present invention can be used as a cutting tool as it is, but by further forming a hard coating layer on the surface thereof, further improving the fracture resistance and the heat plastic deformation resistance. Thus, the tool life can be further extended.
Here, the hard coating layer is, for example, “at least one element selected from the group consisting of IVa group element, Va group element, VIa group element, Al, B and Si of the periodic table, carbon, nitrogen And a compound containing at least one element selected from the group consisting of oxygen, and more specifically, for example, Ti carbide, nitride, carbonitride, Ti and Al composite nitride, It consists of one kind of single layer or two or more kinds of multilayers selected from a composite nitride of Al and Cr, a composite nitride of Ti and Si, and a composite nitride of Ti, Al and Si.

  The WC-based cemented carbide tool and the surface-coated WC-based cemented carbide tool according to the present invention include a WC-based cemented carbide alloy constituting the WC-based cemented carbide in which the Re is dissolved and the high-temperature hardness is increased. By forming a thin Re diffusion layer on the particle surface, the adhesiveness between the binder phase and the hard phase is further increased without lowering the thermal conductivity of the WC particles. Even when used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys, which have excellent plastic deformability and whose cutting edges are locally exposed to high temperatures, there is no occurrence of defects or uneven wear. It exhibits excellent cutting performance over a long period of use.

The schematic diagram of the sintered compact structure in this invention WC group carbide tool is shown. The schematic diagram of the sintered compact structure in the conventional WC base carbide tool (conventional carbide tool 1) is shown. The schematic diagram of the sintered compact structure in another conventional WC group carbide tool (conventional carbide tool 2) is shown.

  Next, the cutting tool of the present invention will be specifically described with reference to examples.

(A) As raw material powder, Co powder, Re powder, VC powder, Cr ₃ C ₂ powder, TiC powder, TaC powder, NbC powder, WC powder, all having an average particle diameter of 0.5 to 5 μm are prepared. These raw material powders are blended in the blending composition shown in Table 1, further added with wax, wet-mixed with a ball mill for 72 hours, dried under reduced pressure, and then given a predetermined diameter in the range of 8 to 26 mm at a pressure of 100 MPa. Press-molding a round bar compact with
(B) These green compacts are held at a sintering temperature shown in Table 1 for 1 hour in a vacuum of 1.3 Pa, and then Ar gas is introduced into the furnace to form a pressurized atmosphere of 6 MPa. And then further cooled to 1150 ° C. at a cooling rate of 1 ° C./min while maintaining the pressure, and then furnace-cooled to room temperature,
(C) The obtained round bar sintered body having a predetermined diameter is processed so as to have a predetermined dimension, and processed so as to have the cutting edge part size shown in Table 2, and is a table composed of a 6-blade square end mill. Cutting tools made of the WC-based cemented carbide of the present invention (referred to as the present cemented carbide tool) 1 to 10 shown in FIG.
For the cemented carbide tools 3, 6, and 10 of the present invention, a hard coating layer having the composition and average film thickness as shown in Table 3 is vapor-deposited on the surface of the tool base using an arc ion plating apparatus. Thus, a cutting tool made of the surface-coated WC-based cemented carbide of the present invention was produced.

In addition, for the purpose of comparison, the raw material powder is blended so as to have the blending composition shown in Table 1, and the cutting edge size shown in Table 2 is obtained by the same process as the cemented carbide tools 1 to 10 of the present invention. Processing was performed to produce comparative example WC-based cemented carbide cutting tools (referred to as comparative example cemented carbide tools) 11 to 18 shown in Table 4 consisting of a 6-blade square end mill.
For the comparative carbide tools 12, 15, and 18, a hard coating layer having the composition and average film thickness as shown in Table 3 is vapor-deposited on the surface of the tool base using an arc ion plating apparatus. Thus, a comparative example surface-coated WC-based cemented carbide cutting tool was produced.

Furthermore, for reference, the raw material powder is blended so as to have the blending composition shown in Table 1, and the cutting edge size shown in Table 2 is obtained by the same process as the cemented carbide tools 1 to 10 of the present invention. Processing was carried out to produce reference examples WC-based cemented carbide cutting tools (referred to as comparative example cemented carbide tools) 19 and 20 shown in Table 4 consisting of a 6-blade square end mill.
In addition, about the reference example cemented carbide tool 20, a reference example is obtained by vapor-depositing a hard coating layer having a composition and an average film thickness as shown in Table 3 on the surface of the tool base using an arc ion plating apparatus. A surface-coated WC-based cemented carbide cutting tool was produced.

The above-mentioned cemented carbide tools 1 to 10 and reference example cemented carbide tools 19 and 20 are observed with a scanning electron microscope (SEM), the area of WC grains is measured by image analysis, and the WC has the same area. The diameter when approximated to a circle was calculated. Also, using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray analyzer (EDS), point analysis is performed every 2 nm from the interface between the WC grains and the binder phase toward the inside of the WC grains. The solid solution Re content in the Re diffusion thin layer formed on the particle surface, the thickness ratio (% of the Re diffusion thin layer (region where the Re content is 0.2 to 7 mass%) occupying the particle size of the WC particles) ) Was measured.
Table 5 shows the average values of the measurement results of 10 WC particles.
In each of the cemented carbide tools 1 to 10 of the present invention, a thin Re diffusion layer is formed on the surface of the WC particles, and the solid solution Re content in the thin diffusion layer is in the range of 0.2 to 7% by mass. It was.
In FIG. 1, the schematic diagram of the sintered compact structure | tissue of this invention cemented carbide tool 3 is shown as an example.
On the other hand, although the reference example carbide tools 19 and 20 had a large amount of Re powder, a Re diffusion thin layer was formed, but the solid solution Re content in the diffusion thin layer was defined in the present invention. Furthermore, the thickness of the diffusion thin layer (the range of Re solid solution from the surface of the WC particles) also extends to a depth region of 22 to 37% of the particle size of the WC particles. On the inner side of the particles (for example, a depth region exceeding 10% and 30% of the particle size of the WC particles), the average solid solution Re content is 3.68% by mass (reference example carbide tool 19), 6.21. A high value of mass% (Reference Example Carbide Tool 20) was shown.

Next, for the above-described carbide tools 1 to 10 of the present invention, comparative carbide tools 11 to 18 and reference carbide tools 19 and 20,
A square material of a Ni-base alloy heat-resistant alloy (Cr: 18.5%, Mo: 3.0%, Al: 0.5%, Nb + Ta: 5.1%, balance: Ni and inevitable impurities) is used as a work material. A cutting test was performed under the various conditions shown in Fig. 2, and the cutting length until the flank wear width at the tip of the outer peripheral blade reached the value for use was measured.
Moreover, this was observed about the abrasion condition of the cutting edge after a cutting test.
The measurement results and observation results are shown in Table 4.

From the results shown in Tables 4 and 5, in the cemented carbide tools 1 to 10 of the present invention, the binder phase of the WC-based cemented carbide sintered body contains 3 to 20% by mass of solid solution Re and is hard. A Re diffusion thin layer is formed on the surface of the WC particles of the phase, and the solid solution Re content in the diffusion thin layer is 0.2 to 5% by mass, without causing a decrease in thermal conductivity. Hardness is improved, and adhesion strength between the binder phase and the hard phase is increased. Excellent high-temperature hardness and excellent heat-resistant plastic deformation, so the cutting edge is locally exposed to high temperatures. Even when it is used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys, it exhibits excellent wear resistance over a long period of use without causing defects or uneven wear.
On the other hand, in the comparative example carbide tools 11 to 18 and the reference example carbide tools 19 and 20, cutting of heat-resistant alloys such as Ni-base alloys and Co-base alloys whose cutting edges are locally exposed to high temperatures. When used for processing, it is apparent that the cutting edge portion is broken and wear resistance is poor, and the service life is reached in a relatively short time.

(A) As raw material powder, Co powder, Re powder, VC powder, Cr ₃ C ₂ powder, TiC powder, TaC powder, NbC powder, WC powder, all having an average particle diameter of 0.5 to 5 μm are prepared. These raw material powders were blended into the blending composition shown in Table 6, added with wax, wet mixed with a ball mill for 72 hours, dried under reduced pressure, and then press-formed into a predetermined shape at a pressure of 100 MPa,
(B) These green compacts are held at a sintering temperature shown in Table 6 in a vacuum of 1.3 Pa for 1 hour, and then Ar gas is introduced into the furnace to form a pressurized atmosphere of 6 MPa. And then further cooling to 1150 ° C. at a cooling rate of 1 ° C./min while maintaining the pressure, followed by furnace cooling,
(C) The obtained sintered body was processed so as to have a predetermined size, and the cemented carbide tools 21 to 28 of the present invention having the insert shape of APMT1604PDER were produced.
For the cemented carbide tools 21, 23, 26, and 28 of the present invention, a hard coating layer having the composition and average film thickness as shown in Table 3 is vapor-deposited on the tool base surface using an arc ion plating apparatus. By doing this, the cutting tool made from this invention surface-coated WC base cemented carbide shown in Table 7 was produced.

In addition, for comparison purposes, the raw material powder was blended so as to have the blending composition shown in Table 6, and in the same manner as the cemented carbide tools 21 to 28 of the present invention, a comparative example cemented carbide tool 31 having an insert shape of APMT1604PDER. ~ 37 were made.
For the comparative carbide tools 31, 33, and 36, a hard coating layer having the composition and average film thickness as shown in Table 3 is vapor-deposited on the tool base surface using an arc ion plating apparatus. Thus, a comparative example surface-coated WC-based cemented carbide cutting tool was produced.

About the said cemented carbide tools 21-28 of this invention, similarly to the case of Example 1, point analysis by TEM-EDS is performed, Re solid solution amount in the binder phase of a sintered structure, the average particle diameter of WC particles, WC The solid solution Re content in the Re diffusion thin layer formed on the particle surface and the thickness ratio (%) of the Re diffusion thin layer to the average particle diameter of the WC particles were measured.
Table 8 shows the average values of the measurement results of 10 WC particles.
In each of the cemented carbide tools 21 to 28 of the present invention, a thin Re diffusion layer is formed on the surface of the WC particles, and the solid solution Re content in the thin diffusion layer is in the range of 0.2 to 7% by mass. It was.

Next, each of the cemented carbide tools 21 to 28 of the present invention and the comparative example cemented carbide tools 31 to 37 were fixed with screws to a cutter made of an alloy steel having a diameter of 32 mm, and a cutting test was performed under the following conditions.
Work Material: Ni-base alloy heat-resistant alloy (Cr: 18.5%, Mo: 3.0%, Al: 0.5%, Nb + Ta: 5.1%, balance: Ni and inevitable impurities),
Cutting speed: 40 m / min,
Axial walk cut: 5.0mm,
Radial depth of cut: 1.0 mm,
Feeding: 0.15 mm / blade In the cutting test, the cutting length until the flank wear width reached 0.2 mm was measured, and the wear state of the cutting edge after the cutting test was observed.
The measurement results and observation results are shown in Table 7.

From the results shown in Tables 7 and 8, in the cemented carbide tools 21 to 28 of the present invention, the binder phase of the WC-based cemented carbide sintered body contains 3 to 20% by mass of solid solution Re and is hard. A Re diffusion thin layer is formed on the surface of the WC particles of the phase, and the solid solution Re content in the diffusion thin layer is 0.2 to 7% by mass, without causing a decrease in thermal conductivity. Hardness is improved and adhesion strength between the binder phase and the hard phase is increased, and the cutting edge is locally exposed to high temperature because of excellent fracture resistance and excellent heat-resistant plastic deformation. Even when it is used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys, it exhibits excellent wear resistance over a long period of use without causing defects or uneven wear.
On the other hand, when the comparative example carbide tools 31 to 37 are used for cutting heat-resistant alloys such as Ni-base alloys and Co-base alloys whose cutting edges are locally exposed to high temperatures, It is clear that the defect of the part occurs and the service life is reached in a relatively short time.

  The WC-based cemented carbide cutting tool and the surface-coated WC-based cemented carbide cutting tool according to the present invention are not only used for cutting heat-resistant alloys such as Ni-based alloys and Co-based alloys, but also for various steels and cast irons. Of course, the present invention can be applied to cutting under the above conditions, and exhibits excellent cutting performance over a long period of use, and is suitable for labor saving and energy saving of cutting work and further cost reduction.

Claims (4)

In a WC-based cemented carbide cutting tool having a tool base of a WC-based cemented carbide containing Co as a binder phase component and the balance being WC as a hard phase component and unavoidable impurities,
The content of Co as a binder phase component is 4 to 12% by mass, and Re is dissolved in the binder phase, and the average Re content in the binder phase is 3 to 20% by mass, A WC-based cemented carbide cutting tool characterized in that a thin Re diffusion layer is formed on the surface of the WC particles constituting the hard phase.   The Re diffusion thin layer is formed from the surface of the WC particle to a depth region of 1 to 10% of the particle size of the WC particle, and the solid solution Re content in the depth region is 0.2 to The WC-based cemented carbide cutting tool according to claim 1, wherein the WC-based cemented carbide cutting tool according to claim 1, wherein the content is 7% by mass, and on the other hand, the solute Re content is less than 0.2% by mass on the inner side of the WC particles. The WC-based cemented carbide cutting tool base further contains a total of 0.1 to 2% by mass of one or more selected from VC, Cr ₃ C ₂ , TiC, TaC, and NbC. A cutting tool made of a WC-based cemented carbide according to claim 1 or 2.   A surface-coated WC-based cemented carbide cutting tool obtained by vapor-depositing a hard coating layer on the surface of the WC-based cemented carbide cutting tool according to any one of claims 1 to 3.

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