Device having a multi-penetration type, corrosion-resistant composite layer

Abstract

To improve corrosion resistance and durability, the present invention provides an apparatus having a multi-penetrating composite corrosion-resistant layer comprising: a base material formed of a metal material, wherein a surface treatment layer is formed on the surface by zinc plating the surface where blackening occurs; a trivalent chromium-based chemical conversion film layer formed by laminating on the surface of the surface treatment layer, wherein a reinforcing compound containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer; and a thermal diffusion treatment layer formed by laminating on the surface of the trivalent chromium-based chemical conversion film layer, wherein a corrosion-resistant composite compound containing silane penetrates into the surface and interior of the trivalent chromium-based chemical conversion film layer.

Description

Technology Field

[0001] The present invention relates to a device equipped with a multi-penetrating composite corrosion-resistant layer, and more specifically, to a device equipped with a multi-penetrating composite corrosion-resistant layer that improves corrosion resistance and durability. Background Technology

[0002] Generally, a white pipe refers to a steel pipe with a surface treated with zinc plating primarily to prevent corrosion. Specifically, it is used to transport fluids including steam, water, oil, and gas, specifically for fluids with relatively low transport pressures.

[0003] At this time, black staining occurred due to corrosion during the storage of steel pipes. This not only compromised the aesthetics of the manufactured products but also caused problems with quality degradation. Accordingly, it was intended to protect the surface of the steel pipes by plating the surface with zinc to prevent corrosion.

[0004] Recently, there have been attempts to increase corrosion resistance by forming a thin chromium layer on the surface of the white pipe. Specifically, conventionally, the surface of the white pipe was treated using hexavalent chromium during chromium plating, but recently, due to heavy metal vapors and wastewater generated during the plating process using hexavalent chromium, it is being replaced with an environmentally friendly plating method using trivalent chromium.

[0005] At this time, the quality of the plating layer using trivalent chromium formed on the surface of the white pipe varied depending on the surface condition of the white pipe, making it difficult to form a uniform plating layer. Specifically, the thickness distribution of the plating layer was locally uneven, resulting in low mechanical strength, and there was a problem of delamination occurring due to insufficient adhesion between the plating layer and the white pipe.

[0006] Therefore, an attempt was made to prevent blackening by forming a separate reinforcing layer on the surface of the plating layer formed on the surface of the white pipe to protect the plating layer, but there was a serious problem in that the reinforcing layer peeled off, causing a portion of the plating layer, which has relatively high adhesion to the reinforcing layer, to peel off instead.

[0007] Therefore, there is an urgent need to develop a device that protects the surface of the white pipe from water and moisture to prevent blackening, while simultaneously possessing excellent durability. Prior art literature

[0008] Korean Published Patent No. 10-2012739 The problem to be solved

[0009] To solve the above-mentioned problems, the present invention provides a device equipped with a multi-penetrating composite corrosion-resistant layer that improves corrosion resistance and durability. means of solving the problem

[0010] To solve the above problem, the present invention comprises: a base material formed of a metal material, wherein a surface treatment layer is formed on the surface by zinc plating the surface where blackening occurs; a trivalent chromium-based chemical conversion coating layer formed by being laminated on the surface of the surface treatment layer, wherein a reinforcing compound containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer; and a thermal diffusion treatment layer formed by being laminated on the surface of the trivalent chromium-based chemical conversion coating layer, wherein a corrosion-resistant composite compound containing silane penetrates into the surface and interior of the trivalent chromium-based chemical conversion coating layer. and a composite corrosion-resistant layer formed by diffusing a silanol composition, formed by reacting the silane of the corrosion-resistant composite mixture with the hydroxyl groups of the trivalent chromium-based chemical conversion film layer, into the surface and interior of the trivalent chromium-based chemical conversion film layer, wherein the reinforcing mixture comprises, based on the total weight of the reinforcing mixture, 5 to 10 wt% of chromium nitrate and chromium phosphate, 1 to 5 wt% of sodium nitrate, 1 to 5 wt% of zirconate fluoride, and 85 to 90 wt% of water, wherein the corrosion-resistant composite mixture comprises, based on the total weight of the corrosion-resistant composite mixture, 5 to 15 wt% of ethanol, 10 to 15 wt% of polyurethane, 1 to 10 wt% of ammonium zirconyl carbonate, 1 to 10 wt% of glycidoxypropyltrimethoxysilane, 0.1 to 5 wt% of phosphoric acid, and 1 to The present invention provides a device equipped with a multi-penetrating composite corrosion-resistant layer characterized by containing 10 weight% and 60 to 70 weight% of water.

[0011] Here, it is preferable that the composite corrosion-resistant layer be formed by heat treatment at 60 to 180°C so as to covalently bond with the hydroxyl groups of the silanol composition and the trivalent chromium-based chemical conversion film layer.

[0012] delete

[0013] delete

[0014] Meanwhile, the present invention provides a method for manufacturing a device having a multi-penetrating composite corrosion-resistant layer, comprising: a first step of forming a surface treatment layer by zinc plating the surface of a base material formed of a metal material; a second step of forming a trivalent chromium-based chemical conversion film layer by penetrating a reinforcing compound containing chromium nitrate and chromium phosphate into the surface and interior of the surface treatment layer; and a third step of forming a thermal diffusion treatment layer by penetrating a corrosion-resistant composite compound containing silane into the surface and interior of the trivalent chromium-based chemical conversion film layer, wherein a silanol composition formed by reacting the silane of the corrosion-resistant composite compound with the hydroxyl group of the trivalent chromium-based chemical conversion film layer diffuses into the surface and interior of the trivalent chromium-based chemical conversion film layer to form a composite corrosion-resistant layer. Effects of the invention

[0015] Through the above-mentioned means of solution, the present invention provides the following effects.

[0016] First, a reinforcing compound containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer to form a stacked trivalent chromium-based chemical conversion film layer, and a corrosion-resistant composite compound containing silane penetrates into the interior of the trivalent chromium-based chemical conversion film layer to form a stacked thermal diffusion treatment layer, thereby protecting the base material from moisture and external contamination, improving corrosion resistance performance, and at the same time, significantly reducing blackening phenomena.

[0017] Second, the trivalent chromium-based conversion film layer is formed by chromium ions and zirconium ions penetrating into the surface and interior of the surface treatment layer and undergoing a chemical conversion reaction between zinc oxide and zinc hydroxide to form an interface fixation, and the thermal diffusion treatment layer is formed by silane penetrating into the surface and interior of the trivalent chromium-based conversion film layer and forming an interlayer bond with chromium and oxygen, so the interlayer delamination prevention performance can be significantly improved.

[0018] Third, the thermal diffusion treatment layer is formed by the chemical conversion of the chromium ions and zirconium ions of the reinforcing compound with the zinc oxide and zinc hydroxide of the surface treatment layer, and the corrosion-resistant composite compound penetrates deeper into the interior of the trivalent chromium-based chemical conversion film layer, thereby significantly improving mechanical durability. Brief explanation of the drawing

[0019] FIG. 1 is a cross-sectional view of a device having a multi-penetrating composite corrosion-resistant layer according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating a method for manufacturing a device equipped with a multi-penetrating composite corrosion-resistant layer according to an embodiment of the present invention. FIG. 3a is a photograph showing the corrosion resistance test of a base material manufactured by adding polyurethane according to an embodiment of the present invention. Figure 3b is a photograph showing the corrosion resistance test of a base material manufactured by treating only trivalent chromium. FIG. 4a is a photograph showing the corrosion resistance test of a substrate equipped with a multi-penetrating composite corrosion-resistant layer manufactured according to an embodiment of the present invention. Figure 4b is a photograph showing the corrosion resistance test of a base material manufactured by treating only trivalent chromium. Specific details for implementing the invention

[0020] Hereinafter, an apparatus equipped with a multi-penetrating composite corrosion-resistant layer according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. In order to clearly explain the present invention, parts unrelated to the description have been omitted from the drawings, and in the drawings, the width, length, thickness, etc., of the components may be exaggerated for convenience.

[0021] FIG. 1 is a cross-sectional view of a device equipped with a multi-penetrating composite corrosion-resistant layer according to an embodiment of the present invention, FIG. 2 is a flowchart showing a method for manufacturing a device equipped with a multi-penetrating composite corrosion-resistant layer according to an embodiment of the present invention, FIG. 3a is a photograph showing a corrosion resistance test of a base material manufactured by adding polyurethane according to an embodiment of the present invention, FIG. 3b is a photograph showing a corrosion resistance test of a base material manufactured by treating only trivalent chromium alone, FIG. 4a is a photograph showing a corrosion resistance test of a base material equipped with a multi-penetrating composite corrosion-resistant layer manufactured according to an embodiment of the present invention, FIG. 4b is a photograph showing a corrosion resistance test of a base material manufactured by treating only trivalent chromium alone.

[0022] It is preferable to understand the device (100) equipped with a multi-penetrating composite corrosion-resistant layer according to one embodiment of the present invention as a coating layer formed when the surface of a steel pipe formed of a metal material is treated. In addition, it is preferable to understand the cross-section of FIG. 2 as a cross-section of a surface-treated steel pipe, and the device (100) equipped with a multi-penetrating composite corrosion-resistant layer according to one embodiment of the present invention can be formed on various metals.

[0023] As shown in FIGS. 1 and 2, the device (100) equipped with the multi-penetrating composite corrosion-resistant layer according to one embodiment of the present invention comprises a base material (10), a trivalent chromium-based chemical conversion film layer (20), and a thermal diffusion treatment layer (30).

[0024] Here, the base material (10) is formed of a metal material, and the surface where blackening occurs is zinc-plated to form a surface treatment layer (not shown). In detail, the base material (10) is provided as a steel pipe, but can be provided with a surface of various metal materials requiring durability and corrosion resistance.

[0025] At this time, the base material (10) may also be provided with an alloy material. Here, the surface treatment layer (not shown) may be formed on the base material (10), and it is preferable to understand that it is not shown in the drawing for convenience.

[0026] And, the trivalent chromium-based chemical coating layer (20) is formed by being laminated on the surface of the surface treatment layer (not shown), and a reinforcing mixture containing chromium nitrate and chromium phosphate penetrates into the surface pores of the surface treatment layer (not shown) and is formed.

[0027] In detail, the trivalent chromium-based chemical coating layer (20) can be formed by dipping the base material (10) into a coating tank containing the reinforcing mixture and then drying it. At this time, a heat treatment coating may be further added by firing the base material (10) coated with the reinforcing mixture at a preset temperature.

[0028] In addition, the reinforcing mixture preferably comprises 5 to 10 weight% of chromium nitrate and chromium phosphate, 1 to 5 weight% of sodium nitrate, 1 to 5 weight% of zirconate fluoride, and 85 to 90 weight% of water, based on the total weight of the reinforcing mixture.

[0029] Specifically, zinc oxide and zinc hydroxide may be formed on the zinc-plated surface of the surface treatment layer (not shown) formed on the surface of the base material (10). At this time, the reinforcing compound has an acidic hydrogen ion concentration index (pH) due to the chromium ions of the chromium nitrate and chromium phosphate of the reinforcing compound and the zirconium ions of the zirconate fluoride.

[0030] Accordingly, the zinc oxide and zinc hydroxide on the zinc-plated surface of the surface treatment layer (not shown) are bonded to the chromium ions and zirconium ions of the reinforcing compound through a chemical conversion reaction. Specifically, the nitric acid of the sodium nitrate in the reinforcing compound can act as an oxidizing agent and a buffer.

[0031] At this time, sodium nitrate acts as a buffer to gently oxidize and etch the surface of the surface treatment layer (not shown) and to re-precipitate the trivalent chromium of chromium nitrate and chromium phosphate into the film. Also, the surface of the surface treatment layer (not shown) can be etched by the fluorine of zirconate fluoride. Furthermore, the corrosion resistance of the trivalent chromium-based conversion film layer (20) can be significantly improved by forming a composite inorganic film structure in which zirconia fine particles of zirconate fluoride are dispersed within a trivalent chromium-based film of chromium nitrate and chromium phosphate.

[0032] Accordingly, the trivalent chromium-based chemical conversion film layer (20) is formed by being laminated on the surface of the surface treatment layer (not shown), and is formed by being fixed at the interface through a chemical conversion reaction with zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown), so that the interlayer bonding strength can be further improved.

[0033] In detail, it is preferable to understand that the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown), the chromium ions of the chromium nitrate and chromium phosphate of the reinforcing mixture, and the zirconium ions of the zirconate fluoride form the trivalent chromium-based chemical coating layer (20) through oxygen-mediated bonding between zinc and chromium and zinc and zirconium.

[0034] Accordingly, the trivalent chromium-based chemical conversion film layer (20) can be formed by the reinforcing compound penetrating into the surface and interior of the surface treatment layer (not shown), thereby further improving the interlayer bonding strength. Additionally, the trivalent chromium-based chemical conversion film layer (20) can be formed more densely and stably through oxygen-mediated bonding between zinc and chromium and between zinc and zirconium, thereby further improving mechanical durability and corrosion resistance.

[0035] At this time, as illustrated in the drawing, it is preferable to understand that the mediating compound (20a) that penetrates and is positioned between the metal particles (M) of the base material (10) is formed by the zinc oxide and zinc hydroxide of the zinc-plated surface of the surface treatment layer (not shown) reacting chemically with the chromium ions and zirconium ions of the reinforcing compound.

[0036] Here, referring to FIG. 1, the surface treatment layer (not shown) plated on the surface of the base material (10) is not shown, and the mediating compound (20a) is shown to be positioned between the metal particles (M) of the base material (10).

[0037] At this time, when the surface treatment layer (not shown) is not formed on the surface of the base material (10) and the trivalent chromium-based chemical conversion film layer (20) is formed on the surface of the base material (10), the reinforcing compound can penetrate between the metal particles (M) of the base material (10) through heat treatment, etc., such as the penetration of the mediating compound (20a).

[0038] And, it is preferable to understand that the mediating compound (20a) that has not penetrated between the metal particles (M) of the base material (10) is depicted on the trivalent chromium-based chemical conversion film layer (20) so that it is easy to distinguish between the base material (10), the heat diffusion treatment layer (30) described later, and the trivalent chromium-based chemical conversion film layer (20) in the drawing.

[0039] Meanwhile, the thermal diffusion treatment layer (30) is formed by being laminated on the surface of the trivalent chromium-based chemical conversion film layer (20). Specifically, the thermal diffusion treatment layer (30) is formed by penetrating a corrosion-resistant composite compound containing silane into the surface and interior of the trivalent chromium-based chemical conversion film layer (20).

[0040] At this time, the heat diffusion treatment layer (30) can be formed by spray coating the corrosion-resistant composite compound onto the base material (10) on which the trivalent chromium-based chemical conversion film layer (20) is formed, and then immersing the base material in a coating tank containing the corrosion-resistant composite compound and drying it.

[0041] Here, the trivalent chromium-based chemical conversion film layer (20) is a conversion film formed by interfacial fixation through a chemical conversion reaction between the chromium ions and zirconium ions of the reinforcing composition and the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown).

[0042] At this time, the chromium ions and zirconium ions of the reinforcing mixture are chemically converted and combined with the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown), thereby forming the trivalent chromium-based conversion film layer (20) into a microporous structure. Here, when the thermal diffusion treatment layer (30) is formed, the corrosion-resistant composite mixture penetrates into the pores of the microporous structure of the trivalent chromium-based conversion film layer (20), thereby forming the thermal diffusion treatment layer (30).

[0043] In detail, the corrosion-resistant composite composition preferably comprises, based on the total weight of the corrosion-resistant composite composition, 5 to 15 weight% ethanol, 10 to 15 weight% polyurethane, 1 to 10 weight% ammonium zirconyl carbonate, 1 to 10 weight% glycidoxypropyltrimethoxysilane, 0.1 to 5 weight% phosphoric acid, 1 to 10 weight% tetraethoxysilane, and 60 to 70 weight% water.

[0044] At this time, it is preferable to further include a composite corrosion-resistant layer (40) formed by the silanol composition formed by reacting the silane of the corrosion-resistant composite mixture with the hydroxyl group of the trivalent chromium-based chemical conversion film layer (20) and diffusing it into the surface and interior of the trivalent chromium-based chemical conversion film layer (20).

[0045] In detail, it is preferable that the composite corrosion-resistant layer (40) be formed by heat treatment at 60 to 180°C so as to covalently bond with the hydroxyl groups of the silanol composition and the trivalent chromium-based chemical conversion film layer (20).

[0046] Specifically, the composite corrosion-resistant layer (40) is formed as a silanol composition (40a) by the silane of the corrosion-resistant composite compound used when forming the heat diffusion treatment layer (30) penetrating into the pores of the trivalent chromium-based chemical coating layer (20) and combining with hydroxyl groups.

[0047] Accordingly, since the composite corrosion-resistant layer (40) is formed by the silanol composition (40a) which is formed by combining the silane penetrating during the formation of the thermal diffusion treatment layer (30) and the hydroxyl group of the trivalent chromium-based chemical conversion film layer (20), it is preferable to understand the area where the trivalent chromium-based chemical conversion film layer (20) and the thermal diffusion treatment layer (30) overlap.

[0048] Here, as shown in the drawing, it is preferable to understand that the silanol composition (40a) that has not penetrated into the trivalent chromium-based chemical conversion film layer (20) is shown in the thermal diffusion treatment layer (30) so that the trivalent chromium-based chemical conversion film layer (20) and the thermal diffusion treatment layer (30) can be easily distinguished in the drawing.

[0049] Specifically, the silanes of the glycidoxypropyltrimethoxysilane and tetraethoxysilane of the corrosion-resistant composite mixture penetrate into the pores of the trivalent chromium-based chemical coating layer (20) formed into a microporous structure.

[0050] Specifically, the silane of the tetraethoxysilane of the corrosion-resistant composite composition penetrates into the pores of the trivalent chromium-based chemical conversion film layer (20) and combines with the hydroxyl groups formed by the oxygen-mediated bonding of chromium and zirconium of the trivalent chromium-based chemical conversion film layer (20) to form the silanol composition (40a).

[0051] Accordingly, when the thermal diffusion treatment layer (30) is formed, the silane penetrates into the pores and combines with the hydroxyl groups of the trivalent chromium-based chemical conversion film layer (20) to form the silanol composition (40a), so that the trivalent chromium-based chemical conversion film layer (20) and the thermal diffusion treatment layer (30) are formed by chemical bonding, and the interlayer bonding can be further improved.

[0052] Here, the phosphoric acid of the corrosion-resistant composite mixture is bonded to the surface of the trivalent chromium-based chemical conversion film layer (20) and used as an adhesion promoter. At this time, glycidoxypropyltrimethoxysilane is used as a coupling agent to connect the trivalent chromium-based chemical conversion film layer (20), which is formed as an inorganic film through an epoxy group, and the thermal diffusion treatment layer (30), which is formed as an organic film, so that they are bonded.

[0053] In addition, the ammonium carbonate zirconyl of the corrosion-resistant composite mixture is provided as a zirconium-based crosslinking agent, and when forming the thermal diffusion treatment layer (30), moisture resistance and mechanical strength are imparted, thereby significantly improving the insolubilization performance and strength performance of the thermal diffusion treatment layer (30).

[0054] At this time, the polyurethane of the corrosion-resistant composite mixture is laminated onto the surface of the trivalent chromium-based chemical conversion film layer (20) to provide corrosion resistance and wear resistance. Accordingly, by laminating the polyurethane of the corrosion-resistant composite mixture onto the surface of the trivalent chromium-based chemical conversion film layer (20), the corrosion resistance and wear resistance of the thermal diffusion treatment layer (30) and the protective performance of the trivalent chromium-based chemical conversion film layer (20) can be significantly improved.

[0055] Here, with reference to FIG. 3a and FIG. 3b, the resistance to corrosion of the base material due to the presence or absence of polyurethane addition can be compared. In the experimental example of the present invention, the corrosion resistance test was conducted for approximately 200 hours.

[0056] Figure 3a shows that excellent corrosion resistance was exhibited by blocking the penetration of moisture and oxygen due to the addition of polyurethane. In addition, in the base material without the addition shown in Figure 3b, areas where corrosion (B) occurred were observed, and areas where blackening (A) occurred, where the surface turned black, were also observed. Accordingly, it can be seen that the protective performance of the chromium phosphate-based conversion film layer was significantly improved by the lamination of polyurethane.

[0057] Meanwhile, with reference to FIG. 2, a method for manufacturing a device equipped with a multi-penetrating composite corrosion-resistant layer is described.

[0058] Specifically, the method includes a first step (s10) in which a surface treatment layer (not shown) is formed by zinc plating the surface of the base material (10), a second step (s20) in which a reinforcing compound penetrates the surface and interior of the surface treatment layer (not shown) to form a trivalent chromium-based chemical conversion film layer (20), and a third step (s30) in which a corrosion-resistant composite compound penetrates the surface and interior of the trivalent chromium-based chemical conversion film layer (20) to form a heat diffusion treatment layer (30).

[0059] First, the surface of the base material (10), which is formed from a metal material in the first step, is subjected to zinc plating to form the surface treatment layer (not shown) (s10). At this time, the surface treatment layer (not shown) can be formed by an immersion method in which the base material (10) is pretreated and then immersed in molten zinc after surface treatment, or by electroplating.

[0060] And, in the second step above, the reinforcing mixture containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer (not shown) to form the trivalent chromium-based chemical conversion film layer (20) (s20).

[0061] Here, zinc oxide and zinc hydroxide may be formed on the zinc-plated surface of the surface treatment layer (not shown) formed on the surface of the base material (10). At this time, the reinforcing compound has an acidic hydrogen ion concentration index (pH) due to the chromium ions of the chromium nitrate and chromium phosphate of the reinforcing compound and the zirconium ions of the zirconate fluoride.

[0062] In detail, it is preferable to understand that the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown), the chromium ions of the chromium nitrate and chromium phosphate of the reinforcing mixture, and the zirconium ions of the zirconate fluoride form the trivalent chromium-based chemical conversion film layer (20) through oxygen-mediated bonding by chemical conversion reactions between zinc and chromium and zinc and zirconium.

[0063] At this time, the mediating compound (20a), formed by the chemical conversion reaction of zinc oxide and zinc hydroxide on the zinc-plated surface of the surface treatment layer (not shown) with the chromium ions and zirconium ions of the reinforcing compound, is shown as being placed between the metal particles (M) of the base material (10) as the surface treatment layer (not shown) is not shown.

[0064] Here, when the surface treatment layer (not shown) is not formed on the surface of the base material (10) and the trivalent chromium-based chemical conversion film layer (20) is formed on the surface of the base material (10), the reinforcing compound can penetrate between the metal particles (M) of the base material (10) through heat treatment, etc., such as the penetration of the mediating compound (20a).

[0065] Meanwhile, in the third step above, the corrosion-resistant composite mixture containing silane penetrates into the surface and interior of the trivalent chromium-based chemical conversion film layer (20) to form the thermal diffusion treatment layer (30). Then, the silanol composition (40a), formed by reacting the silane of the corrosion-resistant composite mixture with the hydroxyl groups of the trivalent chromium-based chemical conversion film layer (20), diffuses into the surface and interior of the trivalent chromium-based chemical conversion film layer (20) to form the composite corrosion-resistant layer (40) (s30).

[0066] Here, the heat diffusion treatment layer (30) can be formed by spray coating the corrosion-resistant composite compound onto the base material (10) on which the trivalent chromium-based chemical conversion film layer (20) is formed, and then immersing the base material in a coating tank containing the corrosion-resistant composite compound and drying it.

[0067] At this time, the trivalent chromium-based conversion film layer (20) is a conversion film formed by interfacial fixation through a chemical conversion reaction between the chromium ions and zirconium ions of the reinforcing mixture and the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown). Here, as the chromium ions and zirconium ions of the reinforcing mixture are combined through a chemical conversion reaction with the zinc oxide and zinc hydroxide on the surface of the surface treatment layer (not shown), the trivalent chromium-based conversion film layer (20) is formed into a microporous structure.

[0068] Accordingly, when forming the heat diffusion treatment layer (30), the corrosion-resistant composite mixture penetrates into the pores of the microporous structure of the trivalent chromium-based chemical coating layer (20) to form it.

[0069] Here, it is preferable that the heat diffusion treatment layer (30) be formed by heat treatment at 60 to 180°C so that the silanol composition (40a) and the hydroxyl groups of the trivalent chromium-based chemical conversion film layer (20) are covalently bonded to form the composite corrosion-resistant layer (40).

[0070] At this time, when the heat diffusion treatment layer (30) is formed, silane penetrates into the pores and combines with the hydroxyl groups of the trivalent chromium-based chemical conversion film layer (20) to form the silanol composition (40a), and the silanol composition (40a) penetrates into the trivalent chromium-based chemical conversion film layer (20) to form the composite corrosion-resistant layer (40).

[0071] Here, as shown in the drawing, it is preferable to understand that the silanol composition (40a) that has not penetrated into the trivalent chromium-based chemical conversion film layer (20) is shown in the thermal diffusion treatment layer (30) so that the trivalent chromium-based chemical conversion film layer (20) and the thermal diffusion treatment layer (30) can be easily distinguished in the drawing.

[0072] Referring to FIG. 4a and FIG. 4b, the reinforcing compound containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer (not shown) to form a laminated trivalent chromium-based chemical conversion film layer (20), and the corrosion-resistant composite compound containing silane penetrates into the interior of the trivalent chromium-based chemical conversion film layer (20) to form a laminated thermal diffusion treatment layer (30), thereby protecting the base material (10) from moisture and external contamination, improving corrosion resistance, and significantly reducing blackening.

[0073] Meanwhile, in FIG. 4b, when the corrosion resistance was tested by treating only trivalent chromium alone, the resistance to corrosion was not formed by the thermal diffusion treatment layer (30), so corrosion (B) was observed and blackening (A) was also detected. Accordingly, it can be confirmed that the substrate (10), in which the thermal diffusion treatment layer (30) is formed by penetrating the multi-penetrating composite corrosion-resistant layer, has significantly improved corrosion resistance performance.

[0074] In addition, the trivalent chromium-based chemical conversion film layer (20) is formed by chromium ions and zirconium ions penetrating into the surface and interior of the surface treatment layer (not shown) and chemically converting with zinc oxide and zinc hydroxide to form an interface fixation, and the thermal diffusion treatment layer (30) is formed by silane penetrating into the surface and interior of the trivalent chromium-based chemical conversion film layer (20) and forming an interlayer bond with chromium and oxygen, so the interlayer delamination prevention performance can be significantly improved.

[0075] In addition, the heat diffusion treatment layer (30) is formed by the chemical conversion reaction between the chromium ions and zirconium ions of the reinforcing mixture and the zinc oxide and zinc hydroxide of the surface treatment layer (not shown), and the corrosion-resistant composite mixture penetrates deeper into the interior of the trivalent chromium-based chemical conversion film layer (20) through the pores of the microporous structure of the trivalent chromium-based chemical conversion film layer (20), thereby significantly improving mechanical durability.

[0076] In this context, terms such as "include," "compose," or "equip" as described above, unless specifically stated otherwise, mean that the relevant component may be inherent; therefore, they should be interpreted as allowing for the inclusion of additional components rather than excluding them. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and, unless explicitly defined in the present invention, should not be interpreted in an ideal or overly formal sense.

[0077] As explained above, the present invention is not limited to each of the embodiments described above, and modifications can be made by those skilled in the art without departing from the scope claimed in the claims of the present invention, and such modifications fall within the scope of the present invention. Explanation of the symbols

[0078] 10: Base material 20: Trivalent chromium-based conversion coating 30: Thermal diffusion treatment layer 40: Composite corrosion-resistant layer 100: Device equipped with a multi-penetrating composite corrosion-resistant layer

Claims

Claim 1 A base material formed of a metal material, wherein a surface treatment layer is formed on the surface by zinc plating the surface where blackening occurs; a trivalent chromium-based chemical conversion coating layer formed by being laminated on the surface of the surface treatment layer, wherein a reinforcing compound containing chromium nitrate and chromium phosphate penetrates into the surface and interior of the surface treatment layer; and a thermal diffusion treatment layer formed by being laminated on the surface of the trivalent chromium-based chemical conversion coating layer, wherein a corrosion-resistant composite compound containing silane penetrates into the surface and interior of the trivalent chromium-based chemical conversion coating layer. and a composite corrosion-resistant layer formed by diffusing a silanol composition, formed by reacting the silane of the corrosion-resistant composite mixture with the hydroxyl groups of the trivalent chromium-based chemical conversion film layer, into the surface and interior of the trivalent chromium-based chemical conversion film layer, wherein the reinforcing mixture comprises, based on the total weight of the reinforcing mixture, 5 to 10 wt% of chromium nitrate and chromium phosphate, 1 to 5 wt% of sodium nitrate, 1 to 5 wt% of zirconate fluoride, and 85 to 90 wt% of water, wherein the corrosion-resistant composite mixture comprises, based on the total weight of the corrosion-resistant composite mixture, 5 to 15 wt% of ethanol, 10 to 15 wt% of polyurethane, 1 to 10 wt% of ammonium zirconyl carbonate, 1 to 10 wt% of glycidoxypropyltrimethoxysilane, 0.1 to 5 wt% of phosphoric acid, and 1 to An apparatus equipped with a multi-penetrating composite corrosion-resistant layer characterized by containing 10 weight% and 60 to 70 weight% of water. Claim 2 delete Claim 3 An apparatus having a multi-penetrating composite corrosion-resistant layer, characterized in that, in claim 1, the composite corrosion-resistant layer is formed by heat treatment at 60 to 180°C to covalently bond with the hydroxyl groups of the silanol composition and the trivalent chromium-based chemical conversion film layer. Claim 4 delete Claim 5 delete

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