690mpa grade weathering bridge steel component stabilizing treatment liquid, treatment process and application

Abstract

The application discloses a kind of stabilizing treatment liquid, for 690MPa grade weathering bridge steel component each component mass percentage content: the content of ferric chloride is 3~7%; The content of sodium bisulfite is 1~2%; The content of chromium sulfate is 3~6%; The content of potassium permanganate is 1~4%; The content of polypropylene glycol is 1~2%; The content of sodium carboxymethyl cellulose is 2~5%; The rest is deionized water.This application also provides the treatment process of stabilizing treatment liquid and its application.The application can realize the rust layer stabilization treatment of 690MPa grade weathering bridge steel component, and the surface of 690MPa grade weathering bridge steel component after treatment forms the brown rust layer of uniform color, no rust liquid flow.

Description

Technical Field

[0001] This invention belongs to the field of corrosion and protection technology, and relates to the protection technology of weathering bridge steel components, specifically to the stabilization treatment liquid and treatment process used for 690MPa grade weathering bridge steel components. Background Technology

[0002] The use of uncoated weathering steel for bridges can significantly reduce coating costs, benefit the environment, shorten construction cycles, and greatly reduce maintenance costs during bridge operation (offering a significant cost advantage over the entire life cycle). However, without rust stabilization treatment, the surface rust layer of weathering steel typically takes 3 to 10 years to gradually stabilize. Furthermore, during the formation of the protective rust layer, rust water can seep out of uncoated weathering steel bridges, affecting aesthetics and causing the steel plates to thin. This leads to rust dripping and spreading, polluting the environment, and severely impacting the consistency of the weathering steel's color during the initial stages of exposed use. This has become a bottleneck restricting the widespread application of uncoated weathering steel for bridges. Therefore, to form a stable rust layer on its surface in a short time, rust stabilization treatment is necessary.

[0003] To adapt to the development of bridge steel structures in my country towards larger spans and higher strengths, the strength grade of high-strength bridge steel plates has been increased to 690 MPa. However, a rust stabilization treatment technology for high-strength weather-resistant bridge steel components has not yet been developed. Furthermore, weather-resistant bridge steel components are assembled from weather-resistant steel plates through processing and welding, and common weather-resistant bridge steel components are approximately cubic in shape. Given the large size of weather-resistant bridge steel components, they are difficult to flip. Therefore, rust stabilization treatment for weather-resistant bridge steel components includes the side, top, and bottom surfaces of the components. Due to the flow of the rust stabilization treatment liquid on various parts of the components, the rust color on the surface of the weather-resistant bridge steel components after rust stabilization treatment is uneven, and the rust liquid flows.

[0004] In the prior art, the patent "Stabilizing Agent for Rust Layer on Weathering Steel Surface Based on Silane Coupling Agent and Its Preparation and Application Method (202111080510.0)" applied for by the Institute of Metal Research, Chinese Academy of Sciences, has the following composition: 1-50% silane coupling agent, 1-10% ethanol, 0.05-0.5% hydrolysis promoter, 0.5-10% rust layer stabilizing promoter, and the remainder is deionized water. The patent applied for by Shougang Group, "A rust stabilizing agent for weathering steel surface and a coating treatment method for weathering steel surface (CN2020106 66089.0)," contains the following components: film-forming agent: 50-80 parts; inducing agent: 1-10 parts; phosphating agent: 0.2-1 parts; accelerator: 1-5 parts; modifier: 1-10 parts; corrosion inhibitor: 1-10 parts; surface additives: 0.05-0.3 parts; wetting and dispersing agent: 0.05-0.4 parts; leveling agent: 0.05-0.4 parts. The patent applied for by Lanzhou University of Technology, "Surface Stabilizing Agent and Treatment Method for Weathering Steel Applicable to Industrial Atmospheric Environment (CN202110934825.0)," includes the following raw materials in the treatment agent: CuSO4 0.8-1.2%, Cr2(SO4)3 2.8-3.2%, NaHSO3 0.5-0.7%, Fe3O4 0.08-0.12%, with the balance being deionized water. The patent applied for by Ansteel, "A rapid rust-stabilizing treatment agent for weathering steel surface and its application method (CN201710068872.5)," consists of two parts: Agent A and Agent B. Agent A is composed of the following components by mass percentage: CuSO4# 0.4%–2%, NaCl# 0.1%–2.5%, FeCl3# 0.5%–3%, HCl# 0.1%–0.5%, with the balance being water. Agent B is an aqueous solution of a humectant, with a humectant mass percentage of 0.2%–3.5%, and the balance being water. The humectant is NaH2PO4 and Na5P3O4. 10 One or more of (NaPO3)6 and C6H5Na3O7·2H2O.

[0005] The aforementioned technologies mainly describe the rust stabilization treatment of weathering steel, but no stabilization treatment liquids or processes involving 690MPa grade weathering bridge steel components were found. The patent applications mentioned above all relate to surface rust stabilization agents and methods for weathering steel, but not to rust stabilization treatment of weathering steel components. Furthermore, the aforementioned technologies do not meet the requirements of this invention for rust stabilization treatment of high-strength (690MPa) weathering bridge steel. Summary of the Invention

[0006] Therefore, to overcome the shortcomings of the above-mentioned technologies and solve problems such as rust stabilization treatment of 690MPa grade weathering steel bridge components, uneven rust color, and rust liquid flow, this invention provides a rust stabilization treatment liquid for 690MPa grade high-strength weathering steel bridge components. Another technical problem to be solved by this invention is to provide a treatment process for the rust stabilization treatment liquid for 690MPa grade high-strength weathering steel bridge components. Yet another technical problem to be solved by this invention is to provide the application of this treatment liquid.

[0007] The technical solution of this invention is a stabilizing treatment fluid for 690MPa grade weathering bridge steel components.

[0008] The stabilization treatment liquid for the 690MPa grade weathering bridge steel components includes an etchant, a rust stabilizer, a moisturizer, and a thickener; the etchant is composed of ferric chloride and sodium bisulfite, the rust stabilizer is composed of chromium sulfate and potassium permanganate, the moisturizer is polypropylene glycol, and the thickener is sodium carboxymethyl cellulose.

[0009] The mass percentage content of each component in the stabilization treatment solution is as follows:

[0010] The content of ferric chloride is 3-7%;

[0011] The sodium bisulfite content is 1-2%;

[0012] The chromium sulfate content is 3-6%;

[0013] The potassium permanganate content is 1-4%.

[0014] The content of polypropylene glycol is 1-2%;

[0015] The content of sodium carboxymethyl cellulose is 2-5%;

[0016] The remainder is deionized water.

[0017] The functions of each component in the stabilization treatment solution for 690MPa grade weathering bridge steel components of the present invention are as follows:

[0018] This invention uses ferric chloride and sodium bisulfite as etchants in the treatment solution. The oxidizing properties of iron ions and the corrosive properties of chloride and bisulfite ions are utilized to erode and rust 690MPa grade weather-resistant bridge steel components, causing the elemental iron in the components to transform into iron oxides. Chromium sulfate and potassium permanganate are added as rust stabilizers. Potassium permanganate has strong oxidizing properties, and together with chromium, it promotes the transformation of fibrous ore and tetragonal fibrous ore in the rust layer into goethite. Chromium can also replace goethite to form the final stable rust layer of the 690MPa grade weather-resistant bridge steel components. Polypropylene glycol is used as a humectant, utilizing its low volatility to retain moisture in the treatment solution and prolong the reaction time of the effective reactive components. Sodium carboxymethyl cellulose is used as a thickener, allowing the treatment solution to fully hydrate and form large molecules, thereby reducing the fluidity of the treatment solution and increasing the residence time of the treatment solution on the side or inclined surfaces of the components. Compared to the absence of these thickeners, the addition of sodium carboxymethyl cellulose in this invention increases the residence time by 3 to 5 times.

[0019] The erosion agent and rust stabilizer components in the treatment solution of this invention promote the formation of a stable rust layer on 690MPa grade weathering bridge steel components. The addition of humectant and thickener increases the electrochemical and chemical reaction time with the component surface. The four components work together to ensure that a uniform brown rust layer with no rust flow is formed on the surface of the 690MPa grade weathering bridge steel components.

[0020] According to the stabilization solution for 690MPa grade weather-resistant bridge steel components of the present invention, preferably, the mass percentage content of each component of the stabilization solution is as follows: ferric chloride content is 4-5%; sodium bisulfite content is 1-1.5%; chromium sulfate content is 4-5%; potassium permanganate content is 2-3%; polypropylene glycol content is 1-1.5%; sodium carboxymethyl cellulose content is 2-3%; and the balance is deionized water.

[0021] This invention also provides a treatment process for a stabilizing fluid for 690MPa grade weathering bridge steel components, comprising the following steps:

[0022] (1) Prepare the stabilization treatment solution according to the above formula for stabilization treatment solution for 690MPa grade weathering bridge steel components by mass percentage, and stir thoroughly; the stirring speed shall not exceed 500 rpm;

[0023] (2) The surface of the weathering bridge steel components is sandblasted to achieve the SA2 level.

[0024] (3) Use a spraying device to evenly spray the treatment liquid onto the side, top, and bottom surfaces of the components;

[0025] (4) Remove any accumulated liquid from the top and bottom surfaces;

[0026] (5) Ensure the components are thoroughly ventilated and dried; a uniform brown rust layer without rust flow forms on the surface of the 690MPa grade weathering bridge steel components.

[0027] The principle of the stabilization treatment process for 690MPa grade weathering bridge steel components of the present invention is as follows:

[0028] During the preparation of the treatment solution, a mixer is used to stir the components. This ensures that the components are mixed evenly and that the thickener components in the treatment solution are fully hydrated to form large molecules, thereby increasing the viscosity of the treatment solution.

[0029] Sandblasting of 690MPa grade weathering steel bridge components can remove iron oxide scale from the surface of the components and increase surface roughness. This increases the adhesion of the treatment solution to the component surface, the reaction time, and improves the rust stabilization effect.

[0030] Since the amount of treatment solution adhering to the component surface directly affects the color of the rust layer after treatment, it is essential to ensure uniform spraying during the treatment process and to eliminate any accumulated solution on the top and bottom surfaces of the component. This will guarantee a uniform surface color after treatment. Ensure the treatment agent dosage is 1–2 liters per square meter.

[0031] Ventilation and drying increase the oxygen content in the treatment solution, promoting the chemical and electrochemical reactions of the stabilization treatment.

[0032] According to the present invention, the treatment process of the stabilization treatment liquid for 690MPa grade weathering bridge steel components is preferably that the stirring in step (1) is carried out by using a mixer; the speed is set to 300-500 rpm.

[0033] Further, the treatment liquid in step (1) is stirred for 1 to 2 hours.

[0034] Preferably, the amount of treatment liquid used in step (3) is 1 to 2 liters per square meter.

[0035] According to the present invention, a treatment process for a stabilizing liquid for 690MPa grade weathering bridge steel components is preferably performed by using a roller brush to remove the accumulated liquid in step (4).

[0036] According to the present invention, the stabilization treatment process of a 690MPa grade weathering bridge steel component is preferably wherein the ventilation drying time is ≥15 days.

[0037] According to the present invention, the stabilization treatment process of a 690MPa grade weathering bridge steel component is preferably carried out outdoors during the ventilation and drying process in step (5).

[0038] When components are placed outdoors, the alternating wet and dry environment created by rain, dew, and sunlight accelerates the formation of a stable rust layer on the component surface.

[0039] More preferably, the ventilation and drying time is 15-30 days. The longer the ventilation and drying time, the more stable the rust layer on the component.

[0040] The stabilized rust layer obtained using the stabilization treatment liquid and treatment process of the present invention for 690MPa grade weathering bridge steel components has the following technical parameters: (1) rust layer thickness on the component surface > 80μm; (2) color difference value ΔE of rust layer on different parts of the component surface < 10; (3) rust layer amount on the component surface > 25g / m 2 .

[0041] Technical parameters for natural rust formation of 690MPa grade weathering steel bridge components: (1) rust layer thickness on the component surface is 10-40μm; (2) rust layer color difference ΔE at different parts of the component surface is 20-50; (3) rust layer amount on the component surface is 5-10g / m 2 .

[0042] This invention also provides the application of the above-mentioned stabilizing treatment liquid in the stabilization treatment of 690MPa grade weathering bridge steel components.

[0043] Beneficial effects:

[0044] Compared with the prior art, the present invention:

[0045] (1) The present invention can achieve rust stabilization treatment on 690MPa grade weathering bridge steel components, and the surface of the treated 690MPa grade weathering bridge steel components forms a brown rust layer with uniform color and no rust liquid flow.

[0046] (2) The treatment liquid for 690MPa grade weathering bridge steel components in this invention is composed of an erosion agent, a rust stabilizer, a moisturizer and a thickener. The treatment liquid can be evenly adhered to the inside, top and bottom of the component and can improve the electrochemical and chemical reaction time with the component surface.

[0047] (3) The rust layer thickness of the 690MPa grade weathering bridge steel components treated by the present invention is >80μm, the color difference value of the rust layer on different parts of the component is ΔE<10, and the rust layer amount on the component surface is >25g / m. 2 . Detailed Implementation

[0048] To better explain the present invention, the stabilization treatment liquid and treatment process for 690MPa grade weathering bridge steel components are described in detail below with reference to specific embodiments:

[0049] Example 1:

[0050] A stabilization treatment solution for 690MPa grade weathering bridge steel components was prepared according to the following mass percentages: ferric chloride 3%, sodium bisulfite 1%, chromium sulfate 3%, potassium permanganate 1%, polypropylene glycol 1%, sodium carboxymethyl cellulose 2%, and the balance being deionized water. The solution was stirred for 1 hour using a mixer at 300 rpm. The surface of the weathering bridge steel components was then sandblasted to achieve an SA2 surface finish. The treatment solution was evenly sprayed onto the side, top, and bottom surfaces of the components using a spray system at a dosage of 1.8 liters per square meter. Any accumulated solution on the top and bottom surfaces was removed using a roller brush. The components were then placed outdoors for 15 days to allow for ventilation and drying. After treatment, the surface of the 690MPa grade weathering bridge steel components forms a uniform brown rust layer without rust flow. The rust layer thickness is 85μm, the color difference value ΔE between different parts of the component is 9, and the rust layer amount is 28g / m². 2 .

[0051] Example 2:

[0052] A stabilization treatment solution for 690MPa grade weathering bridge steel components was prepared according to the following mass percentages: 4% ferric chloride, 1.5% sodium bisulfite, 4% chromium sulfate, 2% potassium permanganate, 2% polypropylene glycol, 3% sodium carboxymethyl cellulose, and the remainder being deionized water. The solution was stirred for 2 hours using a mixer at 400 rpm. The surface of the weathering bridge steel components was then sandblasted to achieve an SA2 surface finish. The treatment solution was evenly sprayed onto the side, top, and bottom surfaces of the components using a spray system at a dosage of 1.5 liters per square meter. Any accumulated solution on the top and bottom surfaces was removed using a roller brush. The components were then placed outdoors for 30 days to allow for ventilation and drying. After treatment, the surface of the 690MPa grade weathering bridge steel components forms a uniform brown rust layer without rust flow. The rust layer thickness is 90μm, the color difference value ΔE between different parts of the component is 5, and the rust layer amount is 30g / m². 2 .

[0053] Example 3:

[0054] A stabilization treatment solution for 690MPa grade weathering bridge steel components was prepared according to the following mass percentages: 7% ferric chloride, 2% sodium bisulfite, 6% chromium sulfate, 4% potassium permanganate, 2% polypropylene glycol, 5% sodium carboxymethyl cellulose, and the balance being deionized water. The solution was stirred for 2 hours using a mixer at 500 rpm. The surface of the weathering bridge steel components was then sandblasted to achieve an SA2 surface finish. The treatment solution was evenly sprayed onto the side, top, and bottom surfaces of the components using a spray system at a rate of 1 liter per square meter. Any accumulated solution on the top and bottom surfaces was removed using a roller brush. The components were then placed outdoors for 28 days to allow for ventilation and drying. After treatment, the surface of the 690MPa grade weathering bridge steel components formed a uniform brown rust layer without rust flow. The rust layer thickness was 88μm, the color difference value ΔE between different parts of the component was 6, and the rust layer amount was 32g / m². 2 .

[0055] Example 4:

[0056] A stabilization treatment solution for 690MPa grade weathering bridge steel components was prepared according to the following mass percentages: ferric chloride 6%, sodium bisulfite 1.6%, chromium sulfate 5.5%, potassium permanganate 3.5%, polypropylene glycol 1.5%, sodium carboxymethyl cellulose 3.5%, and the balance being deionized water. The solution was stirred for 1.5 hours using a mixer at 350 rpm. The surface of the weathering bridge steel components was then sandblasted to achieve an SA2 surface finish. The treatment solution was evenly sprayed onto the side, top, and bottom surfaces of the components using a spray system at a dosage of 1.2 liters per square meter. Any accumulated solution on the top and bottom surfaces was removed using a roller brush. The components were then placed outdoors for 25 days to allow for ventilation and drying. After treatment, the 690MPa grade weathering bridge steel components formed a uniform brown rust layer without rust flow. The rust layer thickness was 88μm, the color difference value ΔE between different parts of the component was 7, and the rust layer amount was 29g / m². 2 .

[0057] Example 5:

[0058] A stabilization treatment solution for 690MPa grade weathering bridge steel components was prepared according to the following mass percentages: ferric chloride 4.5%, sodium bisulfite 1.9%, chromium sulfate 4.5%, potassium permanganate 2.5%, polypropylene glycol 1.7%, sodium carboxymethyl cellulose 3.8%, with the balance being deionized water. The solution was stirred for 1.6 hours using a mixer at 440 rpm. The surface of the weathering bridge steel components was then sandblasted to achieve an SA2 surface finish. The treatment solution was evenly sprayed onto the side, top, and bottom surfaces of the components using a spray system at a rate of 2 liters per square meter. Any accumulated solution on the top and bottom surfaces was removed using a roller brush. The components were then placed outdoors for 29 days to allow for ventilation and drying. After treatment, the surface of the 690MPa grade weathering bridge steel components formed a uniform brown rust layer without rust flow. The rust layer thickness was 92μm, the color difference value ΔE between different parts of the component was 4.5, and the rust layer amount was 27g / m². 2 .

[0059] The above embodiments are merely some preferred examples and are not intended to limit the implementation of the present invention.

Claims

1. A stabilizing treatment fluid for 690MPa grade weathering bridge steel components, characterized in that: The stabilization treatment liquid for the 690MPa grade weathering bridge steel components includes an etchant, a rust stabilizer, a moisturizer, and a thickener; the etchant is composed of ferric chloride and sodium bisulfite, the rust stabilizer is composed of chromium sulfate and potassium permanganate, the moisturizer is polypropylene glycol, and the thickener is sodium carboxymethyl cellulose. The mass percentage content of each component in the stabilization treatment solution is as follows: The content of ferric chloride is 3-7%; The sodium bisulfite content is 1-2%; The chromium sulfate content is 3-6%; The potassium permanganate content is 1-4%. The content of polypropylene glycol is 1-2%; The content of sodium carboxymethyl cellulose is 2-5%; The remainder is deionized water; The stabilizing treatment solution is used in the treatment process of 690MPa grade weathering bridge steel components, and includes the following steps: (1) Prepare the stabilization treatment solution according to the above formula for stabilization treatment solution for 690MPa grade weathering bridge steel components by mass percentage, and stir thoroughly; the stirring speed shall not exceed 500 rpm; (2) The surface of the weathering bridge steel components is sandblasted to achieve the SA2 level. (3) Use a spraying device to evenly spray the treatment liquid onto the side, top, and bottom surfaces of the component; (4) Remove any accumulated liquid from the top and bottom surfaces; (5) Ensure the components are thoroughly ventilated and dried; a uniform brown rust layer without rust flow forms on the surface of the 690MPa grade weathering bridge steel components.

2. The stabilizing treatment fluid for 690MPa grade weathering bridge steel components according to claim 1, characterized in that: The mass percentage content of each component in the stabilization treatment solution is as follows: ferric chloride 4-5%; sodium bisulfite 1-1.5%; chromium sulfate 4-5%; potassium permanganate 2-3%; polypropylene glycol 1-1.5%; sodium carboxymethyl cellulose 2-3%; and the balance is deionized water.

3. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components as described in claim 1, characterized in that: Includes the following steps: (1) Prepare the stabilization treatment solution according to the above formula for stabilization treatment solution for 690MPa grade weathering bridge steel components by mass percentage, and stir thoroughly; the stirring speed shall not exceed 500 rpm; (2) The surface of the weathering bridge steel components is sandblasted to achieve the SA2 level. (3) Use a spraying device to evenly spray the treatment liquid onto the side, top, and bottom surfaces of the component; the amount of treatment liquid used is 1 to 2 liters per square meter; (4) Remove any accumulated liquid from the top and bottom surfaces; (5) Ensure the components are thoroughly ventilated and dried; a uniform brown rust layer without rust flow forms on the surface of the 690MPa grade weathering bridge steel components.

4. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 3, characterized in that: The stirring in step (1) is done using a mixer set to 300-500 rpm.

5. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 3 or 4, characterized in that: The treatment solution in step (1) is stirred for 1 to 2 hours.

6. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 3, characterized in that: Step (4) Use a roller brush to remove the accumulated liquid.

7. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 3, characterized in that: The ventilation and drying time described in step (5) is ≥15 days.

8. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 7, characterized in that: The ventilation and drying time described in step (5) is 15-30 days.

9. The treatment process of the stabilization solution for 690MPa grade weathering bridge steel components according to claim 3, characterized in that: The ventilation and drying process described in step (5) is carried out outdoors.

10. The application of the stabilizing treatment liquid of claim 1 in the stabilization treatment of 690MPa grade weathering bridge steel components.