Cutter for processing wood or paper and method for manufacturing same

Abstract

Provided is a cutter for processing wood or paper, the cutter having high wear resistance and excellent durability.　The cutter has a base metal and a blade tip formed as a clad layer integrated on the base metal by melting a metal material, which contains, by mass, at least 10% of V, at least 5% of Cr, and at least 50% of Fe, using a laser beam while supplying the metal material onto the base metal. It was found that the material exhibits a high level of durability against both abrasive wear and corrosion wear. That is, the incorporation of Cr reduces corrosion wear, and the incorporation of V reduces abrasive wear. In addition, it was found that the clad layer formed by laser cladding has less thermal impact on the base metal as compared to general brazing or the like and can achieve strong joint strength.

Description

Woodworking or paperworking blades and their manufacturing method

[0001] The present invention relates to a woodworking or paperworking blade that can be suitably used for cutting, shearing, crushing, etc., of wood, wood-based materials, paper, etc., and a method for manufacturing the same.

[0002] The cutting edge of woodworking or paperworking blades is affected by moisture in the wood and is therefore significantly affected by corrosive wear in addition to abrasive wear, so a corrosion-resistant material is desirable for the cutting edge material.

[0003] Furthermore, in recent years, paper consumption has increased due to the global population growth. Therefore, waste paper recycling is progressing with the aim of reducing the use of virgin wood pulp, the raw material. In the papermaking process, corrosion prevention measures are important for each piece of equipment, as cellulose, the main component of raw pulp, is chemically treated. In the waste paper recycling process, cutting tools (papermaking pulper cutting tools) are used to crush and defibrate waste paper together with chemicals, and in order to further increase processing capacity, there is a need to improve the corrosion resistance and wear resistance of these cutting tools.

[0004] Therefore, in order to extend the life of the blades, cutting edges of woodworking or paperworking tools are generally made of high-speed steel or cemented carbide (WC, Co), which have excellent wear resistance. The cutting edge material is joined to the base metal by brazing or the like.

[0005] However, when joining to the base metal by brazing or other methods, there is a risk of peeling depending on the quality of the joining, and it is difficult to say that conventional materials have achieved sufficient durability.

[0006] International Patent Publication No. 2018 / 216641

[0007] The present invention was completed in view of the above circumstances, and an object of the present invention is to provide a cutting tool for woodworking or paperworking that is highly wear-resistant and has excellent durability, and a method for manufacturing the same.

[0008] In order to solve the above problems, the inventors have investigated various materials and found a material suitable for wood cutting blades and paper working blades, and have completed the following invention. That is, the woodworking or paper working blade of the present invention, which solves the above problems, comprises a base metal, and a cutting edge formed from a buildup layer that is integrated onto the base metal by supplying a metal material containing, by mass, 10% or more of V, 5% or more of Cr, and 50% or more of Fe onto the base metal and melting the metal material with a laser beam.

[0009] As will be explained in detail in the examples below, it was found that the above material contains Cr to reduce corrosive wear, and V to reduce abrasive wear, and the combined effects of these two elements result in high durability against both abrasive and corrosive wear. Furthermore, it was found that the buildup layer formed by laser buildup has less thermal impact on the base metal than ordinary brazing, and can achieve strong joint strength.

[0010] In particular, the metal material preferably contains 20% or less of V and 15% or less of Cr. Also, the metal material preferably contains 1.0% or more of C by mass and / or more than 0% of W. By including C, vanadium carbide with high hardness is formed, which can further reduce abrasive wear.

[0011] The method of manufacturing a woodworking or paperworking blade of the present invention, which solves the above-mentioned problems, comprises a build-up process in which a metal material containing, by mass, 10% or more of V, 5% or more of Cr, and 50% or more of Fe is supplied onto the base metal and melted with a laser beam to form one or more build-up layers integrated onto the base metal; and a cutting edge formation process in which a cutting edge is formed from the build-up layer.

[0012] Fig. 1 is a schematic perspective view of a flat chamfering cutter used in the examples. Fig. 2 is a schematic front view of a flat chamfering cutter used in the examples. Fig. 3 is a graph showing the amount of recession of the cutting edge when cutting MC nylon as a workpiece in the examples. Fig. 4 is a graph showing the amount of recession of the cutting edge when cutting oak wood as a workpiece in the examples. Fig. 5 is a perspective view of an awl of the examples. Fig. 6 is a schematic view showing the process of making the awl of the examples.

[0013] The woodworking or paperworking blade and its manufacturing method of the present invention will be described in detail below based on embodiments. Unless otherwise specified, the numerical ranges "x to y" described in this specification include a lower limit x and an upper limit y. Furthermore, new numerical ranges can be constructed by arbitrarily combining these upper and lower limits, as well as the numerical values ​​listed in the examples. The new numerical range can also be a range that excludes one or both of the upper and lower limits. Furthermore, numerical values ​​arbitrarily selected from any of the above numerical ranges can be used as the upper and lower limits of the new numerical range.

[0014] (Woodworking or Paperworking Blade) The woodworking or paperworking blade of this embodiment has a base metal and a cutting edge. Examples of the woodworking or paperworking blade of this embodiment include awls, cutters, finger cutters, plane blades, macerating blades, saws, and crushing blades. These woodworking or paperworking blades can be configured so that the cutting edge can be replaced as a replaceable blade, or can be configured so that the blade is integrated as a whole.

[0015] - Base metal The base metal is the part of a woodworking or paperworking blade where the cutting edge is directly formed, and may be made of any material, such as known steel, but may also be made of a material with excellent corrosion resistance, such as stainless steel.

[0016] There are no particular restrictions on the size or shape of the base metal. When a woodworking or paperworking blade is configured so that a replaceable blade formed on the cutting edge can be easily removed, the base metal constitutes the replaceable blade together with the cutting edge, but otherwise, it is a member that constitutes most of the woodworking or paperworking blade other than the cutting edge.

[0017] For example, a flat-chamfering cutter with a flat-blade-shaped replacement blade that can be easily removed has a flat-blade-shaped replacement blade that corresponds to the wood cutting tool of this embodiment, and a cylindrical body with an attachment groove formed on the outer periphery that allows the replacement blade to be easily fixed in place.

[0018] - Cutting edge The cutting edge is integrally formed on the surface of the base metal. The shape of the cutting edge is appropriately selected for each type of wood-cutting or paper-working blade. The cutting edge is formed from a buildup layer that is integrated onto the base metal by melting a metal material with a laser beam while supplying it onto the base metal. After the buildup layer is formed, the cutting edge shape is adjusted by grinding, cutting, polishing, etc. to produce the cutting edge. Details of forming the cutting edge will be explained in the section on the manufacturing method of wood-cutting or paper-working blades described later, so explanation here is omitted. The cutting edge is made of a metal material containing V, Cr, and Fe. Elements other than these elements may also be contained. For example, W, C, Si, Mn, and Mo. These elements may be contained as alloys or may form intermetallic compounds.

[0019] The V content, based on the mass of the metal material, has a lower limit of 10%, and can be 13%, 15%, or 17%, and can have an upper limit of 25%, 23%, 21%, or 19%. These upper and lower limits can be combined in any desired manner.

[0020] The Cr content, based on the mass of the metal material, has a lower limit of 5%, and can be 8%, 11%, or 14%, and can have an upper limit of 20%, 18%, or 16%. These upper and lower limits can be combined in any desired manner.

[0021] The Fe content, based on the mass of the metal material, has a lower limit of 50%, and can be 55%, 60%, or 65%, and can have an upper limit of 85%, 80%, or 75%. These upper and lower limits can be combined in any desired manner.

[0022] The carbon content can be 1.0%, 2.0%, or 3.0% by mass based on the mass of the metal material, and 5.0%, 4.5%, or 4.0% by mass as the upper limit. These upper and lower limits can be combined arbitrarily. Carbon is preferably present as vanadium carbide.

[0023] The W content, based on the mass of the metal material, can have a lower limit of more than 0%, 0.5%, or 1.0%, and an upper limit of 4.0%, 3.0%, or 2.0%. These upper and lower limit values ​​can be combined in any way.

[0024] (Method for manufacturing a wood cutting or paper working blade) The method for manufacturing a wood cutting or paper working blade of this embodiment can be suitably employed to manufacture the wood cutting or paper working blade of this embodiment. The wood cutting or paper working blade manufactured is the same as the wood cutting or paper working blade of this embodiment described above, so further explanation will be omitted. The method for manufacturing a wood cutting or paper working blade of this embodiment includes a build-up step and a cutting edge forming step.

[0025] The build-up process is a process in which one or more build-up layers are formed on the surface of a base metal by supplying a metal material onto the base metal and using a laser beam to build up the material. Unlike plasma arc build-up, laser beam build-up does not involve a large amount of heat entering the base material (base metal), and instead energy is input into a small area in a short period of time, resulting in a faster cooling rate of the build-up layer.

[0026] This results in a higher hardness than with conventional quenching heat treatment, and the metal structure becomes finer and denser, resulting in higher toughness. It also has the effect of suppressing distortion in the case of flat, long products that require straightness. Furthermore, by properly controlling the shape of the metal material supplied in the overlay process, the shape of the overlay layer and, ultimately, the cutting edge shape can be set efficiently based on the intended use, taking into account the amount of regrinding required, for example, in the case of regrinding.

[0027] The laser cladding process is a process in which a metal material is supplied to the surface of a base metal and integrated with the surface of the base metal by a laser beam. The metal material is composed of a material having the composition of the metal material described above for the wood cutting or paper working blade of this embodiment. The form of the metal material is not particularly limited, but a metal powder material or cladding wire can be used. When a metal powder material is used as the metal material, the particle size preferably has a lower limit of 10 μm, 30 μm, or 50 μm and an upper limit of 100 μm, 200 μm, or 300 μm, and it is particularly preferable that the particle size is uniform. These upper and lower limits can be arbitrarily combined. Any method can be used to prepare the metal powder material, but atomization, pulverization, etc. can be used. The wire diameter of the cladding wire is preferably smaller than the thickness of the cladding layer.

[0028] In the cladding process using a laser beam, the surface of the base metal, which is the base material, is also heated and melted, forming an alloy layer at the boundary with the cladding layer, which also helps to eliminate poor bonding due to brazing defects, voids, and poor adhesion. Therefore, it is preferable that the output of the laser beam is at a level that can melt the metal material, and that can firmly bond the cladding layer while minimizing the melting of the base metal.

[0029] The amount of metal material to be supplied is not particularly limited, but it is desirable to supply an amount that allows the entire material to be melted by irradiation with a laser beam and integrated with the surface of the base metal. In particular, it is preferable to supply the material so that the thickness of the cutting edge portion to be formed is approximately 0.1 mm to 10 mm.

[0030] In order to form a cutting edge of the required thickness in a wood cutting tool, the required number of buildup layers are laminated. Reducing the thickness of each buildup layer has the advantage of reducing the amount of heat input to the base metal, thereby suppressing thermal deformation of the base material. Furthermore, the cooling rate due to thermal diffusion from the buildup layer to the base metal is improved, which increases the hardness of the buildup layer.

[0031] Therefore, the thickness of the buildup layer is preferably 10 mm or less, and a thinner buildup layer (for example, about 0.1 mm to 10 mm) can also be formed. When forming a thin buildup layer, the buildup layer is laminated until it reaches the thickness of the cutting edge or greater.

[0032] The build-up process is continued until the size of the build-up layer reaches the required size and shape of the cutting edge. Normally, the area that can be heated by irradiating with a laser beam is often smaller than the size of the cutting edge, so the laser beam is irradiated along the shape of the cutting edge that is to be manufactured (the shape in the direction of expansion of the base metal surface).

[0033] As described above, when forming a buildup layer by the buildup process, it can be performed by stacking multiple layers in the overlapping direction (thickness direction) on the surface of the base metal. It is also possible to form multiple buildup layers by irradiating the surface of the base metal with the laser beam multiple times so as to divide it in two dimensions depending on the size of the cutting edge. It is also possible to supply metal material to the irradiated area while moving the position where the laser beam is irradiated on the base metal.

[0034] The cutting edge forming step is a step of forming a cutting edge by adjusting the cutting edge shape by cutting, grinding, polishing, etc., on the buildup layer formed in the buildup step.

[0035] The method for manufacturing a wood cutting or paper working blade of this embodiment may include other steps such as hardening as necessary. For example, after the cutting edge is shaped in the cutting edge forming step, heating and cooling may be performed according to an appropriate temperature profile.

[0036] The wood cutting tool and the method for manufacturing the same of the present invention will be described in detail below with reference to examples.

[0037] (Wood cutting blade used in the test) As shown in Figures 1 and 2, the wood cutting blade of this example is a flat chamfering cutter having a body 10 and wood cutting blades 20. The body 10 is a cylindrical member to which four wood cutting blades 20 are fixed evenly in the circumferential direction, and fixing holes 10A are formed in the shaft portion of the cylinder. The wood cutting blades 20 are fixed to the body 10 with fixing bolts 30. The wood cutting blade 20 has a base metal 21 and a cutting edge portion 22 formed on the base metal 21. The outer diameter of the cutting edge portion was 125 mm.

[0038] (Test wood cutting blade) Test example 1 A metal powder material containing 15% V, 11% Cr, 70% Fe, 3.0% C, and 0.5% W was used on a base metal 21 (made of carbon tool steel) to form a buildup layer using a laser beam.

[0039] Test Example 2 A wood cutting blade 20 was produced in the same manner as in Test Example 1, except that a metal powder material made of a cobalt-based alloy (Stellite 6) was used.

[0040] Test Example 3 A wood cutting blade 20 was produced in the same manner as in Test Example 1, except that a metal powder material made of a cobalt-based alloy (Stellite 12) was used.

[0041] Test Example 4: A wood-cutting blade 20 was produced in the same manner as in Test Example 1, except that a metal powder material made of martensitic stainless steel (SUS440C) was used. Test Example 5: A cutting edge 22 made of high-speed steel (SKH51) was brazed to a base metal 21 to form a wood-cutting blade 20.

[0042] Test Example 6 A cutting edge 22 made of cemented carbide (WC-Co) was brazed to a base metal 21 to form a wood cutting blade 20.

[0043] (Evaluation) The wood cutting blade 20 of each test example was sharpened and then fixed to the body 10. Then, cutting was performed on the workpiece (MC nylon, oak) under predetermined conditions, and the amount of recession of the cutting edge was measured. The results are shown in Figure 3 (MC nylon) and Figure 4 (oak). The predetermined cutting conditions were a rotation speed of 6000 rpm, 150 cuts for MC nylon, and 300 cuts for oak. Here, one cut means that a workpiece length of 1 meter was cut. The cutting conditions were a feed rate of 2 m / min for MC nylon and a feed rate of 6 m / min for oak.

[0044] (Results) As is clear from Figures 3 and 4, the wood cutting tool of Test Example 1, which is the wood cutting tool of the present invention, showed less recession of the cutting edge compared to wood cutting tools made of other materials. This tendency was the same regardless of whether the work material was MC nylon or oak. In other words, it was clear that wood cutting tools made of materials equivalent to those of the wood cutting tool of the present invention have high wear resistance.

[0045] Furthermore, it was found that the wood cutting blades of test examples 1 to 4, in which the cutting edge was formed using a laser beam, had less peeling of the cutting edge than wood cutting blades in which the cutting edge was joined to the base metal by brazing.

[0046] (Other Examples) The following describes an example of a wood cutting or paper working tool applied to an awl. The wood cutting or paper working tool of this example is an awl for drilling holes in wood. By combining a chisel case around the awl, a chisel awl for drilling square holes can also be constructed.

[0047] As shown in Figure 5, the awl of this embodiment has a cylindrical body 50 and a cutting edge 60 provided at the tip of the body 50. A cutting edge 61 is formed on the cutting edge 60. The body 50 is formed with a spiral ridge 51 and flutes 52.

[0048] When forming the cutting edge 60, as shown in Fig. 6(a), multiple buildup layers 60A are laminated on the tip of the main body 50 to create a rough shape, and then the cutting edge 60 is formed by cutting, grinding, etc. (Fig. 6(b)). The buildup layers are laminated in such a way that the thickness direction of the buildup layers coincides with the axial direction of the awl in this embodiment. By forming only the tip cutting edge 60 from a material derived from a metallic material, the durability of the cutting edge portion can be improved and the cost of the awl as a whole can be reduced.

[0049] 10: Body 10A: Fixing hole 20: Wood cutting tool 21: Base metal 22: Cutting edge 30: Fixing bolt 50: Main body 51: Convex rib 52: Flute 60: Cutting edge 61: Cutting edge

Claims

1. A woodworking or paperworking blade having a base metal and a cutting edge formed from a build-up layer which is integrated onto the base metal by melting it with a laser beam while a metal material containing, by mass, 10% or more of V, 5% or more of Cr, and 50% or more of Fe is supplied onto the base metal.

2. A woodworking or paperworking blade as described in claim 1, wherein the metal material contains 25% or less of V and 20% or less of Cr.

3. A woodworking or paperworking blade as claimed in claim 1 or 2, wherein the metal material contains, by mass, 1.0% or more of C and / or more than 0% of W.

4. A method for manufacturing a woodworking or paperworking blade, comprising: a build-up process in which a metal material containing, by mass, 10% or more V, 5% or more Cr, and 50% or more Fe is supplied onto the base metal and melted by a laser beam to form one or more build-up layers integrated onto the base metal; and a cutting edge forming process in which a cutting edge is formed from the build-up layer.