JP2690792B2 - Cutting tool manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applicable to blades applied to electric razors, hair clippers, lawn mowers, scissors, cutters, knives, etc., particularly comb blades or mesh blades. The present invention relates to a method effective for manufacturing a blade having a complicated shape and a blade material having high hardness.

[Conventional technology]

Conventionally, as disclosed in JP-A-50-84355 and JP-A-52-68553, wear resistance and corrosion resistance are improved by coating the surface of a metal blade with an oxide. It is known. As a method for coating the metal blade with an oxide, there is a physical vapor deposition method or a chemical vapor deposition method such as ion plating disclosed in JP-A-52-92655. Recently, metal blades such as TiN and Z
The rN film is being coated by the sputtering method, or the entire blade is made of a ZrO ₂ ceramic sintered body.

[Problems to be solved by the invention]

However, it is difficult to obtain a sufficient thickness of the coating film by a method such as the above-mentioned ion plating or sputtering. In addition, since the method is complicated, it is impossible to simultaneously coat both sides of the blade, or it is difficult to coat a blade having a complicated shape.

Further, when coated on a metal plate having good flatness, there is a problem that the adhesion between the metal plate and the coating is weak. In order to improve this, an anchor effect is provided between the metal plate and the coating, but for this purpose, a complicated process such as making fine irregularities on the metal plate is required.

Further, when using a ZrO ₂ -based bulk sintered body as a blade, there were problems such as low dimensional accuracy and lack of toughness as compared with a metal blade, resulting in chipping of the blade tip.

The above-mentioned conventional methods are not industrially advantageous because they have their own problems.

As a result of repeated studies on the method for manufacturing a blade coated with aluminum oxide, the inventors have found that high Al-containing ferritic stainless steel and high Al-containing austenitic stainless steel in which aluminum oxide is deposited on the stainless base material with good adhesion. It has been found that the use of can provide a sharp blade with excellent productivity.

However, the hardness of the above-mentioned two types of stainless steel itself is not so high that the Vickers hardness value at room temperature is in the range of 150 to 250, and there is a problem in the life as a blade.

Therefore, the present invention has been proposed in order to solve these problems, the base material has a high hardness, even for blades having a complicated shape such as a comb-shaped blade or a mesh-shaped blade, It is an object of the present invention to provide a method for manufacturing a blade capable of efficiently coating an oxide with an oxide having sufficient adhesion.

[Means for solving the problem]

In order to solve the above problems, the manufacturing method of the blade according to the present invention, the laminated plate is aluminum-containing stainless steel, the base material is a high hardness steel clad material molded into a blade shape, 800 ℃ or more The aluminum oxide film is deposited on the surface of the stainless steel by heating in an oxidizing atmosphere at a temperature of 1300 ° C. or lower.

The aluminum-containing stainless steel used in this invention is
For example, an alloy having the following composition.

The composition is wt%, Cr: 15-30%, Ni: 0-10%, Al:
2-6%, at least one element of Ti, Nb, Zr, Y, Hf, Ce, La, Nd and Gd: 0.05-1.0%, and
Remainder: Fe-Cr- (Ni) -Al based alloy which is substantially Fe.

The composition is wt%, Ni: 12-40%, Cr: 9-24%, Al:
4 to 7%, at least one element of Ti, Nb and Zr: 0.1 to 0.8%, at least one element of rare earth element and Hf: 0.05 to 0.2%, and the balance: substantially
Fe-Ni-Cr-Al-based alloy that is Fe.

Examples of rare earth elements include Y, Ce, La, Nd, and Gd.
Are used.

The fact that the balance is substantially Fe does not only mean that the balance is all Fe, but also means that the balance also contains impurities inevitably present in addition to Fe. .

The high-hardness steel used in the present invention is, among commercially available high-hardness materials, the heat treatment for aluminum oxide precipitation of aluminum-containing stainless steel is 800 ° C. to 1300 ° C., so that it has heat resistance first, and Is higher in deformation resistance than aluminum-containing stainless steel when clad, and it is desirable to make it clad, and to harden the base material by hardening treatment after the aluminum oxide precipitation treatment, The following are suitable:
For example, high hardness tool steel, stainless steel for cutlery, PH stainless steel centering on austenitic and semi-austenitic, maraging steel, high Cr-Ni austenitic heat resistant steel, or super heat resistant steel, etc. It is not limited to.

As a result of earnest research, the inventors have found that a Fe-Cr- (Ni) -Al-based alloy having the above-mentioned specific composition is 800-1 in an oxidizing atmosphere.
For example, by heating to 300 ° C for 0.5 hours or more, or by heating the Fe-Ni-Cr-Al-based alloy having the above-mentioned specific composition at 800 to 1300 ° C for 10 hours or more in an oxidizing atmosphere, a dense, undercoat By precipitating aluminum oxide having good adhesion with the alloy on the surface of the alloy, among the above problems, even for blades having complicated shapes such as comb-shaped blades and mesh-shaped blades It has been found that aluminum can be coated with aluminum oxide. As shown in FIG. 3, the aluminum oxide film 4 is not simply formed in a flat plate shape on the alloy 5 which is the base, but is formed in the process of precipitation from the base, as shown in FIG. 5, so to speak, the roots 6 ... Therefore, the adhesion with the alloy 5 is extremely excellent. With such a method, even in the case of a blade having a complicated shape, the entire surface can be easily coated even in the details, and the thickness t of the aluminum oxide coating 4 formed so that the roots of the alloy 5 are formed (this thickness t
As shown in FIG. 2, the so-called minimum thickness excluding the root portion) is adjusted by appropriately adjusting the heat treatment temperature and / or the heat treatment time to obtain a desired amount, for example, Fe—Cr— In the case of (Ni) -Al alloy, it can be 1 to 30 μm, and in the case of the above Fe-Cr-Al alloy, 1
It is possible to have a thickness of up to 10 μm. Furthermore, when comparing such a method with the ion plating method or the sputtering method, the adhesion is far superior because the oxide is precipitated like rooted in the alloy from the inside of the alloy as described above. There is. The alloy 5 serves as a laminated plate to form a base material and a clad material made of high hardness steel 7. The high hardness steel 7 originally has high hardness and, if necessary, is oxidized. After the aluminum film is formed, it is hardened by further performing a hardening heat treatment, so that the blade material is a high hardness material. Therefore, there is no problem (for example, the dimensional accuracy is low, the cutting edge is chipped) even when the entire cutting tool is formed from the ceramic sintered body.

To make a clad material using the above aluminum-containing stainless steel and high hardness steel, hot / cold pressure welding rolling, explosive welding method, brazing method, etc. can be used. Since the temperature is 800 ° C or higher and 1300 ° C or lower, cold rolling and brazing are not preferable. Since both the aluminum-containing stainless steel and the high hardness steel in the present invention have heat resistance, hot pressure rolling is most suitable. The clad material is produced, for example, as follows. The aluminum-containing stainless steel is vacuum melted and then hot forged and / or hot rolled at 850 to 1000 ° C. to obtain a plate material having a thickness of 1 to 1.5 mm.
After surface cleaning the plate material and high hardness steel material obtained in this way, on one or both sides of the high hardness steel, aluminum-containing stainless steel is laminated, heated to 950 ° C to 1050 ° C, and rolled down. Is repeatedly rolled at about 90% to obtain the desired thickness. At this time, the thickness of the aluminum-containing stainless steel is preferably 0.1 mm or more, for example. If it is less than 0.1 mm, the aluminum-containing stainless steel is likely to crack. Whether to dispose the aluminum-containing stainless steel on both sides of the high hardness steel or on one side may be selected according to the blade to be manufactured.

Such a clad material is formed into a desired blade shape.
The forming method is not particularly limited, and examples thereof include a method of cutting a blade by cutting, a punching process, or a method of making unevenness with a roller during cold rolling and grinding the convex portion. The shape of the blade is not particularly limited, and examples thereof include the shape of the outer mesh of the electric razor, the inner blade, and the like applied to hair clippers, lawn mowers, scissors, cutters, knives, and the like. Particularly, in the present invention, a comb-shaped blade such as a hair clipper, or
It is possible to manufacture blades of intricate shape, such as a mesh blade, such as the outer blade of an electric razor. The cross-sectional shape of the cutting tool may be wedge-shaped or tapered, but the cutting edge need not be sharp if it is not cut at all.

The clad material formed into a blade shape is heat-treated in an oxidizing atmosphere. As an oxidizing atmosphere, oxygen (including not only O ₂ and O ₃ but also compounds forming other elements)
A gas containing, for example, atmosphere is used. The heating temperature needs to be in the range of 800 ° C. or higher (preferably 1000 ° C. or higher) and 1300 ° C. or lower. For example, the heating temperature may be set according to the target thickness of the oxide film. If the temperature is lower than 800 ° C, the production rate of the aluminum oxide film is extremely slow, and it takes a long time to obtain a film of 1 μm or more. If the temperature exceeds 1300 ° C, not only the base metal is softened and deformed, but also However, there is a problem that cracks and peeling are likely to occur in the formed film. The heating time is not particularly limited,
For the above Fe-Cr- (Ni) -Al alloy, 0.5 hours or more, the above F
The e-Ni-Cr-Al-based alloy is preferably set to 10 hours or longer, and may be set within this range according to the intended thickness of the oxide film. If the heating time is shorter than these lower limits, it may be difficult to form an aluminum oxide film of 1 μm or more on the entire surface. At the time of this oxidation treatment, the interface between the base material of the clad material and the laminated plate is protected from the oxidizing atmosphere, so that the aluminum oxide film is not formed on that portion and the interface does not peel.

By the heat treatment, aluminum oxide is deposited on the surface of the aluminum-containing stainless steel. Preferably, an aluminum oxide film is formed.

After the aluminum oxide is deposited, a heat treatment for improving the hardness of the high hardness steel as the base material is performed if necessary. For example,
In the case of JIS SUH660 equivalent steel, which is a high Cr-Ni austenitic heat resistant steel, after oil cooling from 900 ℃ to 1000 ℃, 1 at 700 to 800 ℃
By holding for 2 to 16 hours and then air cooling, Hv becomes 3
You can get from 00 to 370. For other high hardness steels,
It is cured by an appropriate heat treatment.

[Action]

Among the Fe-Cr- (Ni) -Al alloy components, Cr is an element necessary for forming a dense and uniform aluminum oxide film on the surface, and if the concentration is low, such effect is not sufficient. 15% to 30% because the effect will not be better than a certain level even if the concentration is too high and the material cost will be high.
Is appropriate. Ni is for improving the hardness and corrosion resistance of the blade and may not be necessarily used. However, when it is used, if the concentration is too high, aluminum oxide does not precipitate, so 0 to 10% is appropriate. is there. Al is an element necessary for precipitating aluminum oxide, if the concentration is too low, the precipitation of aluminum oxide will be insufficient, conversely if the concentration is too high, the workability of the laminated plate will decrease.
2-6% is suitable. Ti, Nb, Zr, Y, Hf, Ce, La,
Addition of a trace amount of at least one element of Nd and Gd not only improves the brittleness of the aluminum oxide film, but also the film grows like rooting on the laminated plate and the adhesion to the laminated plate is greatly improved. Has the effect of being improved. When the concentration of these elements is too high, the workability of the laminated plate is deteriorated, and the material cost is increased.
% Is appropriate.

Among the Fe-Ni-Cr-Al alloy components, Ni is a basic element for austenite formation. Ferrite-forming element Cr
And Al are lower limits, it is necessary to add 12% or more of Ni, so the lower limit of Ni is 12%. Further, when Cr and Al are the upper limit values, it is necessary to add 34% or more of Ni. However, if the Ni concentration is too high, the material cost will increase, so 40% is the upper limit. Cr is a basic element necessary to obtain high temperature oxidation resistance together with Al, and at the same time a large amount of Al
Is an element necessary for maintaining ductility and toughness of the laminated plate. From these points, Cr is required to be 9% or more, and Ni containing more than 24% must be added in a large amount, and since deterioration of the material such as σ embrittlement is promoted, The upper limit is 24%. Al is an essential element for precipitating aluminum oxide, and if the concentration is too low, the oxide film of Fe, Cr and Ni becomes the main at high temperature,
4% or more is necessary because a uniform coating of aluminum oxide cannot be obtained. On the other hand, if the Al concentration is too high, the workability and toughness of the material deteriorate, so the upper limit is 7%. Ti, Nb, and Zr prevent cracking during hot working, and TI and Zr mix in the aluminum oxide coating to prevent embrittlement of the coating, so any one of Ti, Nb, and Zr or It is necessary to add two or more kinds by 0.1% or more. However, if over 0.8% is added, the workability of the material deteriorates, so the upper limit is 0.8%. By adding a trace amount of rare earth elements such as Y, Ce, and La, and Hf, the aluminum oxide film grows like rooting on the laminated plate, and the adhesion with the laminated plate is significantly improved. . If the concentration of at least one element of the rare earth element and Hf is too high, the workability of the laminated plate is deteriorated and the material cost is increased, so 0.05 to 0.2% is appropriate.

〔Example〕

Hereinafter, specific examples and comparative examples of the present invention will be described, but the present invention is not limited to the following examples.

-Examples 1 to 4-Aluminum-containing stainless steel having the composition shown in Table 1 (the balance being substantially Fe) was vacuum melted, and then hot forged at 850 to 1000 ° C and hot rolled to a thickness of 1 to 1.5 mm. It was made into a plate material.
The surface of this plate material and the plate material of stainless steel for blades, in which Cr: 13%, C: 0.7% and the balance is substantially Fe, are surface-cleaned, then bonded together, and pressure-bonded rolled at 1000 ° C to obtain aluminum-containing stainless steel. A clad material having a thickness of 0.1 mm was obtained.
The clad material is a blade of a comb-shaped clipper as shown in FIG.
Processed into 10 shapes. This is heat-treated at 1070 ° C for 4 hours in the air to give a thickness of 5 on the aluminum-containing stainless steel surface.
Precipitate a μm aluminum oxide film and quench it.
It was tempered at 200 ° C to obtain a hair clipper blade.

-Examples 5 to 8-After vacuum melting aluminum-containing stainless steel having the composition shown in Table 1 (the balance being substantially Fe), hot forging is performed at 850 to 1000 ° C, and hot rolling is performed to obtain a thickness of 1 to 1.5 mm. It was made into a plate material.
This plate material, Cr: 15.1%, Ni: 25.4%, Al: 0.3%, Ti: 2.1
%, The balance is austenitic heat-resistant steel (JIS SUH660 equivalent) plate material consisting essentially of Fe, the surfaces are cleaned, then laminated, and pressure contact rolled at 1000 ° C, and the thickness of the aluminum-containing stainless steel is 0.1 mm. A clad material was obtained. The clad material is a comb-shaped clipper blade as shown in FIG.
Processed into 10 shapes. This is heat-treated at 1070 ° C for 50 hours in the air to give a thickness of 3 on the aluminum-containing stainless steel surface.
A μm aluminum oxide film is deposited, and then the entire blade is
After holding at 720 ° C for 15 hours, it was air-cooled to obtain a clipper blade.

—Comparative Examples 1 and 2— A hair clipper having a TiN film with a thickness of 0.3 μm coated on the alloy blade having the same composition and shape as those used in Examples 1 and 5 by the sputtering method under the following conditions. I got a knife.

Conditions for sputter method Using an RF sputter device, 10 ^-1 to 10 ^-2 Torr of (Ar + N ₂ )
Sputtering was carried out in gas at an applied voltage of 2 kV and a current of 200 mA for 3 hours.

The adhesion of the film on the surface of each of the blades of Examples and Comparative Examples was examined by a vertical tensile strength test (a tensile strength test was performed perpendicularly to the coating surface).
/ mm ² and that of the comparative example was 4 kg / mm ² .

The oxide film of the blade of the example adhered to the details uniformly, and was superior in adhesiveness to the TiN film of the blade of the comparative example. The sharpness was also good.

-Comparative Example 3-The aluminum-containing stainless steel used in Example 1 was vacuum-melted and a comb-shaped clipper blade 10 as shown in FIG.
Processed into a shape. This was heat-treated in air at 1070 ° C. for 4 hours to deposit an aluminum oxide film having a thickness of 5 mm on the surface to obtain a hair clipper blade.

-Comparative Example 4-The aluminum-containing stainless steel used in Example 5 was vacuum-melted to obtain a comb-shaped clipper blade 10 as shown in FIG.
Processed into a shape. This was heat-treated in the air at 1000 ° C. for 50 hours to deposit an aluminum oxide film having a thickness of 3 mm on the surface to obtain a hair clipper blade.

-Comparative Examples 5 and 6-A hair clipper blade was prepared in the same manner as in Example 1 except that aluminum-containing stainless steel having the composition shown in Table 1 (the balance being substantially Fe) was used. Obtained.

-Comparative Example 7-A hair clipper blade was obtained in the same manner as in Example 5 except that aluminum-containing stainless steel having the composition shown in Table 1 (the balance being substantially Fe) was used. .

In Examples 1 to 8, the alumina coating was not formed at the interface between the laminated plate of the clad material and the base material even by the aluminum oxide precipitation heat treatment, and the exfoliation did not occur. Moreover, even when the obtained blade was used, neither peeling nor peeling occurred at each interface of the alumina coating-laminated plate-base material.

The Vickers hardness (Hv) at room temperature of the laminated plate portion and the base material portion of the blades obtained in Examples and Comparative Examples 3 to 7 was examined and shown in Table 1. Table 1 also shows tuberculosis in which the adhesion of the aluminum oxide film and the workability of the clad material were examined. The workability of the clad material was evaluated by ◯ for no cracking or peeling, and x for cracking or peeling on the laminated plate.

As shown in Table 1, the hardness of the base metal was significantly improved in the blades of Examples as compared with the blades of Comparative Examples 3 and 4 constituted only of aluminum-containing stainless steel. Further, in the case of a ceramic blade made of a ceramic sintered body, there were many chippings of the cutting edge when in use, but if the base material is made of high hardness and high as in the present invention, not only is the hardness high, Since it is a metal blade with high toughness, it has little chipping and has a long life.

〔The invention's effect〕

As described above, the manufacturing method of the blade according to the present invention, the laminated plate is aluminum-containing stainless steel, the base material is a high-hardness steel clad material is formed into a blade shape 800 ° C. or more in an oxidizing atmosphere, 1300 Aluminum oxide is deposited on the surface of the clad material by heating to a temperature of ℃ or less. Therefore, according to this manufacturing method, it is possible to manufacture a blade which is coated with an aluminum oxide film having good adhesion and has a good sharpness and a long life.

In the present invention, when an alloy having the above-mentioned specific composition is used as the aluminum-containing stainless steel, the adhesion of the aluminum oxide film is good.

[Brief description of the drawings]

FIG. 1 is a sketch drawing of a hair clipper blade prototyped in an embodiment, and FIG. 2 (a) is an enlarged sectional view schematically showing one embodiment of a cutting tool obtained by the manufacturing method of the present invention. b)
Is an enlarged schematic view of a part thereof, and FIG. 3 is an enlarged view schematically showing a state of an aluminum oxide film formed by a conventional method. 4 ... Aluminum oxide film, 5 ... Aluminum-containing stainless steel that is a laminated plate, 7 ... High hardness steel that is a base material

Claims (2)

(57) [Claims] 1. A clad material, in which a laminated plate is aluminum-containing stainless steel and a base material is high hardness steel, is molded into a blade shape and heated in an oxidizing atmosphere at a temperature of 800 ° C. or higher and 1300 ° C. or lower. A method for manufacturing a blade, wherein an aluminum oxide film is deposited on the surface of the stainless steel. 2. The method for manufacturing a blade according to claim 1, wherein the stainless steel is the following alloy. The composition is wt%, Cr: 15-30%, Ni: 0-10%, Al: 2
~ 6%, at least one element of Ti, Nb, Zr, Y, Hf, Ce, La, Nd and Gd: 0.05-1.0%, and the balance: an alloy essentially of Fe. The composition is wt%, Ni: 12-40%, Cr: 9-24%, Al: 4
~ 7%, at least one element of Ti, Nb and Zr: 0.1-0.8%, at least one element of rare earth elements and Hf: 0.05-0.2%, and the balance: substantially
An alloy that is Fe.