JP2007146268A - Corrosion protection-coated steel material and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a corrosion protection-coated steel material having durability over a long period by efficiently forming a dense film having excellent damage resistance, abrasion resistance and corrosion resistance and hardly having defects on the surface of the steel material, and to provide its production method. <P>SOLUTION: The corrosion protection-coated steel material has a coating film formed by spraying solid particulates made into aerosol and having high hardness and abrasion resistance on the surface of the steel material. Optionally, the surface of a coating film, which is formed by spraying metal or alloy particulates made into aerosol and having sacrificial corrosion preventability on the surface of a steel material, is further provided with the coating film formed by spraying solid particulates made into aerosol and having high hardness and abrasion resistance on the surface of the steel material. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an anticorrosion-coated steel material having a coating film formed by spraying aerosolized solid fine particles having high hardness and wear resistance on the surface of the steel material, and a method for producing the same.

  As a method for imparting scratch resistance and wear resistance to a steel material, a method for improving its surface hardness is known. Specifically, for example, there are methods such as carburizing treatment, nitriding treatment, carbonitriding treatment, surface quenching, hard chromium plating, and chromium infiltration plating.

  Similarly, as a method for imparting scratch resistance and wear resistance to a steel material, there is a method of spraying a material having high hardness and wear resistance onto the steel material.

  On the other hand, in a natural environment, the steel material cannot be maintained at the required strength due to the progress of corrosion as it is. Therefore, the progress of corrosion is usually suppressed by applying an anticorrosion coating treatment.

Recently, as a new film formation method, there are a gas deposition method (see Patent Documents 1 to 3), an aerosol deposition method (see Patent Document 4), and the like. In these methods, fine particles such as metals and ceramics are aerosolized by gas stirring at room temperature, ejected from the nozzle toward the substrate at high speed, and part of the kinetic energy is converted to heat when it collides with the substrate. This is a method of sintering and forming a film on a substrate.
JP 59-80361 A JP-A-6-116743 Japanese Patent No. 3256741 Japanese Patent No. 3348154

  However, the methods such as carburizing, nitriding, carbonitriding, surface quenching, and chromium infiltration plating always provide the necessary scratch resistance and wear resistance because the surface hardness after treatment depends on the steel type. Not always. Further, in the hard chrome plating method, a large amount of hydrogen is absorbed, the porosity is large, and hydrogen embrittlement is likely to occur.

  Further, in the method by thermal spraying, since the thermal spraying is performed at a high temperature, there is a problem that when spraying a metal or an alloy, the flying sprayed particles before coating are easily oxidized, and defects are easily generated in the formed coating film.

  Moreover, although the method of the said patent documents 1-4 is supposed that a fine film can be fundamentally formed on a base material with what kind of microparticles | fine-particles, it has sacrificial corrosion resistance on the steel material surface for the purpose of corrosion protection of steel materials. There is no example of forming a film.

  Accordingly, the present invention provides an anticorrosion coated steel material having durability over a long period of time by efficiently forming a dense film with few defects excellent in scratch resistance, abrasion resistance and corrosion resistance on the surface of the steel material, and its production It aims to provide a method.

In order to solve the above problems, the present invention has the following features.
[1] An anticorrosion-coated steel material having a coating film formed by spraying aerosolized solid fine particles having high hardness and wear resistance on the surface of the steel material.
[2] On a coating film formed by spraying aerosolized metal or alloy fine particles having sacrificial anticorrosive properties on the surface of a steel material, an aerosolized solid having high hardness and wear resistance An anticorrosion-coated steel material having a coating film formed by spraying fine particles of the steel material on the surface of the steel material.
[3] The anticorrosion-coated steel material according to [1] or [2] above, wherein the solid having high hardness and wear resistance is cermet.
[4] The anticorrosion coated steel material according to [3], wherein the cermet is one or more of carbide cermet, graphite cermet, oxide cermet, and nitride cermet. .
[5] In any one of the above [2] to [4], the metal or alloy having sacrificial corrosion resistance contains any one or more of zinc, aluminum, and magnesium. Anticorrosion coated steel.
[6] A method for producing an anticorrosion-coated steel material, characterized in that aerosolized solid fine particles having high hardness and wear resistance are sprayed on the surface of the steel material to form a coating film.
[7] A metal or alloy fine particle having a sacrificial anticorrosive property that has been aerosolized is sprayed onto the surface of the steel material to form a coating film, and then the aerosol is further applied to the coating film to obtain a high hardness and A method for producing an anticorrosion-coated steel material, characterized by spraying solid fine particles having wear resistance and laminating a coating film.
[8] The method for producing an anticorrosion-coated steel material according to [6] or [7] above, wherein the solid having high hardness and wear resistance is cermet.
[9] The anticorrosion coated steel material according to [8], wherein the cermet is any one or more of carbide cermet, graphite cermet, oxide cermet, and nitride cermet. Manufacturing method.
[10] In any one of [7] to [9] above, the sacrificial anticorrosive metal or alloy contains one or more of zinc, aluminum, and magnesium. A method for producing a corrosion-resistant coated steel material.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to form efficiently the fine film with few defects excellent in damage resistance, abrasion resistance, and corrosion resistance on the steel material surface, and the anticorrosion coating steel material which has durability over a long period of time And a method of manufacturing the same.

  Hereinafter, an example of the best mode for carrying out the present invention will be described, but the present invention is not limited thereto.

  Each component of the anticorrosion-coated steel material and the method for producing the anticorrosion-coated steel material according to the present invention will be described below.

[Underlying steel]
The steel material to be coated as a base is not particularly limited, and normal steel, low alloy steel, etc. can be used as the steel type, and in any of thick plate, shape steel, thin plate, steel pipe, wire, etc. Applicable. Further, the state of the surface of the steel material before coating is not particularly limited, but it is preferable to keep the surface clean by blasting, pickling or the like. This is because the adhesion of the coating film is improved.

[Solid fine particles with high hardness and wear resistance]
The solid fine particles having high hardness and wear resistance that can be applied in the present invention are not particularly limited as long as they have high hardness and wear resistance. However, it is preferable to use cermet, and in particular, carbide cermet. (Tungsten carbide cermets (WC-Co, WC-Ni, WC-Co-Cr, WC-Co + Ni-Cr (-Al), etc.), titanium carbide cermets (TiC-Ni, TiC-Co, TiC-Ni-Cr, etc.) , Chromium carbide cermet (Cr ₃ C ₂ —Ni—Cr, Cr ₃ C ₂ —Ni—Al, etc.) silicon carbide cermet (SiC etc.), graphite cermet (Ni—C (Graphite), Al—Si—C ( Graphite)), oxide-based cermets (Al ₂ O ₃ —Ni—Al, Al ₂ O ₃ —Co—Cr—Al) -Y, ZrO ₂ · Y ₂ O ₃ -Ni-Cr, ZrO ₂ · CaO-Ni-Al, ZrO ₂ · MgO-Ni-Al (-Cr), etc.), nitride cermets (silicon nitride cermets (Si ₃ N ₄ -Co, such as Si ₃ N ₄ -Ni), boron nitride Motokei cermet (BN-Ni-Cr-Fe -Al, such as BN-Fe-Al), silicon nitride whisker _{(Si 3} N 4 -ZrO ₂ It is more preferable to use —Y ₂ O ₃ , Si ₃ N ₄ —Al ₂ O ₃ )) or the like.

  The average particle diameter of the solid particles having high hardness and wear resistance is preferably about 0.1 to 5 μm. This is because if the average particle size is less than 0.1 μm, the collision energy becomes insufficient and film formation becomes difficult, and if the average particle size exceeds 5 μm, etching becomes significant and film formation becomes difficult.

  Here, the average particle diameter of the fine particles can be determined by a method such as a laser diffraction method or a laser scattering method.

  In addition, the fine particles are adjusted by adjusting the particle size by pulverizing the solid as a raw material with a pulverizer such as a planetary mill, and then using a classifier such as a dry air classifier or an electrostatic classifier. be able to.

[Metal or alloy fine particles with sacrificial anticorrosive properties]
The fine particles of the metal or alloy having sacrificial corrosion resistance that can be applied in the present invention are not particularly limited as long as they exhibit sacrificial corrosion resistance to the steel material to be coated, but the metal or alloy includes zinc, It is preferable to use one containing at least one of aluminum and magnesium.

  Examples of the alloy include not only Al alloys described in ISO: 14919 and JIS: H8300, but also Al—Cu, Al—Mn, Al—Mg, Al—Mg—Si, and Al—Zn. -Mg, Al-Zn-Mg-Cu, Al-Fe-Cr-Ni, Al-Si, Al-Zn-In-Si-Mg, and the like can be used. In addition, Mg alloys such as Mg—Mn, Mg—Al—Zn, Mg—Al—Zn—Mn, Mg—Zn—Zr, Mg—Al—Mn, and Mg—Al—Si are used. You can also.

  The average particle size of the metal or alloy fine particles having sacrificial corrosion resistance is preferably about 0.1 to 5 μm. This is because if the average particle size is less than 0.1 μm, the collision energy becomes insufficient and film formation becomes difficult, and if the average particle size exceeds 5 μm, etching becomes significant and film formation becomes difficult.

  Here, the average particle diameter of the fine particles can be determined by a method such as a laser diffraction method or a laser scattering method.

  In addition, the fine particles are adjusted by adjusting the particle size by pulverizing the solid as a raw material with a pulverizer such as a planetary mill, and then using a classifier such as a dry air classifier or an electrostatic classifier. be able to.

[Film formation method]
In FIG. 1, an example of the apparatus structure for manufacturing the anti-corrosion coating steel material which concerns on this invention is shown. The apparatus shown in FIG. 1 includes an aerosolization chamber 2 for aerosolizing the above-mentioned solid fine particles having high hardness and wear resistance and / or fine particles 1 of metal or alloy having sacrificial corrosion resistance, and aerosolized fine particles. A classification chamber 3 for classifying the particles, a nozzle 4 for injecting the classified aerosol, a gas generation source 5 for conveying fine particles, a film formation chamber 6 for spraying the aerosolized fine particles onto the steel plate surface, and a film formation chamber 6 includes a vacuum pump 7 for depressurizing 6.

The fine particles 1 are dispersed and aerosolized in the aerosolization chamber 2 by the carrier gas sent from the gas generation source 5. As the carrier gas, an inert gas such as He or N ₂ is preferably used.

  The fine particles aerosolized in the aerosol generation chamber 2 are conveyed to the classification chamber 3 and only fine particles having a predetermined particle diameter are selected. The selection can be performed by using, for example, a filter that allows only fine particles having a predetermined particle diameter to pass through. The classification chamber 3 may not always be necessary if classification is performed in the production stage of the fine particles, but classification may be performed after the classification in the production stage of the fine particles. It is preferable to provide a chamber.

  The selected aerosol having a predetermined particle size is sprayed from the nozzle 4 toward the steel material 8 installed in the film forming chamber 6 and collides with and deposits on the steel material surface to form a film on the steel material surface. Let Here, it is considered that the fine particles colliding with the steel material surface are formed by forming a special reaction field of high temperature and high pressure by releasing energy to a local region for a short time based on a pure mechanical process.

  The linear flow velocity of the fine particles ejected from the nozzle 4 is preferably about 100 m / sec to 800 m / sec. For this purpose, for example, the diameter of the nozzle 4 is about 1 mm, the carrier gas flow rate is about 2 to 10 L / min, and the pressure of the aerosolization chamber 2 is 0.05 to 500 Torr (6.65 Pa to 66.5 kPa). The pressure in the membrane chamber can be set to about 0.05 to 10 Torr (6.65 Pa to 1.33 kPa). When the linear velocity of the fine particles ejected from the nozzle 4 is less than 100 m / sec, film formation becomes difficult because of insufficient collision energy, and when it exceeds 800 m / sec, etching becomes remarkable, and film formation is also difficult. Because it becomes.

  Moreover, it is preferable that the space | interval of the steel material 8 and the nozzle 4 to be coated shall be about 5-25 mm. Although there is the purpose of securing the clearance, by adjusting this distance, the speed of the fine particles immediately before colliding with the steel surface can be adjusted to some extent.

  The steel material 8 to be coated can be formed on a surface of an arbitrary position of the steel material 8 with an arbitrary film thickness by installing the steel material 8 on a gantry having a vertical position adjustment function and an angle adjustment function. It is also possible to cover a necessary part with a necessary amount.

  Furthermore, it is also preferable to install a plurality of aerosolization chambers 2 and classification chambers 3 respectively. As a result, a film having a different composition can be arbitrarily formed only by operating the carrier gas switching valve. For example, the film can be easily formed into multiple layers.

  In the present invention, a film made of solid fine particles having high hardness and wear resistance may be directly formed on the surface of the steel material. In particular, when a film that requires anticorrosion is formed, the steel material is first formed on the surface of the steel material. It is preferable to form a film made of fine particles of metal or alloy having sacrificial corrosion resistance, and then to form a film made of solid fine particles having high hardness and wear resistance on the upper layer. As a result, a dense film having almost no defects excellent in scratch resistance, abrasion resistance and corrosion resistance is formed.

  The coating film and process (manufacturing method) formed by the above method have the following characteristics.

1) The corrosion resistance of the anticorrosion-coated steel material is remarkably improved by being able to coat the solid fine particles with high hardness and wear resistance densely on the steel material with high film adhesion strength.
When the aerosolized fine particles collide with the steel material surface, the fine particles are divided into finer particles by the collision energy, and a film having a very fine particle structure is formed on the steel material surface. As a result, adhesion on the surface of the steel material is improved, extremely high adhesion strength is obtained, and material properties (mechanical properties) of the formed coating layer itself are improved. Therefore, a coating film having higher adhesion strength, excellent scratch resistance and abrasion resistance than that obtained by thermal spraying or plating coating is obtained, and an anticorrosion-coated steel material having excellent long-term durability is obtained.

  2) In the present invention, since a coating material can be freely selected, a material that cannot be coated by other methods such as plating and thermal spraying can be coated. Furthermore, since the present invention enables film formation at room temperature, particles before coating are not oxidized, a film with few defects can be formed, and a substance having a low boiling point can be efficiently coated without being dissipated. Therefore, the porosity in the coating is small, and a dense film is formed as compared with the thermal spraying, so that the sealing process is not required and the cost can be reduced.

  3) Since it is possible to cover only necessary portions, and the film thickness can be easily controlled, it is possible to form a coating film as much as necessary on the portions necessary for anticorrosion, and an optimal anticorrosion design is possible.

[Treatment after film formation]
It is preferable to heat as necessary after forming the coating film on the surface of the steel material. This makes it possible to form a coating that is stronger and has better adhesion. Also, coating or resin may be lined on the coating. Thereby, it becomes possible to further improve corrosion resistance.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

[Invention Examples 1 to 10]
The surface of a 100 mm × 100 mm × 6 mm hot rolled steel sheet (equivalent to JIS SS400) was blasted with a steel grid. The surface roughness was about 50 μm in terms of 10-point average roughness (Rz). This was installed in the film forming chamber 6 of the apparatus shown in FIG. 1, the carrier gas was N ₂ (> 99.999%), and the gas was introduced into the aerosol chamber 2 at a flow rate of 5 L / min. Aerosol chamber 2 was filled with fine particles having an average particle diameter of 1 μm (measured by a laser scattering method) shown in Table 1 as a coating material, and aerosolized with the carrier gas. The pressure in the film forming chamber 6 was set to 0.5 Torr (66.5 Pa) with a vacuum pump, and aerosol was ejected from the nozzle 4 toward the steel plate surface. The film was formed on one side of the steel sheet so as to have a film thickness of about 100 μm while appropriately moving the position of the steel sheet. After the back end portion of the coated steel material produced as described above was sealed with silicon sealant, the red rust occurrence time (SST) was measured by a salt spray test (JIS Z2371) to evaluate the corrosion resistance. Further, the surface hardness (Hv) of the film was measured. The results are also shown in Table 1.

[Invention Examples 11-15]
The surface of a 100 mm × 100 mm × 6 mm hot rolled steel sheet (equivalent to JIS SS400) was blasted with a steel grid. The surface roughness was about 50 μm in terms of 10-point average roughness (Rz). This was installed in the film forming chamber 6 of the apparatus shown in FIG. The aerosolization chamber 2A is filled with fine particles having an average particle diameter of 1 μm (measured by laser scattering method) shown in Table 2 (steel material side (A)) as a coating material, and the carrier gas is N ₂ (> 99.999%). ) And flowed into the aerosolization chamber 2A at a flow rate of 5 L / min for aerosolization. The pressure in the film forming chamber 6 was set to 0.5 Torr (66.5 Pa) with a vacuum pump, and aerosol was ejected from the nozzle 4 toward the steel plate surface. The film was formed on one side of the steel sheet so as to have a film thickness of about 100 μm while appropriately moving the position of the steel sheet. Further, fine particles having an average particle diameter of 1 μm (measured by the laser scattering method) shown in Table 2 (surface layer side (B)) as a coating material were formed on the upper layer so as to have a film thickness of 100 μm by the same method. The fine particles shown in Table 2 (surface layer side (B)) are filled in the aerosolization chamber 2B, and the fine particles shown in Table 2 (steel material side (A)) are laminated on the steel material surface, and then the aerosolization chamber 2B side. By switching the valve of the carrier gas, the coating has a two-layer structure. After the back end portion of the coated steel material produced as described above was sealed with silicon sealant, the red rust occurrence time (SST) was measured by a salt spray test (JIS Z2371) to evaluate the corrosion resistance. Further, the surface hardness (Hv) of the film was measured. The results are also shown in Table 2.

[Comparative Examples 1 to 10]
The surface of a 100 mm × 100 mm × 6 mm hot-rolled steel sheet (equivalent to JIS SS400) was blasted with a steel grid. The surface roughness was about 50 μm in terms of 10-point average roughness (Rz). The material shown in Table 1 was formed into a film thickness of about 100 μm by plasma spraying. After the back end portion of the coated steel material produced as described above was sealed with silicon sealant, the red rust occurrence time (SST) was measured by a salt spray test (JIS Z2371) to evaluate the corrosion resistance. Further, the surface hardness (Hv) of the film was measured. The results are also shown in Table 1.

[Comparative Example 11]
A hot-rolled steel sheet of 100 mm × 100 mm × 6 mm (equivalent to JIS SS400) was pickled and then hard chrome plated to a thickness of 100 μm. After the back end portion of the coated steel material produced as described above was sealed with silicon sealant, the red rust occurrence time (SST) was measured by a salt spray test (JIS Z2371) to evaluate the corrosion resistance. Further, the surface hardness (Hv) of the film was measured. The results are also shown in Table 1.

  In the example of the present invention, the surface hardness was high and the red rust occurrence time (SST) was 4000 hours or more, and it was confirmed that it had durability over a long period of time as compared with the prior art.

It is a figure which shows an example of the apparatus structure for manufacturing the anticorrosion coating | coated steel material which concerns on this invention.

Explanation of symbols

1 Solid particulates having high corrosion resistance 2 Aerosolization chamber 3 Classification chamber 4 Nozzle 5 Carrier gas generation source 6 Deposition chamber 7 Vacuum pump 8 Steel

Claims (10)

  An anticorrosion-coated steel material comprising a coating film formed by spraying aerosolized solid fine particles having high hardness and wear resistance on a steel material surface.   On the coating film formed by spraying aerosolized metal or alloy fine particles with sacrificial anticorrosive properties onto the steel surface, aerosolized solid fine particles with high hardness and wear resistance are further formed. An anticorrosion-coated steel material comprising a coating film formed by spraying on a steel material surface.   The anticorrosion-coated steel material according to claim 1 or 2, wherein the solid having high hardness and wear resistance is a cermet.   The anticorrosion-coated steel material according to claim 3, wherein the cermet is one or more of carbide cermet, graphite cermet, oxide cermet, and nitride cermet.   The anticorrosion-coated steel material according to any one of claims 2 to 4, wherein the metal or alloy having sacrificial corrosion resistance contains one or more of zinc, aluminum, and magnesium.   A method for producing an anticorrosion-coated steel material, characterized in that aerosolized solid fine particles having high hardness and wear resistance are sprayed onto a steel material surface to form a coating film.   After spraying aerosolized metal or alloy fine particles with sacrificial anticorrosive properties on the steel surface to form a coating film, the coating film is further aerosolized to have high hardness and wear resistance. A method for producing an anticorrosion-coated steel material, comprising spraying solid fine particles having properties and laminating a coating film.   The method for producing a corrosion-resistant coated steel material according to claim 6 or 7, wherein the solid having high hardness and wear resistance is cermet.   The method for producing an anticorrosion-coated steel material according to claim 8, wherein the cermet is one or more of carbide cermet, graphite cermet, oxide cermet, and nitride cermet. . The metal or alloy having sacrificial anticorrosive properties contains at least one of zinc, aluminum, and magnesium, and the production of the anticorrosion-coated steel material according to any one of claims 7 to 9 Method.

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