阅读说明：本技术 一种具有稳定锈层的裸用耐候钢及其制造方法 (Bare weathering steel with stable rust layer and manufacturing method thereof ) 是由 吴玮巍 *** 周庆军 祁庆琚 郎丰军 李江文 宋凤明 于 2019-04-30 设计创作，主要内容包括：本发明公开了一种具有稳定锈层的裸用耐候钢,裸用耐候钢的表面具有在2小时以内形成的锈层。此外,本发明还公开了上述的具有稳定锈层的裸用耐候钢的制造方法,其包括步骤：(1)将钢板表面进行清洗后去除残余水分；(2)在钢板表面施加试剂以使钢材表面的单质铁被转变成离子态的铁；(3)在钢板表面喷涂水以使钢材表面被水膜浸润,待钢板表面水膜干透后,再次喷涂水膜,照此重复若干次,以使离子态的铁水解成为铁的氢氧化物沉淀,然后脱水形成锈层。该裸用耐候钢具有均匀的锈层,锈层稳定致密,具有优异的耐腐蚀性,克服了现有技术中常规耐候钢锈层稳定化之前颜色不均等问题,该裸用耐候钢无需在使用现场进行任何表面处理即可直接裸露使用。(The invention discloses a bare weathering steel with a stable rust layer, wherein the surface of the bare weathering steel is provided with the rust layer formed within 2 hours. In addition, the invention also discloses a manufacturing method of the bare weathering steel with the stable rust layer, which comprises the following steps: (1) cleaning the surface of the steel plate and removing residual moisture; (2) applying a reagent on the surface of the steel plate to convert the simple substance iron on the surface of the steel plate into iron in an ionic state; (3) spraying water on the surface of the steel plate to enable the surface of the steel to be soaked by the water film, spraying the water film again after the water film on the surface of the steel plate is dried, repeating the spraying and spraying steps for a plurality of times so as to enable the ionic-state iron to be hydrolyzed into iron hydroxide precipitate, and then dehydrating to form a rust layer. The bare weathering steel has an even rust layer, the rust layer is stable and compact, the corrosion resistance is excellent, the problems of uneven color and the like before the rust layer of the conventional weathering steel is stabilized in the prior art are solved, and the bare weathering steel can be directly used in a bare manner without any surface treatment on the use site.)

1. A bare weathering steel having a stable rust layer, characterized in that the surface of the bare weathering steel has a rust layer formed within 2 hours.

2. The bare weathering steel with stabilized rust layer according to claim 1, characterized in that the rust layer has a thickness of 10 to 200 μm.

3. A method of manufacturing a bare weathering steel with a stable rust layer according to claim 1 or 2, characterized in that it comprises the steps of:

(1) cleaning the surface of the steel plate and removing residual moisture;

(2) converting simple substance iron on the surface of the steel into ionic iron;

(3) spraying water on the surface of the steel plate to enable the surface of the steel to be soaked by the water film, spraying the water film again after the water film on the surface of the steel plate is dried, repeating the spraying and spraying steps for a plurality of times so as to enable the ionic-state iron to be hydrolyzed into iron hydroxide precipitate, and then dehydrating to form a rust layer.

4. The manufacturing method according to claim 3, wherein in the step (1), after the hot rolling or pickling of the steel sheet is completed, the surface of the steel sheet is cleaned.

5. The manufacturing method according to claim 3, wherein in the step (2), the elemental iron on the surface of the steel material is oxidized into the ionic ferrite by any one of three methods:

(a) coating a reducing acid solution on the surface of the steel plate to oxidize elementary iron into ferrous ions;

(b) oxidizing the surface of the steel plate to obtain an oxide layer, and then coating an acidic solution on the surface of the steel plate to dissolve the oxide layer to form iron salt;

(c) The steel sheet surface is directly coated with an oxidizing salt solution, such as a ferric salt.

6. The method according to claim 5, wherein the pH of the reducing acid solution is 3 or less when the method (a) is employed.

7. The method according to claim 6, wherein the pH of the reducing acid solution is 1 or less.

8. The production method according to claim 5, wherein, when the aspect (a) is employed, the reducing acid solution is a hydrochloric acid solution.

9. The production method according to claim 5, wherein, when the method (a) is employed, the reducing acid solution is a mixed solution of a hydrochloric acid solution and a NaCl solution having a mass concentration of 1 to 10%.

10. The manufacturing method according to claim 5, wherein when the method (b) is adopted, the surface of the steel sheet is oxidized to obtain a denser oxide layer by applying the oxidizing solution at room temperature.

11. The method according to claim 10, wherein the oxidizing solution is H having a mass concentration of 0.1 to 10% diluted with a NaCl solution having a mass concentration of 1 to 10%₂O₂And (3) solution.

12. The production method according to claim 10 or 11, wherein the acidic solution is a hydrochloric acid solution having a mass concentration of 0.1 to 5%.

13. The production method according to claim 10 or 11, wherein the acidic solution is a mixed solution composed of a hydrochloric acid solution having a mass concentration of 0.1 to 5% and a NaCl solution having a mass concentration of 1 to 10%.

14. The method of claim 5, wherein when using mode (c), the salt solution is an inert metal cation salt solution less active than iron or a ferric salt solution.

15. The method according to claim 14, wherein the ferric salt solution is FeCl having a concentration of 1 to 10% by mass₃And (3) solution.

16. The manufacturing method according to any one of claims 5 to 15, wherein the temperature of the water and/or the agent sprayed on the surface of the steel sheet is 10 to 100 ℃.

Technical Field

The invention relates to weathering steel and a manufacturing method thereof, in particular to bare weathering steel and a manufacturing method thereof.

Background

Compared with carbon steel, the weathering steel has good atmospheric corrosion resistance. The main reasons are as follows: a stable and compact protective rust layer is formed on the surface of the weathering steel after long-term atmospheric exposure, so that the corrosion medium is prevented from entering, and the rust layer formed on the surface of the carbon steel is often loose, has a large number of microcracks and has poor protection on a matrix.

At present, in a natural environment, it takes 4 years or more for the weathering steel to form a stable protective rust layer, and before the weathering steel forms the stable rust layer, phenomena such as uneven rust layer color, rust liquid sagging, and flying rust slag often occur in an early stage, which affect the surrounding environment and the appearance. However, after 4 years or more, the surface rust layer is stable, and the weathering steel can show a dark brown or coffee appearance with strong sense of thickness, has strong antique art smell, and is popular with people. And the color can be unchanged for years, so that the corrosion medium can be well prevented from further penetrating, and the corrosion is prevented.

Disclosure of Invention

One of the purposes of the invention is to provide the bare weathering steel with the stable rust layer, the bare weathering steel has the uniform and stable rust layer, and the rust layer is compact, so that the bare weathering steel has excellent corrosion resistance and can be directly exposed and used for decades in the conventional atmospheric environment.

In order to achieve the above object, the present invention proposes a bare weathering steel having a stable rust layer, the surface of the bare weathering steel having a rust layer formed within 2 hours.

Further, in the bare weathering steel with stable rust layer according to the invention, the rust layer has a thickness of 10 to 200 μm.

Accordingly, another object of the present invention is to provide a method for manufacturing the above-mentioned bare weathering steel with stable rust layer, which can overcome the disadvantages of the prior art, mass-produce weathering steel with uniform stable rust layer, and the rust layer of the produced weathering steel is stable and compact, has excellent corrosion resistance, and can be directly exposed and used in conventional atmospheric environment for several decades. The weathering steel obtained by the manufacturing method can not have the problems of uneven color, rust flowing and rust slag falling before the rust layer is stabilized, the manufacturing method can avoid the limitation of rust forming treatment in the prior art on fields, manpower, environmental protection and the like, is greatly convenient to use, and has better application prospect.

In order to achieve the above object, the present invention provides a method for manufacturing the above bare weathering steel having the stable rust layer, comprising the steps of:

(1) cleaning the surface of the steel plate and removing residual moisture;

(2) converting simple substance iron on the surface of the steel into ionic iron;

(3) spraying water on the surface of the steel plate to enable the surface of the steel to be soaked by the water film, spraying the water film again after the water film on the surface of the steel plate is dried, repeating the spraying and spraying steps for a plurality of times so as to enable the ionic-state iron to be hydrolyzed into iron hydroxide precipitate, and then dehydrating to form a rust layer.

According to the technical scheme, the bare weathering steel can be rapidly rusted through the steps, so that the surface of the steel is provided with a stable and uniform rust layer, the rust layer is compact, a corrosion medium can be effectively prevented from entering the interior of the steel and reacting with a substrate of the steel, and the corrosion resistance of the material is improved.

The rust layer on the surface of the bare weathering steel obtained by the manufacturing method can be sequentially yellow, brown, coffee and dark coffee from light to dark, the thickness of the rust layer is more than 10 micrometers, the surface color of the material is uniform, the color of the rust layer can be gradually and integrally darkened in the outdoor use process, and the bare weathering steel has a stronger visual effect compared with the prior art.

Further, in the manufacturing method according to the present invention, in the step (1), after the hot rolling or pickling of the steel sheet is completed, the surface of the steel sheet is cleaned to ensure that the surface of the steel sheet is free from oil stains.

Further, in the manufacturing method according to the present invention, in the step (2), the elemental iron on the surface of the steel material may be oxidized into the ionic ferrite by any one of the following three methods:

(a) coating a reducing acid solution on the surface of the steel plate to oxidize elementary iron into ferrous ions;

(b) oxidizing the surface of the steel plate to obtain an oxide layer, and then coating an acidic solution on the surface of the steel plate to dissolve the oxide layer to form iron salt;

(c) the steel sheet surface is directly coated with an oxidizing salt solution, such as a ferric salt.

Preferably, in the production method according to the present invention, when the mode (a) is employed, the pH of the reducing acid solution is 3 or less.

More preferably, in the production method of the present invention, the pH of the reducing acid solution is 1 or less.

Further, in the production method according to the present invention, when the aspect (a) is adopted, the reducing acid solution is a hydrochloric acid solution.

Preferably, in the production method according to the present invention, when the mode (a) is employed, the reducing acid solution is a mixed solution of a hydrochloric acid solution and a NaCl solution with a mass concentration of 1 to 10%.

Further, in the manufacturing method according to the present invention, when the method (b) is employed, the surface of the steel sheet is oxidized by applying the oxidizing solution at room temperature to obtain a denser oxide layer.

In some other embodiments, the surface of the steel plate can be oxidized at a high temperature to obtain a dense oxide layer.

It should be noted that the oxidizing solution may be hydrogen peroxide or other oxidizing solutions as would occur to one skilled in the art.

Further, in the production method of the present invention, the oxidizing solution is H having a mass concentration of 0.1 to 10% which is diluted with a NaCl solution having a mass concentration of 1 to 10%₂O₂And (3) solution.

Further, in the production method of the present invention, the acidic solution is a hydrochloric acid solution having a mass concentration of 0.1 to 5%.

Further, in the production method of the present invention, the acidic solution is a mixed solution composed of a hydrochloric acid solution having a mass concentration of 0.1 to 5% and a NaCl solution having a mass concentration of 1 to 10%.

Further, in the production method of the present invention, when the mode (c) is employed, the salt solution is an inert metal cation salt solution less active than iron or a ferric salt solution.

PreferablyIn the manufacturing method of the invention, the solution of the ferric salt is FeCl with the mass percentage concentration of 1-10 percent₃And (3) solution.

In the scheme, the NaCl solution with the mass concentration of 1-10% is added for preparation, so that the conductivity and the corrosivity of the solution can be increased, and the rust formation speed is increased.

Further, in the manufacturing method of the present invention, the temperature of the water and/or the agent sprayed on the surface of the steel sheet is 10 to 100 ℃.

Compared with the prior art, the bare weathering steel with the stable rust layer and the manufacturing method thereof have the following advantages and excellent effects:

(1) the bare weathering steel prepared by the method for preparing the bare weathering steel with the stable rust layer has a uniform and stable rust layer, and the problems that the rust layer is slowly formed in the using process of the weathering steel in the prior art, the weathering steel is unstable in the initial formation stage, and the unstable rust layer is easy to generate uneven color, yellow rust flowing, rust slag falling and the like are solved.

(2) The bare weathering steel prepared by the manufacturing method of the bare weathering steel with the stable rust layer can provide enough protection, so that the bare weathering steel has excellent corrosion resistance at the initial stage of service, and the bare weathering steel is prevented from corrosion damage at the initial stage of service.

(3) The manufacturing method can utilize assembly line equipment to carry out rapid rust formation treatment on steel, and the process and material cost is far lower than that of coating.

(4) When the manufacturing method disclosed by the invention is used for carrying out rapid rust formation treatment on weather-resistant steel, only conventional salt, weak acid and a small amount of clear water are needed for treatment, substances all participate in the reaction in the process, no emission exists, and the manufacturing process is safe and environment-friendly.

(5) The bare weathering steel obtained by the manufacturing method can be welded only by grinding the groove during welding, and can be normally used without any treatment after welding, and the welding seam can naturally form a protective rust layer in the service process and is integrated with other parts after the final rust layer is stable, so that the welding seam can be simply and quickly rusted if the requirement on the early appearance is high.

(6) The rust forming time can be greatly shortened by adopting the manufacturing method provided by the invention, and in some preferred embodiments, the rust forming time can be shortened by 1-2 hours, so that the method is very favorable for batch production, and finally, the product with uniform rust layers can be directly delivered out of a factory.

(7) The reagent applied by the manufacturing method of the invention does not relate to the use of noble metal salt, has simpler components and lower cost, and is more suitable for batch production.

Drawings

Fig. 1 schematically illustrates the structure of bare weathering steel having a stable rust layer according to the present invention in some embodiments.

Detailed Description

The bare weathering steel with stabilized rust layer and the method for producing the same according to the invention will be further explained and illustrated with reference to the drawings and the specific examples, which, however, should not be construed as an undue limitation on the technical solution of the invention.