KR20190056368A - Steel surface modification structure formed using nickel and zinc infiltration layer and manufacturing method thereof - Google Patents

Abstract

The present invention discloses a steel surface modification structure having high corrosion resistance formed using zinc and nickel penetration layers. Wherein the steel surface modification structure has a high corrosion resistance and is a corrosion resistant alloy structure formed on the surface of a steel substrate and includes an alloy deposition layer and a metal diffusion layer in the order from the surface toward the inside, Wherein the metal deposition layer comprises pearlite, ferrite, quenching-tempering structure, the carbon content of the steel substrate is 0.30 to 0.65%, and the micro-alloy of the steel surface- The Vickers hardness is between 240 and 500. The surface modification structure formed by the zinc and nickel infiltration layers provided by the present invention has an excellent corrosion inhibiting effect and the loss due to corrosion of steel can be greatly reduced. At the same time, the present invention provides a method for manufacturing a steel surface modification structure formed using a zinc-nickel infiltration layer.

Description

Steel surface modification structure formed using nickel and zinc infiltration layer and manufacturing method thereof

TECHNICAL FIELD The present invention relates to a steel modified structure, and more particularly, to a steel surface modification structure having high corrosion resistance and a method for manufacturing the same.

Steel corrosion is causing massive losses to the world. According to related reports, the yearly corrosion of steel materials in the world amounts to more than 20% of annual production, with a loss of about $ 700 billion. This far exceeds the damages caused by natural disasters such as earthquakes, floods, and typhoons. Currently, there are a variety of corrosion protection technologies, corrosion problems of steel materials are mitigated, but still can not meet the corrosion protection needs. The corrosion resistance of the anticorrosion layer made with current corrosion protection technology does not meet the corrosion protection requirement and the hardness is relatively low. Accessories treated with zinc and nickel penetration technology have high corrosion resistance, high abrasion resistance and vibration resistance. Accordingly, there is a need to provide a steel surface modification structure having a high corrosion protection capability formed by zinc and nickel penetration layers.

In view of the above, there is a need to provide a steel surface modification structure having high corrosion resistance formed using zinc and nickel penetration layers.

The present invention relates to a steel surface modification structure formed using a zinc and nickel penetration layer, the steel surface modification structure having a high corrosion resistance, a corrosion resistant alloy structure formed on the surface of a steel substrate, Wherein the steel substrate is a medium carbon or medium carbon low alloy steel, the alloy deposit layer is a zinc iron compound, the metal diffusion layer comprises pearlite, ferrite, quenching-tempering structure, The carbon content of the steel substrate is 0.30-0.65%, and the micro-Vickers hardness of the steel surface modification structure is between 240-500.

Further, when the steel surface modification structure is not quenched and tempered, the hardness of the metal diffusion layer in the steel surface modification structure is higher than the hardness of the steel substrate.

Further, the steel surface modification structure further comprises a quenching-tempering structure formed after the quenching-tempering treatment, and the hardness of the metal diffusion layer is not higher than the hardness of the steel substrate.

When the steel surface modification structure is etched for 10 to 50 seconds with a nitrogen ethanol solution having a volume ratio of 1-5% without quenching-tempering the steel surface modification structure, the color of the pearlite of the metal diffusion layer is It is lighter than the color of pearlite on a steel substrate.

Also, after the quenching-tempering treatment, the metal diffusion layer of the surface-modified structure of the medium carbon steel and the heavy carbon alloy steel is a quenching-tempering structure, and the steel surface modification structure is treated with a nitrogen ethanol solution having a volume ratio of 1-5% Still shows a white and bright color even after etching for a second.

Also, the thickness of the alloy deposit layer is 60-110 占 퐉, and the thickness of the metal diffusion layer is 30-120 占 퐉.

Further, the steel substrate of the high corrosion-resistant surface-modified steel material is a medium carbon steel or a medium carbon alloy steel.

A method of manufacturing a surface modification structure having a high corrosion prevention performance includes the following steps.

S1: Providing a steel substrate - Providing a steel substrate of medium carbon or medium carbon alloy steel.

S2: Alkali cleaning and degreasing - Alkali cleaning and degreasing of the steel substrate surface with alkaline solution.

S3: removing the rust by shot blasting - the steel substrate after step S2 is shot blasted to remove rust.

S4: Step of forming a heat infiltration layer - A steel substrate and a penetrating agent are placed in a sealed steel container, the steel container is rotated at a rotation speed of 5 to 10 rotations / minute and a heating temperature of 370 to 430 DEG C, Wherein the impregnating agent comprises 25-30 wt% of Zn powder, 2-2.5 wt% of Ni powder, 1-2.5 wt% of Al powder, 0.5-1.5 wt% of rare earth, 1-4 wt% of ammonium chloride, The remaining Al ₂ O ₃ The powder is formed by uniformly mixing.

S5: Subsequent cleaning step.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the surface metallographic structure of a steel material having a high corrosion inhibiting performance provided by the present invention. FIG.
2 is a sectional view of the metal structure after the surface modification treatment of the non-quenching-tempering 45 steel provided by the present invention.
3 is a cross-sectional view of the metal structure after the surface modification treatment of quenching-tempering 45 steel provided by the present invention.
4 is a sectional view of the metal structure after the surface modification treatment of quenching-tempered 42CrMoA steel provided by the present invention.
5 is a sectional view of the metal structure after the surface modification treatment of quenching-tempered 35CrMo steel provided by the present invention.
6 is a sectional view of the metal structure after the surface modification treatment of quenching-tempered 35VB steel provided by the present invention.
7 is a cross-sectional view of the metal structure after the surface modification treatment of quenching-tempered 40Cr steel provided by the present invention.

The technical solution in the embodiments of the present invention will be explained clearly and completely below, and the described embodiments are only a part of an embodiment of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on embodiments of the present invention without creative effort are within the scope of the present invention.

The present invention provides a special method for surface modification of steel materials having a high corrosion protection performance formed by zinc and nickel penetration layers, the method comprising the steps of:

Providing a steel substrate of carbon steel or medium carbon low alloy steel in step (S1).

There is provided a steel substrate of at least one medium carbon steel or medium carbon low alloy steel, wherein the steel substrate is a medium carbon or medium carbon alloy steel.

(S2) the surface pretreatment step of the steel substrate.

At this stage, the pretreatment of the surface of the steel substrate involves two processes: alkali cleaning (or ultrasonic cleaning or low temperature heating) degreasing and shot blasting to remove rust.

Alkali cleaning and degreasing: Cleaning of steel substrates using an alkaline liquid. The main components of the alkaline liquid include sodium hydroxide, sodium carbonate, sodium phosphate, sodium silicate and sodium borate or alkaline salts. In general, an alkaline liquid is a mixture containing two or more of the above components. The alkaline liquid includes steel chelating agents such as EDTA, sodium citrate, triethanolamine, and organic additives such as ethylene glycol and ethylene glycol monoethyl ether, which improve the cleaning effect of the alkaline detergent.

Ultrasonic degreasing: Ultrasonic cleaning is a method of dispersing, emulsifying and dispersing contaminants by utilizing the direct and indirect action of liquids and contaminants on the repulsive action of the ultrasonic waves in the liquid, It is necessary to attain the purpose of cleaning by peeling, and to prepare an appropriate detergent for washing.

Low-temperature heating degreasing: When the oil substance reaches the ignition point, the oil substance is burned, volatilized and carbonized to form ash.

Untreated steel substrates are generally coated with contaminants such as rolling oil, engine oil, powder and dust, and if these contaminants are not cleaned, these contaminants in the surface modification process are carbonized at high temperatures to form carbon films Not only affects the appearance, but also seriously affects the surface modification effect. Degreasing can additionally remove surface contaminants and provide the basis for subsequent processing.

Shot blasting to remove rust refers to additional surface cleaning of the degreased steel substrate by a shot blasting process. The shot blasting process uses a shot blasting machine to fire a steel ball toward the surface of a degreased steel substrate and remove contaminants such as surface corrosion layer and oxide scale of the degreased steel substrate through a shot blasting process, To achieve the roughness and cleanliness of the surface of the steel substrate to prepare the process.

(S3) a step of preparing a reforming penetrant;

Depending on the type of alloy and the corrosion protection effect that the alloy must achieve, prepare a surface modifying penetrant. The surface modifying penetrants are entirely in the form of powder, and their composition and proportions are as follows. 25 to 30 wt% of Zn powder, 2 to 2.5 wt% of Ni powder, 1 to 2.5 wt% of Al powder, 0.5 to 1.5 wt% of rare earth and 1 to 4 wt% of ammonium chloride, and the balance being Al ₂ O ₃ powder. The penetrating agent can adjust the proportions of the respective parts depending on the steel substrate or the application.

(S4) performing a surface modification treatment on the steel substrate;

The steel substrate obtained in step S2 and the penetrating agent prepared in step S3 are put together in a sealed steel container and then the sealed steel container is heated and the sealed steel container is rotated while heating, The penetrant and the steel substrate are at the same temperature at which the penetrant penetrates into the surface of the steel substrate to achieve the steel material surface modification goal. In the present invention, since the rotation speed of the sealed steel vessel is 5 to 10 revolutions / minute, the penetrating agent and the steel substrate are uniformly heated to uniformly perform the surface modification treatment on the steel substrate, and the steel having high corrosion- A surface modifying material can be obtained.

The steel substrate may be medium carbon steel, medium carbon low alloy steel, or the like.

The temperature at which the sealed steel vessel is heated at this stage is 370 to 430 ° C. High and low temperatures have a significant influence on the steel surface modification process, and as the temperature increases, the diffusion rate of the penetrator toward the valence steel substrate increases sharply. The heating temperature of the sealed steel vessel and the surface modification treatment time at this temperature differ depending on the type and use of the steel substrate. The surface modification treatment time is between 1 and 10 hours.

In this step, the steel substrate may be subjected to a heat treatment in advance and then mixed with the penetrating agent. The steel substrate can be directly mixed with the penetrating agent at room temperature without heat treatment. The steel substrate and the penetrating agent are subjected to surface modification in the course of heating the sealed steel vessel.

Before performing this step, the steel substrate may be selectively pre-heated according to actual requirements, and the temperature in advance of the heat treatment is 400 to 420 占 폚.

S5, subsequent washing treatment;

The steel substrate treated in the step S4 is cooled in a natural state, and the dust on the surface of the steel substrate is removed and then washed with water to remove the penetrating agent powder or other impurities attached to the surface.

The quench-tempering treatment may be performed prior to surface pretreatment of the steel substrate and forms a quench-tempering texture on the steel substrate surface through quenching-tempering treatment.

After performing the above steps on the steel substrate, a steel surface modification structure having a high corrosion protection performance formed by the zinc and nickel penetration layers can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of the metal structure of a surface modified steel material provided by the present invention. The surface-modified steel material includes an alloy deposition layer, a metal diffusion layer and a steel substrate in order from the outside to the inside. Wherein the metal diffusion layer is an transient section between the steel substrate and the alloy deposit layer, which is close to the steel substrate side.

[Example 1]

2 is a sectional view of the metal structure after the surface modification treatment of the non-quenching-tempering 45 steel provided by the present invention. In this embodiment, the steel substrate is 45 steel in medium carbon steel, and the non-quenching-tempering 45 steel surface modification process is as follows.

In this embodiment, the steel substrate is medium carbon steel, specifically, medium carbon steel is 45 steel, and the surface modification process is as follows.

First, the surface of the steel substrate is pretreated. Specifically, the steel substrate is subjected to alkali washing, degreasing and shot blasting to remove the rust. Specific processes for removing rust by alkali washing, degreasing, and shot blasting have been described above and will not be described here again.

Then prepare a modified penetrant. In the present embodiment, the modified penetrants are entirely in the form of powder, and the composition and the ratio are as follows. 30% by weight of Zn powder, 2% by weight of Ni powder, 2.5% by weight of Al powder, 0.5% by weight of rare earth and 4% by weight of ammonium chloride, and the balance being Al ₂ O ₃ powder.

Further, the steel substrate is subjected to a surface modification treatment. Specifically, the steel substrate and the penetrating agent are placed in a hermetically sealed steel container, the sealed steel container is heated, the sealed steel container is heated and rotated, and through the heat transfer of the hermetically- And the steel substrate are at the same temperature, and the surface modification treatment is performed at this temperature. In the present invention, the rotation speed of the sealed steel vessel is 5 revolutions / minute, and the surface modification treatment is performed on the steel substrate by uniformly heating the penetrating agent and the steel substrate. The surface modification treatment time is 1 hour, the treatment temperature is 400 占 폚, and a steel surface modification material having high corrosion inhibition performance is obtained through the production.

In this embodiment, the heat treatment is not performed in the course of mixing the 45 steel and the penetrating agent. That is, they are mixed directly at ambient temperature and then heated together in the steel vessel to complete the surface modification process. Specifically, when the steel substrate and the penetrating agent are mixed, the steel substrate and the penetrating agent are mixed at room temperature.

In this embodiment, the steel substrate is 45 steel, and a steel surface modification structure is formed on the 45 steel surface. The steel surface modification structure of the 45 steel includes the alloy deposition layer and the metal diffusion layer in the order from the surface to the inside, and the innermost layer is a steel substrate.

At this time, as shown in FIG. 2, in the metal diffusion layer, the color of the pearlite is lighter than the color of the pearlite of the steel substrate to which it belongs. The Vickers hardness of the metal diffusion layer is higher than the Vickers hardness of each steel substrate, and the thickness of the metal diffusion layer is 100 m. The metal structure of the metal diffusion layer includes pearlite and ferrite.

[Example 2]

3 is a cross-sectional view of the metal structure after the surface modification treatment of quenching-tempering 45 steel provided by the present invention, and Fig. 4 is a view showing the surface modification treatment of quenching-tempering 42CrMoA steel provided by the present invention 5 is a cross-sectional view of the metal structure after the surface modification treatment of the quenched and tempered 35CrMo steel provided by the present invention, and Fig. 6 is a cross-sectional view of the metal structure after the surface modification treatment of the quenching- tempered 35VB steel provided by the present invention And Fig. 7 is a sectional view of the metal structure after the surface modification treatment of the quenching-tempered 40Cr steel provided by the present invention.

In this embodiment, the steel substrate is a medium carbon steel or a medium carbon alloy steel. Specifically, it includes 45 steel, 42CrMoA, 35CrMo steel, 35VB and 40Cr. Finally, surface modification materials of a plurality of different steel substrates are obtained.

The difference between this embodiment and the first embodiment is as follows.

(1) In the present embodiment, the modified penetrating agent is entirely in the form of powder, and the composition and the ratio are as follows. 25% by weight of Zn powder, 2.5 wt% Ni powder, a 1 weight% Al powder, 1.5% by weight rare earth, ammonium chloride and 1% by weight, and the rest Al ₂ O ₃ Powder.

(2) Each steel substrate of this embodiment is quenched and tempered prior to surface pretreatment. The micro-Vickers hardness of the quenched-tempered steel surface modification structure having the high corrosion-resistant performance is between 240 and 500.

In this embodiment, the steel substrate is surface-modified to obtain a surface-modified structure. The steel surface modification structure includes an alloy deposition layer and a metal diffusion layer in the order from the surface to the inside, and the innermost layer is a steel substrate.

Quenching-tempering treatment is applied to the steel substrate to form a quench-tempering structure. Specifically, in this embodiment, the metal diffusion layer is a quench-tempering structure. The quenching-tempering tissue is also tempered sorbite and / or tempered troostite.

In this case, when the diffusion layer after the surface modification of each steel substrate was etched for 10 seconds (typically 10 to 50 seconds) with a nitrogen ethanol solution having a volume ratio of 1-5%, all of the diffusion layers were still white and bright , Which explains that the metal diffusion layer of the modifying material is not easily corroded. Further, the thickness of the metal diffusion layer is 30-100 占 퐉, and the hardness of the metal diffusion layer after the modification of the various other materials is lower than the micro Vickers hardness of the respective steel substrates. A metal diffusion layer is formed on the various other metal substrates after the surface treatment, and the metal structure of the metal diffusion layer is tempered sorbite and / or tempered troostite.

Compared with the prior art, the surface modification structure formed by the zinc and nickel penetration layers provided by the present invention has a good corrosion protection effect and can greatly reduce the loss due to steel corrosion. Further, the surface-modified material surface protective layer has excellent abrasion resistance, excellent impact resistance, and does not change the original mechanical properties of the product.

The embodiments of the present invention should not be construed as limiting the scope of the present invention and are not intended to limit the scope of the present invention to the use of the present invention in other technical fields that are directly or indirectly related to changes, Are all included in the patent protection scope of the present invention.

Claims (8)

A steel surface modification structure formed using zinc and nickel penetration layers,
The steel surface modification structure has a high corrosion resistance and is a corrosion resistant alloy structure formed on the surface of a steel substrate and includes an alloy deposition layer and a metal diffusion layer in the order from the surface toward the inside,
The steel substrate is a medium carbon steel or a medium carbon low alloy steel,
Wherein the alloy deposit layer is a zinc iron compound,
Wherein the metal diffusion layer comprises pearlite, ferrite, quench-tempering structure,
The steel substrate has a carbon content of 0.30 to 0.65%
Wherein the micro-Vickers hardness of the steel surface modification structure is in the range of 240-500. The method according to claim 1,
If the steel surface modification structure is not quenched-tempered,
Wherein the hardness of the metal diffusion layer in the steel surface modification structure is higher than the hardness of the steel substrate. The method according to claim 1,
The steel surface modification structure further comprises a quenching-tempering structure formed after the quenching-tempering process,
Wherein the hardness of the metal diffusion layer is not higher than the hardness of the steel substrate. 3. The method of claim 2,
When the steel surface modification structure is etched for 10 to 50 seconds with a nitrogen-ethanol solution having a volume ratio of 1-5% without quenching-tempering the steel surface modification structure,
Wherein the color of the pearlite of the metal diffusion layer is lighter than the pearlite of the steel substrate. The method of claim 3,
After the quenching-tempering treatment, the metal diffusion layer of the surface-modified structure of the medium carbon steel and the medium carbon alloy steel is a quenching-tempering structure,
Wherein the steel surface modification structure is still white and bright after etching for 10 to 50 seconds with a nitrogenous ethanol solution at a volume ratio of 1-5%. 6. The method according to any one of claims 1 to 5,
Wherein the alloy deposit layer has a thickness of 60 to 110 占 퐉 and the metal diffusion layer has a thickness of 30 to 120 占 퐉. The method according to claim 6,
Wherein the steel substrate of the surface-modified steel structure having high corrosion resistance is a medium carbon steel or a medium carbon alloy steel, the steel surface modification structure formed using the zinc and nickel penetration layer. Providing a steel substrate of carbon steel or heavy carbon alloy steel in step (S1)
(S2) an alkaline washing and degreasing step of performing alkaline washing and degreasing treatment on the surface of the steel substrate with an alkaline solution,
(S3) a step of performing a shot blasting on the steel substrate after step S2 to remove rust,
(S4) The steel substrate and the penetrating agent are loaded in a sealed steel container, and the steel container is rotated at a rotation speed of 5-10 rotations / minute and a heating temperature of 370-430 DEG C and heated to form a heat permeation layer , in which the wetting agent is 25 to 30% by weight of Zn powder, Ni powder, 2-2.5% by weight of Al powder, 1-2.5% by weight, 0.5-1.5% by weight rare earth, ammonium chloride 1-4% by weight, and the balance Al ₂ O ₃ The powder is formed by uniformly mixing,
(S5) a subsequent cleaning step. ≪ Desc / Clms Page number 13 > 5. A method of making a steel surface modification structure formed using a zinc and nickel infiltration layer.

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