JP2012086225A - Method for internal chill cemented carbide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problem: manufacture of a composite liner of cemented carbide and high chromium cast iron is difficult and thus the composite liner does not prevail widely since a flux for forming a molecule diffusion layer at the joining surface of the high chromium cast iron and the cemented carbide by kirkendall effect to strongly join the cemented carbide and the high chromium cast iron is required and a coating such as a vacuum thin film must be removed to apply copper plating in casting a recovery cemented carbide tip to the high chromium cast iron.SOLUTION: The strong copper plating is applied to the cemented carbide regardless of the presence/absence of the vacuum thin film by plating in a copper fluoride bath. The liquid flux is coated on the copper plating. Alternately manganese plating, Kanigen plating, or both of the manganese plating and the Kanigen plating is applied on the copper plating. Subsequently the liquid flux is coated to be cast to the high chromium cast iron, so that manufacture of an abrasion resistant liner where the high chromium cast iron and the cemented carbide are completely joined with each other is attained.

Description

  The present invention relates to a method of casting a cemented carbide with a vacuum thin film, which is used as a cutting tool for machining, into high chromium cast iron for the purpose of improving the wear life of a wear resistant liner mainly composed of high chromium cast iron. Cemented carbide used as a cutting tool for machining is often discarded after use, and it has been desired to develop a method for reusing a cemented carbide containing a large amount of expensive W, Co, and Ni.

Conventionally, as a wear countermeasure for equipment requiring wear resistance, a cast wear-resistant liner, coating by hard welding or thermal spraying, or lining construction of a cemented carbide alloy or a ceramic plate has been adopted. Although the coating by hard welding or thermal spraying has high hardness and excellent wear resistance, there is a problem that the coating layer cannot be made thick due to defects of cracking and peeling. Cemented carbide has a problem of low toughness and easy breakage. Moreover, since it is constructed by brazing or bonding, there is a problem that it is easy to peel off. High-chromium liners, which are excellent as cast wear-resistant liners, can be manufactured relatively thickly, so they have a long life against wear and are resistant to impacts. However, high chrome liners have a shorter wear life than cemented carbides. In order to extend the wear life, it is necessary to increase the thickness to some extent, and the cost increases because a large amount of expensive material is used. In addition, the weight increased and much labor and time were required for the installation work on site.

In order to extend the life of high-chromium cast iron, the method of increasing the thickness is the mainstream, but the weight is increased and the cost of materials such as Cr is high, which is expensive. Therefore, a method has been proposed in which cemented carbide is cast together with high chromium cast iron to form a composite with cemented carbide. However, the cemented carbide is expensive and expensive, and when the joining with high chromium cast iron or the like is insufficient, the cemented carbide falls off and there is a problem that the lifetime of the cemented carbide cannot be enjoyed until the end. On the other hand, recovered cemented carbide tips that collect used chips for machining are inexpensive, but the surface of the collected cemented carbide chips is treated with various vacuum thin films such as TiALN, so it is difficult to join high chromium cast iron. It was rarely used as a casting material.

  In Patent Document 1, in a cast composite material in which a wear-resistant material is welded to a predetermined portion of the base material surface by casting, a granular material formed of the wear-resistant material is provided on the predetermined portion of the base material surface. A cast composite material, wherein the granular material layer is formed so as to be covered, and the columnar bodies formed of the wear-resistant material are embedded from the granular material layer into the base material at predetermined intervals. Has been proposed.

  In Patent Document 2, a brazing layer is formed on the surface of a cemented carbide chip or cermet chip in order to improve the bonding strength (interfacial bonding force) between the cemented carbide chip or cermet chip and high chromium cast iron. A method of employing electroless Ni—P plating as a material has been proposed.

  In Patent Document 3, in a wear-resistant sintered body obtained by integrally molding cemented carbide particles as a hard layer by casting by casting, the cemented carbide particles are formed into polygons, and concave portions are provided on the sides. A wear-resistant sintered body characterized by the following has been proposed.

2009-6347 Publicity "Casting Composite" 2001-96182 Public Relations "Casting the Brazing Method" H6-33182 Publicity "Abrasion Resistant Sintered Body and Manufacturing Method" Japanese Laid-Open Patent Publication No. 2009-090368 "Vaporization Flux for Gas Cutting" Japanese Laid-Open Patent Publication No. 2009-297782 “Liquid Flux and Manufacturing Equipment” JP 2010-100441 PR "Liquid Flux and Manufacturing Equipment" JP 2009-255105 PR "Vaporizer"

The problem in the method of Patent Document 1 is that the granular material is peeled off due to poor bonding properties with high chrome cast iron because it is cast into high chrome cast iron without surface treatment of the granular material formed of the wear-resistant material. is there.

The problem with the method of Patent Document 2 is that the electroless Ni—P plating (Kanizen plating) must be processed through a complicated process on the vacuum thin film on the surface before the recovered cemented carbide chip is applied. And that is expensive. In addition, a flux containing metallic boron has been proposed in order to improve the heat resistance of the flux, but the melting point of metallic boron is 2300 ° C, and high flux cast iron cast at 1400-1450 ° C fulfills a sufficient flux function. I could not. For this reason, an oxide is generated at the boundary between the cemented carbide and the high chromium cast iron, so that diffusion bonding cannot be performed.

The problem in the method of Patent Document 3 is that the cemented carbide particles have a polygonal shape, and there are methods of mechanically joining with the contraction force when the high-chromium cast iron cools by providing concave portions on the sides. High chrome cast iron is hardly joined, and as the surrounding high chrome cast iron wears, the hard particles cannot be held and the hard particles fall off.

As described above, when casting cemented carbide and high chrome cast iron, the surface of the cemented carbide is subjected to Kanigen plating to form an alloy layer on the cemented carbide / high chrome cast iron joint surface, or the cemented carbide is formed into an uneven shape. Therefore, a joining method is used in which the cemented carbide is held by a mechanical contraction force when the high chromium cast iron contracts. The most reliable joining method is to apply Kanigen plating to cemented carbide and form an alloy layer with high chromium cast iron. However, there is a problem with the flux that protects Kanigen plating, and perfect joining has not been achieved. That is, in order to firmly join the cemented carbide with the high chromium cast iron, a flux that forms a molecular diffusion layer on the joining surface of the high chromium cast iron and the cemented carbide by the Kirkendall effect is required. Further, when the recovered cemented carbide chip is cast into high chrome cast iron, there is a problem that the coating such as a vacuum thin film must be removed in order to apply the Kanigen plating to the recovered cemented carbide chip. The vacuum thin film requires mechanical blasting and chemical treatment, and requires a great deal of cost and labor. For this reason, there has been a demand for a highly reliable Kanigen plating method without removing the coating. The problem to be solved by the present invention is that, in the method of casting a cemented carbide to high chromium cast iron, without removing the vacuum thin film of the cemented carbide, by performing copper plating on the vacuum thin film and casting it. It is to embody a complete joined body with high chromium cast iron. If copper can be plated on the vacuum thin film of the recovered carbide tip, it is possible to directly cast the recovered carbide tip and high chromium cast iron without Kanigen plating.

According to a first solution, a method of casting a cemented carbide on high chrome cast iron as described in claim 1, copper is plated on the surface of the cemented carbide, and at least a plurality of hooks are formed on the copper plating. High chromium cast iron and cemented carbide which apply liquid flux formed by dissolving fluoride and boride in a solvent, dry the liquid flux to form flux crystals, and cast the cemented carbide into the high chromium cast iron This is a cast-in method.

As a second solution, the copper plating bath is a copper borofluoride bath made of an aqueous boric acid solution, hydrogen fluoride and copper, and the hydrogen fluoride is added to the copper fluoride borofluoride bath. This is a cast-in method of high chromium cast iron and cemented carbide that is electroplated while continuously adding.

A third solution is a casting method of high chromium cast iron and cemented carbide, in which the copper-plated cemented carbide is subjected to manganese plating, Kanigen plating, or manganese plating and Kanigen plating on the copper-plated cemented carbide. is there.

According to a fourth solution, as shown in claim 4, the liquid flux includes cryolite (3NaFAlF3), sodium fluorosilicate (NaSiF6), potassium fluoride (KF), acidic potassium fluoride, potassium borofluoride (KBF4). ), Borax (Na 2 B 4 O 7), boric acid (H 3 BO 3), phosphoric acid (H 3 PO 4), which is produced by dissolving 5 wt% or more in a solvent such as alcohol or acetone. .

According to a fifth solution, as shown in claim 5, a coating agent in which the liquid flux is mixed is applied to the surface of the mold, and the liquid flux is vaporized in a void portion of the mold. This is a cast-in method of high chromium cast iron and cemented carbide injecting the vaporized flux.

As a sixth solution, as described in claim 6, the liquid flux mixed with the coating agent is boric acid (H3BO3), sodium silicofluoride (Na2SiF3), potassium borofluoride (KBF4), acid fluoride. This is a casting method of high chromium cast iron and cemented carbide, in which potassium (KHF2) and phosphoric acid (H3PO4) are dissolved in an alcohol or acetone solvent in an amount of 5 wt% or more.

A seventh solving means is a method of casting the cemented carbide into the high chromium cast iron as shown in claim 7, wherein a through hole is provided in the cemented carbide, and a plurality of the cemented carbide is passed through the through hole. High-chromium cast iron that connects the alloys, supports the skewers with a support at appropriate intervals, attaches the support to the base material 30 to form a module, coats the entire module with a liquid flux, sets it in a mold, and casts it And the cast-in method of cemented carbide.

The eighth solving means is a method of casting the cemented carbide into the high chromium cast iron as shown in claim 8, wherein a vertical or oblique groove is formed in the base material, and the cemented carbide is inserted into the groove. This is a cast-in method of high-chromium cast iron and cemented carbide that is fixed with

According to a ninth aspect of the present invention, as shown in claim 9, in the method of casting the cemented carbide into the high chrome cast iron, a headed pin is passed through the through hole of the cemented carbide, and the headed pin This is a cast-in method of high-chromium cast iron and cemented carbide in which the pin is stabbed into the mold bottom and fixed, and the pin is fixed to the base material.

According to a tenth solution, as set forth in claim 10, in the method of casting the cemented carbide into the high chromium cast iron, the cemented carbide is arranged and stored in a wire mesh, and the wire mesh is disposed in the mold. This is a cast-in method of high chrome cast iron and cast high chrome cast iron and cemented carbide.

  The eleventh solving means is that, as shown in claim 11, the cemented carbide is plated with copper, or after manganese plating, Kanigen plating, or manganese plating and Kanigen plating on the copper plating, the cemented carbide. After the module is immersed in the liquid flux, the liquid flux is applied, and the liquid flux is dried to precipitate a flux crystal. Then, the module is set in the mold and cast with the high chromium cast iron. It is a wear-resistant liner.

The effects of the first solution are as follows: (1) High chromium cast iron and copper plating, high chromium cast iron and manganese plating due to the functions of cleaning action, anti-oxidation action, and surface tension removal action of high chromium cast iron and cemented carbide. Can create a Kirkendall effect between high chrome cast iron and Kanigen plating, and can be diffusion bonded. (2) High chrome cast iron and cemented carbide are integrated so that cemented carbide does not fall off from high chrome cast iron. (3) As a wear resistant liner It is possible to extend the wear life of high chrome cast iron.

The effect of the second solving means is that even when there is a coating material such as a vacuum thin film on the surface like a recovered carbide chip, copper plating can be performed directly on the coating material without peeling off the coating material.

The effect of the third solution is that the manganese-plated manganese (Mn) and the Kanigen-plated phosphorus (P) help the reduction action, the Kirkendall effect is likely to occur, and the Kanigen-plated nickel (Ni) It is to braze cemented carbide and high chromium cast iron.

The effect of the fourth solution is that diffusion bonding by the Kirkendall effect can be performed between the copper-plated Kanigen plating and the high-chromium cast iron by the functions of the cleaning action, the antioxidant action, and the surface tension removing action of the liquid flux.

The effects of the fifth solution are as follows: (1) Moisture and hydrogen in the porous space can be removed by press-fitting the vaporized flux obtained by vaporizing the liquid flux into the mold in advance; (2) The vaporized flux and the applied liquid flux are By rapid heating with hydrocarbons in the solvent, moisture in the mold is reduced to molecular gas and borate glass is generated in the raw sand, so it is possible to prevent pinholes, cast holes, shrinkage, etc. in the molten metal contact area (3) Since additives such as Fe2O3 and KMnO2 in the coating agent are weak as low melting point reactants, a basic liquid flux was added to cover this, so that they adhered to the mold surface by drying. The liquid flux (the solvent evaporates and only the solid part remains) and the vaporization flux that is press-fitted into the mold produce a violent oxidation-reduction action and recovers in a short time. Hardness is the ability to complete the bonding reaction between the chip and Haikuromu cast iron.

The effect of the sixth solution is that by producing a liquid flux suitable for brazing the cemented carbide and the high chromium cast iron, (1) the cleaning action and the antioxidant action of the liquid flux of the high chromium cast iron and the cemented carbide. By the function of removing the surface tension, diffusion bonding can be performed by producing a Kirkendall effect between high chromium cast iron and copper plating, high chromium cast iron and manganese plating, and high chromium cast iron and Kanigen plating.

The effects of the seventh solution are as follows: (1) Cemented carbide with a higher specific gravity than high chrome cast iron can be prevented, and the cemented carbide can be placed in the high chrome cast iron as designed. (2) Cemented carbide This is a wear-resistant liner that is strong against impact because it is skewered and bundled.

The effects of the eighth solution are as follows: (1) The cemented carbide having a higher specific gravity than the high chromium cast iron is prevented from floating and the cemented carbide can be arranged in the high chromium cast iron as designed. (2) The cemented carbide Are arranged in a wall shape in high-chromium cast iron, so that it is possible to produce a wear-resistant liner resistant to wear and impact.

The effects of the ninth solution are as follows: (1) The cemented carbide having a higher specific gravity than that of the high chromium cast iron can be prevented from floating, and the cemented carbide can be arranged in the high chromium cast iron as designed. (2) The cemented carbide Can be arranged on the surface of high chrome cast iron, so that a wear-resistant liner having a large area can be manufactured.

The effects of the tenth solution are as follows: (1) The cemented carbide having a higher specific gravity than the high chrome cast iron is prevented from floating, and the cemented carbide can be arranged in the high chrome cast iron as designed. (2) The cemented carbide Can be arranged on the surface of the high chrome cast iron so that a wear-resistant liner having a large area can be manufactured. (3) The high chrome cast iron melt easily flows into the cemented carbide through the mesh of the wire mesh.

The effect of the eleventh solution is to provide a wear-resistant liner in which high chromium cast iron and cemented carbide are brazed with copper, manganese, or nickel. This is because the high-chromium cast iron and the cemented carbide are integrally joined by the Kirkendall effect, so that the problem that the cemented carbide is separated from the high-chromium cast iron has been solved.

Cross section before cemented carbide Cross section of cemented carbide and high chromium cast iron Cross section before cemented carbide Flux crystal model Cross section of cemented carbide and high chromium cast iron Cross section before cemented carbide Cross section of cemented carbide and high chromium cast iron Cross section before cemented carbide

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, 7, and 8.

A first solution is to apply a copper plating 12 to the surface of the cemented carbide 10 and cast at least a plurality of fluorides and boron on the copper plating 12 in the method of casting the cemented carbide 10 on the high chromium cast iron 20. A high-flux cast iron 20 that applies a liquid flux 15 formed by dissolving a chemical compound in a solvent, dries the liquid flux 15 to form a flux crystal 15, and casts the cemented carbide 10 into the high-chromium cast iron 20; This is a cast-in method for cemented carbide 10.

An explanation will be given taking as an example the casting of cemented carbide 10 having a through hole (not shown) in the center. In FIG. 1, a plurality of cemented carbides 10 are connected through a skewer 32 to a through hole of the cemented carbide. The skewer 32 is supported by the support 31 at appropriate intervals. The support 31 is welded to the base material 30. In order to increase the contact area between the high chromium cast iron 20 and the cemented carbide 10 and strengthen the bondability, a spacer 33 is provided between the cemented carbides 10 to form a gap. The cemented carbide 10, the base material 30, the support 31, the skewer 32, and the spacer 33 are an integrated module 60. By forming the module 60, the cemented carbide 10 can be arranged in the mold 40 as designed. The molten high chrome cast iron 20 is poured into the mold 40 via the filter 50. The substrate 30 is preferably warped in advance toward the inside of the mold 40 in consideration of thermal strain. FIG. 2 shows an abrasion resistant liner 70 made of high chromium cast iron 20 and cemented carbide 10. The material of the base material 30 can be a cast iron material such as high chrome cast iron, a cast steel material, a carbon steel material such as SS400, or a metal material such as SUS material. The support 31, the skewer 32, and the spacer 33 can be made of carbon steel, SUS, or the like. Ceramics etc. can be used for the filter 50 material.

The cemented carbide 10 is a composite carbide such as tungsten carbide (WC), MoC, VC, NbC, TiC, etc., bonded between particles with Ni or Co. Chemical vapor deposition (CVD) of hard materials such as titanium nitride (TiN), titanium carbonitride (TiCN), titanium aluminum nitride (TiALN), aluminum chrome nitride (ALCrN) on the tool surface made of cemented carbide 10 And physical vapor deposition (PVD) cutting tools are becoming mainstream.

The chemical composition of the high chromium cast iron 20 is generally weight percent, C: 2.5 to 3.5%, Si: 0.3 to 0.5%, Mn: 0.4 to 0.6, P: 0.00. 02 or less, S: 0.02 or less, Cr: 24 to 28, Ni: max 2%, remaining Fe, and chromium carbide Cr2C7 is the main force. Depending on the application, Mo, Nb, V, W, Ti, AL, etc. may be added.

It is also possible to improve the hardness of the high chromium cast iron 20 based on the chemical components of the conventional high chromium cast iron 20 by adding elements that form carbides thereto. In addition to the conventional main component chromium carbide (Cr2C7), carbides such as niobium carbide (NbC2), molybdenum carbide (MoC), vanadium carbide (VC), tungsten carbide (WC) and titanium carbide (TiC) are deposited. The hardness of the high chrome cast iron 20 can be Hv 900 to 1200 by adopting a microstructure. Among the additive elements, Ti, V, Ni, and Mo function as crystal refiners in addition to improving hardness. High chromium cast iron 20 is easily cracked because it becomes acicular carbide when rapidly heated and cooled, but by adding elements that promote crystal refinement such as Ti, V, Ni, and Mo, semi-austenite is produced in martensite and cementite. Plays the role of cushioning material and is difficult to break. The main carbides for improving the hardness are Cr2C7, NbC2, and WC, which occupy about 95% of the carbides in the high chromium cast iron 20. When various carbide forming elements are added to the high chromium cast iron 20, there are problems such as deterioration of the bondability with the cemented carbide 10 and easy cracking. However, by applying the liquid flux 15 to the copper plating 12, these problems occur. I was able to solve the problem.

In order to ensure the quality of the high chromium cast iron 20, it is necessary to improve the fluidity of the molten metal, and it is desirable that the molten metal temperature is raised to around 1600 ± 50 ° C. which is the maximum heat resistant temperature of the zirconia brick. Since the cemented carbide 10 acts as a chilling metal, the molten metal temperature is set to about 100 ° C. higher than that of normal casting in order to alleviate the rapid cooling of the molten metal. For this reason, the flux also needs to exhibit the effect of oxidation prevention and cleaning action in a temperature range of 1650 to 1750 ° C. The use limit of sodium silicate (Na2SiO3) generally used as a flux is 1200 to 1400 ° C at maximum, and borax (Na2B4O7) is 800 to 1000 ° C. Therefore, the conventional flux has a limit of 1400 ° C. and is not necessarily the best flux for high chromium cast iron 20. The liquid flux 15 (flux crystal 15) used in the present invention exhibits a function in a wide temperature range covering from a low temperature range of 200 to 300 ° C to a high temperature range of 1650 to 1750 ° C.

The liquid flux 15 and the vaporization flux according to the present invention are disclosed in Japanese Patent Application Laid-Open No. 2009-090368, “Gas Cutting Vaporization Flux” (Patent Document 1) and Japanese Patent Application Laid-Open No. 2009-297782, “Method for Producing Liquid Flux”. And its apparatus "(Patent Document 2), JP 2010-100441 PR" Liquid Flux Production Method, Manufacturing Apparatus and Liquid Flux "(Patent Document 3), JP 2009-255105 PR" Vaporizer "(Patent Document) 4) Therefore, it can manufacture. It is formed by dissolving at least a plurality of fluorides and borides in a solvent such as alcohol or acetone. Fluorides and borides are essential materials, and various compounds can be blended depending on the application.

A boride is a general term for a compound between boron and an element having a lower electronegativity. For example, boric acid (H3BO3), borax (Na2B4O7, boron oxide (B2OB), trimethylyl borate ((CH3O) 3B), potassium borate (K2B4O7), borofluoric acid (HBF4), ammonium borofluoride (NH4BF4) , Lithium borofluoride (LiBF4), sodium borofluoride (NaBF4), and the like, which can be selected according to conditions such as the components of the high chromium cast iron and the casting temperature.

Examples of the fluoride include potassium fluoride (KF), sodium fluoride (NaF), boron trifluoride (BF3), silicon tetrafluoride (SiF4), acidic sodium fluoride (NaHF2), potassium borofluoride (KBF4), Sodium borofluoride (NaBF4), ammonium borofluoride (NH4BF4), tetrafluoroboric acid (HBF4), potassium silicofluoride (K2SiF6), sodium fluoride aluminum (liquid crystal stone, Na3ALF6), potassium aluminum fluoride (potassium calcite, K3ALF6), hexafluorosilicic acid (H2SiF6), acidic potassium fluoride (KHF2), sodium silicofluoride (NaHF6), sodium silicofluoride (NaHF6), etc., selected according to conditions such as components of high chromium cast iron and casting temperature can do. Potassium borofluoride (KBF4) and sodium borofluoride (NaBF4), which are common compounds of fluoride and boride, are exemplified for both the fluoride and boride.

The melt of the high chromium cast iron 20 is welded to the cemented carbide 10 by the interaction between the copper plating 12 and the liquid flux 15 in the temperature range of 1000 to 1100 ° C. during the slow cooling. The liquid flux 15 is baked when the mold 40 is preheated and the solvent disappears, but the flux crystal 15 (residual component) fixed to the copper plating 12 becomes a thin film-like flux film, removes the surface tension of the high chromium cast iron 20 molten metal, cleans, and oxidizes. Enables cast-in brazing by preventing action.

After the liquid flux 15 is applied to the surface of the cemented carbide 10, the alcohol component evaporates and a flux crystal 15 (liquid flux 15) of about 0.1 mm is uniformly deposited. This is because a plurality of electrolytes are dissolved in the liquid flux 15 at a maximum concentration of 30 wt% in alcohol. Since the cemented carbide 10 serving as the cast-in base material is made into a module 60 and has a large heat capacity, it is preheated to about 200 to 300 ° C. before casting. This is to prevent the cemented carbide 10 from being cooled and solidifying the molten metal. The liquid flux 15 becomes a flux crystal 15 by evaporating the solvent after drying. When this flux crystal 15 is preheated at 200 to 300 ° C., it is solidified into a glass and firmly adhered to the cemented carbide 10 and does not peel off. The flux crystal 15 is hardened into a glass shape so that it does not peel off while sticking to the cemented carbide 10 even if a molten metal of 1400 to 1450 ° C. flows into the mold. That is, the liquid flux 15 needs to have a function of sticking to the cemented carbide 10 in a temperature range of 200 to 1450 ° C. in order to fulfill the function as a flux. The role of the liquid flux 15 is (1) removing the oxide on the surface of the cemented carbide 10 and having a cleaning action, (2) maintaining the activation up to the brazing temperature (1086 ° C.) of the copper plating 12, (3 ) To maintain the fluidity and spreadability of brazing. When these conditions are satisfied, the flux crystal 15 on the surface of the cemented carbide 10 exhibits a flux function when a molten high chromium cast iron 20 at 1400 to 1450 ° C. is poured, and the surface tension of the high chromium cast iron 20 is instantaneously broken and stabilized. Thus, it is possible to braze and join the copper plating 12.

A second solution is that the plating bath of the copper plating 12 is a copper borofluoride bath composed of an aqueous boric acid solution, hydrogen fluoride, and copper, and the hydrogen fluoride is continuously added to the copper borofluoride bath. This is a cast-in method for high-chrome cast iron 20 and cemented carbide 10 to be electroplated.

Copper plating baths include a copper sulfate bath, a copper pyrophosphate bath, a copper cyanide bath, and a copper borofluoride bath. However, the copper borofluoride bath does not require a stabilizer and has a wide temperature adjustment range, so it has excellent workability. Copper borofluoride (Cu (BF4) 2) is produced by blowing hydrogen fluoride into a liquid in which copper powder is mixed in a boric acid (H3BO3) aqueous solution. The reaction formula is Cu (copper powder) + 2H3BO3 (boric acid) + 8HF (hydrogen fluoride) → Cu (BF4) 2 + 6H2O + 2H. The current density of the copper plating 12 is 6 to 30 A / dm2. The voltage is 3-12V.

A hydrogen fluoride solution having a concentration of 10 wt% is continuously added to the borofluoride bath. Hydrogen fluoride is a strong acid of PH1. The reason why hydrogen fluoride is continuously added to the borofluoride bath is that the vacuum thin film 11 of the cemented carbide 10 is continuously pickled with a bubble impact of hydrogen fluoride and a strong acid. Copper plating 12 can be formed on the vacuum thin film 11 without peeling the vacuum thin film 11 by the action of hydrogen fluoride and boric acid in the borofluoride bath. Prior to copper plating 12, the cemented carbide chip is degreased with caustic soda (NaOH, PH2) at 50 to 80 ° C. After copper plating is completed, it can be neutralized by mixing a used borofluoride bath and caustic soda.

The wear-resistant liner 70 in which the cemented carbide 10 is cast into the high chromium cast iron 20 has a lifespan that is 3 to 10 times longer than that of a conventional high chromium cast iron single-unit liner, but the cemented carbide 10 for casting into the high chromium cast iron 20. It will be expensive to make new. The method of reusing the recovered cemented carbide tip 10 is the best way to reduce the cost. However, the surface of the recovered cemented carbide chip 10 is coated with a hard vacuum thin film 11 with a thickness of about 0.03 to 0.05 mm. It was impossible to attach 12 strongly. The recovered cemented carbide tip 10 has a very complicated cutting relief angle due to the heavy wear of the lathe, milling machine, medium grinder, plano mirror, saver and heavy impact on the cutting edge, and has a complicated blade shape according to the model. ing. A vacuum thin film 11 made of a high hardness material is formed on the recovered cemented carbide chip 10 by a vacuum thin film process such as CVD, PVD, or AIP. Since these vacuum thin films 11 suppress the mutual diffusion between the recovered cemented carbide tip 10 and the high chromium cast iron 20, no strong bonding based on the mutual diffusion layer occurs between the recovered cemented carbide tip 10 and the high chromium cast iron 20. In other words, simply by casting the recovered cemented carbide tip 10, the recovered cemented carbide tip 10 is only mechanically held by the contraction stress at the time of solidification contraction of the high chromium cast iron 20. Even if the copper plating 12 is directly applied on the vacuum thin film 11, the adhesion strength is weak, and it peels off only by rapid heating.

Japanese Laid-Open Patent Publication No. 2001-96182 discloses a method in which the surface of the recovered cemented carbide chip 10 is subjected to Kanigen plating 14 through special pretreatment and base plating. This method has many steps and is complicated and expensive. In order to firmly coat the copper plating 12 on the recovered cemented carbide chip 10, it was necessary to remove the vacuum thin film 11 in advance. Mechanically, there is a barrel sand shot as a method for removing the vacuum thin film 11. As chemical treatment, there is a method of repeating shock waves due to the Bach effect several times by injecting hydrogen peroxide (H 2 O 2) after heating to 100 ° C. for 30 to 60 minutes in an alkaline solution (for example, 15 to 20% NaOH solution). is there. When the vacuum thin film 11 is based on titanium, TiN (Hv2500) and TiC (Hv3000) can be alkali-dissolved with NaOH, but the intermediate layer is coated with Cr-N (Hv1800), TiALN (Hv3000), etc. It cannot be removed by alkaline dissolution. Moreover, although the vacuum thin film 11 by PVD (physical vapor deposition) is easy to remove, the vacuum thin film 11 of the recovered cemented carbide chip 10 is mostly coated by CVD (vacuum chemical vapor deposition). Therefore, it cannot be removed only by dissolution with NaOH, and a troublesome mechanical removal step is indispensable. In addition, since the cost of removing the vacuum thin film 11 by blasting is expensive, the removal process of blasting the vacuum thin film 11 remaining after the dissolution process using an alkali is usually first performed. Since the recovered cemented carbide chip 10 is a small article, it is blasted in a barrel rotating device, but the wear of the steel on the barrel itself is a large and laborious work. The recovered cemented carbide chip 10 has a small adhesion of the copper plating 12 unless the vacuum thin film 11 is peeled off. The reuse of the recovered cemented carbide chip 10 is not progressing because there is no peeling technique of the vacuum thin film 11 and the strong copper plating 12 cannot be directly formed on the vacuum thin film 11.

A third solution is a cast-in method of high-chrome cast iron 20 and cemented carbide 10 in which manganese plating 13 or Kanigen plating 14 or manganese plating 13 and Kanigen plating 14 are applied on the copper-plated 12 cemented carbide. .

This means is to apply a copper plating 12 to the cemented carbide 10, a manganese plating 13 on the copper plating 12, a Kanigen plating 14 on the manganese plating 13, and a liquid flux 15 on the Kanigen plating 14. Thus, it is cast with the high chromium cast iron 20. The high chrome cast iron 20 is cast without removing the vacuum thin film 11 applied to the surface of the recovered cemented carbide chip 10, and good bonding between the high chrome cast iron 20 and the recovered cemented carbide chip 10 is realized.

The main point of interest of the present invention is that the solvent of the liquid flux 15 is evaporated to form a uniform film-like flux crystal 15 having a uniform flux function therein. The flux crystal 15 is obtained by dissolving an individual compound having an antioxidant function, a cleaning function, and a surface tension removing function once in a solvent and re-depositing it. The effect of the flux crystal 15 can smoothly cause the Kirkendall effect at the boundary surface between the high chromium cast iron 20 and the copper plating 12, the high chromium cast iron 20 and the manganese plating 13, and the high chromium cast iron 20 and the Kanigen plating 14, so that the copper plating 12, Diffusion bonding between the cemented carbide 10 and the high chromium cast iron 20 is possible using the manganese plating 13 and the Kanigen plating 14 as brazing materials.

FIG. 3 shows an outline of plating. A copper plating 12 is applied to the surface of the cemented carbide 10, a manganese plating 13 is applied on the copper plating 12, and a Kanigen plating 14 (electroless Ni—P plating 14) is applied on the manganese plating 13. A liquid flux 15 (flux crystal 15) is applied thereon. When the cemented carbide 10 is the recovered cemented carbide chip 10, the copper thin film 11, the manganese plating 13, and the Kanigen plating 14 are directly applied to the vacuum thin film 11 without peeling off the vacuum thin film 11. The Kirkendall effect is produced by the reducing action, cleaning action, and surface tension removing effect of the liquid flux 15, and the casting of the high chromium cast iron 20 molten metal and the cemented carbide 10 is completed in an instant. The Ni of the Kanigen plating 14 forms and welds an alloy layer of Ni with the copper plating 12 of the recovered cemented carbide chip 10 and the high chromium cast iron 20 melt. Manganese in the manganese plating 13 exhibits a reducing action as manganese oxide (MnO 2). Phosphorus in the Kanigen plating 15 exhibits a reducing action as phosphorus pentoxide (P2O5). The cemented carbide 10 can be cast into the high chromium cast iron 20 in a completely brazed state by a reduction reaction of phosphorus (P) and manganese (Mn).

Manganese plating 13 is possible with a solution of manganese nitrate (2) hexahydrate (H12MnN2O12) or manganese sulfate (2) pentahydrate (H10MnO9S).

In the present invention, at least a copper plating 12 is applied to the surface of the cemented carbide 10, a manganese plating 13, a Kanigen plating 14, or a manganese plating 13 and a Kanigen plating 14 are applied, and a liquid flux 15 is applied on the Kanigen plating 14. It casts with high chromium cast iron 20. Since the solvent evaporates immediately after the liquid flux 15 is applied to the cemented carbide 10, the flux crystal 15 remains. Between the cemented carbide 10 and the high chromium cast iron 20, the presence of the flux crystal 15, which is a residue of the Kanigen plating (electroless Ni-P plating) 14 and the liquid flux 15, exists between the high chromium cast iron 20 and the cemented carbide 10. As a result, a brazed joint surface is formed to improve the joint strength. The reason why the copper plating 12 is performed between the cemented carbide 10 and the Kanigen plating 14 is that the diffusion bonding strength between the high chromium cast iron 20 and the copper plating 12 is high. Further, according to the copper plating 12 method of the present invention, the copper plating 12 can be firmly applied to the cemented carbide 10 regardless of the presence or absence of the vacuum thin film 11.

The liquid flux 15 has an antioxidant action, a cleaning action, and a surface tension removing action. By using this flux function, it is possible to braze the copper plating 12, the manganese plating 13, the Kanigen plating 13 and the high chromium cast iron 20. The liquid flux 15 is applied as a flux dedicated to casting, and is applied uniformly and thinly to a thickness of 0.1 ± 0.05 mm of the flux crystal 15 when the liquid flux 15 is dried. This thickness can be achieved by setting the concentration of the liquid flux 15 to about 30 wt%. The present inventor has already embodied a method for producing a liquid flux 15 having a concentration of 30 wt% at room temperature.

A liquid flux 15 is applied on the copper plating 12, the manganese plating 13, and the Kanigen plating 13. The coating thickness of the liquid flux 15 is preferably 0.1 ± 0.05 mm in the thickness of the flux crystal 15 after drying.

According to Japanese Laid-Open Patent Publication No. 2001-96182, a cemented carbide 14 is subjected to Kanigen plating 14, and a flux containing boric acid, borax, fluoride, and metal boron 1 to 2 wt% is applied onto the Kanigen plating 14 by applying high chromium. A cast iron 20 and casting method has been proposed. The conventional flux is simply a mixture of a plurality of compounds, and the flux compound is sparsely distributed on the Kanigen plating 14 for each compound alone, whereas the liquid flux 15 is completely uniform. Precipitates in a film state. For example, FIG. 4A shows a state where the liquid flux 15 is dried and the flux crystal 15 is deposited. The flux crystal 15 is attached to the cemented carbide 10 in the form of a uniform film. The compound of the liquid flux 15 is once completely dissolved in the solvent and the solvent evaporates. Then, the compounds partially form a new compound, and the film is uniformly formed on the surface of the cemented carbide 10 as a film-like flux crystal 15. Precipitate. Therefore, when viewed microscopically, in the flux crystal 15, the component that functions as the flux is uniformly distributed in any minute portion, and at the moment when the melt of the high chromium cast iron 20 is injected, the flux crystal 15 is uniform on the surface of the cemented carbide 10. In addition, a molecular diffusion layer can be formed between the high chromium cast iron 20 and the Kanigen plating 14 by the Kirkendall effect, which functions as a flux. FIG. 4B shows a conventional flux application state. For example, boric acid 15a, borax 15b, fluoride 15c, and metal boron 15d are sparsely distributed for each simple substance. Therefore, when viewed microscopically, a uniform flux function cannot be achieved instantaneously on the surface of the cemented carbide 10. Conventionally, various kinds of fluxes have been produced, but there is no flux that forms a uniform film as the flux crystal 15 by applying the liquid flux 15 as in the present invention.

A fourth solution is that the liquid flux 15 is cryolite (3NaFAlF3), sodium silicofluoride (NaSiF6), potassium fluoride (KF), potassium acid fluoride, potassium borofluoride (KBF4), borax (Na2B4O7). This is a cast-in method of high chromium cast iron 20 and cemented carbide 10 which is produced by dissolving 5 wt% or more of boric acid (H3BO3) and phosphoric acid (H3PO4) in a solvent such as alcohol or acetone.

The fluoride contains cryolite (3NaFALF3), sodium silicofluoride (NaSiF6), potassium fluoride (KF), and acidic potassium fluoride (KHF2). As boride, potassium borate (KBF4), borax (NaB4O7), and boric acid (H3BO3) are contained. In addition, phosphoric acid (H3PO4) is contained in order to inoculate P as a reduction accelerator.

In the casting of the cemented carbide 10, the cemented carbide 10 becomes a cooling metal for the molten metal. When 1400 to 1450 ° C. hot water is cooled, the hot water flow becomes worse no matter how much hot water is pushed. Phosphorous (P), manganese (Mn), boron (B), and aluminum (AL) improve the hot water flow. Phosphorus and manganese are always contained in general castings such as cast steel, cast iron, and stainless steel castings. When the oxidized product is reduced, it generates heat. In order to maintain this function, the components of the cast-in liquid flux 15 are, for example,% by weight, K: 12.99, Na: 11.09, Si: 1.74, P: 2.10, AL: 1.83. , B: 8.77, H: 1.43, O: 31.10, F: 28.95. The contents of Si, P, AL, and B are 14.44%. By introducing an element that has a reducing action and improves the hot water flow by removing the surface tension and has an exothermic effect, the disadvantage that the cemented carbide 10 becomes a cooling metal is prevented.

A fifth solution is that a coating agent 41 mixed with a liquid flux 15 is applied to the surface of the mold 40, and a vaporized flux obtained by vaporizing the liquid flux 15 is injected into a gap of the mold 40. This is a cast-in method for high-chromium cast iron 20 and cemented carbide 10.

Since bengara (Fe2O3), potassium permanganate (KMnO4), etc. contained in the coating agent 41 applied to the surface of the mold 40 are weak as low melting point reactants, the liquid flux 15 having a complex action of base is applied. The maximum amount of 20% in the mold 41 is supplemented. In order to expel the moisture in the mold 40, the vaporized flux obtained by vaporizing the liquid flux 15 is injected and press-fitted into the mold 40 in advance. Since the flux crystal 15 is preheated to 200 to 300 ° C. in the sand mold (mold) 40, it is fired by the heat at that time and sticks to the cemented carbide 10 thinly. The water in the sand mold 40 is also removed to nearly 100% by preheating. The flux crystal 15 functions as follows during pouring. (1) Removes oxides from the molten metal and cleans it. (2) Prevent oxidation of the surface of the Kanigen plating 14. (3) Improves the fluidity of the pouring, expands the expandability and reduces the surface tension, and suppresses the formation of cast holes and pinholes.

When pouring, the surface of the mold 40 is exposed to the heat of the molten metal and is easily destroyed. In order to prevent this state, various coating agents 41 are applied to the surface of the mold 40. This painting process is called coating mold. This material is referred to as a coating agent 41. The role of the coating agent 41 is important for casting the cemented carbide 10 on the high chromium cast iron 20. The coating agent 41 needs to have heat resistance, adhesion, covering property, air permeability, reactivity, and viscosity. Examples of the coating agent 41 include graphite, charcoal, coal powder, coke powder, mica powder, bengara (Fe2O3), potassium permanganate (KMnO2), silicon, and zircon flour. Liquid flux 15 was added to solid fluxes such as conventional coal, coke powder, Fe2O3, and KMnO2 to add a borate glass shielding effect and reducing action. A liquid flux 15 having a concentration of 20 to 30 wt% is added to the solid flux 15 to 35 wt% and mixed well. When the solvent of the liquid flux 15 evaporates, the flux crystal 15 remains in the coating agent 41. The flux crystal 15 forms borate glass at a molten metal temperature of 1400 to 1450 ° C. and prevents hydrogen gas from entering the molten metal. Oxygen is removed by the reducing action of the liquid flux 15 (flux crystal 15), moisture (hydrogen) in the raw sand mold 40 is converted into acetylene gas (C2H2) with coal and coke powder, and burned. A hydroxyl group OH is formed by thermal decomposition of Fe2O3, KMnO2, etc., and moisture in the green sand mold is comprehensively removed.

When the coating agent 41 is applied, the coating amount is set within 0.01 to 0.10 g / cm 2. In order to firmly adhere to the mold 40 and to be reusable as recycled sand after mold release, it is necessary to keep within this range. It is also possible to apply the liquid flux 15 directly to the mold 40 by brushing or air spraying. The liquid flux 15 is obtained by dissolving an electrolyte in a solvent such as alcohol or acetone at a maximum weight ratio of 30%. The oxides are floated by the reducing action in the molten metal to suppress hydrogen absorption and enable the recovery of green sand.

The gate 42 becomes easier to form an oxide as the temperature of the casting becomes higher (1400 to 1700 ° C.). Therefore, a porous ceramic filter 50 (network object) made of ZrO 2 or AL 2 O 3 is installed at the gate 42 to remove the oxide. However, the liquid flux 15 is applied to the filter 50 and dried (because of the alcohol component, it is naturally dried in 1 to 2 minutes). A flux crystal 15 having a thickness of 0.005 to 0.08 mm is added per application. This is repeated several times to deposit the flux crystal 15 having an average thickness of 0.1 mm along the filter 50. The oxide of the high chromium cast iron 20 melt is lightened by the oxidation heat generation action of the flux at the gate 42 and floated together with the hot water. P, Si, Mn, and B, which are components of the liquid flux 15 mixed with the coating agent 41 in an amount of 15 to 35 wt%, are used as elements responsible for this action. By applying the coating agent 41 to the runner, the weir, and the pouring gate, the reaction progressed violently even during the short time of pouring of only a few seconds, making it possible to perform complicated casting.

Moisture in the mold 40 is reduced by being rapidly heated because of the hydrocarbon of methanol (CH 3 OH) as a solvent contained in the liquid flux 15 and the vaporized flux, and converted into a molecular gas of hydrogen and oxygen, and borate glass in the raw sand. To prevent pinholes, cast holes, shrinkage, etc. in the molten metal contact portion. The copper plating 12, manganese plating 13, Kanigen plating 14, etc. on the surface of the cemented carbide 10 are melted by the amount of heat of the high-temperature molten metal, and the high chromium cast iron 20 and the cemented carbide 10 are brazed. High chromium cast iron melt (M) + H2O → MO + 2H ↑, 2H + 2C → C2H2 ↑ (acetylene gas). M is a metal. Moisture in the raw sand is further removed by the generated and burned acetylene gas, and the sand grains are bound by the borate glass remaining in the raw sand, so that it can sufficiently withstand the internal pressure of casting.

In general, a molten metal at a low temperature of 1400 to 1450 ° C. has little high-temperature oxidation and may cause run-off due to casting defects. However, since furan resin or the like is used as a binder, fresh sand can be recycled. On the other hand, when the temperature is high from 1450 to 1700 ° C., high-temperature oxidation is intense, and thus a technique for floating oxide by a flux is required. When sodium silicate (NaSiO2) is used as the binder for high temperature, the hot water is improved, but the fresh sand is hard to regenerate because the fresh sand is hardened by CO2. The regeneration of casting sand is important in terms of cost and is the main reason why organic binders are mainly used for inorganic materials. Since the concentration of the liquid flux 15 used for the coating agent 41 is 30 wt% at the maximum and is low, the green sand is dissolved when it is washed with water. Later drainage is also harmless. Since the fluoride is removed as 100% hydrogen fluoride gas, it becomes green sand in which only borate glass remains.

In order to make a cast hole using the green sand mold 40, it is important to eliminate defects called pinholes, cast cavities, and dents near the casting surface. In the case of small casting, the mold 40 is dried to about 400 to 500 ° C. with raw sand, but when large casting is performed, the complete raw sand cannot be dried. Heating (200 to 300 ° C.) and coating agent 41 are applied. Also, an oxidant (CuO, Fe2O3, Ag2O, NiO, MnO2, ZnO, ZrO2, etc.) was mixed with about 20% carbonate (SiO2, Na2O, K2O, CaO, MgO, B2O3, PbO, AL2O3, general glass, etc.). Patent Document 1 and Patent Document 2 propose a method of adding a thing, coal powder or coke powder to green sand.

In the case of high-chromium cast iron 20 molten metal, CrO + H2O → CrO2 + 2H ↑, and chromium oxide easily reacts with moisture in raw sand to generate hydrogen gas. The molten high-chromium iron 20 absorbs hydrogen during solidification and becomes a pinhole. It was. In order to prevent such defects, when Fe2O3 (Bengara) is added as the coating agent 41, 3Fe2O3 + 2H2O → 2Fe3O + 2H2 ↑ + 4O2 ↑, 2Fe3O + 2H2 + 4O2 + C2 → 2Fe3O + 2CO2 + 2H2 + 2O2, 2Fe3O + 2C2 + 2H2 + 2 ↑ 2 + C2 + 2 Acetylene gas) + 2CO2 ↑ (carbon dioxide gas) + 2Fe3O, and acetylene gas and carbon dioxide gas are generated. Pinholes were removed because water in the raw sand could be removed as carbon dioxide or acetylene gas by putting coal powder or coke powder into the raw sand.

Fe2O3 (Bengara) and KMnO2 (potassium permanganate) exhibit a water removal effect in the case of casting hot water in a high temperature range such as 1450 to 1700 ° C. However, in the case of castings in a low temperature range such as 1400 to 1450 ° C., oxides such as Fe 2 O 3 (Bengara) and KMnO 2 (potassium permanganate) have a weak thermal decomposition reaction, so It was difficult to suppress the cause defect rate, and it was not possible to provide a high quality casting.

An object of the present invention is to precisely cast and braze the cemented carbide 10 to the high chromium cast iron 20 even in a casting at a relatively low temperature range such as 1400 to 1450 ° C. For this purpose, a vaporized flux that is vaporized by blowing air, nitrogen, argon or the like into the liquid flux 15 is pressed into the green sand mold 40. The raw sand mold 40 has a space of about 20% (porosity 20%), and the vaporization flux fills this space. The components contained in the vaporized flux are combined with each other by casting heat, and borate glass is generated in the green sand mold 40. Shielding action with borate glass prevents hydrogen from entering the molten metal from the raw sand. Previously, argon gas was sealed in the raw sand to prevent hydrogen gas from entering the molten metal, but since the raw sand was shielded with borate glass, it was possible to shut out the hydrogen gas intrusion into the molten metal almost completely. Became.

As the solid flux for coating agents, the heat resistance of sodium silicate (Na2SiO3), which is generally used in the past, has a maximum heat resistance of 1200 to 1400 ° C, the borax (Na2B4O7) has a temperature of 800 to 1000 ° C, and the cryolite (3NaFALF3) has a temperature of 1400 to 1800 ° C. It is. In the conventional coating agent 41, these solid fluxes are mixed with a liquid in a powder state and applied to the surface of the metal base material or the mold 40. However, since a certain coating thickness is required, the coating thickness becomes thick or uneven. There is a problem of becoming a pinhole and a cast hole. As an improved type, there is a method in which water glass (Na2SiO3) having a concentration of about 5 to 10% and fluoride are mixed and sprayed. However, the water glass bulges due to the rapid heating of the molten metal and becomes bubbles and accumulates in places where the hot water is poor. As a result, the quality of the high chromium cast iron 20 is extremely undesirable.

When melting at a high temperature of 1450 to 1700 ° C., the main component of the mold 40 is zirconia (ZnO 2), which is very expensive. In order to reduce the cost, it is necessary to enable casting by melting using a graphite crucible in a temperature range of 1400 to 1450 ° C. The molten metal having a higher melting temperature has a higher thermal energy, so the hot water flow is better. However, the moisture in the raw sand rapidly heats and expands rapidly, so the internal pressure of the mold 40 increases. Corresponding to the internal pressure of the mold 40, it is necessary to make the green sand strong and hard, so degassing is worsened and the defect rate is increased. In order to reduce casting defects, it is necessary to devise techniques such as hot water temperature control, runner design, degassing, wall thickness difference, and method of using chill metal, and experience greatly affects. The liquid flux 15 for the coating agent is mixed with the coating agent 41 and applied to the mold 40, or the liquid flux 15 for the coating agent is injected into the raw sand, so that the low temperature casting at 1400 to 1450 ° C. It became possible to reduce the cost.

In the sixth solution, the liquid flux 15 mixed with the coating agent 41 is boric acid (H3BO3), sodium silicofluoride (Na2SiF3), potassium borofluoride (KBF4), acidic potassium fluoride (KHF2), phosphorus This is a cast-in method of high chromium cast iron 20 and cemented carbide 10 in which acid (H3PO4) is dissolved in a solvent of alcohol or acetone by 5 wt% or more.

As shown in FIGS. 1 and 2, the seventh solution is a method in which the cemented carbide 10 is modularized and cast, and a through hole 16 is provided in the cemented carbide 10 and a skewer 32 is passed through the through hole 16. A plurality of the cemented carbides 10 are connected, the skewers 32 are supported by support bodies 31 at appropriate intervals, the support bodies 31 are attached to a base material 30 to form a module 60, and the entire module 60 is formed with a liquid flux 15. This is a casting method of the high chromium cast iron 20 and the cemented carbide 10 which are coated and set in the mold 40 and cast.

The reason why the cemented carbide 10 is made into the module 60 is to fix the flowing or floating of the cemented carbide 10 when the molten high chromium cast iron 20 is poured into the mold 40. Since the recovered cemented carbide tip 10 is normally used as a cutting tool for machine cutting, there is a chip provided with a dedicated through hole 16 which can be utilized.

The cemented carbide 10 made into the module 60 is preferably immersed in the liquid flux 15 and applied uniformly. The liquid flux 15 may be applied by brush or spray. After applying the liquid flux 15, the solvent of the liquid flux 15 is evaporated and dried to precipitate the flux crystal 15 on the surface of the cemented carbide 10. The target of the thickness of the flux crystal 15 is 0.1 ± 0.05 mm. Before applying the liquid flux 15, the assembly module 60 may be cleaned with a commercially available detergent to remove surface tension. By immersing the module 60 of the cemented carbide 10 in the liquid flux 15, the liquid flux 15 can be uniformly applied to the whole including the support material 31. For the base material 30, the support 31, and the skewer 32, carbon steel, SUS, or the like can be used. By depositing the flux crystal 15 on the base material 30, the support 31, the skewer 32, etc., the Kirkendall effect is produced, diffusion bonding between the high chrome cast iron 20 and the metal material is possible, and the module 60 and the high chrome cast iron 20 are completely integrated. A wear-resistant liner 70 can be formed. The base material 30, the support 31 and the skewer 32 are preferably plated with copper in order to improve the bondability with the high chromium cast iron.

As shown in FIG. 5, the eighth solution is a method in which the cemented carbide 10 is cast into a module 60, and vertical or oblique grooves 34 are formed in the base material 30, and the cemented carbide is formed in the grooves 34. This is a cast-in method of high chromium cast iron 20 and cemented carbide 10 in which 10 is inserted and fixed.

The substrate 30 can be made of carbon steel, SUS, or the like. The base material 30 is preferably plated with copper in order to improve the bondability with the high chromium cast iron. In FIG. 5, since the grooves are vertical grooves 34, the cemented carbide is vertical, but by using the oblique grooves 34, the cemented carbide 10 can be inclined in the material flow direction. By tilting the cemented carbide 10, the projected area of the cemented carbide 10 is widened and the life of the wear resistant liner 70 can be extended.

As shown in FIGS. 6 and 7, the ninth solution is a method of casting the cemented carbide 10 in a modular manner, by inserting a headed pin 35 into the through hole 16 of the cemented carbide 10, This is a casting method of the high chromium cast iron 20 and the cemented carbide 10 in which the headed pin 35 is pierced and fixed to the mold bottom 40 a and the headed pin 35 is fixed to the base material 30.

The headed pin 35 can be made of carbon steel, SUS, or the like.

As shown in FIG. 8, the tenth solving means is a method in which the cemented carbide 10 is cast into the high chromium cast iron 20, and the cemented carbide 10 is arranged and accommodated in a wire mesh 36, and the wire mesh 36 is placed in the mold 40. This is a casting method of the high chromium cast iron 20 and the cemented carbide 10 which are disposed and cast.

In order to improve the fluidity of the high-chromium cast iron 20, the wire mesh 36 is preferably made as large as possible and thin in the linear shape. It is important to select so that the cemented carbide 10 does not move due to the flow of the molten metal. By arranging and storing them in the wire mesh 36, the cemented carbide 210 can be easily made into multiple layers according to the application. The wire mesh 36 is preferably plated with copper to improve the bondability with the high chromium cast iron 20.

As shown in FIGS. 2, 5, and 7, the eleventh solving means is that the cemented carbide 10 is plated with copper 12, or the copper plating 12 is coated with manganese plating 13, Kanigen plating 14, or manganese plating 13. After the Kanigen plating 14, the cemented carbide 10 is made into a module 60, the module 60 is immersed in the liquid flux 15, the liquid flux 15 is applied, and the liquid flux 15 is dried to precipitate a flux crystal 15. Then, the wear-resistant liner 70 in which the module 60 is set in the mold 40 and cast with the high chrome cast iron 20.

The form of the module 60 includes, for example, forms according to seventh, eighth, and ninth solving means. Various other forms are conceivable, but in any form, the liquid flux 15 is applied by applying the copper plating 12 to the cemented carbide 10 or the manganese plating 13 and the Kanigen plating on the copper plating 12. 14 and the like, and the liquid flux 15 is applied thereon, and all of them are included in the present invention.

10: Cemented carbide 11: Vacuum thin film 12: Copper plating 13: Manganese plating 14: Kanigen plating 15: Flux crystal 15a: Boric acid (H3BO3)
15b: Borax (Na2B4O7)
15c: fluoride 15d: metallic boron 16: through hole 20: high chromium cast iron 30: base material 31: support 32: skewer 33: spacer 34: groove 35: headed pin 36: wire mesh 40: mold, fresh sand mold
40a: mold bottom 41: coating agent 42: spout 50: filter 60: module 70: wear-resistant liner

Claims (11)

In the method of casting a cemented carbide on high chromium cast iron, the surface of the cemented carbide is subjected to copper plating, and a liquid flux generated by dissolving at least a plurality of fluorides and borides in a solvent on the copper plating. A casting method of high chromium cast iron and cemented carbide comprising applying and drying the liquid flux to produce flux crystals and casting the cemented carbide into the high chromium cast iron.   The copper plating bath is a copper borofluoride bath composed of an aqueous boric acid solution, hydrogen fluoride and copper, and electroplating while continuously adding the hydrogen fluoride to the copper borofluoride bath. The cast-in method of the high chromium cast iron and cemented carbide alloy according to claim 1. 3. The high chrome cast iron and cemented carbide casting method according to claim 1, wherein manganese plating or Kanigen plating or manganese plating and Kanigen plating are performed on the copper-plated cemented carbide. The liquid flux includes cryolite (3NaFAlF3), sodium silicofluoride (NaSiF6), potassium fluoride (KF), acidic potassium fluoride, potassium borofluoride (KBF4), borax (Na2B4O7), boric acid (H3BO3), phosphorus 4. A cast alloy of high chromium cast iron and cemented carbide according to claim 1, wherein the acid (H3PO4) is produced by dissolving 5 wt% or more in a solvent such as alcohol or acetone. Method.   The mold material mixed with the liquid flux is applied to the surface of the mold, and the vaporized flux obtained by vaporizing the liquid flux is injected into the gap of the mold. 5. A cast-in method of high chromium cast iron and cemented carbide according to claim 1, claim 2, claim 3, and claim 4. The liquid flux mixed with the coating agent is boric acid (H3BO3), sodium silicofluoride (Na2SiF3), potassium borofluoride (KBF4), acidic potassium fluoride (KHF2), phosphoric acid (H3PO4) in alcohol or acetone. The high chrome cast iron and cemented carbide casting method according to claim 1, 2, 3, 4 and 5, characterized by being dissolved in a solvent by 5 wt% or more. In the method of casting the cemented carbide into the high chrome cast iron, a through hole is provided in the cemented carbide, a plurality of the cemented carbides are connected through the skewer through the through hole, and the skewer is supported by a support at an appropriate interval. The support is attached to the substrate 30 to form a module, and the entire module is coated with a liquid flux, set in a mold, and cast. A cast-in method of high chromium cast iron and cemented carbide according to claim 4, claim 5 and claim 6. 3. The method of casting the cemented carbide into the high chromium cast iron, wherein a vertical or oblique groove is formed in the base material, and the cemented carbide is inserted and fixed in the groove. A casting method of high chromium cast iron and cemented carbide according to claim 3, claim 4, claim 5 and claim 6. In the method of casting the cemented carbide into the high chromium cast iron, a headed pin is passed through the through hole of the cemented carbide, the headed pin is pierced and fixed to a mold bottom, and the pin is fixed to the base material. The method of casting a high-chromium cast iron and a cemented carbide according to claim 1, 2, 3, 4, 5, and 6, characterized by being cast into high-chromium cast iron. 2. The method of casting the cemented carbide into the high chromium cast iron, wherein the cemented carbide is arranged and accommodated in a wire mesh, the wire mesh is disposed in the mold and cast with the high chromium cast iron. The cast-in method of high chromium cast iron and cemented carbide according to claim 2, claim 3, claim 4, claim 5, and claim 6.   Copper-plating the cemented carbide, or manganese plating or Kanigen plating or manganese plating and Kanigen-plating on the copper plating, modularizing the cemented carbide, and immersing the module in the liquid flux A wear-resistant liner, wherein a liquid flux is applied, the liquid flux is dried to precipitate a flux crystal, and then the module is set in the mold and cast with the high chromium cast iron.

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