WO2011013361A1 - Liquide de traitement pour former un film protecteur pour élément en acier comportant une couche de composé d'azote, et film protecteur de couche composite - Google Patents

Liquide de traitement pour former un film protecteur pour élément en acier comportant une couche de composé d'azote, et film protecteur de couche composite Download PDF

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WO2011013361A1
WO2011013361A1 PCT/JP2010/004781 JP2010004781W WO2011013361A1 WO 2011013361 A1 WO2011013361 A1 WO 2011013361A1 JP 2010004781 W JP2010004781 W JP 2010004781W WO 2011013361 A1 WO2011013361 A1 WO 2011013361A1
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compound layer
protective film
treatment liquid
metal
steel material
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PCT/JP2010/004781
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Japanese (ja)
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小西知義
池田芳宏
別府正昭
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日本パーカライジング株式会社
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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
    • 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
    • C23C8/02—Pretreatment of the material to be coated
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • 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
    • C23C8/40—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 liquids, e.g. salt baths, liquid suspensions
    • C23C8/42—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 liquids, e.g. salt baths, liquid suspensions only one element being applied
    • C23C8/48—Nitriding
    • C23C8/50—Nitriding of ferrous surfaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/42—Induction heating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
    • C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/004—Dispersions; Precipitations
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite
    • 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a hardened steel material used as a mechanical structural component having excellent mechanical strength such as surface pressure strength, wear resistance, bending fatigue strength, a manufacturing method thereof, and a treatment liquid used therefor.
  • nitriding treatment including soft nitriding treatment
  • carburizing and quenching induction hardening, etc.
  • induction hardening etc.
  • a compound layer made of nitride formed on the outermost surface by nitriding treatment is known to have excellent sliding properties, wear resistance, and high seizure resistance (hereinafter referred to as nitrogen compound).
  • nitrogen compound high seizure resistance
  • Called layer effect I a compound layer made of nitride formed on the outermost surface by nitriding treatment
  • nitrogen compound high seizure resistance
  • Called layer effect I in general, nitriding treatment is inferior in surface pressure strength, fatigue strength, etc. compared to carburizing quenching and induction quenching. For example, when a roller pitching test is performed, the nitrogen compound layer peels from the steel substrate.
  • the nitrogen compound layer was widely believed to have a negative effect in fatigue tests at high surface pressures exceeding 2 GPa.
  • the present inventors have found that this factor is not in the compound layer itself but because the hardened layer depth of the substrate supporting the compound layer is shallow. In other words, the nitriding unit alone has insufficient the depth of the hardened layer immediately below it in order to make full use of the good slidability of the outermost compound layer.
  • a steel material containing nitrogen has a finer martensite structure obtained after quenching than a steel material not containing nitrogen, so that the hardness is increased, and the hardening depth is increased by improving the hardenability.
  • the nitriding treatment can also be used as a nitrogen diffusion pretreatment for forming a nitrogen diffusion layer for improving hardenability (hereinafter referred to as effect II by forming a nitrogen compound layer). That is, the characteristics that can be obtained by using this effect II are not due to the action of the nitrogen compound layer itself, but due to the action of diffused nitrogen in the steel immediately below the nitrogen compound layer generated when the nitrogen compound layer is formed.
  • the nitrogen-containing martensite structure obtained by quenching has high surface pressure strength and high fatigue strength due to resistance to temper softening, resistance to crack initiation and growth, in addition to the above-mentioned high hardness and hardenability improvement. It has been known.
  • the quenching temperature When induction hardening is performed as it is after nitriding, the quenching temperature must be at least the temperature Ac3 transformation point at which an austenite structure is formed, and is usually selected from a temperature range of 750 to 1050 ° C.
  • the nitrogen compound layer formed at a nitriding temperature of 570 ° C. is a combination of iron and nitrogen. When reheated to 650 ° C. or higher in an air atmosphere, the nitrogen compound layer undergoes oxidation and decomposes. It is released as a gas and the nitrogen compound layer disappears. This has been reported for a long time (Non-Patent Document 1).
  • the combined heat treatment technique by nitriding and quenching usually uses only the effect II of the nitrogen diffusion layer obtained by nitriding, and does not use the effect I of the nitrogen compound layer formed by nitriding. That is, the nitrogen compound layer does not stop disappearing during quenching, which is a subsequent process of nitriding.
  • the composite heat treatment described in Patent Documents 1 to 5 can be mentioned.
  • Patent Document 6 discloses a composite heat treatment method in which a nitriding treatment is performed at a temperature of 600 ° C. or higher to form a nitrogen compound layer having a thickness of 5 ⁇ m or less, followed by induction hardening to obtain a quenched member having a nitrogen compound layer having a thickness of 2 ⁇ m or less. ing.
  • the reason why the nitriding condition is set to a high temperature of 600 ° C. or higher in the present technology is that a higher concentration of nitrogen diffusion can be expected at the deeper side of the steel material.
  • Patent Document 7 discloses this.
  • Patent Document 8 to be used for both effects I and II, a hard nitride layer is formed on the surface of a steel material, and further, Ti, Zr, Hf, V, Nb, Ta, Cr, W are formed thereon.
  • a hardened steel member is disclosed in which an inorganic compound layer containing at least one metal oxide selected from the group consisting of Mo and Al is formed.
  • Patent No. 3193320 Japanese Patent No. 3327386 Japanese Patent No. 3145517 JP-A-7-90364 JP 2007-154254 A JP 2007-77411 A JP 58-96815 JP 2008-038220 Heat treatment Vol.16 No.4 P206 1976
  • the present invention investigates and elucidates the mechanism by which the nitrogen compound layer obtained by nitriding treatment causes oxidation during the subsequent high-frequency heat treatment, and develops an effective antioxidant that prevents it. Therefore, it is an object of the present invention to provide a method for producing a quenched steel material, a steel material, and a treatment liquid used therefor that prevent oxidation by induction quenching of a compound layer formed on the surface of the steel material by nitriding.
  • the present invention (2) is a non-aqueous treatment liquid for forming a protective film according to claim 1 for protecting the nitride on a nitride layer formed after nitriding treatment on a steel material, At least one dissolved metal selected from the group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo
  • a compound layer protective film-forming treatment solution containing an alkoxide, metal acetylacetonate and / or metal carboxylate.
  • the treatment liquid is selected from the group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo.
  • At least one dissolved metal alkoxide selected from: metal acetylacetonate and / or metal carboxylate and / or Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Dispersed particles having an average particle diameter of 4 to 40 nm including at least one selected from the group consisting of Al, Sr, Zn, Mg, and Mo; and Si, Ti, Zr, Hf, V, Ta, Ca, And dispersed particles having an average particle diameter of 40 to 400 nm including at least one selected from the group consisting of Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo.
  • the present invention (4) is the compound layer protective film-forming treatment liquid according to the invention (2) or (3), wherein the treatment liquid contains 0.1 to 400 g / L of at least one amine. is there.
  • the compound layer protective film formed from the treatment liquid according to any one of the inventions (2) to (4) is the nitride.
  • the compound layer protective film formed from the treatment liquid according to any one of the inventions (2) to (4) is the nitride.
  • it is heated for 0.3 to 5 seconds until reaching a predetermined heating temperature, and subjected to induction hardening processing at which the reaching temperature is 750 to 860 ° C. It is a hardened steel material.
  • the present invention (6) is an application process in which a steel material having a nitride layer formed on the surface by nitriding treatment is prepared, and the treatment liquid according to any one of the inventions (2) to (4) is applied onto the nitride layer.
  • a method for producing a hardened steel material comprising: heating and induction hardening with an ultimate temperature of 750 to 860 ° C.
  • the protective layer forming film of the present invention is formed on the compound layer obtained by nitriding treatment.
  • the compound layer protective film it is possible to effectively suppress oxidative decomposition of the compound layer due to subsequent induction hardening.
  • the steel member obtained by the present invention maintains the mechanical strength, sliding resistance, wear resistance and the like based on the characteristics of the compound layer as a result of the remaining compound layer having good sliding characteristics.
  • steel members whose hardenability has been improved by the diffused nitrogen can obtain a deep hardening depth and high hardness by induction hardening, and therefore have high mechanical strength in terms of surface pressure strength, wear resistance, and bending fatigue strength. It can be suitably used for machine structural parts that require strength.
  • the steel material to which the present invention is applied is not particularly limited, and examples thereof include carbon steel, low alloy steel, medium alloy steel, high alloy steel, cast iron and the like.
  • a preferable material in terms of cost is carbon steel, low alloy steel, or the like.
  • carbon steel for machine structural use (S20C to S58C) is suitable as carbon steel, and nickel chrome steel (SNC 236 to 836), nickel chrome molybdenum steel (SNCM 220 to 815), chrome, etc. as low alloy steel.
  • Molybdenum steel (SCM 415 to 445, 822), chromium steel (SCr 415 to 445), manganese steel for mechanical structure (SMn 420 to 443), manganese chrome steel (SMnC 420, 443) and the like are suitable.
  • a tempered steel material H material
  • a tempered steel material that has not been tempered and remains in a ferrite-pearlite structure
  • alloy steel tends to have higher surface hardness
  • a sufficiently deep hardening depth can be obtained even with carbon steel because of the effect of improving the hardenability of effect II by nitrogen.
  • due to the effect II by nitrogen it is not always necessary to use tempered steel, and even a non-tempered steel of ferrite-pearlite structure can provide sufficient mechanical strength.
  • the nitrogen compound layer on the surface of the steel material is obtained by a surface hardening treatment that diffuses active nitrogen on the surface of the steel material to generate a hard and stable nitride.
  • a nitrogen compound layer it is usually composed mainly of Fe as a base material component, and a nitride containing Ti, Zr, Mo, W, Cr, Mn, Al, Ni, C, B, Si, etc. It is preferable that it is a layer.
  • a nitrogen compound layer having an effect I such as salt bath nitriding treatment such as tuftride treatment, isonite treatment, and pulsonite treatment, gas soft nitriding treatment, ion nitriding treatment, plasma nitriding treatment, and nitrogen immediately below the nitrogen compound layer
  • Any nitriding method can be used as long as it is a method in which a region in which is diffused.
  • the nitriding heat treatment temperature for forming the nitrogen compound layer for achieving the effect I is preferably 600 ° C. or lower, more preferably 580 ° C. or lower, and further preferably 570 ° C. or lower.
  • the thickness of the nitrogen compound layer obtained at a processing temperature exceeding 600 ° C. is increased, the effect I can no longer be expected because the hardness decreases.
  • a minimum is not specifically limited, For example, it is 350 degreeC.
  • the thickness of the nitrogen compound layer obtained by nitriding before induction hardening is not particularly limited, but it is usually sufficient if it is formed with a thickness of 1 to 30 ⁇ m, more preferably 2 to 20 ⁇ m, and even more preferably 3 ⁇ 15 ⁇ m.
  • a protective film is formed using a non-aqueous treatment liquid for protecting the nitrogen compound layer.
  • This treatment liquid is a non-aqueous treatment liquid, and a metal group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo It is preferable to contain at least one dissolved metal alkoxide, metal acetylacetonate and / or metal carboxylate selected from among the above.
  • the non-aqueous treatment liquid in the present invention refers to a solvent having a single phase and a water content of 30% by mass or less in the solvent.
  • the concentration containing the dissolved metal alkoxide, metal acetylacetonate and / or metal carboxylate is a concentration that allows the compound layer protective film to have a predetermined adhesion amount depending on the coating method and the number of repeated coatings.
  • the content may be 0.5 to 100 g / L.
  • the treatment liquid of the present invention is at least selected from the group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo. 1 dissolved metal alkoxide, metal acetylacetonate and / or metal carboxylate and / or Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn , Dispersed particles having an average particle size of 4 to 40 nm including at least one selected from the group consisting of Mg and Mo, Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb , Cr, W, Al, Sr, Zn, Mg and Mo, and dispersed particles having an average particle size of 40 to 400 nm including at least one selected from the group consisting of Mo, Mo and Mo.
  • the average particle diameter in this specification can be measured, for example using the particle size distribution measuring apparatus by a dynamic light scattering method.
  • Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg and Mo decompose and oxidize the nitrogen compound layer during high-frequency heating performed thereafter. It is the main component of the protective film to prevent, and its oxide is thermally and chemically stable.
  • Si, Ti, Zr, Ce, Cr, W, Al, and Mo are more preferable because the diffusion rate of ions in these metal compounds is small.
  • the main components of the protective film Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo are film forming components and stress relaxation components. It is preferable to be composed of two.
  • the film forming component is at least one selected from the group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo.
  • the stress relaxation component of the protective film is selected from the group consisting of Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg, and Mo. It is preferable to contain dispersed particles having an average particle diameter of 40 to 400 nm including at least one kind.
  • oxides, hydroxides, nitrides, fluorides, carbonates, and phosphate compounds can be used as the dispersed particles of the film forming component and the stress relaxation component. Oxide particles are particularly preferable.
  • the film forming component and the stress relaxation component are both incorporated into the film and formed, and the mass ratio of the two in the dry solid state (the dry solid state in the protective film before quenching) is 1:10 to 10 When it is set to 1, the action as a protective film for the nitrogen compound layer is most enhanced.
  • the “dried solid state” in the claims and the present specification refers to an oxide equivalent value assuming that all of the metal-containing components as raw materials are oxides. In practice, there may be components that volatilize or exist in other forms or remain in the form of raw material components. However, the ⁇ dry solid state '' in the claims and the specification is only It is an assumed value (theoretical value) on a raw material basis.
  • the technique described in Japanese Patent Application Laid-Open No. 2008-038220 is not necessarily sufficient for preventing the oxidation of the nitrogen compound layer.
  • a part of the surface layer of the nitrogen compound layer is oxidatively decomposed after high-frequency heating.
  • the role required of the protective film is not only to prevent decomposition and oxidation of the nitrogen compound layer that occurs during high-frequency heating performed after the formation of the protective film, but first of all.
  • the nitrogen compound layer has higher corrosion resistance than the iron base itself, it decomposes and oxidizes when it is heated to 50 ° C or higher, especially during wet semi-drying, until the treatment solution is applied and fixed and dried as a protective film.
  • Cheap When wet with a temperature load of about 50 to 200 ° C, it is wet, so in some cases, decomposition and oxidation of the nitrogen compound layer occur compared to the case of high-frequency heating load with a dry protective film performed at 750 to 860 ° C. It becomes easy. From the point of protection of the nitrogen compound layer, it was found that decomposition and oxidation of the compound layer are effectively suppressed when the solvent of the treatment liquid is a non-aqueous organic solvent.
  • the non-aqueous processing liquid is composed of a single phase solvent, and the water content in the solvent is 30% by mass or less, more preferably 10% by mass or less, and further preferably 2% by mass. % Or less.
  • the non-aqueous solvent is not particularly limited as long as it dissolves metal alkoxide, metal acetylacetonate, and / or metal carboxylate, and examples thereof include non-polar hydrocarbons such as hexane, octane, benzene, toluene, and tetralin.
  • non-polar hydrocarbons such as hexane, octane, benzene, toluene, and tetralin.
  • acetylacetone, methanol, ethanol, propanol, propionic acid, ethyl acetate, butyl acetate and the like can be used. These may be used alone or in combination of two or more depending on the type of metal alkoxide, metal acetylacetonate, or metal carboxylate.
  • the treatment liquid of the present invention preferably further contains 0.1 to 400 g / L of amines. More preferably, it is 0.5 to 200 g / L, and still more preferably 1 to 100 g / L.
  • the amines also have high adsorptivity to the surface of the nitrogen compound layer until the dried compound layer protective film is fixed from the treatment liquid, and effectively suppress the dissolution of the compound layer. It has in processing liquid.
  • These amines also have an effect of suppressing oxidation / decomposition of the nitrogen compound layer during high-frequency heating. As a mechanism for this, the present inventors have released nitrogen during high-frequency heating, and the nitrogen is on the nitrogen compound layer side. I guess to spread. These amines only need to be compatible with the organic solvent of the treatment liquid used.
  • an antifoaming agent or a surfactant called a wettability improver for obtaining a uniform film on the surface to be coated, a thickener, and other organic / inorganic additions are appropriately supplemented. It can also be added.
  • the method for applying the treatment liquid is not particularly limited, and dip coating, spin coating, spraying, brushing, and the like can be used.
  • the coating drying / firing temperature at the time of application is preferably 60 to 550 ° C., more preferably 100 to 400 ° C., and further preferably 120 to 300 ° C.
  • the heating time may be 30 seconds to 60 minutes, for example, and it may be sufficiently solidified, dried and fixed by exposure to the atmosphere.
  • the atmosphere during drying is preferably an inert atmosphere, but may be an air atmosphere.
  • air-drying is performed at room temperature or below 50 ° C, and then firing at a predetermined temperature is adopted. Also good.
  • coating and drying may be repeated a plurality of times to adjust the film thickness.
  • the compound layer protective film is formed by coating Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, and the like on a nitride layer formed after nitriding treatment on a steel material as a dry solid state. Containing at least one metal selected from the group consisting of Cr, W, Al, Sr, Zn, Mg, and Mo, and 0.05 to 3 g / m 2 in total in terms of the metal Formed in range. More preferably, it is 0.1 to 1 g / m 2 .
  • Protective effect of total nitride layer is less than 0.05 g / m 2 of the metal basis is insufficient, also already effective economically undesirable to saturate it exceeds 30000 mg / m 2.
  • the film thickness is about 2 to 4 ⁇ m, which is overwhelmingly thinner than Patent Document 7 covering a millimeter-order film and does not impair hardenability. It is thick.
  • induction hardening performed after forming the compound layer protective film it is subjected to induction heating by heating for 0.3 to 5 seconds so as to reach a predetermined heating temperature set at 750 to 860 ° C. After reaching a predetermined temperature, it is immediately cooled by a coolant, whereby a fine martensitic structure containing nitrogen can be obtained.
  • a more preferable heating temperature is 770 to 840 ° C.
  • a further preferable heating temperature is 780 to 830 ° C.
  • the heating time is more preferably 0.8 to 3 seconds, and further preferably 1 to 2 seconds.
  • the heating exceeds 860 ° C., the effect of the compound layer protective film is no longer effective, and the decomposition of the compound layer can no longer be suppressed, and excessive residual austenite tends to be generated in the martensite structure immediately below the compound layer. It is not preferable. Even if the heating time is 0.3 seconds or less, nitrogen is diffused, but it is not sufficiently austenitized, resulting in insufficient quenching. A heating time exceeding 5 seconds is not preferable because the effect of the heating time is almost saturated and the function of the compound layer protective film is lowered.
  • the nitrogen compound layer is sufficiently suppressed from oxidation and decomposition even when the atmosphere during high-frequency heating is in the air.
  • the atmosphere during high-frequency heating may be a vacuum atmosphere, an inert atmosphere with argon gas or nitrogen gas, a low oxygen atmosphere, a hydrocarbon-based reducing atmosphere, an ammonia gas atmosphere, or the like. it can.
  • a multistage temperature raising method including preheating can be appropriately performed. After quenching by high-frequency heating, tempering treatment may be performed under appropriate conditions in the same manner as a normal quenching technique.
  • the compound layer protective film may or may not be removed and can be selected as necessary.
  • the removal of the protective film of the compound layer can be easily performed because the hardness is lower than that of the compound layer, and can be appropriately performed by, for example, lapping, emery paper polishing, buffing, shot blasting, shot pinning, or the like.
  • the nitrogen compound layer remains with the compound layer protective film of the present invention, but the nitrogen compound layer does not necessarily remain 100% of the state of the compound layer before the high frequency heating, and the minimum film thickness is 1 ⁇ m or more.
  • the layer thickness should just be ensured. More preferably, it is 2 ⁇ m or more, and more preferably 3 ⁇ m or more.
  • the hardness of the nitrogen compound layer is HV630 or more in terms of Vickers hardness
  • the hardness region exceeding HV550 of the hard layer containing a fine martensite structure is 200 ⁇ m or more, preferably 400 ⁇ m or more, more preferably 600 ⁇ m or more in terms of the distance from the surface.
  • a steel material having an existing hardness distribution can be obtained.
  • an upper limit is not specifically limited, For example, it is 1.5 mm.
  • the machine part subjected to the treatment of the present invention has high slidability and seizure resistance due to the nitrogen compound layer formed on the outermost surface, and high temper softening resistance due to the nitrogen-containing fine martensite structure. It has crack resistance / crack growth resistance, surface pressure resistance, high fatigue strength, and deep cure depth.
  • the quenching by induction heating by the composite heat treatment according to the present invention is 750 to 860 ° C., and the quenching temperature is sufficiently lower than the induction quenching and carburizing quenching usually performed at temperatures exceeding 900 ° C. This is extremely advantageous in terms of thermal deformation and cracking, and enables a significant reduction in the post-cutting process for adjusting the dimensional accuracy performed after general induction hardening or carburizing and quenching.
  • the steel material to which the present invention is applied is not necessarily required to use a tempered steel because of the effect of improving the hardenability of the effect II caused by nitrogen. Sufficient mechanical strength can be obtained even with steel.
  • alloy steel tends to have a slightly higher surface hardness
  • a sufficiently deep hardening depth can be obtained even with inexpensive carbon steel due to the effect II of nitrogen.
  • carbon steel for mechanical structures such as S45C is a heat treatment material having a hardness profile with sufficient hardness and sufficient depth.
  • S45C is not necessarily a tempered material, and even if the heat treatment of the present invention is applied to a steel member having a non-tempered ferrite-pearlite structure, sufficient martensitic transformation occurs, and sufficient mechanical properties are obtained. It can be a heat-treated machine part with high strength.
  • the application of the present invention improves the mechanical strength of the parts, reduces the cutting process and switches to inexpensive materials, thereby reducing the size and weight of the entire mechanical parts by downsizing the parts, and nitriding and induction hardening. It is possible to reduce the actual cost by surplus to compensate for the cost increase due to the combined processing.
  • the compound layer protective film of the present invention is formed after nitriding treatment by, for example, laser quenching by short-time heating for a few seconds at the most, or impact quenching for a short heating of several milliseconds.
  • nitriding treatment by, for example, laser quenching by short-time heating for a few seconds at the most, or impact quenching for a short heating of several milliseconds.
  • the hardened steel member according to the present invention is suitable for those used in a high load / high surface pressure region.
  • the shape and part type of the steel member are not particularly limited, and examples thereof include shafts, gears, pistons, shafts, cams, and the like, which are suitable for transmission-related parts and powertrain parts for automobiles and construction machinery.
  • Example 1 SCM440 tempered material having a diameter of 8 mm and a length of 50 mm was used as a base material, and after degreasing and cleaning the surface, salt bath soft nitriding treatment at 560 ° C. for 1 hour in a molten salt bath (Isonite treatment: Nippon Parkerizing Co., Ltd.) And a nitrogen compound layer mainly composed of iron nitride having a thickness of about 7 ⁇ m was formed on the surface of the steel material.
  • Isopropyl alcohol as the main solvent alcohol-dispersed silica sol having an average particle size of 5 to 40 nm (“Colcoat P” manufactured by Colcoat Co.) as the film-increasing component is 20 g / L as silica (9.3 g / L as Si), stress As a relaxing component, isopropyl alcohol-dispersed silica sol having an average particle size of 70 to 100 nm (“IPA-ST-ZL” manufactured by Nissan Chemical Industries, Ltd.) as silica is 5 g / L (Si is 2.3 g / L), and monomethylamine is 5 g / L. Each of the treatment liquids containing was prepared.
  • the treatment liquid was applied to the substrate using a dip coating method, and after removing the excess liquid, the process of drying at 50 ° C. ⁇ 10 minutes was repeated twice, and finally, baking was performed at 200 ° C. for 10 minutes.
  • the amount of Si deposited on the substrate was measured with a fluorescent X-ray analyzer, the amount of deposited Si was 310 mg / m 2 .
  • the ratio of the film-forming component / stress-relaxing component was 4 for the calculated silica-forming component and the stress-relaxing component.
  • the heating is stopped immediately after reaching 860 ° C. in 0.8 seconds after the start of heating using an induction hardening apparatus. Then, it was cooled and quenched. Later, the steel surface was shot blasted to remove only the compound layer protective film.
  • Example 2 S45C tempered material having a diameter of 8 mm and a length of 50 mm was used as a base material. After degreasing and cleaning this surface, salt bath soft nitriding treatment (Isonite treatment: Nippon Parkerizing Co., Ltd.) at 560 ° C. in a molten salt bath for 2 hours And a nitrogen compound layer mainly composed of iron nitride having a thickness of about 13 ⁇ m was formed on the surface of the steel material.
  • salt bath soft nitriding treatment Isonite treatment: Nippon Parkerizing Co., Ltd.
  • a treatment solution containing isopropyl alcohol as a main solvent, titanium tetraisopropoxide as a film-increasing component as titanium oxide, 40 g / L (24 g / L as Ti), and 10 g / L of triethylamine was prepared.
  • the treatment liquid was applied to the substrate using the dip coating method, and after removing the excess liquid, the process of drying at 150 ° C. ⁇ 30 minutes was repeated 5 times, and finally, baking was performed at 300 ° C. for 10 minutes.
  • the amount of Ti deposited on the substrate was measured with a fluorescent X-ray analyzer, the amount deposited as Ti was 510 mg / m 2 .
  • the steel material in which the compound layer protective film containing titanium oxide is formed on the nitrogen compound layer is further heated immediately after reaching 820 ° C. in 1.0 second after the start of heating using an induction hardening apparatus. After stopping, it was cooled and quenched. Later, the steel surface was shot blasted to remove the compound layer protective film.
  • Example 3 An S45C non-refined material (ferrite / pearlite structure) having a diameter of 8 mm and a length of 50 mm was used as a base material. After degreasing and cleaning this surface, salt bath soft nitriding treatment (Isonite) at 560 ° C. for 1 hour in a molten salt bath Treatment: manufactured by Nihon Parkerizing Co., Ltd.) and water-cooled to form a nitrogen compound layer mainly composed of iron nitride having a thickness of about 12 ⁇ m on the steel surface.
  • salt bath soft nitriding treatment Isonite
  • molten salt bath Treatment manufactured by Nihon Parkerizing Co., Ltd.
  • Isopropyl alcohol-dispersed silica sol having an average particle size of 40 to 100 nm as a stress relaxation component (Nissan Chemical Industries, Ltd.) using ethanol as a main solvent, tetraethoxysilane as a film thickening component as silica (4.7 g / L as Si), and stress relaxation component
  • a treatment solution containing 40 g / L of silica (“IPA-ST-UP”) manufactured by the company (18.7 g / L as Si) was prepared. This treatment liquid was applied to the substrate using a dip coating method, and after removing excess liquid, baking was performed at 320 ° C. for 10 minutes.
  • the adhesion amount on the substrate was measured with a fluorescent X-ray analyzer, the adhesion amount as Si was 160 mg / m 2 .
  • the ratio of the film-forming component / stress-relaxing component was 0.3 for the calculated silica-forming component and the stress-relaxing component.
  • the heating is stopped immediately after reaching 820 ° C. in 1.0 second after the start of heating using the induction hardening apparatus. Then, it was cooled and quenched. Later, the steel surface was shot blasted to remove the compound layer protective film.
  • Table 1 shows a list of evaluation results.
  • the effective curing depth in the table is the depth (mm) from the surface of the portion having a hardness of Hv550 or higher.
  • FIGS. 1, 2 and 3 show cross-sectional photographs of Example 1, Example 2 and Comparative Example 1, respectively.
  • FIG. 4 shows the cross-sectional hardness distribution of Example 3.

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  • Physics & Mathematics (AREA)
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Abstract

L'invention porte sur des moyens pour empêcher l'oxydation d'une couche composite par durcissement à haute fréquence, ladite couche composite ayant été formée sur la surface d'un matériau en acier par nitruration. Il est décrit de façon spécifique un liquide de traitement pour former un film protecteur de couche composite, lequel est un liquide de traitement non aqueux pour former un film protecteur sur une couche de nitrure dans le but de protéger le composé, ladite couche de nitrure ayant été formée sur un matériau en acier après nitruration. Le liquide de traitement pour former un film protecteur de couche composite est caractérisé en ce qu'il contient au moins un alcoxile de métal, un acétylacétonate de métal et/ou un carboxylate de métal fondu d'un métal sélectionné parmi le groupe de métaux comprenant Si, Ti, Zr, Hf, V, Ta, Ca, Ce, Sc, Nb, Cr, W, Al, Sr, Zn, Mg et Mo.
PCT/JP2010/004781 2009-07-31 2010-07-28 Liquide de traitement pour former un film protecteur pour élément en acier comportant une couche de composé d'azote, et film protecteur de couche composite WO2011013361A1 (fr)

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JP2009178496A JP5520536B2 (ja) 2009-07-31 2009-07-31 窒素化合物層を有する鉄鋼部材の保護膜形成処理液、および化合物層保護膜
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JP5886537B2 (ja) * 2011-04-18 2016-03-16 日本パーカライジング株式会社 高耐久性エンジンバルブ
JP6321842B2 (ja) * 2017-02-23 2018-05-09 シャープ株式会社 データ処理方法およびプログラム

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5183846A (fr) * 1975-01-21 1976-07-22 Hino Motors Ltd
WO1996010710A1 (fr) * 1994-10-04 1996-04-11 Nippon Steel Corporation Union de tuyaux d'acier presentant une resistance elevee au grippage et traitement de surface destine a cet effet

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JP5328545B2 (ja) * 2009-07-31 2013-10-30 日本パーカライジング株式会社 窒素化合物層を有する鉄鋼部材、及びその製造方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5183846A (fr) * 1975-01-21 1976-07-22 Hino Motors Ltd
WO1996010710A1 (fr) * 1994-10-04 1996-04-11 Nippon Steel Corporation Union de tuyaux d'acier presentant une resistance elevee au grippage et traitement de surface destine a cet effet

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