JP2690793B2 - Cutting tool manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method effective for manufacturing a thin blade having a complicated shape such as an inner blade and an outer blade of an electric razor.

[Conventional technology]

Conventionally, as disclosed in JP-A-50-84355 and JP-A-52-68553, by coating the surface of a metal blade with an oxide, wear resistance and corrosion resistance are improved. It has been 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 have been coated with TiN or ZrN films by sputtering.

[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.

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

As a result of repeated studies on the method of manufacturing a blade coated with aluminum oxide, the inventors have found that aluminum oxide is deposited on the stainless steel base material with good adhesion, high Al-containing ferritic stainless steel or high Al-containing austenitic stainless steel. It has been found that the use of steel makes it possible to supply sharp blades with excellent productivity.

However, since the above two types of stainless steels contain a large amount of Al, they have poor workability, and in normal hot rolling,
It was impossible to reduce the thickness to less than 0.2 mm.

Therefore, the present invention has been proposed in order to solve these problems, and is a thin plate-shaped blade having good workability even for a blade having a complicated shape such as a steel grain-shaped blade. An object of the present invention is to provide a method for manufacturing a blade which can be formed into a shape and which can be efficiently coated on the entire surface with an oxide having sufficient adhesion.

[Means for solving the problem]

In order to solve the above problems, the method for manufacturing a blade according to the present invention is one in which a molten metal having a composition of aluminum-containing stainless steel is rapidly solidified and then molded into a blade shape, 800 ° C. or higher in an oxidizing atmosphere, By heating to a temperature of 1300 ° C. or lower, aluminum oxide is deposited on the surface.

The composition that becomes the aluminum-containing stainless steel used in the present invention is, for example, 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. .

A metal having a composition to be the aluminum-containing stainless steel is placed in, for example, an alumina crucible and subjected to high-frequency vacuum melting to produce a master alloy. This mother alloy is put into a quartz nozzle, and is subjected to high frequency melting again in an inert gas atmosphere such as an argon atmosphere, and the molten metal is rapidly solidified. A desired thickness is obtained by this rapid solidification, or a desired thickness is obtained by cold rolling after rapid solidification as described later. As the rapid solidification method, there are many methods such as a single roll method, a twin roll method, a drum method, and a disk method, which may be appropriately selected and used. For example, the case of using the single roll method will be described in detail. For example, when a roll of SUS304 having a diameter of 750 mm is used and the peripheral speed of the roll is about 40 m / sec, the thickness is 40 μm.
A thin strip having a thickness of 200 μm is obtained at a rate of about 4 m / sec. The material of the nozzle is, for example, transparent quartz, and the tip of the nozzle is provided with a slit having a width of 0.3 mm and a length of 50 mm. The distance between the tip of the nozzle and the roll is set to 1 mm, for example. The obtained ribbon has a thickness of 40 to 200 mm, a width of about 50 mm and a length of 2 to 3 m. This thin strip can be formed into a desired blade shape as it is, or can be formed into a desired thickness by cold working, for example, 40 to 100.
After making it to μm, it is formed into a desired blade shape. In the thin strip obtained by the rapid solidification method, the cast structure may be present perpendicularly to the thin strip surface, or the entire thickness may not be uniform. Therefore, it is preferable to carry out cold rolling at 30 to 50% to homogenize the thickness and mechanical properties. The thus obtained ribbon having a thickness of 100 mm or less is formed into an outer or inner blade of an electric razor. In this case, the inner blade of the electric razor can be formed by punching from a thin strip, and cracking does not occur. Further, in the manufacture of the outer blade of the electric razor, the shape as shown in FIG. 1 (a) is obtained by punching a thin strip or making irregularities with a roller during cold rolling and grinding the convex portions. Can be formed into a blade 10. In this case also, no crack occurs. In addition,
The blade shape is not limited to the outer blade and the inner blade of the electric razor.

The alloy formed into a blade shape is heat-treated in an oxidizing atmosphere. As the oxidizing atmosphere, a gas containing oxygen (including not only O ₂ and O ₃ but also the case of forming a compound with another element), for example, the atmosphere is used. The heating temperature is 80
It is necessary to set the temperature in the range of 0 ° C. or higher (preferably 1000 ° C. or higher) and 1300 ° C. or lower. For example, it may be set within this range according to the target thickness of the oxide film. If it is less than 800 ° C, the formation rate of aluminum oxide film is extremely slow, and 1
There is a problem that it takes a long time to obtain a film having a thickness of μm or more, and if it exceeds 1300 ° C., there is a problem that not only the base material is softened and deformed but also cracks and peeling are likely to occur in the formed film. The heating time is not particularly limited, but the above Fe-Cr-
In the case of (Ni) -Al alloy, it is preferably 0.5 hours or more, and in the case of the Fe-Ni-Cr-Al alloy, it is preferably 10 hours or more, and the thickness of the target oxide film is within this range. It may be set according to. 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.

Aluminum oxide is deposited on the alloy surface by the heat treatment. Preferably, an aluminum oxide film is formed.

[Action]

A molten metal having the composition of aluminum-containing stainless steel is rapidly cooled and solidified into a blade shape, and heated to 800 to 1300 ° C in an oxidizing atmosphere to form a dense base material (or base material, base phase). Aluminum oxide having good adhesion to the alloy is deposited on the surface of the alloy. According to this method, in a thin plate shape, and even for a blade having a complicated shape such as a steel grain-shaped blade, it is possible to form a blade shape with good workability,
In addition, the entire surface can be efficiently coated with an oxide having sufficient adhesion.

As shown in FIG. 3, the aluminum oxide film 1 is not simply formed in a flat plate shape on the alloy 2 as a base material, but as shown in FIG. 2 during the precipitation process from the base material. , So to speak, the roots 3 are formed on the alloy 2.
Therefore, the adhesion with the alloy 2 is extremely excellent. With such a method, even a blade having a complicated shape can be easily coated on the entire surface in detail, and the thickness t of the aluminum oxide film 1 formed so as to have roots on the alloy 2 (this thickness As shown in FIG. 2, t is the minimum thickness excluding the so-called root portion), and by appropriately adjusting the heat treatment temperature and / or the heat treatment time,
The desired amount, for example, the Fe-Cr- (Ni) -Al-based alloy can be 1 to 20 µm, and the Fe-Ni-Cr-Al-based alloy can be 1 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.

Of 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 effects are not sufficient. Also, if the concentration is too high, the effect will not be better than a certain level, and the material cost will be high, so 15-30%
Is appropriate. Ni is for improving the hardness and corrosion resistance of the blade, and it is not always necessary to use it. 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 essential element for precipitating aluminum oxide, and if the concentration is too low, the precipitation of aluminum oxide will be insufficient, and conversely, if the concentration is too high, the workability of the base material will decrease. ~
6% is suitable. At least one element selected from Ti, Nb, Zr, Y, Hf, Ce, La, Nd, and Gd not only improves the brittleness of the aluminum oxide film, but also causes the film to become rooted in the base metal. It has the effect of growing as if it had grown and greatly improving the adhesion to the base material. When the concentration of these elements is too high, the workability of the base material is deteriorated and the material cost is increased, so 0.05 to 1.0% 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 that is necessary to maintain the ductility and toughness of the base metal. From these points, Cr needs to be 9% or more, and if it exceeds 24%, a large amount of Ni must be added, 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. If the concentration is too low, the oxide film of Fe, Cr and Ni becomes the main component at high temperature, and a uniform film of aluminum oxide cannot be formed, so 4% or more is necessary. is there. 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 base material, and the adhesiveness with the base material 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 base material will be deteriorated and the cost of the material will increase, 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.

-Example 1-The composition is wt%, Cr: 18%, Ni: 6%, Al: 4.5%, Ti: 0.
3%, Zr: 0.2%, Y: 0.1%, Hf: 0.2%, La: 0.05%, Ce: 0.
05%, Nd: 0.05%, Gd: 0.05%, and the balance is substantially
An alloy made of Fe was melted in a vacuum, formed into a ribbon having a thickness of 100 μm by the rapid solidification method using the single roll described above, and then cold rolled to a thickness of 40 μm. This thin strip was processed into the shape of a blade 10 on the outside of a mesh-shaped electric shaver as shown in FIG. 1 (a). This is heat-treated at 1200 ℃ for 2 hours in the atmosphere,
An aluminum oxide film having a thickness of 5 μm was deposited on the surface to obtain an electric razor outer blade.

-Example 2-The composition is wt%, Ni: 26%, Cr: 20%, Al: 5%, Ti: 0.3
%, Zr: 0.3%, Y: 0.02%, Hf: 0.06%, Ce: 0.01%, La:
An alloy consisting of 0.01% and the balance consisting essentially of Fe is vacuum-melted and the thickness is obtained by the rapid solidification method using the single roll described above
After forming a ribbon of 100 μm, it was cold-rolled to a thickness of 40 μm. This thin strip was processed into the shape of a blade 10 on the outside of a mesh-shaped electric shaver as shown in FIG. 1 (a). This is heat-treated in the air at 1200 ℃ for 150 hours, and the surface is 5μm thick.
The aluminum oxide film was deposited to obtain the outer blade of the electric razor.

-Comparative Examples 1 and 2-Coating a TiN film on the alloy blade having the same composition and shape as those used in Examples 1 and 2 by the sputtering method under the following conditions,
A clipper blade having a TiN film with a thickness of 0.3 μm on the surface was obtained.

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 blade of Examples 1 and 2 and Comparative Examples 1 and 2 was examined by a vertical tensile strength test (a tensile strength test was performed perpendicularly to the coating surface). It was 10 kg / mm ² , and that of Comparative Examples 1 and 2 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.

〔The invention's effect〕

The manufacturing method of the blade according to the present invention, as described above, the alloy having a specific composition is rapidly solidified, and then the alloy formed into the blade shape is heated to a temperature of 800 ° C or higher and 1300 ° C or lower in an oxidizing atmosphere. As a result, aluminum oxide is deposited on the surface of the alloy. Therefore, according to this manufacturing method, it is possible to manufacture a thin plate-shaped blade which is coated with the aluminum oxide film having good adhesion and has a good sharpness.

In the present invention, if the above specific composition is used, the adhesion of the aluminum oxide film is improved.

[Brief description of the drawings]

FIG. 1 (a) is a sketch of a part of an outer blade of an electric shaver prototyped in an example, FIG. 1 (b) is a sketch of a part of an inner blade of an electric shaver, FIGS. 2 (a) and (b). )
FIG. 3 is a cross-sectional view showing one embodiment of the manufacturing method of the present invention in the order of steps, and FIG. 3 is an enlarged view schematically showing the state of the aluminum oxide film formed by the conventional method. 1 ... Aluminum oxide coating, 2 ... Alloy, 4 ... Inner blade of electric razor, 10 ... Outer blade of electric razor

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C22C 38/50 C22C 38/50

Claims (3)

(57) [Claims] Claims: 1. A molten metal having a composition that becomes aluminum-containing stainless steel is rapidly solidified and then formed into a blade shape, which is then heated in an oxidizing atmosphere to a temperature of 800 ° C or more and 1300 ° C or less A method for manufacturing a blade for depositing aluminum oxide. 2. The composition of stainless steel is wt%, Cr: 1.
5-30%, Ni: 0-10%, Al: 2-6%, Ti, Zr, Y, Hf, C
At least one element of e, La, Nd and Gd: 0.05
~ 1.0%, and the balance: substantially Fe.
The manufacturing method of the described knife. 3. The composition of stainless steel is wt%, Ni: 1.
2-40%, Cr: 9-24%, Al: 4-7%, at least one element of Ti and Zr: 0.1-0.8%, at least one element of rare earth elements and Hf: 0.05-0.2 %, And the balance: substantially Fe. The method for manufacturing a blade according to claim 1.