Cutting tool

Abstract

To provide a cutting tool which shows excellent abrasion resistance and hardly causes breakage of a blade tip part.SOLUTION: A cutting tool includes a base body part and a blade body which continues from the base body part and is positioned along the base body part. The base body part includes a first metal, and the blade tip part includes a second metal and a plurality of hard particles including tungsten carbide of hardness which is higher than that of the second metal. The blade tip part includes the second metal and a plurality of the hard particles of higher hardness than the second metal. The hard particle includes the tungsten carbide. The second metal includes at least nickel, chrome, and iron. In the blade tip part, the content of the iron in a matrix region where the hard particles do not exist is 10 mass% or more, and a mass ratio (Fe / W) between the content of the iron and the content of the tungsten is 1 or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to cutting tools. [Background technology]

[0002] Conventionally, kitchen knives made of materials containing metal as a main component have been used, and in recent years, kitchen knives made of stainless steel containing nickel and chromium as components have become increasingly popular (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-189682 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] Such conventional knives have problems such as brittle cutting edges that are prone to cracking and chipping, so there is a demand for knives with cutting edges that are less susceptible to breakage.

[0005] An object of the present disclosure is to provide a blade having excellent wear resistance and a cutting edge that is less likely to break. [Means for solving the problem]

[0006] (1) A blade according to the present disclosure comprises a base portion and a cutting edge portion connected to and positioned along the base portion. The base portion includes a first metal, and the cutting edge portion includes a second metal and a plurality of hard particles including tungsten carbide having a higher hardness than the second metal. The cutting edge portion includes the second metal and a plurality of hard particles having a higher hardness than the second metal. The hard particles include tungsten carbide. The second metal includes at least nickel, chromium, and iron. In the cutting edge portion, the iron content in a matrix region where no hard particles are present is 10 mass% or more, and the mass ratio (Fe / W) of the iron content to the tungsten content is 1 or more.

[0007] (2) In the blade described in (1) above, the second metal includes a metal having a lower hardness than the first metal. (3) In the blade according to (2) or (2) above, the hard particles include hard particles having an angular polyhedral shape. (4) In the cutting tool according to any one of (1) to (3) above, the hard particles include a material having a higher hardness than the first metal. (5) In the blade according to any one of (1) to (4) above, the cutting edge contains hard particles in a proportion of 5% by volume to 40% by volume. (6) In the cutting tool according to any one of (5) above, the cutting edge has a tungsten content of 15 mass % or less in a matrix region where no hard particles are present. (7) In the blade described in any one of (1) to (6) above, the cutting edge portion has a cutting edge and a pair of side surfaces located on either side of the cutting edge, and at least one of the hard particles is exposed from the side surface. (8) In the cutting tool according to any one of (1) to (7) above, at least one of the hard particles is exposed from the cutting edge. (9) In the blade according to any one of (1) to (8) above, at least one of the hard particles has a recess, and in at least one of the hard particles having a recess, the recess is exposed from the surface of the cutting edge. [Effects of the Invention]

[0008] The blade according to the present disclosure has the above-described configuration, and therefore has excellent wear resistance, and the cutting edge is less likely to break. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view showing a blade according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan perspective view of the blade shown in FIG. [Figure 3] FIG. 2 is a view of the blade shown in FIG. 1 as seen from the cutting edge side. [Figure 4]FIG. 4 is an enlarged cross-sectional view for explaining a region X in FIG. 3. [Figure 5] FIG. 5 is an enlarged cross-sectional view of the cutting edge side in FIG. 4. [Figure 6] FIG. 6 is an enlarged cross-sectional view showing a cutting edge portion including hard particles different from the hard particles shown in FIG. 5. [Figure 7] 2 is an explanatory diagram for explaining an embodiment of a method for manufacturing the blade shown in FIG. 1. FIG. [Figure 8] FIG. 2 is a cross-sectional view illustrating an example of a laser cladding technique in one embodiment of a method for manufacturing the blade shown in FIG. 1. [Figure 9] 1. FIG. 4 is a cross-sectional view illustrating another example of laser cladding technology in the embodiment of the method for manufacturing the blade shown in FIG. [Figure 10] 3 is a cross-sectional view of an embodiment of a method for manufacturing the blade shown in FIG. 1, and is an enlarged cross-sectional view of a portion corresponding to region X in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] The blade according to the present disclosure will be described with reference to Figures 1 to 6. The drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily correspond to the actual ones.

[0011] A blade 1 according to an embodiment of the present disclosure will be described below. The blade 1 according to the embodiment includes a blade 1a and a handle 1b connected to the blade 1a.

[0012] The blade 1a is set to a shape and size that matches the intended use of the blade 1. When the blade 1 is a kitchen knife, examples include Japanese knives (such as a deba knife or a santoku knife), Western knives (such as a gyuto knife), and Chinese knives, and the blade 1a is set to match the shape of each knife. When the blade 1a is something other than a kitchen knife (such as a knife or surgical instrument), the shape of the blade 1a is set to match the intended use other than the kitchen knife.

[0013] The handle 1b connected to the blade 1a is for a person to hold when using the blade 1. Like the blade 1a, the handle 1b is set to a shape and size that suits the intended use of the blade 1.

[0014] The blade 1a and the handle 1b may be formed integrally or separately. The blade 1 is not limited to having the handle 1b, and may be composed of only the blade 1a. In this embodiment, the blade 1a and the handle 1b are formed separately, and a part of the blade 1a is inserted into the handle 1b and fixed to the handle 1b at the inserted part.

[0015] The handle 1b is made of, for example, wood, resin, ceramic, or metal. Metal materials include rust-resistant materials such as titanium and stainless steel. Resins include, for example, ABS resin (a copolymer of acrylonitrile, butadiene, and styrene) and polypropylene resin.

[0016] The size of the blade 1 is not limited and is set appropriately depending on the application. For example, as shown in FIGS. 1 and 2, the overall length Ht1 in the longitudinal direction (x-axis direction) of the blade 1 may be 5 cm or more and 40 cm or less. As shown in FIGS. 1 and 2, the overall length Ht2 in the longitudinal direction (x-axis direction) of the cutting edge 2 (described later) may be 2 cm or more and 35 cm or less. As shown in FIG. 3, the length Ht3 of the blade 1a in the width direction (y-axis direction) perpendicular to the overall length Ht1 may be 10 mm or more and 150 mm or less. As shown in FIG. 3, the thickness Ht4 (z-axis direction) of the blade 1a at its thickest point may be 1 mm or more and 5 mm or less. The length (x-axis direction) and thickness (z-axis direction) of the handle 1b may also be set appropriately. For example, the thickness of the handle 1b may be 5 mm or more and 30 mm or less.

[0017] The blade 1a has a base portion 3 and a cutting edge portion 2 that is connected to the base portion 3 and is located along the base portion 3. The base portion 3 includes a first metal. The first metal is not limited to, and examples thereof include steel, synthetic steel, stainless steel, and titanium alloy.

[0018] Examples of synthetic steel include materials containing at least one metal selected from the group consisting of chromium (Cr), molybdenum (Mo), vanadium (V), tungsten (W), cobalt (Co), and copper (Cu). Examples of stainless steel include chromium-nickel and chromium-based materials. Examples of titanium alloys include so-called 64 titanium, a titanium alloy containing 6% by mass of aluminum (Al) and 4% by mass of vanadium. When the first metal is stainless steel, the corrosion resistance of the base portion 3 against rust and the like can be improved.

[0019] In the blade 1 according to one embodiment, the first metal is the main component of the base 3. The main component means a component that accounts for more than 70% by mass of the total components constituting the base 3 (100% by mass).

[0020] As shown in Fig. 2, the base portion 3 includes an exposed portion 31 exposed from the handle 1b and a core 32 inserted inside the handle 1b. The exposed portion 31 has a back portion 3A extending along the longitudinal direction (x-axis direction) and an end portion 3C extending along the longitudinal direction (x-axis direction) as shown in Fig. 4. The width of the exposed portion 31 narrows near the end of the exposed portion 31 in the longitudinal direction, and the end portion 3C and the back portion 3A are connected at the end of the exposed portion 31. The cutting edge portion 2 is connected to the end portion 3C along the end portion 3C as shown in Fig. 4.

[0021] As shown in FIG. 4, the end 3C of the base 3 may be parallel to the thickness direction (z-axis direction) of the base 3, or may be inclined relative to the z-axis direction. Alternatively, the end 3C of the base 3 may be curved or bent relative to the z-axis direction. When the end 3C is curved or bent, the bonding area between the base 3 and the cutting edge 2 increases. This increases the bonding strength between the base 3 and the cutting edge 2, and improves the durability of the blade 1.

[0022] Core 32 is narrower in the width direction (y-axis direction) than exposed portion 31, and is inserted into handle 1b. Core 32 in blade 1 according to one embodiment has at least one hole 32a. By inserting a portion of handle 1b into hole 32a, blade 1a and handle 1b are firmly fixed together.

[0023] The cutting edge 2 includes a second metal 2a and a plurality of hard particles 4. The second metal 2a is a metal containing at least nickel (Ni), chromium (Cr), and iron (Fe). If the second metal 2a is a metal containing at least nickel, chromium, and iron, the cutting edge 2 has improved corrosion resistance and is less susceptible to cracking. Examples of metals containing at least nickel, chromium, and iron include alloys such as Inconel (registered trademark) and Colmonoy (registered trademark).

[0024] In the blade 1 according to one embodiment, the second metal 2a contained in the cutting edge portion 2 may contain a metal having a lower hardness (Vickers hardness) than the first metal contained in the base portion 3. With this configuration, the blade 1 can combine the advantages of both the first metal and the second metal 2a. That is, the first metal of the base portion 3 can increase the overall strength of the blade 1, and the second metal 2a of the cutting edge portion 2 can reduce the occurrence of cracks or chips in the cutting edge portion 2 due to stress applied during use of the blade 1, thereby improving the durability of the cutting edge portion 2.

[0025] The hard particles 4 contained in the cutting edge 2 have a higher hardness (Vickers hardness) than the second metal 2a contained in the cutting edge 2, and contain tungsten carbide (WC). This configuration can improve the hardness of the entire cutting edge 2, and can improve the wear resistance of the cutting edge 2. Furthermore, the hard particles 4 are made of a material that has a higher hardness than the second metal 2a. Therefore, when the blade 1 is in use, the hard particles 4 come into contact with the object, thereby improving the sharpness of the cutting edge 2 when used on the object.

[0026] The hard particles 4 may contain a material that is not only harder than the second metal 2a but also harder than the first metal. That is, the hard particles 4 may contain a material harder than the first metal, in addition to tungsten carbide. Examples of such materials include cermets containing titanium carbide (TiC), titanium nitride (TiN), tantalum carbide (TaC), or vanadium carbide (VC). By using hard particles 4 with sufficient hardness, the cutting edge 2 can be further improved in terms of sharpness and wear resistance. The hard particles 4 may have a Vickers hardness of, for example, 1000 Hv or more and 4000 Hv or less.

[0027] The cutting edge 2 may contain the hard particles 4 in a proportion of 2 volume % or more and 25 volume % or less. When the cutting edge 2 contains the hard particles 4 in a proportion of 2 volume % or more, the sharpness and wear resistance can be further improved. When the cutting edge 2 contains the hard particles 4 in a proportion of 25 volume % or less, the productivity of laser cladding can be maintained high.

[0028] The content of hard particles 4 can be determined by observing the cross section (cross section parallel to the yz plane) of the cutting edge 2 using a scanning electron microscope and determining the ratio of the total area of ​​the hard particles 4 to the entire area of ​​the cutting edge 2 as volume % from a photograph of the observed image. Specifically, the content of hard particles 4 is calculated as follows: First, the cross section of the cutting edge 2 is observed at five different positions at approximately equal intervals along the length direction (x-axis direction) of the cutting edge 2. Next, the area ratios of the hard particles 4 are measured at these five positions. The average value of the area ratios of the hard particles 4 at these five positions is determined. The average value of these area ratios is considered to be the content of hard particles 4, and the content of hard particles 4 is calculated.

[0029] In the cutting edge 2, the tungsten content in the matrix region where the hard particles 4 are not present may be 15 mass % or less. If the tungsten content is 15 mass % or less, the matrix region where the hard particles 4 are not present has high toughness, and the cutting edge 2 is less likely to chip.

[0030] The shape of the hard particles 4 is not limited, and various shapes can be adopted. Examples of the shape of the hard particles 4 include a spherical shape, an ellipsoidal shape, and a polyhedral shape. Among these, the hard particles 4 may have a polyhedral shape. Among the polyhedral shapes, the hard particles 4 may have an angular polyhedral shape. When the hard particles 4 have an angular polyhedral shape, the adhesion between the hard particles 4 and the second metal 2a can be improved. The hard particles 4 are not limited to those having a regular shape such as a spherical shape, an ellipsoidal shape, or a polyhedral shape, and may have an irregular shape, such as a shape with a needle-like sharpness or a shape with a recess (a recess 4a as shown in FIG. 6 ). The hard particles 4 may be particles having a single shape or a mixture of particles having various shapes.

[0031] At least one of the hard particles 4 contained in the cutting edge portion 2 may be exposed from the cutting edge portion 2. As shown in Figures 4 and 5, the cutting edge portion 2 includes a cutting edge 2A and a pair of side surfaces 2c located on either side of the cutting edge 2A. At least one of the hard particles 4 may be exposed, for example, from the side surface 2c of the cutting edge portion 2, or from the cutting edge 2A.

[0032] If at least one of the hard particles 4 is exposed from the side surface 2c of the cutting edge 2, the hard particle 4 comes into contact with the object when the blade 1 is used to cut the object. As a result, the cutting edge 2 has good sharpness and the wear resistance of the cutting edge 2 can be improved. As shown in FIGS. 4 and 5, in the blade 1 according to one embodiment, a plurality of hard particles 4 are exposed from both side surfaces 2c of the cutting edge 2. This further improves the sharpness and wear resistance of the cutting edge 2.

[0033] On the other hand, if at least one of the hard particles 4 is exposed from the cutting edge 2A of the cutting edge portion 2, the hard particle 4 exposed from the cutting edge 2A comes into contact with the object when cutting the object using the blade 1. As a result, the sharpness of the cutting edge 2A can be improved.

[0034] As shown in Fig. 6, in at least one of the hard particles 4 having a recess 4a, the recess 4a may be exposed from the surface of the cutting edge 2. By having the recess 4a exposed from the surface of the cutting edge 2, the sharpness of the cutting edge 2 is further improved. Furthermore, the sliding properties of the blade 1 are further improved by reducing the contact area.

[0035] In order to make it easier for the hard particles 4 to be exposed on the surface of the cutting edge portion 2 even when the cutting edge portion 2 is polished, the hard particles 4 may be dispersed inside the cutting edge portion 2 not only in the length direction (x-axis direction) and width direction (y-axis direction) of the base portion 3, but also in the thickness direction (z-axis direction) of the base portion 3.

[0036] The hard particles 4 may have a particle diameter of, for example, 5 μm or more and 50 μm or less. To obtain hard particles 4 having such a particle diameter, particles having a particle diameter of less than 5 μm and particles having a particle diameter of more than 50 μm may be separated, for example, using a sieve.

[0037] The Vickers hardness of the hard particles 4, the first metal, and the second metal 2a may be measured using a method in accordance with JIS Z 2244 (ISO 6507-2, the same applies hereinafter). If measurement using this method is difficult, the compositions of the hard particles 4, the first metal, and the second metal 2a may be identified, samples having compositions approximately equal to the identified compositions may be prepared, and these samples may be measured using a method in accordance with JIS Z 2244.

[0038] In the cutting tool according to the present disclosure, it is sufficient to be able to grasp the magnitude relationship between the Vickers hardness of the first metal, the second metal 2a, and the hard particles 4. Therefore, even if there is a discrepancy between the identified composition and the composition of the sample, it is acceptable as long as it does not substantially affect the magnitude relationship.

[0039] In one embodiment of the blade 1, the cutting edge portion 2 has an iron content of 10 mass % or more in the matrix region where no hard particles 4 are present, and the mass ratio (Fe / W) of the iron content to the tungsten content is 1 or more.

[0040] If the iron content in the matrix region where the hard particles 4 are not present is 10% by mass or more, the cutting edge 2 of the blade 1 according to one embodiment is less likely to break. It is presumed that if the matrix region where the hard particles 4 are not present contains 10% by mass or more of iron, an Fe-rich FeNi alloy is formed. As a result, it is presumed that the thermal expansion coefficient decreases, the thermal stress of the metal decreases, and the occurrence of cracks decreases. There is no upper limit to the iron content in the matrix region where the hard particles 4 are not present, and it may be, for example, 40% by mass or less.

[0041] In the matrix region where hard particles 4 are not present, if the tungsten content is high, the hardness of the matrix region increases, making it more likely that cracks or chips will occur in the cutting edge 2. In the matrix region where hard particles 4 are not present, if the mass ratio (Fe / W) of the iron content to the tungsten content is 1 or more, i.e., if the tungsten content is lower than the iron content, the iron content is high and tungsten is less likely to dissolve in the matrix, reducing the increase in hardness of the matrix region and improving the toughness of the cutting edge 2. The mass ratio (Fe / W) of the iron content to the tungsten content is not limited as long as it is 1 or more, and the upper limit may be about 20, for example.

[0042] Next, a method for manufacturing the blade 1 according to one embodiment will be described. There are no limitations on the method as long as it can produce the blade 1 according to one embodiment. One embodiment of the method for manufacturing the blade 1 will be described with reference to Figs. 7 to 9.

[0043] 7 to 10 are diagrams illustrating an embodiment of a method for manufacturing the blade 1 shown in Fig. 1. The embodiment of the method for manufacturing the blade 1 includes, for example, the following steps (a) to (d). (a) A step of preparing a base portion 3 containing a first metal. (b) A step of preparing metal powder, iron-containing metal, and hard particles 4 that constitute the second metal 2a. (c) A process of spraying the metal powder, iron-containing metal, and hard particles 4 constituting the second metal 2a onto the end 3C of the base portion 3 while baking the metal powder and iron-containing metal, thereby forming a blade member 6 in which the iron content in the matrix region where the hard particles 4 are not present is 10 mass% or more and the mass ratio (Fe / W) of the iron content to the tungsten content is 1 or more. (d) A step of polishing the blade member 6 and the base portion 3.

[0044] In step (a), a base 3 containing a first metal is prepared. The base 3 has a shape as shown in FIG. 7. The base 3 is prepared, for example, by pressing a stainless steel plate to punch out a predetermined blade shape, and then quenching the plate. The quenching may involve repeating preheating, quenching, and cooling several times. The hardness of the base 3 can be increased by quenching.

[0045] During the preheating process, the base 3 is heated to a lower temperature than the quenching process that will be carried out later. Preheating can reduce the occurrence of cracks and other defects that are likely to occur if the quenching temperature is too high. The quenching conditions can be set appropriately depending on the material; for example, they can be set to conditions that heat the base 3 to a temperature of 1000°C or higher. During the cooling process, the base 3 is rapidly cooled from the quenching temperature. Cooling can fix the materials that have been activated by the quenching together.

[0046] Next, in step (b), metal powder constituting the second metal 2a, iron-containing metal, and hard particles 4 are prepared. The second metal 2a and hard particles 4 are as described above, and detailed description thereof will be omitted. Examples of iron-containing metals include iron, stainless steel, and alloys containing iron as a main component. Examples of stainless steel include SUS410L and SUS316.

[0047] Next, in step (c), the metal powder constituting the second metal 2a, the metal powder of the iron-containing metal, and the hard particles 4 are sprayed onto the end 3C of the base portion 3, and the metal powder and the metal powder of the iron-containing metal are baked, thereby forming a blade member 6 in which the iron content in the matrix region where the hard particles 4 are not present is 10 mass% or more, and the mass ratio (Fe / W) of the iron content to the tungsten content is 1 or more.

[0048] Examples of a method for baking the metal powder constituting the second metal 2a and the metal powder of the iron (Fe)-containing metal include a method of melting and baking with a laser, etc. Examples of such a method include a cladding technique using a laser.

[0049] Specifically, as shown in FIG. 8, a cladding material 6a containing a metal powder of the second metal 2a and a metal powder of an iron (Fe)-containing metal is supplied from a nozzle 7 to the side of the laser beam 7a near the end 3C of the base 3. This melts the cladding material 6a, which is the material constituting the cutting edge 2, and metallurgically bonds it to the end 3C. An inert gas 7b is sprayed toward the end 3C from the outside of the cladding material 6a. This makes the cladding material 6a more susceptible to the laser beam 7a. Examples of the inert gas 7b include argon gas. The inert gas 7b can be discharged from the same path as the laser beam 7a, as shown in FIG. 9. This allows the inert gas 7b to be sprayed toward the end 3C from inside the cladding material 6a.

[0050] When melting the cladding material 6a, the hard particles 4 are mixed in. The cladding material 6a other than the hard particles 4 is melted by the laser light 7a and adheres to the end portion 3C. On the other hand, the hard particles 4 have a high melting point and are not easily melted by the laser light 7a, but some of the tungsten carbide (WC) in the hard particles 4 decomposes, and the tungsten (W) dissolves into the matrix during machining of the blade member 6. By mixing the hard particles 4 in the cladding material 6a when melting it, it is possible to disperse multiple hard particles 4 in the cutting edge portion 2.

[0051] In order to make the iron content in the matrix region of the cutting edge 2 where the hard particles 4 are not present 10% by mass or more, the amount of iron added derived from the iron-containing metal can be adjusted appropriately, taking into account the iron content contained in the metal powder constituting the second metal 2a. For example, the amount of iron added derived from the iron-containing metal can be adjusted to 5% by mass or more, and at most about 30% by mass.

[0052] Taking into consideration the trace amount of tungsten contained in the second metal 2a, the tungsten derived from the hard particles 4, and the iron content described above, the mass ratio (Fe / W) of the iron content to the tungsten content in the matrix region where the hard particles 4 are not present may be set to 1 or more.

[0053] Next, in step (d), the blade member 6 and the base portion 3 are polished. Polishing is performed using a grinding stone having a surface coated with, for example, aluminum oxide (Al2O3), silicon carbide (SiC), diamond, or a mixture of these particles. Polishing may be performed in multiple steps. For example, as shown in FIG. 10, a first polishing may be performed along dotted line L1, and then a second polishing may be performed along dotted line L2.

[0054] By using this method, a blade 1 having excellent wear resistance and a cutting edge 2 that is less likely to break can be obtained. [Example]

[0055] A base 3 as shown in FIG. 7 was manufactured using stainless steel. Next, a metal powder constituting the second metal 2a, a metal powder of an iron (Fe)-containing metal, and hard particles 4 were sprayed onto an end 3C of the obtained base 3, and the metal powder was baked onto the end 3C. A mixture of Inconel 600 and an iron (Fe)-containing metal was used as the metal powder. SUS410L was used as the iron (Fe)-containing metal. Particles formed of tungsten carbide (WC) were used as the hard particles 4. The metal powder was adjusted to 85 mass% and the hard particles 4 (tungsten carbide) to 15 mass%. The iron (Fe)-containing metal was used so that the amount of iron added was the amount shown in Table 1 (5 mass%, 10 mass%, 15 mass%, 20 mass%, 25 mass%, and 30 mass%).

[0056] The metal powder was baked onto the end 3C using an apparatus such as that shown in FIG. 8. Specifically, a mixture of Inconel 600 and iron-containing metal (cladding material 6a) was supplied from a nozzle 7 to the side of the laser beam 7a toward the end 3C of the base 3. Next, hard particles 4 were mixed in when the cladding material 6a was melted. The cladding material 6a, excluding the hard particles 4, was melted by the laser beam 7a and adhered to the end 3C. On the other hand, the hard particles 4 had a high melting point and were not easily melted by the laser beam 7a. However, some of the tungsten carbide in the hard particles 4 decomposed, and the tungsten dissolved into the matrix. When the cladding material 6a was supplied from the nozzle 7, an inert gas 7b (argon) was sprayed toward the end 3C from outside the cladding material 6a.

[0057] In this way, the cladding material 6a that constitutes the cutting edge was melted and metal-bonded to the end 3C of the base 3, and further, a plurality of hard particles 4 was dispersed in the cutting edge. The proportions of the components that constitute the cutting edge of the obtained blades (samples No. 1 to 6) are shown in Table 1.

[0058] The strength of the cutting edge of the obtained blades (samples No. 1 to 6) was examined. Specifically, a drop test was performed in which an iron ball was dropped freely from a certain height onto the cutting edge to examine the strength of the cutting edge. The cutting edge was visually inspected for the presence of damage such as cracks or chips. If no damage such as cracks or chips was present on the cutting edge, it was evaluated as "absent," and if damage such as cracks or chips was present, it was evaluated as "present." The results are shown in Table 1.

[0059] [Table 1]

[0060] As shown in Table 1, the blades according to the present disclosure (samples No. 1 to 6) did not suffer from damage such as cracks or chips at the cutting edge. As such, the blades (samples No. 1 to 6) in which the mass ratio of iron content to tungsten content (Fe / W) was 1 or more in the matrix region where no hard particles were present and the iron content was 10 mass% or more did not suffer from damage such as cracks or chips at the cutting edge.

[0061] Next, blades (samples No. 7 to 25) were obtained using the same procedures as for blades No. 1 to 6, except that the amounts of iron contained in the iron-containing metal and hard particles 4 were changed to those shown in Table 2. The strength of the cutting edge of the obtained blades (samples No. 7 to 25) was verified using the same procedures as above. The results are shown in Table 2.

[0062] [Table 2]

[0063] As shown in Table 2, the blades according to the present disclosure (samples Nos. 7 to 19) did not suffer from damage such as cracks or chips at the cutting edge. On the other hand, blades (samples Nos. 20 to 25) in which the mass ratio of iron to tungsten (Fe / W) was 1 or less, or the iron content was less than 10 mass %, in the matrix region where no hard particles were present, suffered from damage such as cracks or chips at the cutting edge.

[0064] When iron derived from an iron-containing metal is added so that the Fe content in the matrix region where the hard particles 4 are not present is 10% by mass or more, the amount of WC added to the hard particles 4 is preferably 10% by mass or more and 35% by mass or less. When the amount of WC added to the cutting edge portion 2 is 10% by mass or more and 35% by mass or less, the WC particle content increases, improving wear resistance. The cutting edge portion 2 is easy to sharpen even when the cutting edge becomes dull. This allows the blade 1 to be used for a long time. When the amount of WC added to the cutting edge portion 2 is less than 10% by mass, the WC particle content decreases, reducing wear resistance.

[0065] In the cutting edge portion 2, the WC content of the hard particles 4 can be calculated in volume %. 3 ), and the density of SUS410L is 7.74 (g / cm 3 ), and the density of WC is 15.6 (g / cm 3 ) In the case where the amount of WC added to hard particles 4 is small, i.e., metal powder (Inconel + SUS410L):hard particles (WC) = 95% by mass (Inconel: 90% by mass + SUS410L: 5% by mass):5% by mass, the volume ratio is metal powder:hard particles (WC) = 11.34 (90 / 8.42 + 5 / 7.74):0.32 (5 / 15.6), and the volume percentage is 0.32 / (11.34 + 0.32) = 0.32 / 11.64 = 2.7%. Here, the W content of the matrix is ​​2.38% by mass (Sample No. 7) from Table 2. If the amount of dissolved W is X, then X / (95 + X) = 0.0238, so X = 2.32. It is estimated that 2.32 / 15.6 = 0.15% by volume will dissolve. Therefore, the cutting edge portion 2 contains 2.55% by volume of WC hard particles 4.

[0066] In the case of hard particle 4, where the WC content is high, metal powder (Inconel + SUS410L):hard particles (WC) = 60% by mass (30% by mass Inconel + 30% by mass SUS410L):40% by mass, the volume ratio is metal powder:hard particles (WC) = 7.44 (30 / 8.42 + 30 / 7.74):2.56 (40 / 15.6), and the volume percentage is 2.56 / (7.44 + 2.56) = 2.56 / 10 = 25.6%. From Table 2, the W content of the matrix is ​​19% by mass (Sample No. 19). If the amount of dissolved W is X, then X / (60 + X) = 0.19, so X = 14.1. Therefore, it is estimated that 14.1 / 15.6 = 0.9% by volume will dissolve. Therefore, the cutting edge portion 2 contains 24.7% by volume of hard particles of WC. [Explanation of symbols]

[0067] 1. Cutlery 1a blade 1b pattern 2 Cutting edge 2a Second metal 2A cutting edge 2c side 3 Base 31 Exposed part 32 Core 32a hole 3A Back 3C End 4 hard particles 4a Recess 6 Blade member 6a Cladding Materials 7 nozzles 7a Laser light 7b Inert gas

Claims

1. a base portion; a cutting edge portion connected to the base portion and positioned along the base portion; The blade has the base portion includes a first metal; the cutting edge portion includes a second metal and a plurality of hard particles having a hardness higher than that of the second metal; the hard particles include tungsten carbide; the second metal includes at least nickel, chromium, and iron; the cutting edge portion has a matrix region in which the hard particles are not present having an iron content of 10% by mass or more, and a mass ratio (Fe / W) of the iron content to the tungsten content of 1 or more; blade

2. The cutting tool according to claim 1 , wherein the second metal comprises a metal having a lower hardness than the first metal.

3. The cutting tool according to claim 1 or 2, wherein the hard particles include hard particles having an angular polyhedral shape.

4. The cutting tool according to claim 1 or 2, wherein the hard particles include a material having a higher hardness than the first metal.

5. The blade according to claim 1 or 2, wherein the cutting edge portion contains the hard particles in a proportion of 2% by volume or more and 25% by volume or less.

6. The cutting tool according to claim 1 or 2, wherein the cutting edge portion has a tungsten content of 15 mass % or less in a matrix region where no hard particles are present.

7. The blade according to claim 1 or 2, wherein the cutting edge portion has a cutting edge and a pair of side surfaces located on either side of the cutting edge, and at least one of the hard particles is exposed from the side surfaces.

8. The cutting tool according to claim 1 or 2, wherein at least one of the hard particles is exposed from the cutting edge.

9. The blade according to claim 1 or 2, wherein at least one of the hard particles has a recess, and in at least one of the hard particles having the recess, the recess is exposed from the surface of the cutting edge.

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