JPS60184633A - Treatment of cutlery - Google Patents

Abstract

PURPOSE:To obtain a blade having extremely good cutting quality, considerably decreased internal stress and good durability in tempering of the blade in which a high energy beam is irradiated on a heat-treated metallic material to be worked by making the irradiation of said beam intermittent and discontinuous. CONSTITUTION:A high energy beam such as laser is bent by a prism 5 and the beams in the range between energy fluxes 4 and 14 are focused so that the focus 10 or 20 is formed near the surface or the inside of a required depth in an edge part 1 to be worked as shown by a solid line 2 or dotted line 12. The focus 10 part to be irradiated of the edge part 1 is heated like a spot or down to the deep part forming the circular heating part of a fairly wide area on the surface to a required temp. The heating surface of the focusing spot 22 is thus formed. The spot 22 is intermittently or discontinuously moved and is irradiated to form discontinuous heating parts 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of heat-treating cutlery such as scissors, knives, and cooking utensils to produce cutlery having required strength and sharpness.

Conventionally, a high-energy beam such as a laser is irradiated onto the part of the cutter to be hardened, and at that time, the energy beam is focused on the surface of the cutter or at a desired depth, and is continuously scanned. A method has been used in which the surface of the workpiece is heated to a required temperature, and the heated portion is appropriately cooled by controlling the scanning speed of the beam to provide the required strength and sharpness. According to this method, since the heat treatment is affected by the structure of the heated part of the workpiece and the melting state of the alloy components contained in it, adjustment is required to properly obtain these changes. According to energy beam irradiation, the required heat treatment can be easily performed simply by controlling and projecting an energy beam with a constant power density. However, the conventional treatment method is to continuously scan and move a high-energy beam to irradiate the entire blade part at a constant temperature either in a straight line from one end to the other or in a continuous band with a constant width in the perpendicular direction. It was discovered that sufficient effects could not be obtained because the treatment involved heating and cooling.

That is, even if the energy beam is applied at a constant intensity or at a selected intensity with a change that adapts to the part, it will not be continuous.
It has been found that simply increasing the hardness continuously through irradiation does not improve the sharpness, and continuous processing of the entire surface leaves distortions, making the cutting edge more likely to fray.

In view of the above-mentioned drawbacks, the present invention aims to provide a method that overcomes all the problems of the conventional methods. In order to achieve this purpose, the method is characterized by a method in which the irradiation position of a high-energy beam is moved intermittently and discontinuously to a predetermined part of a shaped cutter to form a hard and soft shape, thereby obtaining the required strength and sharpness. do.

Next, the present invention will be explained by showing an example. An electron beam, ion beam, laser beam, or the like is used as the irradiation energy. The energy beam emitted from the energy generator (laser generator device in this case) 6 is bent by the prism 5, and the energy beam in the range between 4 and 14 is focused by the lens 3 and applied to the workpiece 1 as shown by the solid line 2. The focal point 10 is set in the interior close to the surface. In this way, the focal point 10 of the surface of the workpiece to be irradiated is heated to the required temperature in a spotwise manner. Furthermore, if the irradiation position is moved to another location or the irradiation is interrupted, the workpiece will be cooled, and if the component metals of the workpiece are properly taken, the workpiece will be hardened by air cooling. Depending on the component, it is hardened by rapidly cooling after heating. Also, by moving the lens 3, the focus 2 is placed inside the workpiece as shown by the dotted line 12.
You can also tie 0.

In this way, a circular heating part with a wide area is formed on the surface, and the deep part is heated to the required temperature.

This forms a heated surface of focal spot 22 as shown in FIG. In the present invention, as shown in FIG. 2, the focal spot is moved and irradiated in an intermittent and discontinuous manner to form a discontinuous heating section 22, and heating is not performed in a continuous line or a wide band. FIG. 3A shows a portion of a scissor blade showing typical intermittent, discontinuous heating spots, and FIG. 3B shows a kitchen knife with intermittent, discontinuous, relatively closely spaced heating spots on the thin blade portion 11. A heating section 22 is formed. FIG. 3C shows both blades, one blade having relatively closely spaced discontinuous heating spots 22 and the other blade having spaced intermittent heating spots 22. The following conclusions were obtained from the results of these series of experiments.

, in these test cutlery, the diameter t1 of one heating interior 22
Approximately 5 to 30 microns is appropriate, and in most cases, 10 microns is preferable.The spacing t2 between these heating spots can be adjusted depending on the purpose of use, since the original buds are still soft. Hard and soft parts exist alternately along the blade surface, and through use or polishing, high-strength, high-hardness parts and soft but high-toughness parts alternately compensate for good tempering. It creates irregularities, shows a wavy pattern, and the cutting edge is not a -iK line, which increases the sharpness. In addition, distortion due to heat treatment,
Distortion caused by final polishing, etc. is absorbed by the untreated areas between the heating spots, and processing can be performed without leaving any distortion.
Can be treated with a highly tough blade.

Although the cutting edge 11 in FIG. 3B shows a portion 22 that has been subjected to intermittent heating in relatively close locations, care should be taken to prevent the cutting edge from becoming brittle. This is done by selecting the spot spacing and spot diameter according to the alloy composition of the blade.

Next, one applied example will be described. It is preferable to heat the entire blade parts 1 and 11 to a relatively low temperature of about 200 to 400°C, remove internal strain, perform internal diffusion to homogenize, and then perform the above-mentioned intermittent and discontinuous spot heating. There are cases. Also,
Intermittent heating should not proceed in one direction continuously, but should be performed one by one, then returned to the next, and then proceeded one by one, or at zigzag intervals to eliminate deformation and prevent the generation of internal strain. effective.

Another example of application is to use WC, cBN, or TiN on the blade part to strengthen hardening in areas that are subjected to intermittent heating.

When powder for diffusion such as WMoC is spread to a thickness of about 10 to 100 μm and the above-mentioned intermittent energy is applied, these particles will be diffused or fused into the base material to increase its strength and hardness. This allows you to increase sharpness.

As another example of application, a fine wire cutter can be obtained by winding a thin stellite wire around the outer periphery of a heat-resistant and acid-resistant metal wire, such as stainless steel wire, fusing the contact points of the drawing wires, and then subjecting the wire to the intermittent heating described above.

The intermittent hardened cutter thus manufactured has good sharpness, can be given appropriate strength and hardness, has very little internal stress, naturally forms unevenness, and has good durability. It has the advantage of being easy to manufacture and requires less labor and cost.

[Brief explanation of the drawing]

FIG. 1 is an exemplary front view of the energy irradiation device. FIG. 2 shows an intermittent irradiation section of an embodiment of the present invention. FIGS. 3A, 3B, and 3C are partial views of the intermittent treatment of the blade in one application of the present invention applied to a blade. 1.11... Workpiece blade part 2.12... Irradiation energy focusing part 4.14... Irradiation energy flux 5... Prism tl... Heating spot diameter t2... Heating spot interval 22... Heating spot portion 10, 20... Beam illumination point

Claims (1)

[Scope of Claims] l In the refining of a cutter that irradiates high energy to the surface or a required deep part of a metal heat-treated workpiece, a high-energy beam generated from a high-energy beam generator device is used in the cutter refining section. The surface of the surface or the required depth is focused and irradiated, and the irradiation position is moved intermittently and discontinuously, and the tempered area is heated to the required temperature and cooled to permanently form the hardened area. A method for processing cutlery characterized by attaching continuously generated blades. 2 Fine powder (D TiN, cBN,
The method for treating cutlery according to claim 1, wherein a metal powder of We, WC-MoC, or a mixed composition thereof is placed and subjected to a refining treatment by high-energy beam irradiation.