US3922405A - Method for forming of a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article - Google Patents

Method for forming of a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article Download PDF

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US3922405A
US3922405A US355280A US35528073A US3922405A US 3922405 A US3922405 A US 3922405A US 355280 A US355280 A US 355280A US 35528073 A US35528073 A US 35528073A US 3922405 A US3922405 A US 3922405A
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article
molten bath
borate
carbide
chloride
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US355280A
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Noboru Komatsu
Tohru Arai
Yoshihiko Sugimoto
Masayoshi Mizutani
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Toyota Central R&D Labs Inc
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Toyota Central R&D Labs Inc
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C10/00—Solid state diffusion of only metal elements or silicon into metallic material surfaces
    • C23C10/18—Solid state diffusion of only metal elements or silicon into metallic material surfaces using liquids, e.g. salt baths, liquid suspensions
    • C23C10/20—Solid state diffusion of only metal elements or silicon into metallic material surfaces using liquids, e.g. salt baths, liquid suspensions only one element being diffused
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
    • C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31678—Of metal

Definitions

  • ABSTRACT A method for forming a carbide layer of a V-a group element V, Nb or TA of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article in a treating molten bath, comprising heating a mixture of boric acid or a borate and a chloride of said V-a group element of the periodic table to its fusing state and immersing the article in the treating molten bath of said mixture, thereby forming a very hard carbide layer of said V-a group element on the surface of said article.
  • the method of this invention can be carried out without ageing the treating bath and can form a very smooth carbide layer on the surface of the article.
  • the carbide layer formed represents a high value of hardness and a superior resistance performance against wear and is thus highly suitable for the surface treatment of moulds such as dies and punches, tools such as pinchers and screwdrivers, parts for many kinds of tooling machines, and automobile parts to be subjected to wear.
  • the carbide of a V-a group element is much harder and less reactive with iron or steel at a high temperature than the tungsten carbide forming cemented carbide is. Therefore, the formation of the carbide layer of a V-a group element on the surface of a cutting tool composed of a cemented carbide greatly increases the durability of the tool.
  • the method mentioned above requires a relatively long time for preparing the treating bath due to the slowness of dissolution of the treating metal particles. Sometimes the treating metal particles deposit into the carbide layer formed which makes the surface of the layer rough. I
  • FIG. 1 is a photomicrograph showing a vanadium carbide layer formed on the surface of a carbon tool steel according to Example 1;
  • FIG. 2 is a photomicrograph showing a vanadium carbide layer formed on the surface of a cemented carbide containing 9 percent by weight (hereinafter percent means percent by weight) of cobalt according to Example 3;
  • FIG. 3 is an X-ray diffraction chart of the layer shown in FIG. 2;
  • FIG. 4 is a photomicrograph showing a niobium carbide layer formed on a cemented carbide according to Example 4.
  • the present invention is directed to an improvement of the method for forming a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article in a molten bath and is characterized in that the molten bath is composed of boric acid or a borate and a chloride of a V-a group element and in that the iron, ferrous alloy or cemented carbide article to be treated contains at least 0.05% of carbon.
  • the method of the present invention comprises preparing a treating molten bath consisting of boric acid or a borate and a chloride of a V-a group element and immersing the iron, ferrous alloy or cemented carbide article into the treating molten bath so as to form the carbide layer on the surface of said article.
  • a chloride of a V-a group element is employed as a main ingredient of the treating molten bath instead of the powders of a V-a group element used in the previously developed method mentioned above.
  • Said chloride is easily dissolved in a molten boric acid or borate and does not remain as solid particles. Therefore, the treating molten bath can be used as soon as the treating material is melted without the ageing of the bath and a very smooth carbide layer can be formed on the surface of the article.
  • a boric acid or a borate and a chloride of a V-a group element are mixed together and then the mixture is heated to its fusing state, or the boric acid or borate is heated to its fusing state and then the chloride is added into the molten boric acid or borate.
  • the chloride of a V-a group element vanadium chloride (VCl VCl niobium chloride (NbCl and tantalum chloride (TaCl and the like can be used.
  • the borate sodium borate (borax) (Na B O potassium borate (X 8 0 and the like can be used.
  • one or more than one kind of the chloride and borate, boric acid or a mixture of boric acid and a borate can be used.
  • the boric acid and borate have the functions of dissolving metallic oxides and keeping the surface of the article to be treated clean. Also, the boric acid and borate are not poisonous and hardly vaporize. Therefore the method of the present invention can be carried out in the open air.
  • the chloride of a V-a group element may be included in the molten bath in a quantity between about 1 to 40%. With use of a less amount of the chloride than 1%, the formation of the carbide layer would not be uniform and would be formed too slowly for practical purposes. If the chloride is added in amounts more than 40%, the viscosity of the molten bath becomes too high to be normally operated and the corrosiveness of the molten bath becomes too strong.
  • the remainder of the treating molten bath is boric acid, a borate or mixtures thereof.
  • Said boric acid or borate may be mixed in a quantity between 60 and 99%.
  • a salt such as a chloride or fluoride of an alkali metal can be added to the treating molten bath.
  • the iron, ferrous alloy or cemented carbide article to be treated must contain at least 0.05% of carbon, and should preferably contain 0.1% of carbon or higher.
  • the carbon in the article forms a carbide during the treatment. Namely it is supposed that the carbon in the article diffuses to the surface thereof and reacts with the V-a group element from the treating molten bath to form the carbide on the surface of the article. A higher content of the carbon in the article is more preferable for forming the carbide layer.
  • the iron, ferrous alloy or cemented carbide article containing less than 0.05% of carbon may not be formed with a uniform and thick carbide layer by treatment.
  • the article containing at least 0.05% of carbon only in the surface portion thereof can be treated to form a carbide layer on the surface of the article.
  • a pure iron article which is casehardened to increase the carbon content in the surface portion thereof, can be used as the article of the present invention.
  • cemented carbide means a sintered tungsten carbide containing cobalt.
  • Said cemented carbide may include a small amount of titanium carbide, niobium carbide, tantalum carbide and the like.
  • the carbon contained in the treating molten bath can be used as the source of the carbon for forming the carbide layer on the surface of the article.
  • the formation of the carbide layer is not stable and the use of the carbon in the treating molten bath is not practical.
  • the treating temperature may be selected within a wide range from the melting point of boric acid or borate to the melting point of the article to be treated.
  • the treating temperature may be selected within the range from 800 to 1,lC.
  • the treating time depends upon the thickness of the carbide layer to be formed. Heating shorter than minutes will, however, provide no practically accepted formation of said layer, although the final determination of the treating time depends on the treating temperature. With the increase of the treating time, the thickness of the carbide layer will be increased accordingly. In practice, an acceptable thickness of the layer can be realized within 30 hours or shorter. The prefera- 4 ble range of the treating time is from 10 minutes to 30 hours.
  • the vessel for maintaining the treating molten bath of the present invention can be made of graphite or heat resistant steel.
  • EXAMPLE 1 100 grams of borax was introduced into a graphite crucible having an inner diameter of 35mm innerdiameter and heated up to 900C for melting the borax in an electric furnace in the air, and then 16 grams of vanadium chloride (VCl powder was poured into the molten borax and mixed together for preparing a treating molten bath. Next, a specimen, 5mm diameter and 40mm long, made of carbon tool steel (JlS 8K4, containing 1.0% of carbon) was immersed into the treating molten bath and kept therein for 2 hours, taken out therefrom and air-cooled. Treating material which has adhered to the surface of the specimen was removed by washing with hot water and then the specimen treated was investigated. The surface of the specimen was very smooth.
  • the specimen was micrographically observed, and it was found that a layer as shown in FIG. 1 was formed.
  • the thickness of the layer was about 7 microns.
  • the layer was identified to be vanadium carbide (VC) by an X-ray diffraction method and by an X-ray microanalyzer. Boron was not detected from the specimen treated.
  • VC vanadium carbide
  • EXAMPLE 2 700 grams of borax was introduced into a graphite crucible having an inner diameter of mm and heated up to 950C for melting the borax in an electric furnace under air, and then 120 grams of niobium chloride powder was poured into the molten borax and mixed together for preparing a treating molten bath. Next, a specimen, 8mm in diameter and 40mm long, made of tool alloy steel (JIS SKD61, containing 0.45% of carbon) was immersed into the treating molten bath and kept therein for 2 hours, taken out therefrom and aircooled. Treating material adhered to the surface of the specimen was removed by washing with hot water.
  • JIS SKD61 tool alloy steel
  • the surface of the specimen treated was very smooth. After cutting and polishing the specimen, the cross section of the specimen was micrographically observed and tested by an X-ray diffraction method and by an X-ray microanalyzer.
  • the layer formed was identified to be niobium carbide and the thickness of the layer was about 4 microns.
  • EXAMPLE 3 grams of borax powder was introduced into a graphite crucible and heated up to l,00OC for melting the borax in an electric furnace under air, and then 38 grams of vanadium chloride (VCl powder of less than 100 mesh was poured into the molten borax together with mixing.
  • VCl powder vanadium chloride
  • a specimen, lmm thick, 5.5mm wide and 30mm long made of cemented carbide composed of 91% of tungsten carbide and 9% of cobalt was immersed into the treating molten bath and kept therein for 15 hours, taken out therefrom and air-cooled. Treating material adhered to the surface of the specimen was removed by dipping the specimen into hot water. The surface of the specimen treated was smooth.
  • the cross sectional area of the specimen was micrographically observed and tested by an X-ray diffraction method and by an X-ray microanalyzer.
  • a layer as shown in FIG. 2 was found.
  • strong vanadium carbide (VC) diffraction lines were detected from the layer.
  • FIG. 3 the chart of the X-ray diffraction is shown.
  • the layer was found to contain a large amount of vanadium.
  • the Hv hardness (Micro-Vickers Hardness) of the layer measured from the surface of the specimen was found to be about 2983. Also the Hv hardness (Micro- Vickers Hardness) of the mother material of the specimen was measured to be about 1525.
  • EXAMPLE 4 In the same manner as described in Example 3, a treating molten bath composed of 100 grams of borax and 25 grams of niobium chloride was prepared. Then a specimen having the same sizes and made of the same material as the specimen in Example 3 was treated for 4 hours at l,000C. By the treatment, a layer shown in FIG. 4 was formed on the surface of the specimen. Also the layer was tested by an X-ray diffraction method, an X-ray microanalyzer and Vickers Hardness Tester. Strong niobium carbide (NbC) diffraction lines were detected. The layer was found to contain a large amount of niobium, and the Hv hardness of the layer was about 2750.
  • NbC X-ray microanalyzer
  • a method for forming a carbide layer on the surface of an iron, ferrous alloy or cemented carbide article in a molten bath comprising the steps of preparing the molten bath consisting essentially of a chloride of an element selected from the group consisting of vanadium, niobium, tantalum and mixtures thereof and one member selected from the group consisting of boric 6 acid, a borate and mixtures thereof, immersing the article containing at least 0.05 percent of carbon into said molten bath, maintaining said article in said molten bath for forming the carbide layer of said element on the surface of said article, and removing the article out of the molten bath.
  • said article is a ferrous alloy selected from the group consisting of carbon steel and alloy steel containing at least 0.05 percent of carbon.
  • step of preparing the molten bath comprises heating boric acid or the borate up to its fusing state, adding the chloride into said molten boric acid or borate and mixing said chloride and said molten boric acid or borate.
  • step of preparing the molten bath comprises preparing the mixture of the chloride and boric acid or borate and heating said mixture up to its fusing state.
  • said molten bath contains chloride or fluoride of an alkali metal for lowering the viscosity of the molten bath.
  • cemented carbide article is made of a sintered tungsten carbide containing cobalt.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Powder Metallurgy (AREA)
  • Chemically Coating (AREA)
  • Chemical Treatment Of Metals (AREA)
US355280A 1973-04-12 1973-04-27 Method for forming of a carbide layer of a V-a group element of the periodic table on the surface of an iron, ferrous alloy or cemented carbide article Expired - Lifetime US3922405A (en)

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US (1) US3922405A (enrdf_load_stackoverflow)
JP (1) JPS5137893B2 (enrdf_load_stackoverflow)
DE (1) DE2322158C3 (enrdf_load_stackoverflow)
FR (1) FR2225544B1 (enrdf_load_stackoverflow)
GB (1) GB1378478A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2819856A1 (de) * 1977-05-09 1978-11-23 Toyoda Chuo Kenkyusho Kk Verfahren und material zur erzeugung einer carbidschicht auf gegenstaenden aus kohlenstoffhaltiger eisenlegierung
US4169913A (en) * 1978-03-01 1979-10-02 Sumitomo Electric Industries, Ltd. Coated tool steel and machining tool formed therefrom
US4202705A (en) * 1977-06-30 1980-05-13 Kabushiki Kaisha Toyoto Chuo Kenkyusho Treating bath, forming a mixed carbide layer of Va-Group elements on a ferrous alloy surface and resulting product
US4339484A (en) * 1977-05-17 1982-07-13 University Of Sydney Solar collector
EP0063386A1 (en) * 1981-04-20 1982-10-27 Kabushiki Kaisha Toyota Chuo Kenkyusho Method for forming a carbide layer on the surface of a ferrous alloy article or a cemented carbide article
US5234721A (en) * 1989-05-26 1993-08-10 Rostoker, Inc. Method for forming carbide coating on various metals and their alloys
US5458754A (en) 1991-04-22 1995-10-17 Multi-Arc Scientific Coatings Plasma enhancement apparatus and method for physical vapor deposition

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5123458B2 (enrdf_load_stackoverflow) * 1973-04-19 1976-07-16
GB2000814B (en) * 1977-07-07 1982-03-17 Toyoda Chuo Kenkyusho Kk Coating ferrous articles
CA1179242A (en) * 1980-06-17 1984-12-11 Norimasa Uchida Method for treating surfaces
RU2164963C1 (ru) * 2000-04-14 2001-04-10 Буйлов Валерий Николаевич Способ борирования деталей
JP4773486B2 (ja) * 2008-06-24 2011-09-14 株式会社ケンテック 表面処理方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3073717A (en) * 1958-12-31 1963-01-15 Robert J Pyle Coated carbon element for use in nuclear reactors and the process of making the element
US3451843A (en) * 1967-01-09 1969-06-24 Crucible Steel Co America Method of chromizing metal
US3600284A (en) * 1969-02-18 1971-08-17 Us Interior Method of adding refractory metal halides to molten salt electrolytes
US3719518A (en) * 1969-11-01 1973-03-06 Toyoda Chuo Kenkyusho Kk Process of forming a carbide layer of vanadium, niobium or tantalum upon a steel surface
US3778301A (en) * 1967-04-28 1973-12-11 Atomic Energy Commission Method of coating graphite tubes with refractory metal carbides

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3073717A (en) * 1958-12-31 1963-01-15 Robert J Pyle Coated carbon element for use in nuclear reactors and the process of making the element
US3451843A (en) * 1967-01-09 1969-06-24 Crucible Steel Co America Method of chromizing metal
US3778301A (en) * 1967-04-28 1973-12-11 Atomic Energy Commission Method of coating graphite tubes with refractory metal carbides
US3600284A (en) * 1969-02-18 1971-08-17 Us Interior Method of adding refractory metal halides to molten salt electrolytes
US3719518A (en) * 1969-11-01 1973-03-06 Toyoda Chuo Kenkyusho Kk Process of forming a carbide layer of vanadium, niobium or tantalum upon a steel surface

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2819856A1 (de) * 1977-05-09 1978-11-23 Toyoda Chuo Kenkyusho Kk Verfahren und material zur erzeugung einer carbidschicht auf gegenstaenden aus kohlenstoffhaltiger eisenlegierung
US4158578A (en) * 1977-05-09 1979-06-19 Kabushiki Kaisha Toyota Chuo Kenkyusho Method for forming a carbide layer of a Va-Group element of the periodic table or chromium on the surface of a ferrous alloy article
US4339484A (en) * 1977-05-17 1982-07-13 University Of Sydney Solar collector
US4202705A (en) * 1977-06-30 1980-05-13 Kabushiki Kaisha Toyoto Chuo Kenkyusho Treating bath, forming a mixed carbide layer of Va-Group elements on a ferrous alloy surface and resulting product
US4169913A (en) * 1978-03-01 1979-10-02 Sumitomo Electric Industries, Ltd. Coated tool steel and machining tool formed therefrom
EP0063386A1 (en) * 1981-04-20 1982-10-27 Kabushiki Kaisha Toyota Chuo Kenkyusho Method for forming a carbide layer on the surface of a ferrous alloy article or a cemented carbide article
US4400224A (en) * 1981-04-20 1983-08-23 Kabushiki Kaisha Toyota Chuo Kenkyusho Method for forming a carbide layer on the surface of a ferrous alloy article or a cemented carbide article
US5234721A (en) * 1989-05-26 1993-08-10 Rostoker, Inc. Method for forming carbide coating on various metals and their alloys
US5458754A (en) 1991-04-22 1995-10-17 Multi-Arc Scientific Coatings Plasma enhancement apparatus and method for physical vapor deposition
US6139964A (en) 1991-04-22 2000-10-31 Multi-Arc Inc. Plasma enhancement apparatus and method for physical vapor deposition

Also Published As

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DE2322158B2 (de) 1978-01-12
DE2322158C3 (de) 1978-09-07
JPS49127832A (enrdf_load_stackoverflow) 1974-12-06
DE2322158A1 (de) 1974-11-07
GB1378478A (en) 1974-12-27
JPS5137893B2 (enrdf_load_stackoverflow) 1976-10-19
FR2225544B1 (enrdf_load_stackoverflow) 1975-08-22
FR2225544A1 (enrdf_load_stackoverflow) 1974-11-08

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