JP2007069227A - Build-up welding material, excavating tool which is hard-faced by using the same, and wear preventing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a build-up welding material which has excellent dispersion property in a hardened build-up layer, in which sintered cemented carbide particles and binder metal are firmly welded together, and which imparts sufficient wear resistance and toughness, and an excavating tool which is hard-faced by using the same and a wear preventing plate. <P>SOLUTION: In the build-up welding material 1 composed of a steel tube 2 and the sintered cemented carbide particles 3 which are filled up in the inside of the steel tube 2, in the sintered cemented carbide particles 3, WC is dispersed and arranged in the binding phase of Co, or the binding phase of Co and Ni and also one or more kinds of TiC, TaC, NbC, VC and Cr are contained by 0.4-5.0 wt.% to the weight of the sintered cemented carbide particles 3 and the grain diameter of the sintered cemented carbide particle 3 lies within the range of 7-80 mesh, the weight ratio of the sintered cemented carbide particles 3 to the build-up welding material 1 is taken as 45-70 wt.% and also the weight ratio of the steel tube is taken as 25 to 50 wt.% to the weight of the build-up welding material 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an overlay welding material for hardening a drilling tool used for excavation of, for example, rock or ground, a drilling tool hardened using the welding material, and a wear-preventing plate.

  Conventionally, for example, drilling tools for excavating rocks, grounds, and the like have been embedded with a hard blade formed by sintering tungsten carbide, for example, on the tip side, and in particular, a tool body near the hard blade is excavated. In order to prevent wear along with this, a hardfacing layer is formed in the vicinity of the hard blade by using, for example, a martensitic welding material or an iron-based welding material containing 30 wt% chromium (Cr) in a weight ratio. Some drilling tools are hardened.

However, the hardfacing layer formed by martensitic welding material or iron-based welding material containing 30 wt% chromium (Cr) by weight ratio has a lower hardness than hard blades sintered with tungsten carbide, and is excavated. It has not been possible to sufficiently suppress the wear in the vicinity of the hard blade of the tool. On the other hand, the welding material for building up for forming a hardened layer includes, for example, tungsten carbide (WC) or tungsten carbide and ditungsten carbide (W) inside a steel pipe made of a soft iron-based metal. ₂ C) eutectic is filled with sintered cemented carbide particles bonded to a binder phase such as cobalt (Co) (see, for example, Patent Document 1). When using the welding material for build-up with sintered cemented carbide particles containing tungsten carbide, for example, when overlay welding is performed in the vicinity of the hard blade of the drilling tool by gas welding or electric welding, Since the sintered cemented carbide particles are dispersed in the bonded metal of the steel pipe to form a hardfacing layer having a very high hardness, it is possible to improve the wear resistance of the drilling tool.
JP-A-6-269987

  However, in the above welding materials for overlaying and excavation tools hardened using the same, sintered cemented carbide particles with tungsten carbide have a very large hardness, but conversely, the toughness is reduced. In particular, in excavation tools that perform excavation with an impact force applied, the sintered cemented carbide particles in the hardfacing layer are destroyed in advance with the impact, resulting in defects in the hardfacing layer, As a result, there has been a problem that it may not be possible to satisfy the life of the excavation tool.

  In addition, at the time of welding, at the boundary between the cemented cemented carbide particles and the bonded metal where the steel pipe is melted, the reaction hardens in a state where the reaction does not proceed sufficiently, and a hardfacing layer may be formed. In this case, the sintered cemented carbide particles and the bonding metal are not firmly welded, and there is a problem that the sintered cemented carbide particles easily fall off from the hardfacing layer along with excavation.

  On the other hand, the sintered cemented carbide particles as disclosed in JP-A-10-258390 have a binder phase weight ratio of 2.0 to 5.0 Wt% and a relative density of 98%. There is also a welding material for build-up with a porous structure that is less than the above. In this overlay welding material, the sintered cemented carbide particles are imparted with toughness while maintaining their hardness, and during welding, the bonded metal is allowed to penetrate into the porous portions of the sintered cemented carbide particles, so The sintered cemented carbide particles and the bonding metal are firmly integrated so that the sintered cemented carbide particles do not fall off from the hardfacing layer during excavation.

  However, even in the case of using the welding material for overlaying as disclosed in JP-A-10-258390, the bonded metal that has penetrated into the sintered cemented carbide particles is affected by heat during welding and cooling. The hardness of sintered cemented carbide particles may decrease due to the volume shrinkage of the steel. In such a case, the sintered cemented carbide particles are likely to be destroyed, and the hardfacing layer is damaged. There was a problem that would occur.

  In general, during welding, heat is applied to the overlay welding material to melt each component of the overlay welding material, and a large amount of oxygen is taken in from the air. Among the oxygen taken into the hardfacing layer, some oxygen combines with the components of the welding material for overlaying, while the remaining oxygen remains as activated oxygen as pores in the hardfacing layer . For this reason, in the hardfacing layer formed using the above welding material for overlaying, in addition to the pores that are taken in and remain at the time of welding, the pores of sintered cemented carbide particles having a porous structure, The bonded metal may not enter due to the influence of oxygen taken in at the time of welding, and the hardfacing layer may be made porous by these remaining pores. In such a case, the holding power of the sintered cemented carbide particles by the bonding metal is weakened, and the sintered cemented carbide particles fall off from the hardfacing layer. There was a problem that the service life of the product decreased.

  In view of the above circumstances, the present invention is provided with sintered cemented carbide particles having excellent dispersibility in the hardfacing layer and having excellent wear resistance and toughness. It is an object of the present invention to provide a welding material for building-up capable of forming a hard-welded hardfacing layer, an excavation tool hardened using the welding material, and a wear-preventing plate.

  In order to achieve the above object, the present invention provides the following means.

  The welding material for build-up according to the present invention is a welding material for building-up comprising a steel pipe and sintered cemented carbide particles filled in the steel pipe, wherein the sintered cemented carbide particles are cobalt or cobalt and nickel. In addition, tungsten carbide is dispersed and disposed in the binder phase, and one or more of titanium carbide, tantalum carbide, niobium carbide, vanadium carbide and chromium are added to the weight of the sintered cemented carbide particles. 0.4 to 5.0 Wt% with respect to the weight of the welded material for overlaying, and the particle size of the sintered cemented carbide particles is in the range of 7 mesh to 80 mesh. The weight ratio of the sintered cemented carbide particles is 45 to 70 Wt%, and the weight ratio of the steel pipe is 25 to 50 Wt% with respect to the weight of the welding material for build-up. To do.

  Moreover, in the welding material for overlaying according to the present invention, the sintered cemented carbide particles may be one or two of ferromanganese and ferrosilicon in a weight ratio with respect to the weight of the welding material for overlaying of 0.5 to 0.5. It is desirable to include 5.0 Wt%.

  Furthermore, in the welding material for overlaying according to the present invention, the sintered cemented carbide particles have an HRA hardness of 86 to 95, and a weight ratio of the binder phase of 2.0 to 20.0 Wt%. It is desirable.

  Moreover, in the welding material for overlaying according to the present invention, it is more desirable that the sintered cemented carbide particles have a particle size that remains in the range of 63 mesh to 80 mesh, and the weight ratio is at least 80 Wt% or more. .

  Furthermore, in the welding material for build-up of the present invention, the inside of the steel pipe is filled with sodium silicate together with the sintered cemented carbide particles, and the weight ratio of the sodium silicate to the weight of the welding material for build-up, More preferably, it is 0.5 to 3.0 Wt%.

  The excavation tool of the present invention is characterized in that the welding material for build-up is build-up welded and hardened on at least a part of the outer surface of the excavation tool excluding the hard blade body.

  The wear preventing plate of the present invention is a wear preventing plate that is fixed to at least a part of the outer surface of a drilling tool excluding a hard blade and is used to harden the drilling tool. The welding material is overlay welded.

  According to the welding material for build-up of the present invention, tungsten carbide is dispersed and disposed in a bonded phase of cobalt or cobalt and nickel in sintered cemented carbide particles filled in a steel pipe, and titanium carbide and tantalum carbide. By adding 0.4 to 5.0 Wt% of one or more of niobium carbide, vanadium carbide and chromium with respect to the weight of the sintered cemented carbide particles, Stable cemented carbide even when impact is applied to the hardfacing layer formed by using this welding material for overlaying, while maintaining high hardness while maintaining its toughness. It is possible to prevent the particles from being destroyed and to improve the wear resistance of the hardfacing layer. If the content of one or more of the carbides (titanium carbide, tantalum carbide, niobium carbide, vanadium carbide) and chromium is less than 0.4 Wt%, the hardness of the sintered cemented carbide particles becomes insufficient. Abrasion resistance decreases, and if the content of one or more of the carbides and chromium is greater than 5.0 Wt%, the hardness of the sintered cemented carbide particles increases and the wear resistance is improved. However, the toughness of the material decreases, and the sintered cemented carbide particles tend to break. In order to obtain suitable toughness while maintaining wear resistance in this way, the content of one or more of the carbides and chromium should be 0.4 to 1.0 Wt%. preferable.

  Further, by making the sintered cemented carbide particles have a particle size in the range of 7 mesh to 80 mesh, coarse particles and fine particles can coexist, and further, the filling rate is increased and sintered. Since cemented carbide particles can be filled inside the steel pipe, the sintered cemented carbide particles can be evenly dispersed in the bonded metal (hardened cladding layer) in which the steel pipe has melted during welding. It becomes.

  In particular, by making sintered cemented carbide particles having a particle size in the range of 63 mesh to 80 mesh 80 wt% or more by weight ratio with respect to the entire sintered cemented carbide particles, firing in the hardfacing layer is performed. It becomes possible to further uniformly disperse the cemented carbide particles.

  Furthermore, the sintered cemented carbide particles contain one or two of ferromanganese and ferrosilicon in a weight ratio of 0.5 to 5.0 Wt% with respect to the weight of the welding material for build-up, and are generated during welding. It is possible to reduce the amount of activated oxygen remaining without being combined in the hardfacing layer by combining and removing the activated oxygen. As a result, the welding strength between the sintered cemented carbide particles and the bonding metal can be made high and stable, and the sintered cemented carbide particles fall off from the hardfacing layer when an impact is applied. Can be prevented. In addition, the said effect can be more reliably provided by making the weight ratio with respect to the weight of the welding material for 1 or 2 types of build-up of ferromanganese and ferrosilicon into 0.5 to 2.5 Wt%. It is possible.

  Moreover, by setting the weight ratio of the binder phase of sintered cemented carbide particles to 2.0 to 20.0 Wt%, the hardness can be set to 86 to 95 with HRA, and the wear resistance can be maintained. It is possible to impart toughness. When the weight ratio of the binder phase of sintered cemented carbide particles is less than 2.0 Wt%, the wear resistance is improved, but sufficient toughness to withstand impacts cannot be obtained, and conversely, When the weight ratio of the binder phase of the cemented carbide particles is greater than 20.0 Wt%, the wear resistance is lowered.

  Furthermore, the sodium silicate filled with the sintered cemented carbide particles inside the steel pipe is 0.5 to 3.0 Wt% in weight ratio with respect to the weight of the welding material for build-up, and at the time of welding, together with the steel pipe The sodium silicate is melted, whereby the sintered cemented carbide particles are appropriately adhered to each other, and the sintered cemented carbide particles can be prevented from flowing down from the inside of the steel pipe with heating. Further, since this sodium silicate is welded so as to cover the surface when the hardfacing layer is formed, it is possible to prevent the hardened layer from being oxidized after curing. Therefore, it is possible to form a stable hardfacing layer.

  According to the excavation tool of the present invention, by being hardened with a hardfacing layer to which the above-described effect is imparted, it is possible to obtain an excavation tool having excellent wear resistance, and it is possible to excavate a work piece suitably. It becomes possible to make a simple excavating tool.

  Further, according to the wear preventing plate of the present invention, excavation having excellent wear resistance is achieved by fixing the wear preventing plate formed with the hardfacing layer to which the above-described effects are provided to the outer surface of the excavating tool. It can be a tool, and an excavation tool capable of suitably excavating a workpiece can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. The present embodiment relates to a welding material for overlaying to harden an excavation tool by performing overlay welding on an excavation tool for excavating rock or ground, for example, to form a hardened overlaying layer. It is.

As shown in FIGS. 1 to 2, the welding material 1 for build-up according to the present embodiment is formed in a cylindrical rod shape, is formed by granulation with a steel pipe 2 made of a soft iron-based metal, and is formed inside the steel pipe 2. It is composed of filled sintered cemented carbide particles 3. Further, in the steel pipe 2 of the welding material 1 for build-up according to the present embodiment, the sintered cemented carbide particles 3 and sodium silicate (Na ₂ O · nSiO ₂ · xH ₂ O) are added to the welding material 1 for building-up. It is filled so that it may become in the range of 0.5-3.0Wt% by weight ratio with respect to the weight of. Furthermore, the steel pipe 2 is formed so that the weight ratio with respect to the weight of the welding material 1 for overlaying is in the range of 25 to 50 Wt%.

  The sintered cemented carbide particles 3 are formed by dispersing WC (tungsten carbide) in a bonded phase of Co (cobalt) or Co and Ni (nickel). The sintered cemented carbide particles 3 have an HRA (Rockwell hardness) of 86 to 95, and the weight ratio of the binder phase to the total weight of the sintered cemented carbide particles 3 is 2. The range is 0 to 20.0 Wt%. Further, at this time, in this bonded phase, one or two of TiC (titanium carbide), TaC (tantalum carbide), NbC (niobium carbide), VC (vanadium carbide), and Cr (chromium) together with WC. The seeds or more are contained so as to be in the range of 0.4 to 5.0 Wt% with respect to the weight of the sintered cemented carbide particles 3. Further, the sintered cemented carbide particles 3 include one or two of FeMn (ferromanganese) and FeSi (ferrosilicon) in a weight ratio of 0.5 to 5.0 Wt with respect to the weight of the welding material 1 for build-up. It is contained so that it may become the range of%. In the present invention, when two or more of TiC, TaC, NbC, VC and Cr are contained in the binder phase, the combined weight ratio of the two or more is the sintered cemented carbide. It is set to 0.4 to 5.0 Wt% with respect to the weight of the particles. Similarly, when both FeMn and FeSi are contained, the combined weight ratio of FeMn and FeSi is set to 0.5 to 5.0 Wt% with respect to the weight of the welding material 1 for build-up.

  Further, the inside of the steel pipe 2 is filled with the sintered cemented carbide particles 3 as described above so as to be within a range of 45 to 70 Wt% with respect to the weight of the welding material 1 for overlaying. The sintered cemented carbide particles 3 have a particle size in the range of 7 mesh to 80 mesh. Further, at this time, the sintered cemented carbide particles 3 are filled so that the ratio of those remaining in the range of 63 mesh to 80 mesh is 80 Wt% or more by weight with respect to the total sintered cemented carbide particles 3. Yes.

  For example, as shown in FIG. 3, the welding material 1 for overlaying constructed as described above is implanted on the tip side of the excavation tool 10 and sintered tungsten carbide. It is used to harden the tool body 10a by forming the hardened layer 12 on the outer surface 10b of the tool body 10a in the vicinity of the formed hard blade body 11. The hardened layer 12 is formed by dispersing the sintered cemented carbide particles 3 in the bonded metal 2a in which the steel pipe 2 has been melted by heating, and hardening it with cooling. Note that the welding material 1 for build-up according to the present embodiment is not limited to being used for directly welding the outer surface 10b of the tool body 10a to harden the excavation tool 10, but a plate for wear prevention described later. As described above, the steel plate may be subjected to build-up welding to form the hardened build-up layer 12, and the plate may be fixed and used to harden the excavation tool 10.

  Here, when the drilling tool is hardened using a conventional welding material for overlaying, the sintered cemented carbide particles provided with tungsten carbide have a very large hardness, but conversely, the toughness is high. Especially in drilling tools that perform drilling with impact force applied, the sintered cemented carbide particles in the hardfacing layer are destroyed prior to the impact and are lost in the hardfacing layer. As a result, there was a problem that the wear resistance of the drilling tool could not be satisfied. In addition, there is a problem that the welding strength between the bonding metal and the sintered cemented carbide particles becomes insufficient, and the sintered cemented carbide particles fall off from the hardfacing layer.

  On the other hand, when the welding material 1 for build-up of this embodiment is used, the sintered cemented carbide particles 3 filled in the steel pipe 2 are carbonized in the bonded phase of cobalt or cobalt and nickel. While tungsten is dispersedly arranged, one or more of titanium carbide, tantalum carbide, niobium carbide, vanadium carbide and chromium are 0.4 to 5.0 Wt based on the weight of the sintered cemented carbide particles 3. %, The toughness can be improved in a state where the hardness of the sintered cemented carbide particles 3 is kept high, and impact or the like is applied to the sintered cemented carbide particles 3 in the hardfacing layer 12. Even when a load is applied, the hardened layer 12 can be prevented from being broken without being broken by the improvement of toughness.

  Moreover, in this embodiment, the sintered cemented carbide particles 3 are provided with a particle size in the range of 7 mesh to 80 mesh, and the coarse and fine particles are preferably coexisted so that the steel pipe 2 In addition, the sintered cemented carbide particles 3 can be filled at a high filling rate, and at the time of welding, the sintered cemented carbide particles 3 are evenly distributed in the bonded metal 2a (in the hardfacing layer 12) in which the steel pipe 2 is melted. Can be dispersed.

  At this time, the ratio of the sintered cemented carbide particles 3 having a particle diameter in the range of 63 mesh to 80 mesh is 80 Wt% or more in terms of the weight ratio with respect to the weight of all the sintered cemented carbide particles 3, thereby hardening It is possible to make the dispersion state of the sintered cemented carbide particles 3 in the built-up layer 12 more uniform.

  Furthermore, 1 type or 2 types of ferromanganese and ferrosilicon are contained in the sintered cemented carbide particles 3 in a ratio of 0.5 to 5.0 Wt% by weight with respect to the weight of the welding material 1 for build-up. Thus, activated oxygen generated during welding is removed from the hardfacing layer 12 while being combined, and the amount of activated oxygen remaining in the hardfacing layer 12 without being combined is kept small. It is possible. For this reason, the welding strength between the sintered cemented carbide particles 3 and the bonding metal 2a of the hardfacing layer 12 formed of the welding material 1 for building-up can be increased, and an impact is applied to the sintered super-hard alloy layer 3a. It is possible to prevent the hard alloy particles 3 from falling off the hardfacing layer 12.

  Moreover, by setting the weight ratio of the binder phase of the sintered cemented carbide particles 3 to 2.0 to 20.0 Wt%, the hardness of the sintered cemented carbide particles 3 can be set to 86 to 95 by HRA. Sufficient wear resistance and toughness can be obtained.

  Furthermore, the inside of the steel pipe 2 is filled with sodium silicate together with the sintered cemented carbide particles 3, and this sodium silicate is 0.5 to 3.0 Wt% by weight with respect to the weight of the welding material 1 for overlaying. Therefore, at the time of welding, the sodium silicate is melted together with the steel pipe 2, and thereby, an effect of appropriately adhering the sintered cemented carbide particles 3 to each other can be obtained. The welding operation can be performed without the particles 3 flowing down from the inside of the steel pipe 2. Further, since this sodium silicate is welded so as to cover the surface of the hardfacing layer 12, it is possible to impart an effect of preventing oxidation of the hardfacing layer 12. It is possible to improve the stability of the layer 12.

  Therefore, according to the welding material 1 for build-up, the hard build-up layer 12 that is hard and has excellent toughness that does not cause the sintered cemented carbide particles 3 to fall off can be formed. The excavation tool 10 formed with the built-up layer 12 and hardened can be surely used as the excavation tool 10 having excellent wear resistance.

  In addition, the welding material for overlaying of this invention is not limited to said one Embodiment, It can change suitably in the range which does not deviate from the meaning. For example, in this embodiment, the welding material 1 for build-up is composed of a steel pipe 2 and sintered cemented carbide particles 3 formed by granulation filled therein. The particles 3 may be formed as a rod-like sintered body or semi-sintered body that can be inserted into the steel pipe 2.

  Next, a first embodiment of an excavation tool according to the present invention will be described with reference to FIGS. 4 (a) to 4 (c). The excavation tool of the present embodiment is a shield cutter that is detachably attached to the distal end surface of a rotating disk disposed at the distal end of an excavation machine such as a shield machine and is used for excavation of the ground. Here, Fig.4 (a) has shown the front view of the shield cutter of this embodiment, FIG.4 (b) has shown the top view, FIG.4 (c) has shown the left view. .

  As shown in FIGS. 4A to 4C, the shield cutter 20 includes a hard blade 21 made of cemented carbide and a shank portion (tool body) 22 that holds the hard blade 21. Has been. The shank portion 22 is a block-shaped steel material having a substantially rectangular shape when viewed from the upper surface 22a side. Further, the upper surface 22a of the shank portion 22 is formed so as to be inclined toward the lower surface 22b as it goes from the front end 20a to the rear end 20b in the longitudinal direction, and the front end surface 22c is closer to the rear end 20b as it goes from the upper surface 22a to the lower surface 22b. It is formed to recede. Further, the shank 22 has a hard blade that is cut out on the top surface 22a side on the tip 20a side so as to open to the tip 20a side, the top surface 22a side, and both side surfaces 22d side, and extends along the tip surface 22c. A body mounting seat 23 is formed.

  The shank portion 22 is formed with a hardfacing layer 12 that is welded by using the above-described welding material 1 for building-up on the portion of the upper surface 22a and both side surfaces 22d that are located in the vicinity of the hard blade mounting seat 23. ing. Here, the hardfacing layer 12 formed on each of the both side surfaces 22d is formed in a band shape so as to surround the hard blade mounting seat 23 from the tip 20a side to the upper surface 22a, and extends in the width direction of the shank portion 22. It is formed so as to be continuous with the hardfacing layer 12 on the upper surface 22 a side formed in a strip shape so as to be parallel to the hard blade mounting seat 23. Further, the hardfacing layer 12 welded using the above-described welding material 1 for overlaying is also formed on the distal end surface 22c. The cured built-up layer 12 on the front end surface 22c is formed so that three cured built-up layers 12 formed in an X shape are connected by connecting the ends of the adjacent cured built-up layers 12 together.

  On the other hand, the hard blade 21 is formed in a substantially plate shape, and is brazed to the hard blade mounting seat 23 so as to be integrated with the shank portion 22. In addition, the hard blade 21 is attached to the hard blade mounting seat 23 so that the upper surface 21 a forms the same plane as the inclined upper surface 22 a of the shank portion 22, and the front end surface of the hard blade 21. 21 b is formed so as to be flush with the tip surface 22 c of the shank portion 22, and a portion where the upper surface 21 a and the tip surface 21 b of the hard blade 21 intersect at an acute angle protrudes toward the tip 20 a side of the shield cutter 20. Is formed.

  The shield cutter 20 having the above-described configuration has a shank portion 22 fastened to, for example, a bolt on the tip surface of a rotating disk disposed at the tip of the excavating machine, and the tip portion of the hard blade 21 protrudes outward of the excavating machine. Can be attached. And this shield cutter 20 is cut into the ground while rotating together with the rotating disk, and is used for excavation of the ground. At this time, the excavated scraps are violently brought into contact with the shank portion 22, particularly the vicinity of the hard blade mounting seat 23. On the other hand, in the present embodiment, the hardfacing layer 12 is formed on the upper surface 22a, the side surface 22d, and the front end surface 22c of the shank portion 22 in the vicinity of the hard blade attachment seat 23 where the excavated scraps come into intense contact, and Since the hardfacing layer 12 is formed of the above-described welding material 1 for surfacing, the hardened layer 12 has excellent wear resistance, and the hardened portion is less likely to be worn during excavation. Is done.

  Therefore, according to the shield cutter 20 described above, the hardened layer 12 is formed using the above-described welding material 1 for buildup, and thus a shield that is hardened by forming a conventional hardened layer. Compared with the cutter, it is considered to be excellent in wear resistance against excavated scraps that come in contact with excavation, and excavation can be suitably performed while improving the durability of the shield cutter 20.

  In addition, the excavation tool of this invention is not limited to 1st Embodiment of said excavation tool, In the range which does not deviate from the meaning, it can change suitably.

  Next, a second embodiment of the excavation tool according to the present invention will be described with reference to FIGS. 5 (a) to 5 (b). The excavation tool of the present embodiment is a roller cutter that is rotatably mounted on the tip surface of a rotating disk disposed at the tip of an excavation machine such as a shield machine and is used for excavation of the ground. Here, Fig.5 (a) has shown sectional drawing of the roller cutter of this embodiment, FIG.5 (b) is the side view which showed the cutting blade part 32 mentioned later.

  As shown in FIGS. 5 (a) to 5 (b), the roller cutter 30 includes a substantially cylindrical cutter body (tool body) 31 and a cemented carbide alloy implanted on the outer peripheral surface 31 a of the cutter body 31. The cutter body 31 is interposed between the cutter body 31 and the shaft member 33. The cutter body 31 is interposed between the cutter body 31 and the shaft member 33. The main component is a bearing 34 that is supported by the bearing.

  The cutter body 31 is provided with a plurality of cutting edge portions 32 projecting radially outward from the outer peripheral surface 31a and extending endlessly in the circumferential direction. This cutting edge portion 32 is shown in FIG. In the cross-sectional view in the direction perpendicular to the axis shown in Fig. 2, the top portion 32a has a chevron shape that faces radially outward. The cutting blade portion 32 is formed with a plurality of hard blade body mounting holes 32b that are recessed radially inward from the top portion 32a, and these hard blade body mounting holes 32b have a predetermined interval in the circumferential direction. Are arranged side by side. The hard blade body mounting hole 32b formed in this way is mounted using a means such as shrink fitting or press fitting so that the hard blade body 35 formed of, for example, cemented carbide is integrated with the cutter body 31. The portion that protrudes radially outward from the hard blade attachment hole 32b of the hard blade 35 is formed so as to form a surface that is continuous with the outer surface of the cutting blade 32, and the hard blade attachment hole 32b is formed. The cross-sectional chevron shape of the non-cutting portion 32 and the cross-sectional shape of the portion where the hard blade mounting hole 32b is provided and the hard blade body 35 is mounted have the same shape.

  Furthermore, in this embodiment, the outer surface 31a facing the radial outer side of the cutter body 31 in the vicinity of the cutting blade portion 32 and the outer surface 31a in the vicinity of the cutting blade portion 32 is formed using the welding material 1 for overlaying. A hard welded layer 12 that is welded and welded is formed.

  The roller cutter 30 configured as described above is fixed to the front end surface of a rotating disk disposed at the front end of the excavating machine with, for example, a bolt, and the top 32a side on which the hard blade body 35 of the cutting blade portion 32 is disposed. It is attached by protruding outward from the excavating machine. Then, as the rotating disk rotates, the cutter body 31 is rotated so that the plurality of hard blades 35 arranged in parallel in the circumferential direction are sequentially arranged outside the excavating machine, and this is cut into the ground. The ground is excavated. At this time, the digging waste comes into contact with the cutter body 31 violently. In contrast, in this embodiment, the hardened meat is applied to the outer surface of the cutting edge portion 32 and the outer surface 31a of the cutter body 31 with which this digging waste comes into contact. Since the build-up layer 12 is formed and the hard build-up layer 12 is formed by using the above-described welding material 1 for build-up, the wear-resistant portion is excellent for excavation. It is assumed that it is not worn with it.

  Therefore, according to said roller cutter 30, compared with the roller cutter which gave and hardened the conventional hardfacing layer by forming the hardfacing layer 12 using the above-mentioned welding material 1 for surfacing. And since it can be made excellent in the abrasion resistance with respect to the digging waste which contacts violently with excavation, durability of the cutter main body 31 can be improved and excavation can be performed suitably.

  In addition, the excavation tool of this invention is not limited to 2nd Embodiment of said excavation tool, In the range which does not deviate from the meaning, it can change suitably.

  Next, a third embodiment of the excavation tool according to the present invention will be described with reference to FIGS. 6 (a) to 6 (c). The excavation tool of this embodiment is an earth auger cutter that is attached to a cutter holder provided at a screw end of an earth auger and is used for excavation of the ground. 6A is a top view of the earth auger cutter of the present embodiment, FIG. 6B is a side view, and FIG. 6C is a bottom view. Yes.

  As shown in FIGS. 6 (a) to 6 (c), the earth auger cutter 40 includes a hard hard blade body 41 such as cemented carbide and a shank portion (tool body) for holding the hard blade body 41. 42. The shank portion 42 is a block-shaped steel material having a substantially rectangular bar shape. Further, the upper surface 42b and the lower surface 42c on the front end 42a side of the shank portion 42 are located at the center axis O1 side extending in the longitudinal direction and positioned approximately at the center in the height direction from the rear end 42d side in the longitudinal direction toward the front end 42a. It is formed to be inclined. Furthermore, a hard blade attachment seat 43 is formed on the shank portion 42 so that the upper surface 42b on the tip 42a side is notched so as to be recessed toward the lower surface 42c.

  Further, the shank portion 42 is hardened by welding to the upper surface 42b, the lower surface 42c and both side surfaces 42e on the tip 42a side located in the vicinity of the hard blade mounting seat 43 using the above-described welding material 1 for overlaying. The raised layer 12 is formed so as to be integrally connected.

  On the other hand, the hard blade body 41 is formed in a substantially plate shape, and is brazed to the above-mentioned hard blade body mounting seat 43 so as to be integrated with the shank portion 42. In addition, the hard blade 41 is attached to the hard blade mounting seat 43, and the tip 41a portion arranged on the outer side in the central axis O1 direction has a mountain shape in plan view from the upper surface 41a side of the hard blade 41. The tip 41a is positioned on the central axis O1 and protrudes outward from the tip 42a of the shank portion 42 in the central axis O1 direction.

  In the earth auger cutter 40 having the above-described configuration, a cutter holder having, for example, a substantially U-shaped block shape is welded to a mounting groove provided at a screw end of an earth auger (not shown), and the opening is grounded. The shank portion 42 of the auger cutter 40 is inserted and held by the earth auger. At this time, for example, the shank portion 42 is fastened to the cutter holder with bolts and integrated with the earth auger cutter 40. In this state, the tip 41a portion of the hard blade 41 of the earth auger cutter 40 is outside the excavating machine. It protrudes in the direction and is united. And the hard blade 41 is cut into the ground by rotating the earth auger around its axis and moving forward in the axial direction, and is used for excavation of the ground. By excavating the ground, the excavated scraps are vigorously brought into contact with the shank portion 42, particularly the portion near the hard blade attachment seat 43. On the other hand, in the present embodiment, the hardfacing layer 12 is formed on the upper surface 42b, the lower surface 42c, and the side surface 42e of the shank portion 42 in the vicinity of the hard blade attachment seat 43 where the excavated scraps are in violent contact, and this Since the hardfacing layer 12 is formed of the above-described welding material 1 for surfacing, it is assumed that the hardened layer 12 is excellent in wear resistance, and the shank portion 42 subjected to this hard wearing is worn with excavation. Not supposed to be.

  Therefore, according to the above-mentioned earth auger cutter 40, since the hardfacing layer 12 is formed by using the above-described welding material 1 for overlaying, the cutter for earth auger that has been subjected to conventional overlaying and hardened. Compared to the above, it is excellent in wear resistance against excavation scraps that come in contact with excavation, improve the durability of the earth auger cutter 40, and perform excavation appropriately.

  In addition, the excavation tool of this invention is not limited to 3rd Embodiment of said excavation tool, In the range which does not deviate from the meaning, it can change suitably.

  Next, a fourth embodiment of the excavation tool according to the present invention will be described with reference to FIGS. 7 (a) to 7 (b). The excavation tool of this embodiment is an inner ring provided with a hard blade on the inner peripheral side of a tool body formed in a ring shape. Here, Fig.7 (a) has shown the front view of the inner ring of this embodiment, FIG.7 (b) is the figure which expanded the inner peripheral side of the cutting blade part vicinity of Fig.7 (a). is there.

  As shown in FIGS. 7A to 7B, the inner ring 50 includes a plurality of hard blades 52 at a constant interval in the circumferential direction on the inner peripheral side of the tool body 51 formed in a ring shape. These hard blades 52 are made of cemented carbide or the like, and are arranged so that the tip 52a side slightly protrudes radially inward. In addition, the tool body 51 is formed such that an inner peripheral edge 51a at a substantially center in the circumferential direction between adjacent hard blades 52 has a circular arc shape in section from the inner peripheral edge 51a toward the outer peripheral edge 51b. .

  On the other hand, a hardened layer 12 welded by using the above-described welding material 1 for building-up is formed on the inner peripheral edge 51 a located between the adjacent hard blades 52 of the tool body 51.

  The inner ring 50 thus formed is fed around the ground while maintaining the direction of the axis O2 while rotating around the axis O2, and the ground is excavated by the hard blade body 52 facing radially inward. When this ground is excavated, the excavated waste comes into violent contact with the tool body 51, particularly the inner peripheral edge 51a located between the adjacent hard blades 52. On the other hand, in the present embodiment, the hardfacing layer 12 is formed on the inner peripheral edge 51a of the tool body 51 with which the excavated scraps are in violent contact, and the hardfacing layer 12 is formed by the aforementioned welding for overlaying. Since it is formed of the material 1, the wear resistance is excellent, and the tool body 51 to which this hard wearing is applied is not worn with excavation.

  Therefore, according to the inner ring 50 described above, since the hardfacing layer 12 is formed using the above-described welding material 1 for overlaying, compared to the inner ring that has been subjected to conventional overlaying and hardened, It is excellent in wear resistance against excavated waste that comes in contact with excavation, and the durability of the inner ring 50 can be improved.

  In addition, the excavation tool of this invention is not limited to 4th Embodiment of said excavation tool, In the range which does not deviate from the meaning, it can change suitably.

  Next, a fifth embodiment of the excavation tool according to the present invention will be described with reference to FIGS. 8 (a) to 8 (b). The excavation tool of this embodiment is an outer ring provided with a hard blade on the outer peripheral side of a tool body formed in a ring shape. Here, Fig.8 (a) has shown the front view of the outer ring of this embodiment, and FIG.8 (b) is the figure which expanded the outer peripheral side of the hard blade body vicinity of Fig.8 (a). .

  As shown in FIG. 8A to FIG. 8B, the outer ring 60 has a plurality of hard blades 62 at regular intervals in the circumferential direction on the outer peripheral side of the tool body 61 formed in a ring shape. These hard blades 62 are formed of cemented carbide or the like, and are arranged so that the tip 62a side slightly protrudes radially outward. Moreover, the tool main body 61 is formed so that the outer peripheral edge 61a in the center in the circumferential direction between the adjacent hard blades 62 has a circular arc shape in cross section from the outer peripheral edge 61a toward the inner peripheral edge 61b. .

  On the other hand, on the outer peripheral edge 61a located between the adjacent hard blades 62 of the tool body 61 and the outer peripheral edge 61a side of the side surface 61c of the tool body 61 orthogonal to the axis O3, the above-described welding material 1 for overlaying is provided. A hardfacing layer 12 that is welded using is formed.

  The outer ring 60 formed in this manner is fed around the ground while maintaining the direction of the axis O3 while rotating around the axis O3, and excavates the ground with the hard blade body 62 facing radially outward. When this ground is excavated, the excavation debris violently contacts the tool body 61, particularly the outer peripheral edge 61a located between the adjacent hard blades 62 and the side face 61c on the outer peripheral edge 61a side. Become. On the other hand, in the present embodiment, the hardfacing layer 12 is formed on the inner peripheral edge 61a side of the tool main body 61 with which the excavated scraps are in violent contact, and the hardfacing layer 12 is used for the above-mentioned surfacing. Since it is formed of the welding material 1, it is excellent in wear resistance, and the tool body 61 to which this hard wearing is applied is not worn with excavation.

  Therefore, according to said outer ring 60, since the hardfacing layer 12 is formed using the above-mentioned welding material 1 for overlaying, compared with the outer ring which gave the conventional overlaying and was hardened, It is excellent in abrasion resistance against excavation waste that comes in contact with excavation, and the durability of the outer ring 60 can be improved.

  In addition, the excavation tool of this invention is not limited to 5th Embodiment of said excavation tool, In the range which does not deviate from the meaning, it can change suitably.

  Next, an embodiment of the wear preventing plate according to the present invention will be described with reference to FIGS. The wear-preventing plate of the present embodiment is for fixing the excavation tool by adhering to at least a part of the outer surface of the tool main body of the excavation tool except for the hard blade. A cured build-up layer is formed using Here, FIG. 9A shows a front view of the wear preventing plate, and FIG. 9B shows a top view.

  As shown in FIGS. 9A to 9B, the wear preventing plate 70 of the present embodiment includes a steel plate body 71 formed in a rectangular rectangular plate shape, and an upper surface of the plate body 71. It is comprised from the hardfacing layer 12 formed in this. The cured build-up layer 12 is formed using the above-described weld material 1 for build-up, and is provided on the entire upper surface of the plate body 71.

  Thus, by forming the hardfacing layer 12 using the above-described welding material 1 for building-up, the wear-preventing plate 70 is hardened in a state excellent in wear resistance. Then, the wear preventing plate 70 configured in this way is replaced with, for example, the hardfacing layer 12 formed on the tool body of the excavating tool of the first to fifth embodiments described above, on the outer surface of the tool body. The lower surface of the plate body 71 is fixedly provided by brazing, for example.

  When the excavation tool with the wear prevention plate 70 fixed is used for excavation of the ground, the wear prevention plate 70 with the hardfacing layer 12 formed thereon is fixed to the tool main body where the excavation waste comes into contact violently. In addition, since the hardfacing layer 12 is formed of the above-described welding material 1 for building-up, wear resistance is surely given, and the tool body is not worn with excavation. It is said.

  Therefore, the wear-preventing plate 70 including the hardfacing layer 12 formed of the above-described welding material 1 for building-up is fixed to the excavating tool, so that the wear-resistant against excavating debris that comes in violent contact with excavation. The excavation tool can be made excellent in durability.

  In this embodiment, the wear prevention plate 70 is formed to have a rectangular shape. However, the shape of the wear prevention plate 70 is not particularly limited. This should just be formed according to the shape of the tool main body in which this is installed.

  Example 1 of the present invention will be specifically described below. However, the present invention is not limited to this example.

  In the present embodiment, the excavation tool 40 shown in FIG. 6 which is hardened with the above-described welding material 1 for overlaying is used to stir the abrasive material imagining the ground excavation debris for a certain period of time. The wear state of the buildup layer 12 is confirmed, and the superiority of the welding material 1 for buildup of the present invention and the excavation tool 40 in which the hardened buildup layer 12 is formed using the welding material 1 is clarified. Specifically, the abrasive material is stirred using the welding material 1 for build-up, in which the weight ratio of the sintered cemented carbide particles 3 to the weight of the welding material 1 for build-up is changed to 35 to 75 Wt%, and the wear By confirming the state, the advantage by setting the weight ratio of the sintered cemented carbide particles 3 to 45 to 70 Wt% is clarified.

First, the welding material 1 for build-up used will be described.
In the welding material 1 for build-up of the present embodiment, the sintered cemented carbide particles 3 are formed by dispersing tungsten carbide in a cobalt binder phase. Moreover, the sintered cemented carbide particles 3 filled in the steel pipe 2 have a weight ratio of 20 Wt% and a particle diameter in the range of 63 mesh to 80 mesh with a particle diameter in the range of 7 mesh to 63 mesh. The ratio of those having a weight ratio of 80 Wt%. Further, the binder phase has a weight ratio of 5 Wt% with respect to the weight of the sintered cemented carbide particles 3.

  In this example, the test was performed using the excavation tool 40 in which the hardfacing layer 12 was formed with each of the nine kinds of welding materials 1 for Case 1 to Case 9, respectively. The weight ratio of sintered cemented carbide particles 3 to weight is 35 Wt% for Case 1, 40 Wt% for Case 2, 45 Wt% for Case 3, 50 Wt% for Case 5, 55 Wt% for Case 5, 60 Wt% for Case 6, 65 Wt% for Case 7, and Case 8 The hardfacing layer 12 is formed using the welding material 1 for surfacing that is 70 Wt% and Case 9 is 75 Wt%.

  Here, Case 1 using the welding material 1 for build-up in which the weight ratio of the sintered cemented carbide particles 3 is 35 Wt% is assumed to be that of the weight ratio of the sintered cemented carbide particles 3 that are generally used. In the example, this Case 1 is used as a reference for comparing with other cases.

Next, the used abrasive will be described.
The abrasive used in this example is a mix of 10 kg of No. 7 silica sand, 10 kg of barrel stone and 5 liters of water. No. 7 silica sand has a particle size of 0.2 mm or less, and its composition is 94% or more of SiO ₂ , 2.5% or less of Al ₂ O ₃ , 1.0% or less of Fe ₂ O ₃ , and MgO It is 0.2% or less and CaO is 0.2% or less. Moreover, the barrel stone uses Tosarit CAB for light grinding manufactured by Uji Electric Chemical Co., Ltd.

Next, test conditions for stirring the abrasive with the excavation tool 40 will be described.
Excavation tools 40 each having a hardened layer 12 formed using the welding materials 1 for overlaying Case 1 to Case 9 are embedded in the above-mentioned abrasive, and stirred for 120 hours at a drilling speed of 83 rpm. ing. At this time, the peripheral speed of the hard blade 41 of the excavating tool 40 is 53 m / min, and the sliding distance between the hardfacing layer 12 and the abrasive is about 381.6 km by stirring for 120 hours.

Next, the evaluation method will be described.
First, the weight of the drilling tool 40 before the test of Case 1 and the weight of the drilling tool 40 after the test are measured, and the wear amount of Case 1 is confirmed. Then, the ratio of the wear amount of Case 9 from the other Case 2 to the wear amount of Case 1 is obtained, and the evaluation is performed by comparing the amount of wear of Case 1 and the wear amount of Case 2 to Case 9 as a reference. . That is, when the ratio of the amount of wear of Case 1 is 1, and the ratio of the amount of wear of Case 2 to Case 9 to Case 1 is smaller than 1, it is determined that the wear resistance is superior to Case 1 and the wear resistance is evaluated. .

  Next, Table 1 shows the results of testing under the above test conditions and the like.

  Table 1 shows the case 1 after the completion of stirring from Case 2 to Case 9 in which the hardfacing layer 12 was formed by using the welding material 1 for build-up in which the weight ratio of the sintered cemented carbide particles 3 to the Case 1 sequentially increased. The amount of wear is shown relative to the amount of wear of Case 1 as a reference.

  As a result, as shown in Table 1, when the hardfacing layer 12 is formed by using the welding material 1 for overlaying Case 2 to Case 8, the relative ratio of the wear amount of Case 1 to 0.92 is 0.95, Case 3 is 0.83, Case 4 is 0.78, Case 5 is 0.74, Case 6 is 0.67, Case 7 is 0.75, Case 8 is 0.89. In particular, the weight ratio of the sintered cemented carbide particles 3 is In Case 3 to Case 8 with 45 to 70 Wt%, the cured build-up layer 12 having better wear resistance than Case 1 was formed. On the other hand, in Case 9 in which the weight ratio of the sintered cemented carbide particles 3 was 75 Wt%, the relative ratio of the wear amount was 1.12, resulting in inferior wear resistance compared to Case 1.

  From the above results, the weight ratio of the sintered cemented carbide particles 3 with respect to the weight of the welding material 1 for overlaying is set to 45 to 70 Wt%, and the cured overlaying layer 12 of the excavation tool 40 using this welding material 1 for building up. It has been demonstrated that excellent wear resistance can be obtained by forming the above.

  Next, Example 2 of the present invention will be specifically described below. However, the present invention is not limited to this example.

  This example shows the superiority or inferiority of the wear resistance when the particle size distribution of the sintered cemented carbide particles 3 is changed with respect to the welding material 1 for overlaying Case 1 to Case 9 shown in Example 1. It has been confirmed. Here, the particle size of the sintered cemented carbide particles 3 is 40 Wt% by weight in the range of 7 mesh to 63 mesh (ratio in the range of 63 to 80 mesh is 60 Wt% by weight), 30 Wt%. (70 Wt%), 25 Wt% (75 Wt%), 20 Wt% (80 Wt%), 10 Wt% (90 Wt%), and 0 Wt% (100 Wt%).

  On the other hand, in this embodiment, the binder phase of the sintered cemented carbide particles 3 is set to 5 Wt% with respect to the weight of the sintered cemented carbide particles 3 as in the first embodiment. Here, the same abrasive as in Example 1 was used, and the test conditions and the evaluation method were the same as in Example 1.

  Table 2 shows the results in the case where the hardfacing layer 12 was formed with each of the welding materials 1 for building-up.

  Table 2 shows the result of a relative comparison between the wear amount of Case 1 to Case 9 when the particle size distribution of the sintered cemented carbide particles 3 is changed, with the wear amount of Case 1 as a reference.

As a result, as shown in Table 2, the weight ratio of the sintered cemented carbide particles 3 having a particle size in the range of 7 mesh to 63 mesh is 0 to 20 wt% (having a particle size in the range of 63 mesh to 80 mesh). When the weight ratio of the sintered cemented carbide particles 3 is 80 to 100 Wt%), in the case 3 to the case 8 where the weight ratio of the sintered cemented carbide particles 3 is 45 to 70 Wt%, as in Example 1. It was confirmed that the wear resistance was remarkably improved.
On the other hand, the weight ratio of sintered cemented carbide particles 3 having a particle size in the range of 7 mesh to 63 mesh is 25 to 40 wt% (sintered cemented carbide particles having a particle size in the range of 63 mesh to 80 mesh). When the weight ratio of 3 was 60 to 75 Wt%), the wear resistance of Case 3 and Case 8 was reduced.

  From the above results, it is possible to improve the wear resistance by setting the particle size of the sintered cemented carbide particles 3 in the range of 7 mesh to 80 mesh, and in particular, 63 mesh to 80 mesh. It was proved that this effect is remarkably recognized when the weight ratio of the sintered cemented carbide particles 3 having a particle size in the range of 80 Wt% or more is achieved.

  Next, Example 3 of the present invention will be specifically described below. However, the present invention is not limited to this example.

  In the present example, the welding material 1 for build-up of Case 1 to Case 9 shown in Example 1 is made of FeMn and FeSi contained in the sintered cemented carbide particles 3 with respect to the weight of the welding material 1 for build-up. This confirms the superiority or inferiority of the wear resistance when the weight ratio is changed. Here, the weight ratio of FeMn and FeSi is changed in five stages of 0.5 Wt%, 1.0 Wt%, 2.5 Wt%, 5.0 Wt%, and 6.0 Wt%.

  On the other hand, in this example, the weight ratio of the binder phase of the sintered cemented carbide particles 3 is set to 5 Wt% as in the first example. Similarly to Example 1, the sintered cemented carbide particles 3 have a weight ratio of 20 Wt% in the range of 7 mesh to 63 mesh, and a ratio of 63 mesh to 80 mesh in the weight ratio of 80 Wt%. Has been. Here, the same abrasive as in Example 1 was used, and the test conditions and evaluation method were the same as in Example 1.

  Table 3 shows the results when the hardfacing layer 12 is formed with the above welding material 1 for overlaying.

  Table 3 shows the result of relatively comparing the wear amount of Case 1 to Case 9 when the weight ratio of FeMn and FeSi of the sintered cemented carbide particles 3 is changed, based on the wear weight of Case 1. .

  As a result, as shown in Table 3, when the weight ratio of FeMn and FeSi was 0.5 to 5.0 Wt%, the wear resistance was improved in Case 3 to Case 8. On the other hand, in the case where the weight ratio of FeMn and FeSi is 6.0 Wt%, a great advantage is recognized by adding FeMn and FeSi as compared with the results shown in Table 1 of Example 1 described above. It was confirmed that it was not possible.

  From the above results, it was demonstrated that the wear resistance can be improved by setting the weight ratio of FeMn and FeSi in the sintered cemented carbide particles to 0.5 to 5.0 Wt%. .

  Next, Example 4 of the present invention will be specifically described below. However, the present invention is not limited to this example.

  In this example, the welded material 1 for overlaying Case 1 to Case 9 shown in Example 1 is made to contain FeMn and FeSi in the sintered cemented carbide particles 3, respectively, and the weight of the welded material 1 for overlaying The weight ratio of FeMn and FeSi to 0.5 Wt%. Moreover, the superiority or inferiority of the wear resistance is confirmed when sodium silicate is filled into the steel pipe 2 together with the sintered cemented carbide particles 3 and the weight ratio is changed. Here, the weight ratio of sodium silicate is changed in five stages of 0.5 Wt%, 1.0 Wt%, 1.5 Wt%, 3.0 Wt%, and 4.0 Wt%.

  In this example, the binder phase of the sintered cemented carbide particles 3 is set to 5 Wt% with respect to the weight of the sintered cemented carbide particles 3 as in the first example. Further, as in Example 1, the sintered cemented carbide particles 3 have a particle diameter in the range of 7 mesh to 63 mesh, and a ratio of 20 Wt% by weight ratio and a particle diameter in the range of 63 mesh to 80 mesh. The ratio is 80 Wt% by weight. Here, the same abrasive as in Example 1 was used, and the test conditions and evaluation method were the same as in Example 1.

Table 4 shows the results when the hardfacing layer 12 was formed with the above welding material 1 for surfacing.

  Table 4 shows the wear amount of Case 1 to Case 9 when the weight ratio of sodium silicate is changed with the weight ratio of FeMn and FeSi of the sintered cemented carbide particles 3 being constant at 0.5 Wt%. The result of the relative comparison based on the quantity is shown.

  As a result, as shown in Table 4, by setting the weight ratio of sodium silicate to 0.5 to 3.0 Wt%, a stable hardfacing layer 12 is formed, and based on this, particularly in Case3 to Case8, It was confirmed that the wearability was further improved.

  From the above results, it was proved that the wear resistance can be further improved by setting the weight ratio of sodium silicate to 0.5 to 3.0 Wt%.

  Example 5 of the present invention will be specifically described below. However, the present invention is not limited to this example.

  In the present embodiment, overlay welding is performed on a steel plate (test plate) by gas welding using the above-described welding material 1 for build-up, and the presence or absence of generation of pores and weld metal on the outer surface of the hardfacing layer 12 By confirming such a situation, the superiority by adding TiC, NbC, and Cr is clarified.

Here, in this example, the weight ratio of the sintered cemented carbide particles 3 to the weight of the welding material 1 for overlaying is 60 Wt%, the weight ratio of the binder phase is 8.0 Wt%, and the weight ratio of FeMn is 2.0 Wt. %, And the weight ratio of sodium silicate is 2.0 Wt%. Further, the sintered cemented carbide particles 3 have a weight ratio of 12 Wt% with a particle size ranging from 7 mesh to 63 mesh, and a ratio with a particle size ranging from 63 mesh to 80 mesh is 88 Wt% by weight. It is said that.
Furthermore, in this example, 0.6 Wt% of TiC, NbC, and Cr are added to the sintered cemented carbide particles 3 by weight.

  Further, in this example, the cured build-up layer 12 formed on the test plate is observed visually and with a magnifying glass, and the outer surface pores and the presence or absence of weld metal are confirmed and evaluated. ing.

  As a result, when 0.6 wt% of TiC, NbC, and Cr are added to the sintered cemented carbide particles 3, the generation of pores is greatly improved as compared with the conventional sintered cemented carbide particles. It was confirmed that Also, in the microscopic examination, it was confirmed that the sintered cemented carbide particles 3 were distributed substantially uniformly, and the generation of pores was very small.

  From the above results, the weight ratio of the sintered cemented carbide particles 3 with respect to the weight of the welding material 1 for overlaying is set to 45 to 70 Wt%, and the welding tool 1 for overlaying is used to overlay the excavation tool. It has been demonstrated that it is possible to obtain excellent wear resistance.

  In addition, it was confirmed that the same result can be obtained even when 1.0 wt% of TiC, NbC, and Cr are added by weight ratio.

It is the figure shown as one Embodiment of the overlay welding material which concerns on this invention. It is an AA arrow line view of FIG. It is a figure which shows the hardening build-up layer formed using the build-up welding material of FIG. It is the figure shown as 1st Embodiment of the excavation tool which concerns on this invention. It is the figure shown as 2nd Embodiment of the excavation tool which concerns on this invention. It is the figure shown as 3rd Embodiment of the excavation tool which concerns on this invention. It is the figure shown as 4th Embodiment of the excavation tool which concerns on this invention. It is the figure shown as 5th Embodiment of the excavation tool which concerns on this invention. It is the figure shown as one Embodiment of the plate for abrasion prevention which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Welding material for overlay 2 Steel pipe 3 Sintered cemented carbide particle 10 Excavation tool 10a Tool body 10b Outer surface 11 Hard blade 12 Hardfacing layer 20 Shield cutter (excavation tool)
21 Hard blade 22 Shank (Tool body)
30 Roller cutter (excavation tool)
31 Cutter body (Tool body)
32 Cutting Edge 35 Hard Blade 40 Earth Auger Cutter (Drilling Tool)
41 Hard blade 42 Shank (Tool body)
50 Inner ring (excavation tool)
51 Tool Body 52 Hard Blade 60 Outer Ring (Excavation Tool)
61 Tool body 62 Hard blade 70 Abrasion prevention plate

Claims (7)

In the welding material for build-up consisting of steel pipe and sintered cemented carbide particles filled inside the steel pipe,
The sintered cemented carbide particles are obtained by dispersing tungsten carbide in a binder phase of cobalt or cobalt and nickel, and one kind of titanium carbide, tantalum carbide, niobium carbide, vanadium carbide and chromium, or Two or more kinds are included in an amount of 0.4 to 5.0 Wt% with respect to the weight of the sintered cemented carbide particles, and the particle size of the sintered cemented carbide particles is in the range of 7 mesh to 80 mesh. The weight ratio of the sintered cemented carbide particles to the weight of the welding material for overlaying is set to 45 to 70 Wt%, and the weight ratio of the steel pipe is set to the weight of the welding material for overlaying. On the other hand, the welding material for overlaying characterized by being made into 25 to 50 Wt%. In the welding material for overlaying according to claim 1,
The sintered cemented carbide particles include one or two of ferromanganese and ferrosilicon in a weight ratio of 0.5 to 5.0 Wt% with respect to the weight of the welding material for overlaying. Welding materials. In the welding material for build-up according to claim 1 or claim 2,
The sintered cemented carbide particles have a hardness of 86 to 95 by HRA, and the weight ratio of the binder phase is 2.0 to 20.0 Wt%. In the welding material for overlaying according to any one of claims 1 to 3,
The welded material for build-up, wherein the sintered cemented carbide particles have a particle size that remains in the range of 63 mesh to 80 mesh, and the weight ratio is at least 80 Wt%. In the welding material for overlaying according to any one of claims 1 to 4,
The steel pipe is filled with sodium silicate together with the sintered cemented carbide particles, and the weight ratio of the sodium silicate to the weight of the welding material for build-up is 0.5 to 3.0 Wt%. This is a welding material for overlaying. In an excavation tool in which a hard blade is implanted on the tip side of a steel tool body,
The welding material for build-up according to any one of claims 1 to 5 is welded and hardened on at least a part of an outer surface of the excavation tool excluding the hard blade body. Drilling tool. An anti-abrasion plate for adhering to the at least part of the outer surface of the excavation tool excluding the hard blade,
6. A plate for wear prevention, wherein the welding material for build-up according to claim 1 is build-up welded.

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