WO2021106233A1 - Composant métallique et son procédé de production - Google Patents

Composant métallique et son procédé de production Download PDF

Info

Publication number
WO2021106233A1
WO2021106233A1 PCT/JP2020/005455 JP2020005455W WO2021106233A1 WO 2021106233 A1 WO2021106233 A1 WO 2021106233A1 JP 2020005455 W JP2020005455 W JP 2020005455W WO 2021106233 A1 WO2021106233 A1 WO 2021106233A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
metal
chromium compound
base material
chromium
Prior art date
Application number
PCT/JP2020/005455
Other languages
English (en)
Japanese (ja)
Inventor
尚男 冨士川
渡辺　崇則
宏之 渡邊
博貴 宮下
Original Assignee
エア・ウォーターＮｖ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2020013197A external-priority patent/JP7370263B2/ja
Application filed by エア・ウォーターＮｖ株式会社 filed Critical エア・ウォーターＮｖ株式会社
Priority to CN202080071298.9A priority Critical patent/CN114585768B/zh
Publication of WO2021106233A1 publication Critical patent/WO2021106233A1/fr

Links

Images

Classifications

    • 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
    • C23C10/28—Solid state diffusion of only metal elements or silicon into metallic material surfaces using solids, e.g. powders, pastes
    • C23C10/34—Embedding in a powder mixture, i.e. pack cementation
    • C23C10/36—Embedding in a powder mixture, i.e. pack cementation only one element being diffused
    • C23C10/38—Chromising
    • 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
    • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
    • 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
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/24—Nitriding

Definitions

  • the present invention relates to a metal product and a method for manufacturing the same.
  • Patent Document 1 a technique shown in Patent Document 1 below.
  • Patent Document 2 the applicant has grasped the following Patent Document 2 as prior art related to the related technology.
  • Patent Document 1 is intended to form a surface layer made of chromium carbonitride by subjecting an iron alloy material to a nitriding treatment in advance and then a chromasing treatment.
  • the above-mentioned Patent Document 1 has the following description.
  • the metal surface modification method according to claim 1 prepares a base material which is an iron-based metal or a nickel-based metal.
  • the surface of iron-based metals and nickel-based metals is covered with an oxide film or a passivation film.
  • the presence of an oxide film or a passivation film on the surface generally tends to hinder the diffusion and permeation of nitrogen atoms.
  • the nitriding treatment is performed in which the base material is heated and held in an atmosphere containing a nitriding source gas. By this nitriding treatment, nitrogen atoms are diffused and permeated on the surface of the base material activated by the halogenation treatment.
  • the nitrided base material is subjected to a chromaze treatment in which the nitrided base material is present in a powder containing metallic chromium powder and is heated and held at a temperature of 850 to 1200 ° C.
  • a chromaze treatment in which the nitrided base material is present in a powder containing metallic chromium powder and is heated and held at a temperature of 850 to 1200 ° C.
  • chromium treatment chromium atoms are diffused and permeated into the surface layer portion where nitrogen atoms are diffused and permeated, and a surface modification layer is formed.
  • 5 (a) and 5 (b) show the elemental distribution of the surface modification layer formed in the examples. The measurement was carried out by measuring the concentration distribution of the material cross section by EPMA (X-ray microanalyzer).
  • FIG. 5A is a surface modification layer formed by subjecting the SUS304 base material to a fluorine treatment, a soft nitriding treatment, and a chromaze treatment. The soft nitriding treatment was performed at 570 ° C. for 2 hours.
  • FIG. 5B is a surface modification layer formed by subjecting the SUS304 base material to a fluorine treatment, a nitriding treatment, and a chromaze treatment. The nitriding treatment was performed at 570 ° C. for 30 minutes. In each case, a layer having a high concentration of Cr and N and a low concentration of Fe is formed at a thickness of about 50 ⁇ m on the surface side. This can be regarded as a chromium nitride layer.
  • the chromium nitride layer is chromium about 82 wt%, nitrogen about 11% by weight, can be identified as a Cr 2 N. Further, at a thickness of about 60 ⁇ m on the lower side thereof, a layer having a low nitrogen concentration and a high Fe and Cr concentration is formed. This can be seen as a chromium-enriched layer in which chromium is diffused and permeated into the base material.
  • Patent Document 2 when a carbide coating layer is formed on an iron-based base material, an intermediate layer composed of a composite carbide of an element to be coated and iron of the base material is formed, and thermal expansion of the base material and the coating layer is performed. This is an attempt to prevent cracking of the coating layer due to a coefficient difference.
  • the sliding member of the present invention is characterized in that the steel member is coated with a chromium carbide layer via an intermediate layer composed of a composite carbide (Fe, Cr) C of iron and chromium. And. This layer structure is shown in FIG. 1 (a). As shown in FIG. 1A, cracking of the coating film can be prevented.
  • the present invention is a method for manufacturing a sliding member in which a chromium carbide layer is coated on a steel material portion via an intermediate layer composed of a composite carbide (Fe, Cr) C of iron and chromium by diffusion permeation treatment, and the steel material structure is It is characterized by containing cementite in advance and performing diffusion permeation treatment in the austenite + cementite region on the Fe—C system state diagram.
  • Fe 3 C is stably present in the austenite + cementite region. Therefore, Cr is supplied from the outside to react with Fe 3 C, as shown in FIG.
  • An intermediate layer made of (Fe, Cr) C can be reliably formed on the surface of the steel member.
  • an austenitic metal is subjected to a nitriding treatment and then a chromaze treatment.
  • This forms a surface layer of Cr 2 N layer, a chromium-concentrated layer of the inside.
  • the Cr 2 N layer is ceramic, the thermal expansion coefficient of 9 ⁇ 10 -6 / °C and small.
  • Thermal expansion coefficient of austenitic base material for most present inside is 17 ⁇ 10 -6 / °C, becomes about twice as compared with the Cr 2 N layer. Further, nitrogen is substantially not present in the chromium-enriched layer.
  • the coefficient of thermal expansion of the chromium-enriched layer is not significantly different from the coefficient of thermal expansion of the austenitic base metal.
  • the Cr 2 N layer is the outermost layer, in between the chromium-concentrated layer and the base material which exists as a lower layer, the thermal expansion coefficient is largely different divergence.
  • a thermal stress caused by repeated heating and cooling which may cause peeling or cracking of the Cr 2 N layer.
  • conventional metal products have restrictions on the environment in which they can be used and their uses.
  • the iron-based sliding member obtained by the technique of Patent Document 2 is subjected to diffusion permeation treatment of Cr or the like using an iron-based material containing cementite as a steel material structure in advance as a base material.
  • an iron-based material containing cementite as a steel material structure in advance
  • a carbide layer on the surface layer and an intermediate layer made of a composite carbide of iron and Cr or the like are formed inside the carbide layer.
  • the base material needs to be an iron-based material containing cementite in advance, that is, containing 0.6% by weight or more of carbon. Therefore, the intermediate layer cannot be formed with a material having high corrosion resistance, for example, stainless steel or heat-resistant steel, which has a low carbon content.
  • the compound precipitated in the intermediate layer is a carbide such as a Cr-based carbide, and is more easily decomposed when heated to a high temperature as compared with a Cr-based nitride or the like. Therefore, there is also a problem that the performance tends to deteriorate when used in a high temperature environment.
  • the present invention has been made to solve the above problems, and provides a metal product having the following object and a method for producing the same.
  • a metal product having a heat-resistant / corrosion-resistant and wear-resistant surface layer having high resistance to repeated thermal stress and a method for producing the same.
  • the metal product according to claim 1 adopts the following configuration in order to achieve the above object.
  • a base material which is an iron-based metal or a nickel-based metal and a surface modification layer formed on the surface of the base material are provided.
  • the surface modification layer is The chromium compound layer existing on the surface side and It is formed between the chromium compound layer and the base metal, and includes a precipitation layer in which the chromium compound is precipitated in the base metal constituting the base metal.
  • the metal product according to claim 2 adopts the following configuration in addition to the configuration according to claim 1. The closer the precipitation layer is to the chromium compound layer on the surface side, the larger the precipitation amount of the chromium compound.
  • the metal product according to claim 3 adopts the following configuration in addition to the configuration according to claim 1 or 2.
  • the base material is any one of stainless steel, heat-resistant steel, and nickel-based alloy having a carbon concentration of 0.6% by weight or less, and the chromium compound is a chromium nitride.
  • the method for producing a metal product according to claim 4 employs the following configuration in order to achieve the above object.
  • base metal that is iron-based metal or nickel-based metal Nitriding treatment is performed to heat and hold the base metal in an atmosphere containing a nitriding source gas.
  • a chromaze treatment in which the above-mentioned nitriding base material is present in a powder containing metallic chromium powder and heat-held.
  • the chromium compound layer existing on the surface side and A surface-modified layer exists between the chromium compound layer and the base metal, and is formed by including a precipitation layer in which the chromium compound is precipitated in the base metal constituting the base metal.
  • the nitriding treatment produces a nitriding layer having a thickness of at least 1.5 times or more the thickness of the chromium compound layer contained in the finally formed surface modification layer.
  • the method for producing a metal product according to claim 6 in addition to the configuration according to claim 5, the following configuration is adopted.
  • the nitriding layer produced by the nitriding treatment is subjected to a time to reach a predetermined thickness.
  • the metal product according to claim 1 includes a base material which is an iron-based metal or a nickel-based metal, and a surface modification layer formed on the surface of the base material.
  • the surface modification layer includes a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material. That is, a precipitation layer exists between the chromium compound layer, which is a hard ceramic layer, and the base material, which is an iron-based or nickel-based metal.
  • the precipitation layer is formed by precipitating a chromium compound in the base metal constituting the base material. Therefore, the coefficient of thermal expansion of each layer gradually increases from the surface to the deep part, with the chromium compound layer ⁇ precipitation layer ⁇ base material.
  • the difference in the coefficient of thermal expansion between the layers is smaller than that in the prior art in which the coefficient of thermal expansion greatly deviates between the chromium compound layer on the surface, the chromium-concentrated layer, and the base material.
  • the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained.
  • the environment and applications that can be used are wider than before.
  • the coefficient of thermal expansion of the precipitation layer gradually increases from the surface to the deep part. Therefore, the coefficient of thermal expansion changes continuously rather than stepwise from the chromium compound layer on the surface side to the base material.
  • the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained.
  • the environment and applications that can be used are wider than before.
  • the metal product according to claim 3 is any one of stainless steel, heat-resistant steel, and nickel-based alloy having a carbon concentration of 0.6% by weight or less as the base material.
  • a surface modification layer containing two layers, a chromium compound layer and a precipitation layer, on such a base material a metal product having excellent properties can be obtained.
  • Stainless steels, heat-resistant steels, and nickel-based alloys having a carbon concentration of 0.6% by weight or less do not contain high concentrations of carbon such that cementite is present in the base material. Therefore, it is not possible to form an intermediate layer made of a carbide layer on the surface layer and a composite carbide of iron and Cr or the like inside the carbide layer only by performing the diffusion permeation treatment of chromium.
  • a chromium nitride layer is formed as a chromium compound layer on the surface, and the difference in coefficient of thermal expansion between the base material and the like is formed. It is possible to form a precipitation layer in which chromium nitride is precipitated in the base metal in order to alleviate the above.
  • This metal product has extremely high hardness, excellent heat resistance and corrosion resistance, and exhibits excellent performance in environments such as high-temperature oxidation, high-temperature corrosion, erosion, and cavitation.
  • the above metal products exhibit excellent performance in an acid / alkali environment, a neutral environment, and a corrosive environment such as chloride such as seawater.
  • the metal product can be applied to parts that require heat resistance and wear resistance in a turbocharger, for example, in the case of automobile parts.
  • a turbocharger for example, in the case of automobile parts.
  • it prevents melting damage to the alloy and maintains excellent performance.
  • it can be applied to many parts such as blade materials, valve materials, pump materials, etc. in the environment such as chemical industry, thermal power generation, and alternative energy.
  • it can be applied to materials and parts used in an acid / alkali environment, a neutral environment, and a corrosive environment such as chloride such as seawater.
  • the method for producing a metal product according to claim 4 is to perform a nitriding treatment on a base material which is an iron-based metal or a nickel-based metal by heating and holding the base material in an atmosphere containing a nitride source gas, and containing metallic chromium powder. Chromize treatment is performed in which the above-mentioned nitriding base material is present in the powder and is heated and held. As a result, a surface modification layer is formed on the surface of the base material.
  • the surface modification layer is made to include a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material.
  • the precipitation layer has a structure in which a chromium compound is precipitated in the base metal metal constituting the base material. Therefore, the coefficient of thermal expansion of each layer gradually increases from the surface to the deep part, with the chromium compound layer ⁇ precipitation layer ⁇ base material. Therefore, the difference in the coefficient of thermal expansion between the layers is smaller than that in the prior art in which the coefficient of thermal expansion greatly deviates between the chromium compound layer on the surface, the chromium-concentrated layer, and the base material. As a result, the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained. The environment and applications that can be used are wider than before.
  • the method for producing a metal product according to claim 5 is a nitride layer having a thickness of at least 1.5 times or more the thickness of the chromium compound layer contained in the surface-modified layer finally formed by the nitriding treatment. To generate. Thereby, the precipitation layer as described above can be surely formed.
  • the chromaze treatment is carried out for a period of time during which the nitriding layer produced by the nitriding treatment has a predetermined thickness. Thereby, the precipitation layer as described above can be surely formed.
  • FIG. 1 It is a schematic diagram explaining the difference between a conventional product and this invention. It is a diagram which shows the element distribution state of the surface modification layer, (A) is Comparative Example 1, and (B) is Example 1. It is a cross-sectional photomicrograph of a surface layer portion, (A) is Comparative Example 1, and (B) is Example 1. It is a diagram which shows the cross-sectional hardness distribution of Comparative Example 1 and Example 1. FIG. It is an appearance observation photograph after a shot blast test, (A) is Comparative Example 1, and (B) is Example 1. It is an appearance observation photograph after the heating and cooling repeated test, (A) is Comparative Example 1, and (B) is Example 1. It is a cross-sectional micrograph of the surface layer part of Example 2.
  • ⁇ is a ceramic layer Cr 2 N layer Background of development surface, chromium-concentrated layer of the inside and a base material alloy layer at the interface of the ceramic layer and the alloy layer, the thermal expansion coefficient is deviated Is the root of the problem. That is, the chromium rich layer of the alloy layer present between the Cr 2 N layer and the base material, there is no nitrogen. For this reason, the coefficient of thermal expansion at the above-mentioned layer interface deviates, and the resistance to repeated thermal stress is not sufficient.
  • the alloy layer interposed between the Cr 2 N layer and the base material was recalled that precipitating chromium compound is a ceramic. That is, between the Cr 2 N layer and the base material, to form a layer of the thermal expansion coefficient of the medium between the ceramic layer and the alloy layer. As a result, the dissociation of the coefficient of thermal expansion at the layer interface described above is alleviated, and the problem is solved.
  • the chromium compound it is preferable to precipitate a chromium nitride instead of a carbide such as a chromium carbide.
  • Nitride has a higher decomposition temperature than carbide and is hard to decompose even at high temperature when heated, so the performance to alleviate the deviation of the coefficient of thermal expansion of the precipitated layer does not deteriorate when used in a high temperature environment. Because it is effective.
  • FIG. 1 is a schematic view illustrating the difference between the above-mentioned conventional product and the present invention.
  • (A) is a conventional product
  • (B) is an invention of the present application.
  • FIG. 1 (A) conventional products, thermal expansion coefficient of the Cr 2 N layer and chromium-concentrated layer (high-chrome alloy layer) is greatly different. Nitrogen does not exist in the chromium-enriched layer of the alloy layer, and the coefficient of thermal expansion deviates at the layer interface.
  • the present invention is, in the deposition layer is present nitrogen, toward the base material via deposition layer from Cr 2 N layer (Cr 2 N deposition layer), thermal expansion coefficient gradually Has changed to. The deviation of the coefficient of thermal expansion at the layer interface is alleviated.
  • the coefficient of thermal expansion increases toward the bottom of the vertical axis.
  • the metal product of the present embodiment includes a base material which is an iron-based metal or a nickel-based metal, and a surface modification layer formed on the surface of the base material.
  • Base material An iron-based metal or a nickel-based metal is used as the base metal metal constituting the base metal.
  • iron-based metal various steel materials and iron-based alloys can be used.
  • steel materials and iron-based alloys include carbon steel, alloy steel, nickel chrome steel, nickel chrome molybdenum steel, chrome steel, chrome molybdenum steel, manganese steel, tool steel, stainless steel, heat resistant steel, nitrided steel, and skin.
  • Various steel types such as hardened steel can be applied.
  • a nickel-based alloy can be used as the nickel-based metal.
  • the nickel-based alloy for example, an alloy having a nickel content of 50% by weight or more can be used.
  • nickel-copper type Monel
  • nickel-chromium type Inconel
  • nickel-molybdenum type Hastelloy
  • any one of stainless steel, heat-resistant steel, and nickel-based alloy having a carbon concentration of 0.6% by weight or less for example, ferritic stainless steels such as SUS410L and SUS430, martensitic stainless steels such as SUS410 and SUS420J2, two-phase stainless steels such as SUS821L1, SUS323L and SUS329J31, SUS329J3L, SUS329J4L and SUS327L1, SUS304, SUS316 and SUS310.
  • Ferritic stainless steels such as SUH21 and SUH409, martensitic heat resistant steels such as SUH3 and SUH11, austenitic heat resistant steels such as SUH35 and SUH660, heat resistant cast steels such as SCH21 and SCH22, and nickel groups such as ALLOY625 and ALLOY800H.
  • An alloy or the like can be preferably used.
  • Such a stainless steel, heat-resistant steel, and nickel-based alloy having high corrosion resistance that does not contain cementite in the base material are subjected to, for example, nitriding treatment to diffuse and permeate nitrogen atoms, and then chromium diffusion and permeation treatment.
  • nitriding treatment to diffuse and permeate nitrogen atoms
  • chromium diffusion and permeation treatment In order to form a chromium nitride layer as a chromium compound layer on the surface and alleviate the difference in thermal expansion coefficient between the base metal and the base metal, it is possible to form a precipitation layer in which chromium nitride is precipitated in the base metal. ..
  • the surface modification layer is composed of a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material.
  • the surface modification layer can be formed on the surface of the base material by subjecting the base material to a nitriding treatment and a chromaze treatment. At this time, if necessary, a halogenation treatment is performed before the nitriding treatment.
  • the chromium compound layer is formed by combining the nitrogen atoms of the nitride layer formed on the surface of the base metal by the above-mentioned nitriding treatment and the chromium atoms that have penetrated into the above-mentioned nitride layer by the above-mentioned chromizing treatment.
  • the nitrided layer is an iron nitride layer on the surface and a nitrogen diffusion layer in the deep part thereof. The iron nitride layer on the surface may not be formed depending on conditions such as nitriding treatment.
  • Chromium compound constituting the chromium compound layer is preferably a Cr 2 N.
  • the chromium compound layer can be formed to a thickness of about 5 to 50 ⁇ m from the viewpoint of performance and economy.
  • the precipitation layer is formed by precipitating a chromium compound in the base metal metal constituting the base material.
  • the precipitation layer is formed by invading the nitrogen diffusion layer in which nitrogen atoms are diffused in the base metal by the above-mentioned nitriding treatment by the above-mentioned chromium treatment. That is, the chromium atom that has penetrated deeper than the chromium compound layer forms a chromium compound with the nitrogen atom existing in the nitrogen diffusion layer and precipitates. Since it is on the deeper side than the surface, the nitrogen atom concentration in the nitrogen diffusion layer is low, and the chromium compound does not form a layer as in the above-mentioned chromium compound layer, but the particulate chromium compound is precipitated.
  • the coefficient of thermal expansion of each layer increases sequentially from the surface to the deep part with the chromium compound layer ⁇ precipitation layer ⁇ base material. Therefore, the difference in the coefficient of thermal expansion between the layers becomes small. This increases the resistance of the surface layer to repeated thermal stresses.
  • the closer the precipitation layer is to the chromium compound layer on the surface side the larger the precipitation amount of the chromium compound.
  • the closer the precipitation layer is to the base material in the deep part the smaller the precipitation amount of the chromium compound is.
  • the chromium compound is preferably a chromium nitride, not a carbide such as a chromium carbide.
  • Nitride has a higher decomposition temperature than carbide and is less likely to decompose even at high temperatures when heated, so the performance of mitigating the deviation of the coefficient of thermal expansion of the precipitated layer is less likely to deteriorate when used in a high temperature environment. Because.
  • the nitrogen concentration of the precipitation layer is higher as it is closer to the chromium compound layer on the surface side, and is lower as it is closer to the base material in the deep part.
  • the coefficient of thermal expansion of the precipitation layer gradually increases from the surface toward the deep part. Therefore, the coefficient of thermal expansion between each layer gradually increases from the surface chromium compound layer toward the deep base material. This makes the surface layer more resistant to repeated thermal stresses. That is, peeling and cracking can be prevented by absorbing the strain generated by the thermal stress.
  • the precipitation layer can be formed to have a thickness of about 5 to 100 ⁇ m at a portion where the nitrogen concentration is 5 atomic% or more. A more preferable range of the thickness of the precipitation layer is 8 to 50 ⁇ m.
  • nitrogen is combined with Cr whose concentration decreases toward the inside, Cr 2 N whose precipitation amount decreases toward the inside is formed, and the precipitation layer of the present invention is formed. In such a precipitation layer, the hardness gradually decreases toward the inside.
  • the metal product of the present embodiment includes a base material which is an iron-based metal or a nickel-based metal, and a surface modification layer formed on the surface of the base material.
  • the surface modification layer includes a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material. That is, a precipitation layer exists between the chromium compound layer, which is a hard ceramic layer, and the base material, which is an iron-based or nickel-based metal.
  • the precipitation layer is formed by precipitating a chromium compound in the base metal constituting the base material. Therefore, the coefficient of thermal expansion of each layer gradually increases from the surface to the deep part, with the chromium compound layer ⁇ precipitation layer ⁇ base material.
  • the difference in the coefficient of thermal expansion between the layers is smaller than that in the prior art in which the coefficient of thermal expansion greatly deviates between the chromium compound layer on the surface, the chromium-concentrated layer, and the base material.
  • the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained.
  • the environment and applications that can be used are wider than before.
  • the coefficient of thermal expansion of the precipitation layer gradually increases from the surface to the deep part. Therefore, the coefficient of thermal expansion changes continuously rather than stepwise from the chromium compound layer on the surface side to the base material.
  • the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained.
  • the environment and applications that can be used are wider than before.
  • the base material is any one of stainless steel, heat-resistant steel, and nickel-based alloy having a carbon concentration of 0.6% by weight or less.
  • a surface modification layer containing two layers, a chromium compound layer and a precipitation layer By forming a surface modification layer containing two layers, a chromium compound layer and a precipitation layer, on such a base material, a metal product having excellent properties can be obtained.
  • Stainless steels, heat-resistant steels, and nickel-based alloys having a carbon concentration of 0.6% by weight or less do not contain high concentrations of carbon such that cementite is present in the base material. Therefore, it is not possible to form an intermediate layer made of a carbide layer on the surface layer and a composite carbide of iron and Cr or the like inside the carbide layer only by performing the diffusion permeation treatment of chromium.
  • a chromium nitride layer is formed as a chromium compound layer on the surface, and the difference in coefficient of thermal expansion between the base material and the like is formed. It is possible to form a precipitation layer in which chromium nitride is precipitated in the base metal in order to alleviate the above.
  • This metal product has extremely high hardness, excellent heat resistance and corrosion resistance, and exhibits excellent performance in environments such as high-temperature oxidation, high-temperature corrosion, erosion, and cavitation.
  • the above metal products exhibit excellent performance in an acid / alkali environment, a neutral environment, and a corrosive environment such as chloride such as seawater.
  • the metal product can be applied to parts that require heat resistance and wear resistance in a turbocharger, for example, in the case of automobile parts.
  • a turbocharger for example, in the case of automobile parts.
  • it prevents melting damage to the alloy and maintains excellent performance.
  • it can be applied to many parts such as blade materials, valve materials, pump materials, etc. in the environment such as chemical industry, thermal power generation, and alternative energy.
  • it can be applied to materials and parts used in an acid / alkali environment, a neutral environment, and a corrosive environment such as chloride such as seawater.
  • the base metal which is an iron-based metal or a nickel-based metal
  • nitriding treatment the base metal is heated and held in an atmosphere containing a nitriding source gas.
  • chromaze treatment the nitrided base material is present in a powder containing metallic chromium powder and is heated and held.
  • a halogenation treatment can be performed prior to the nitriding treatment.
  • the halogenation treatment is performed by heating and holding the base metal in an atmosphere gas containing halogen using a heating furnace capable of controlling the atmosphere.
  • halogen gas such as F 2 , Cl 2 , HCl, NF 3 or a halide gas can be used.
  • a mixed gas containing 0.5 to 20% by volume of halogen and the balance being nitrogen gas, hydrogen gas, an inert gas or the like can be used.
  • the halogenation treatment activates the surface by heating and holding the base material at 200 to 550 ° C. for about 10 minutes to 3 hours in the atmospheric gas.
  • nitriding treatment In the nitriding treatment, if necessary, the halogenated base material is heated and held in an atmosphere containing a nitriding source gas.
  • any method of gas nitriding treatment, gas nitrocarburizing treatment, salt bath nitriding treatment, vacuum nitriding treatment, and ion nitriding (plasma nitriding) treatment can be applied.
  • the gas nitriding / gas nitrocarburizing is performed in an atmosphere of nitriding or soft nitriding, that is, in an atmosphere in which NH 3 is used as a nitrogen source and N 2 , CO, CO 2 , H 2 and the like are mixed as necessary. This can be done by heating and holding the base metal that has been halogenated.
  • the salt bath nitriding can be performed by heating and holding the base metal in a salt bath containing cyanide or cyanic acid as a main component.
  • ion nitriding In ion nitriding (plasma nitriding), a glow discharge is generated by applying a DC voltage of several hundred volts with the furnace body as the anode and the object to be treated as the cathode in a nitrogen mixed gas atmosphere of 0.1 to 10 Pa.
  • the ionized gas component is accelerated at high speed to collide with the surface of the object to be treated, which is heated and nitriding is promoted by a sputtering action or the like.
  • the heating temperature and holding time can be appropriately determined according to the nitriding method to be adopted and the characteristics of the target surface modification layer. For example, it can be heated and held at a predetermined temperature within the range of 350 to 900 ° C. (preferably 350 to 650 ° C.) for a predetermined time.
  • a nitrogen diffusion layer having a high nitrogen concentration is formed on the surface layer portion of the base material.
  • the chromium atom that diffuses and permeates by the chromium treatment and the nitrogen atom existing in the nitrogen diffusion layer are bonded to form a chromium nitride layer as a chromium compound layer.
  • the soft nitriding treatment is performed as the above nitriding treatment, a carbon dioxide diffusion layer having a high nitrogen concentration and a high carbon concentration is formed on the surface layer portion of the base material.
  • the chromium atom that diffuses and permeates by the chromium treatment is bonded to the nitrogen atom and the carbon atom existing in the carbon dioxide diffusion layer, and a chromium nitride layer is formed as a chromium compound layer.
  • a diffusion layer in which nitrogen is diffused at a nitrogen concentration of 10 atomic% or more and a thickness of 5 ⁇ m or more by the above nitriding treatment.
  • a treatment for normalizing the surface can be performed if necessary.
  • a process such as shot peening or a barrel can be adopted.
  • the nitrided base material is present in a powder containing metallic chromium powder and is heated and held.
  • chromium treatment chromium atoms are diffused and permeated from the surface of the base metal after the nitriding treatment.
  • the chromaze treatment is performed only for a time when the nitriding layer (compound layer + diffusion layer) generated by the nitriding treatment has a predetermined thickness.
  • the nitriding layer compound layer + diffusion layer
  • the chromaze treatment can be performed by the powder packing method.
  • the powder pack method is This is performed by burying the base metal that has been subjected to the nitriding treatment in the treatment agent powder filled in the heat-resistant case, placing the heat-resistant case in an atmosphere furnace, and heating and holding the heat-resistant case while flowing a gas for promoting the reaction. By doing so, the chromium atoms are treated so as to diffuse and permeate from the surface of the base metal after the nitriding treatment.
  • a metal chromium powder or an iron-chromium alloy powder, an Al 2 O 3 powder for preventing sintering, and a powder agent to which a small amount of NH 4 Cl or NH 4 F for promoting a reaction is added are used. Can be done.
  • H 2 or Ar As the gas for promoting the reaction, H 2 or Ar can be used.
  • Heat holding is held at a predetermined temperature within the range of 850 to 1200 ° C. (preferably 900 to 1200 ° C.) for a predetermined time. By doing so, chromium atoms are diffused and permeated from the surface of the base metal after the nitriding treatment to form a surface modification layer.
  • a surface modification layer is formed on the surface of the base material by subjecting the above-mentioned base material to a nitriding treatment and a chromaze treatment.
  • the surface modification layer includes a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material.
  • the precipitation layer is formed by precipitating a chromium compound in the base metal constituting the base material.
  • Chromium compounds to form the chromium compound layer is preferably a Cr 2 N.
  • the precipitation layer inside the Cr 2 N layer can be rephrased as the inclined structure layer of Cr 2 N.
  • Such a precipitated layer is thermodynamically not high enough to form Cr 2 N in layers.
  • amount of precipitation of Cr 2 N decreases as the nitrogen concentration decreases.
  • the nitrogen concentration becomes such that Cr 2 N cannot be precipitated. In this manner, the deposition layer is than an inclined deposition layer of Cr 2 N.
  • the Cr 2 N is higher decomposition temperature than carbides, for difficult to decompose at high temperatures when heated, deterioration in performance to mitigate the divergence of the thermal expansion coefficient of the deposited layer when used in a high temperature environment This is because it is difficult to do.
  • a base material which is an iron-based metal or a nickel-based metal is subjected to a nitriding treatment in which the base material is heated and held in an atmosphere containing a nitride source gas, and a powder containing metal chromium powder is performed. Chromize treatment is performed in which the above-mentioned nitriding base material is present and held by heating. As a result, a surface modification layer is formed on the surface of the base material.
  • the surface modification layer is made to include a chromium compound layer existing on the surface side and a precipitation layer existing between the chromium compound layer and the base material.
  • the precipitation layer has a structure in which a chromium compound is precipitated in the base metal metal constituting the base material. Therefore, the coefficient of thermal expansion of each layer gradually increases from the surface to the deep part, with the chromium compound layer ⁇ precipitation layer ⁇ base material. Therefore, the difference in the coefficient of thermal expansion between the layers is smaller than that in the prior art in which the coefficient of thermal expansion greatly deviates between the chromium compound layer on the surface, the chromium-concentrated layer, and the base material. As a result, the surface layer has higher resistance to repeated thermal stress than before, and the heat resistance, corrosion resistance, and wear resistance of the surface layer can be maintained. The environment and applications that can be used are wider than before.
  • FIG. 2A shows the elemental distribution of the surface modified layer formed by subjecting the SUS304 base material to fluorine treatment, nitriding treatment and chromaze treatment under the following conditions.
  • Fluorine treatment Atmosphere: Fluorine-based gas (NF 3 : 10 vol% + N 2 : 90 vol%) Temperature: 300 ° C Time: 15 minutes ⁇ Nitriding treatment Atmosphere: NH 3 : 50 vol% + N 2 : 50 vol% Temperature: 570 ° C Time: 30 minutes ⁇ Chromize treatment
  • Treatment agent Powdered Cr or Fe-Cr alloy to which a required amount of Al 2 O 3 for preventing sintering is added and a small amount of NH 4 Cl for reaction promotion is added.
  • Air flow Hydrogen Or argon airflow Temperature: 1050 ° C Time: 10 hours
  • FIG. 2B shows the elemental distribution of the surface modified layer formed by subjecting the SUS310S base material to a fluorine treatment, a nitriding treatment, and a chromaze treatment under the following conditions.
  • Treatment agent Metal Cr grains or Fe-Cr alloy grains + Al 2 O 3 for anti-sintering + Small amount NH 4 Cl for reaction promotion
  • Airflow Hydrogen or Argon Temperature: 1050 ° C Time: 2 hours
  • a layer having a high concentration of Cr and N and a low concentration of Fe is formed at a thickness of about 10 to 20 ⁇ m on the surface side.
  • This can be regarded as a chromium nitride layer.
  • the chromium nitride layer contains about 80% by weight of chromium and about 10% by weight of nitrogen as measured by the weight concentration ratio shown in FIG. 2 (A).
  • chromium is about 60 atomic% and nitrogen is about 30 atomic%. This allows identified as Cr 2 N.
  • a layer having a high concentration of Fe and Cr is formed at a thickness of about 10 to 60 ⁇ m on the lower side thereof. This is a chromium-enriched layer in which chromium is diffused and permeated into the base material.
  • the surface in FIG. 2A is the position where Cr and N rise.
  • Comparative Example 1 is nitrogen in the high Cr concentration layer underlying the Cr 2 N layer has not been detected, are not substantially nitrogen present.
  • the layer having this inclined composition is the precipitation layer of the present invention.
  • FIG. 3A is a cross-sectional micrograph of the surface layer portion of Comparative Example 1.
  • FIG. 3B is a cross-sectional micrograph of the surface layer portion of Example 1 above. Comparative Example 1, Cr 2 N layer on the surface, the interface of the high-Cr diffusion layer and the base material are clearly observed. Example 1, the interface of the deposited layer and the base material with Cr 2 N layer and under it, not clearly observed as compared to Comparative Example 1.
  • FIG. 4 shows the results of measuring the cross-sectional hardness of Comparative Example 1 and Example 1.
  • the hardness is as high as MHv1500 or more at about 10 ⁇ m from the surface, but the hardness is sharply lowered to about MHv500 or less at a depth of 20 ⁇ m or more from the surface. Nitrogen is not substantially present in this portion, substantially free even precipitation of Cr 2 N.
  • Example 1 a layer having a high hardness of about 20 ⁇ m is present from the surface, and a hardness gradient layer is formed in which the hardness gradually decreases from about MHv1400 to about MHv500 or less toward the base material side. That is, about 20 ⁇ m from the surface is a chromium compound layer having the hardness of the chromium compound layer, and a portion having a depth of about 50 ⁇ m or more from the surface is the base material layer having the hardness of the base material. It is a hardness gradient layer between the material layers, but the hardness gradually decreases.
  • the chromium concentration and the nitrogen concentration are gradually decreased. At least 5 atomic% or more nitrogen atoms is combine with chromium Cr 2 N by Kuromaizu process performed at 850 ° C. or higher. Therefore, under the Cr 2 N layer, a layer of chromium concentration and the nitrogen concentration decreases gradually is formed.
  • This layer is a deposition layer of the present invention that Cr 2 N is the precipitation amount toward the base material side dispersed precipitates is gradually reduced.
  • FIG. 5A is an appearance observation photograph of Comparative Example 1 after shot blasting was performed for 10 seconds.
  • FIG. 5B is an appearance observation photograph of Example 1 after shot blasting was performed for 30 seconds.
  • a large number of peelings caused by the impact of shot blasting occurred in the portions indicated by some arrows as an example. No such peeling or cracking occurred on the surface of Example 1.
  • FIG. 6A is an appearance observation photograph of Comparative Example 1.
  • FIG. 6B is an appearance observation photograph of Example 1.
  • Example 2 SUS329J4L, which is a duplex stainless steel, was used as a base material and subjected to fluorine treatment, nitriding treatment and chromaze treatment under the following conditions.
  • FIG. 7 is a cross-sectional micrograph of the surface layer portion of Example 2.
  • Example 2 also, on the inner side of the Cr 2 N layer have increases and N concentration, the austenite phase is stabilized, precipitation of the ⁇ layer is not observed.
  • FIG. 8 is a diagram showing the element distribution state of the surface modification layer of Example 2.
  • Example 2 also, be graded composition region is formed as going inside the Cr 2 N layer clearly seen.
  • Example 2 it can be seen that the SUS329J4L ferritic stainless steel has a structure in which precipitation of the ⁇ phase is suppressed and peeling is difficult.
  • FIG. 9 is an appearance observation photograph after performing a shot blast test (glass powder: 0.4 MPa ⁇ 30 seconds) in Example 2 above.
  • FIG. 10 is an appearance observation photograph after performing a test in which heating and cooling from 1000 ° C. to room temperature is repeated 100 times in Example 2. In this case as well, no peeling or cracking occurred.
  • Table 1 below shows the treatment conditions, the thickness of each treatment layer, and the presence or absence of peeling or cracking in Examples 1 to 8 and Comparative Examples 1 to 4.
  • the hardness of Cr 2 N layer becomes MHv1400 or more, MHv1400 since following MHv500 more regions of Cr 2 N is in the dispersed precipitated hardness is increased hardness gradient layer, to identify the thickness of MHv500 ⁇ 1400 from a cross-sectional hardness measurement results, expressed as the deposition layer thickness It was done.
  • the thickness of MHv500 to 1400 is similarly specified and described from the cross-sectional hardness measurement result.
  • the thickness of the nitrided layer (compound layer + diffusion layer) formed by the nitriding treatment is the surface modified layer finally formed. It is at least 1.5 times the thickness of the thickness of the chromium compound layer (Cr 2 N layer) contained.
  • nitride layer thickness formed by the nitriding treatment is 1.5 times or less the thickness of the finally formed by the chromium compound layer (Cr 2 N layer).

Abstract

L'invention concerne un composant métallique ayant une couche de surface qui est résistante à la chaleur/à la corrosion et à l'usure, la couche de surface ayant une durabilité élevée vis-à-vis d'un stress thermique répété.　La présente invention comprend un matériau parent qui est un métal à base de fer ou un métal à base de nickel, et une couche d'amélioration de surface formée sur la surface du matériau parent. La couche d'amélioration de surface est configurée de manière à comprendre une couche de composé de chrome qui est présente sur le côté surface, et une couche de dépôt qui est présente entre la couche de composé de chrome et le matériau parent, la couche de dépôt étant telle que le composé de chrome est déposé dans un métal de matériau parent constituant le matériau parent.　Les coefficients de dilatation thermique de ces couches augmentent séquentiellement de la surface vers une section profonde de sorte que le coefficient de dilatation thermique de la couche de composé de chrome est inférieur à celui de la couche de dépôt qui, à son tour, est inférieur à celui du matériau parent. En particulier, la différence de coefficient de dilatation thermique entre chacune des couches est faible. Ceci permet d'augmenter la durabilité de la couche de surface par rapport à un stress thermique répété et de maintenir les caractéristiques de résistance à la chaleur/corrosion et de résistance à l'usure de la couche de surface. Il existe de nombreux environnements et de nombreuses applications dans lesquels la présente invention peut être utilisée.
PCT/JP2020/005455 2019-11-26 2020-02-13 Composant métallique et son procédé de production WO2021106233A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202080071298.9A CN114585768B (zh) 2019-11-26 2020-02-13 金属制品及其制造方法

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2019-212791 2019-11-26
JP2019212791 2019-11-26
JP2020-013197 2020-01-30
JP2020013197A JP7370263B2 (ja) 2019-11-26 2020-01-30 金属製品およびその製造方法

Publications (1)

Publication Number Publication Date
WO2021106233A1 true WO2021106233A1 (fr) 2021-06-03

Family

ID=76129288

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2020/005455 WO2021106233A1 (fr) 2019-11-26 2020-02-13 Composant métallique et son procédé de production

Country Status (1)

Country Link
WO (1) WO2021106233A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57134551A (en) * 1981-02-14 1982-08-19 Sumitomo Metal Ind Ltd Manufacture of corrosion resistant steel pipe with superior workability and high temperature strength
JP2000178711A (ja) * 1997-11-28 2000-06-27 Maizuru:Kk 鉄系材料の表面処理方法およびそれに用いる塩浴炉
JP2008144654A (ja) * 2006-12-08 2008-06-26 Honda Motor Co Ltd 動弁装置の摺動部品
JP2010007134A (ja) * 2008-06-27 2010-01-14 Air Water Inc 鋼材の表面処理方法および表面処理装置ならびにそれらによって得られる鋼材
JP2017043837A (ja) * 2015-08-28 2017-03-02 株式会社椿本チエイン チェーン部品、及びチェーン

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57134551A (en) * 1981-02-14 1982-08-19 Sumitomo Metal Ind Ltd Manufacture of corrosion resistant steel pipe with superior workability and high temperature strength
JP2000178711A (ja) * 1997-11-28 2000-06-27 Maizuru:Kk 鉄系材料の表面処理方法およびそれに用いる塩浴炉
JP2008144654A (ja) * 2006-12-08 2008-06-26 Honda Motor Co Ltd 動弁装置の摺動部品
JP2010007134A (ja) * 2008-06-27 2010-01-14 Air Water Inc 鋼材の表面処理方法および表面処理装置ならびにそれらによって得られる鋼材
JP2017043837A (ja) * 2015-08-28 2017-03-02 株式会社椿本チエイン チェーン部品、及びチェーン

Also Published As

Publication number Publication date
CN114585768A (zh) 2022-06-03

Similar Documents

Publication Publication Date Title
CN106687615B (zh) 金属的表面改性方法及金属制品
JP2005531694A (ja) 表面改質ステンレス鋼
US20050244668A1 (en) Heat-resistant ti alloy material excellent in resistance to corrosion at high temperature and to oxidation
WO2004031434A1 (fr) Pieces en acier inoxydable carbonitrure en surface possedant une excellente resistance a l'usure et leurs procedes de fabrication
JP3029546B2 (ja) クロム拡散浸透耐熱合金部材とその製法
JPS6035989B2 (ja) ガスによる鋼のクロマイジング方法に関する改良
WO2020053443A1 (fr) Objet en acier inoxydable ayant une surface modifiée avec du chrome
JP2008231563A (ja) 浸炭部品の製造方法
WO2021106233A1 (fr) Composant métallique et son procédé de production
JP7370263B2 (ja) 金属製品およびその製造方法
CN114585768B (zh) 金属制品及其制造方法
JP4598499B2 (ja) 複合層被覆部材の製造方法
JP6101058B2 (ja) フェライト系表面改質金属部材の製造方法
CN105803385B (zh) 用于蒸汽环境的阀门及其表面处理方法
JP2021014611A (ja) 耐摩耗被膜を備える摺動部材及び耐摩耗被膜の形成方法
Taczała-Warga et al. Low-pressure ferritic nitrocarburizing: a review
Ratayski et al. Influence of elevated temperature and reduced pressure on the degradation of iron nitride compound layer formed by plasma nitriding in AISI D2 tool steels
JPH10330906A (ja) オーステナイト系ステンレス製品の製法
JP2014070269A (ja) オーステナイト系表面改質金属部材およびオーステナイト系表面改質金属部材の製造方法
JPH0971855A (ja) 浸炭硬化食器類およびその製法
Kianicová Cyclic Oxidation of Diffusion Aluminide Coatings
Tarelnyk et al. Energy Dispersive X-Ray Microanalysis of Part Surface Layer Carburized by Electric Spark Alloying
Naeem et al. Improved surface properties of AISI-420 steel by TiC based coating using graphite cathodic cage with titanium lid in plasma deposition
JP2004190560A (ja) ピストンリング
Mikołajczak et al. Laser alloying of 316L steel with boron and nickel

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20894659

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20894659

Country of ref document: EP

Kind code of ref document: A1