阅读说明：本技术 一种合金防腐涂层用钝化液 (Passivation solution for alloy anticorrosive coating ) 是由 王涛 贾恒琼 祝和权 张恒 杜存山 李海燕 吴韶亮 魏曌 王玮 杜玮 伊钟毓 于 2020-05-29 设计创作，主要内容包括：本发明提供一种合金防腐涂层用钝化液及其制备方法和应用。所述合金防腐涂层用钝化液的pH＝2～4,按重量百分比计,包括：钼酸钠或钼酸钾0.2％～5％,氟化钠或氟化钾0.1％～2％,十二烷基苯磺酸钠或十二烷基硫酸钠0.005％～0.1％,水分散性纳米二氧化硅0.001％～0.01％,水分散性纳米氧化铈0.001％～0.005％,硝酸铈或醋酸铈0.01％～0.05％,聚苯胺溶液0.01％～0.8％,pH调节剂1％～15％,余量为水。本发明还提供一种具有钝化膜的钢筋及其制备方法,所述钝化膜由上述钝化液形成,所述钢筋在所述钝化膜下具有合金防腐涂层。本发明提供的钝化液可以显著提高钢筋的耐腐蚀性能。(The invention provides a passivation solution for an alloy anticorrosive coating, and a preparation method and application thereof. The pH value of the passivation solution for the alloy anticorrosive coating is 2-4, and the passivation solution comprises the following components in percentage by weight: 0.2 to 5 percent of sodium molybdate or potassium molybdate, 0.1 to 2 percent of sodium fluoride or potassium fluoride, 0.005 to 0.1 percent of sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, 0.001 to 0.01 percent of water dispersible nano silicon dioxide, 0.001 to 0.005 percent of water dispersible nano cerium oxide, 0.01 to 0.05 percent of cerium nitrate or cerium acetate, 0.01 to 0.8 percent of polyaniline solution, 1 to 15 percent of pH regulator and the balance of water. The invention also provides a steel bar with a passivation film and a preparation method thereof, wherein the passivation film is formed by the passivation solution, and the steel bar is provided with an alloy anticorrosive coating under the passivation film. The passivation solution provided by the invention can obviously improve the corrosion resistance of the steel bar.)

1. A passivation solution for an alloy anticorrosive coating, with the pH of 2-4, comprises the following components in percentage by weight: 0.2 to 5 percent of sodium molybdate or potassium molybdate, 0.1 to 2 percent of sodium fluoride or potassium fluoride, 0.005 to 0.1 percent of sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, 0.001 to 0.01 percent of water dispersible nano silicon dioxide, 0.001 to 0.005 percent of water dispersible nano cerium oxide, 0.01 to 0.05 percent of cerium nitrate or cerium acetate, 0.01 to 0.8 percent of polyaniline solution, 1 to 15 percent of pH regulator and the balance of water.

2. The passivation solution for the alloy anticorrosive coating according to claim 1, wherein the passivation solution for the alloy anticorrosive coating has a pH of 2-4, and comprises the following components in percentage by weight: 0.5 to 2 percent of sodium molybdate or potassium molybdate, 0.2 to 1 percent of sodium fluoride or potassium fluoride, 0.01 to 0.05 percent of sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, 0.002 to 0.005 percent of water dispersible nano silicon dioxide, 0.002 to 0.004 percent of water dispersible nano cerium oxide, 0.015 to 0.025 percent of cerium nitrate or cerium acetate, 0.02 to 0.5 percent of polyaniline solution, 1 to 15 percent of pH regulator and the balance of water.

3. The passivation solution for the alloy anticorrosive coating according to claim 1 or 2, wherein the pH adjuster is citric acid.

4. The passivation solution for the alloy anticorrosive coating according to claim 1 or 2, wherein the polyaniline solution is prepared by the following method: respectively weighing 79 parts of deionized water, 14 parts of phytic acid and 1 part of p-phenylenediamine in parts by weight, placing the materials into a three-neck flask, stirring and mixing the materials, respectively adding 1 part of aniline and 5 parts of ammonium persulfate, stirring and mixing the materials, and placing the materials into an ice-water bath at 0 ℃ for treatment for 3 hours to obtain a polyaniline solution with the water content of more than 80%.

5. The preparation method of the passivation solution for the alloy anticorrosive coating according to any one of claims 1 to 4, comprising the steps of preparing the components according to a ratio, uniformly mixing the components except for the pH regulator, and regulating the pH to 2-4 by using the pH regulator.

6. Use of a passivation solution for an alloy anticorrosive coating according to any one of claims 1 to 4 or prepared by the method according to claim 5 for metal corrosion protection, the metal being covered with an alloy anticorrosive coating;

preferably, the process of applying comprises: soaking the metal substrate in the passivation solution for the alloy anti-corrosion coating, or spraying the passivation solution for the alloy anti-corrosion coating on the surface of the metal substrate, and then drying; the surface of the metal substrate is covered with an alloy anticorrosive coating;

preferably, the metal substrate is a ribbed or non-ribbed steel bar covered with an alloy corrosion protection coating.

7. A reinforcing steel bar having a passivation film formed from the passivation solution for an alloy anticorrosive coating of any one of claims 1 to 4 or the passivation solution for an alloy anticorrosive coating prepared by the method of claim 5, the reinforcing steel bar having an alloy anticorrosive coating under the passivation film;

preferably, the rebar is a ribbed or non-ribbed rebar.

8. The method of manufacturing the steel bar of claim 7, comprising the steps of:

step 1: mechanical rust removal

Removing dust, impurities, oxide skin and rusty materials attached to the surface of the steel bar with ribs or without ribs by adopting a sand blasting or shot blasting mechanical rust removing method, wherein the surface cleanliness of the steel bar base material after mechanical rust removing treatment reaches Sa3 level, and the surface roughness reaches Rz 40-100 mu m;

step 2: thermal spraying

Within 0.2h after mechanical rust removal, immediately spraying an aluminum alloy wire onto the surface of the steel bar matrix with or without ribs qualified in the mechanical rust removal treatment by adopting thermal spraying to form a thermal spraying alloy anticorrosive coating;

and step 3: passivation of

Within 0.2h after the thermal spraying in the step 2, atomizing the alloy anticorrosive coating preheated to 40-80 ℃ by using a high-pressure atomizing spray gun, and then spraying the atomized passivation solution onto the surface of the thermal spraying alloy anticorrosive coating with ribs or without ribs at a high speed, wherein the spray speed of mist is more than 2m/s, and the passivation time is 1-100 s; drying after passivation;

and 4, step 4: package (I)

And (3) wrapping and protecting the passivated steel bar with ribs or without ribs with the thermal spraying alloy anticorrosive coating by adopting a soft object such as a plastic film or soft cloth, and then packaging and storing or operating the steel bar.

9. The production method according to claim 8, wherein in the step 2, the aluminum alloy wire is any one or two of aluminum alloy wires containing 0.5 to 2.5% (w/w) of ni, 1.5 to 7.5% (w/w) of cu, and 0.05 to 0.2% (w/w) of re; preferably, the aluminum alloy wire may be selected from any one or any two of ZnAl15, AlMg3, AlMg5, 1060Re, almgare, 5a02 and 5154;

preferably, the thickness of the thermal spraying alloy anticorrosive coating formed in the step 2 is 60-180 μm, and more preferably 100-120 μm;

preferably, in the step 3, the drying specifically comprises: drying the passivated steel bar with ribs or without ribs by hot dry air at the temperature of 60-80 ℃ through an air spray gun for 1-100 s, wherein the spraying speed is more than 1 m/s.

10. A steel bar having a passive film prepared by the method of claim 9, the steel bar having a thermally sprayed alloy corrosion protection coating under the passive film.

Technical Field

The invention belongs to the technical field of metal corrosion prevention and surface engineering, and particularly relates to a passivation solution for an alloy anticorrosive coating, and a preparation method and application thereof.

Background

The metal matrix is easy to rust when exposed in the air, and the rust is further accelerated when the metal matrix is in a severe corrosion environment (such as seawater, tunnels, plateau frozen soil layers and the like). In order to improve the corrosion resistance of metals, surface corrosion prevention treatment is generally carried out, such as thermal spraying of alloy corrosion prevention coating, passivation and the like. Passivation can form a layer of protective film on the surface of the metal to prevent corrosive substances from contacting the metal, thereby improving the corrosion resistance of the metal. Therefore, passivation is widely applied to the field of metal corrosion prevention, and is one of important means for improving the corrosion resistance of metal materials.

At present, chromate passivation is the most widely used at home and abroad. The hexavalent chromium salt can form a passivation film with self-healing capability on the surface of the metal, so that the comprehensive corrosion resistance of the metal is improved. For example, the Chinese patent application publication No. CN110592566A (12.20.2019) discloses a stainless steel passivator, which comprises 45-50g/L potassium dichromate and 300-350ml/L nitric acid. However, hexavalent chromium has great toxicity and is a great harm to the environment and the human body. There are severe restrictions on the use of chromate both domestically and abroad, and even some countries have banned the use of chromate passivation. Researches and developments of a chromium-free passivation process with no toxicity, high performance and low cost are imperative.

The Chinese patent application publication No. CN110578139A (published 2019, 12 and 17) discloses a chromium-free passivation solution suitable for aluminum alloy surface passivation, which comprises an additive and a carrier, wherein the raw materials in the formula comprise the following components in percentage by weight: 0.5-6% of cobalt acetate tetrahydrate, 10-35% of potassium hexafluorosilicate, 1-10% of potassium hexafluorozirconate, 0-3% of a silane coupling agent, 0-2.5% of sodium fluoride, 5-20% of inositol phosphate, 10-20% of deionized water and 30-60% of a catalyst. However, the application does not disclose the chemical composition of the catalyst nor the preservative effect of the passivation solution.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a passivation solution for an alloy anticorrosive coating. The passivation solution does not contain chromium salt, has good safety, and can remarkably improve the corrosion resistance of the metal matrix.

In the present specification, unless otherwise specified, "reinforcing steel bar" means "ribbed reinforcing steel bar" and/or "non-ribbed reinforcing steel bar".

The invention adopts the following technical scheme:

a passivation solution for an alloy anticorrosive coating, with the pH of 2-4, comprises the following components in percentage by weight: 0.2 to 5 percent of sodium molybdate or potassium molybdate, 0.1 to 2 percent of sodium fluoride or potassium fluoride, 0.005 to 0.1 percent of sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, 0.001 to 0.01 percent of water dispersible nano silicon dioxide, 0.001 to 0.005 percent of water dispersible nano cerium oxide, 0.01 to 0.05 percent of cerium nitrate or cerium acetate, 0.01 to 0.8 percent of polyaniline solution, 1 to 15 percent of pH regulator and the balance of water.

Preferably, the passivation solution for the alloy anticorrosive coating has a pH of 2-4, and comprises the following components in percentage by weight: 0.5 to 2 percent of sodium molybdate or potassium molybdate, 0.2 to 1 percent of sodium fluoride or potassium fluoride, 0.01 to 0.05 percent of sodium dodecyl benzene sulfonate or sodium dodecyl sulfate, 0.002 to 0.005 percent of water dispersible nano silicon dioxide, 0.002 to 0.004 percent of water dispersible nano cerium oxide, 0.015 to 0.025 percent of cerium nitrate or cerium acetate, 0.02 to 0.5 percent of polyaniline solution, 1 to 15 percent of pH regulator and the balance of water.

Preferably, the pH adjusting agent is citric acid.

Preferably, the polyaniline solution is prepared as follows: respectively weighing 79 parts of deionized water, 14 parts of phytic acid and 1 part of p-phenylenediamine in parts by weight, placing the materials into a three-neck flask, stirring and mixing the materials, respectively adding 1 part of aniline and 5 parts of ammonium persulfate, stirring and mixing the materials, and placing the materials into an ice-water bath at 0 ℃ for treatment for 3 hours to obtain a polyaniline solution with the water content of more than 80%.

Except for the polyaniline solution, other raw materials of the passivation solution for the metal anticorrosive coating are all commercial products. For example, the water-dispersible nano-silica can be selected from nano-silica aqueous slurry with the mark of MG-Si024A, which is produced by Shanghai ink high-tech materials, and the content of the silica is 20 percent; and the nano silicon oxide water dispersion produced by Shenzhen crystal material chemical Limited can also be selected, the silicon dioxide content is 30 +/-1%, and the particle size is 20-30 nm or 40-50 nm. The water-dispersible nano cerium oxide can be produced by Shenzhen crystal material chemical industry Limited, and has an average particle size of 30-40 nm.

The invention also aims to provide a preparation method of the passivation solution for the alloy anticorrosive coating, which comprises the steps of preparing the components according to the proportion, uniformly mixing the components except the pH regulator, and regulating the pH to 2-4 by using the pH regulator.

The third purpose of the invention is to provide the application of the passivation solution for the alloy anticorrosive coating or the passivation solution for the alloy anticorrosive coating prepared by the method in metal corrosion prevention, wherein the metal is covered by the alloy anticorrosive coating.

Preferably, the process of applying comprises: soaking the metal substrate in the passivation solution for the alloy anti-corrosion coating, or spraying the passivation solution for the alloy anti-corrosion coating on the surface of the metal substrate, and then drying; the surface of the metal substrate is covered with an alloy anticorrosive coating.

Preferably, the metal substrate is a ribbed or non-ribbed steel bar covered with an alloy corrosion protection coating.

The invention also provides a steel bar with a passivation film, wherein the passivation film is formed by the passivation solution for the alloy anticorrosive coating, and the steel bar is provided with the alloy anticorrosive coating under the passivation film.

Preferably, the rebar is a ribbed or non-ribbed rebar.

In addition, the invention provides a preparation method of the steel bar, which comprises the following steps:

step 1: mechanical rust removal

Removing dust, impurities, oxide skin and rusty materials attached to the surface of the steel bar with ribs or without ribs by adopting a sand blasting or shot blasting mechanical rust removing method, wherein the surface cleanliness of the steel bar base material after mechanical rust removing treatment reaches Sa3 level, and the surface roughness reaches Rz 40-100 mu m;

step 2: thermal spraying

Within 0.2h after mechanical rust removal, immediately spraying an aluminum alloy wire onto the surface of the steel bar matrix with or without ribs qualified in the mechanical rust removal treatment by adopting thermal spraying to form a thermal spraying alloy anticorrosive coating;

and step 3: passivation of

Within 0.2h after the thermal spraying in the step 2, atomizing the alloy anticorrosive coating preheated to 40-80 ℃ by using a high-pressure atomizing spray gun, and then spraying the atomized passivation solution onto the surface of the thermal spraying alloy anticorrosive coating with ribs or without ribs at a high speed, wherein the spray speed of mist is more than 2m/s, and the passivation time is 1-100 s; drying after passivation;

and 4, step 4: package (I)

And (3) wrapping and protecting the passivated steel bar with ribs or without ribs with the thermal spraying alloy anticorrosive coating by adopting a soft object such as a plastic film or soft cloth, and then packaging and storing or operating the steel bar.

Preferably, in the step 2, the aluminum alloy wire is any one or two of aluminum alloy wires containing 0.5-2.5% (w/w) of Ni0.5-2.5% (w/w), Cu1.5-7.5% (w/w) and Re0.05-0.2% (w/w). Preferably, the aluminum alloy wire may be selected from any one or any two of ZnAl15, AlMg3, AlMg5, 1060Re, almgare, 5a02 and 5154.

Preferably, the thickness of the thermal spraying alloy anticorrosive coating formed in the step 2 is 60-180 μm, and more preferably 100-120 μm.

Preferably, in the step 3, the drying specifically comprises: drying the passivated steel bar with ribs or without ribs by hot dry air at the temperature of 60-80 ℃ through an air spray gun for 1-100 s, wherein the spraying speed is more than 1 m/s.

The invention also provides the steel bar with the passive film, which is prepared by the method, and the steel bar is provided with the thermal spraying alloy anticorrosive coating under the passive film.

The preparation method is preferably realized by adopting flow line production. The assembly line consists of a straightening and surface treatment section, a feeding and conveying section, a rolling spraying section, a passivation section and a packaging section.

The passivation section on the production line is continuously butted with the rolling spraying section, at least 2 passivation operation areas and 2 drying operation areas are arranged on the hot sprayed steel bars along the running direction of the production line, wherein the passivation operation areas are that rolling driving units and high-pressure atomizing spray gun groups are sequentially installed at intervals from one end to the upper part of the other end of the hot sprayed steel bars, and the spraying width of the high-pressure atomizing spray gun group installed at the back completely covers the steel bars which are not sprayed by the high-pressure atomizing spray gun under the rolling driving units installed at the front; the 2 drying operation areas are characterized in that rolling driving units and dry hot air spray gun groups are sequentially installed on the upper portion of the other end of the passivated steel bar from one end to the other end at intervals, the rolling driving units and the dry hot air spray gun groups between the two adjacent drying operation areas are sequentially and alternately arranged, and the dry hot air spray gun groups installed at the back completely cover the steel bars which are not sprayed by the dry hot air spray guns and correspond to the rolling driving units installed at the front.

The included angle between the jet axis of the hot spraying spray gun, the high-pressure atomizing spray gun and the dry hot air spray gun and the horizontal plane of the assembly line is 60-45 degrees, so that the injection operation efficiency can be further improved, and the loss of the various injection operations caused by the mutual gaps of the reinforcing steel bars can be reduced.

The surface of the steel bar running track is sprayed with an anti-slip coating, and the anti-slip coefficient of the anti-slip coating is more than or equal to 0.4. The problem of sliding of the steel bars in the rolling operation process on the surface of the operation track is prevented.

The running linear speed of the driving belt is 10-100 mm/s, and the driving belt can be optimized and adjusted according to the production line work efficiency design, the steel bar specification and the like.

The surface of the driving belt can be added with a soft surface layer with the thickness of 3-10 mm, the soft surface layer is made of vulcanized rubber or high-density polyethylene foam, the soft surface layer can be combined with a driving belt base body to form a soft surface driving belt by adopting the prior art of bonding and the like, and the materials and the bonding are the prior art. The flexible surface layer can prevent the steel bar from rolling resistance caused by uneven or slightly bent surface or longitudinal and transverse ribs on the surface of the ribbed steel bar when ensuring that the surface of the driving belt is in contact with the steel bar to form enough friction force, and the flexible surface layer on the surface of the driving belt can absorb the resistance of the deformation part to the operation of the driving belt when the steel bar rolls. The vulcanized rubber layer is preferably a product with the modulus of less than or equal to 0.2MPa, the tensile strength of less than or equal to 0.2MPa and the elongation at break of more than or equal to 400 percent.

And a mist recovery device is respectively arranged below the production line sprayed by the high-pressure atomizing spray gun and the dry hot air spray gun, is similar to a thermal spraying dust collection recovery device arranged below the steel bar production line by the thermal spraying spray gun, and realizes the recovery and reutilization of passivation liquid or dry hot air. Wherein the high-pressure atomization spray gun mist recovery device separates and purifies liquid in the mist, and then recovers the purified liquid to passivation liquid on a production line for reuse in a storage container, and the gas is discharged after the purification treatment is qualified; the dry hot air spray gun mist recovery device cools and separates liquid in the mist, purifies the liquid, and then recovers the liquid to passivation liquid on a production line for reuse in a storage container, and the gas is discharged after being purified and qualified.

After the alloy anticorrosion coating steel bar is passivated by the passivation solution provided by the invention, the corrosion resistance of the alloy anticorrosion coating is obviously improved, but the conductivity of the alloy anticorrosion coating steel bar is not obviously reduced, and the relative bonding strength of the steel bar and concrete is not reduced; meanwhile, the passivation film also ensures the effective combined action of the alloy anticorrosion coating steel bar and the impressed cathodic current protection system in the concrete.

Drawings

The invention is further described below with reference to the accompanying drawings.

Fig. 1 is a schematic layout and flow chart of a production line for manufacturing the steel bar with the passivation film and the thermal spray alloy anticorrosive coating in example 6.

Fig. 2 is a longitudinal sectional view of the production line for manufacturing the steel bar having the passivation film and the thermal spray alloy anticorrosive coating in example 6, taken along the running direction.

FIG. 3 is a schematic cross-sectional view of the working area of the production line for producing the steel bar having the passivation film and the thermal spray alloy corrosion prevention coating in example 6, taken along the running direction.

FIG. 4 is a schematic view of the operation of the rolling drive unit in the production line operation area for preparing the steel bar with the passivation film and the thermal spray alloy anticorrosive coating in example 6.

FIG. 5 is a schematic diagram of the space between the steel bars and the spray gun jet in the production line operation area for preparing the steel bars with the passivation films and the thermal spray alloy anticorrosive coatings in example 6.

FIG. 6 is a schematic view of the flexible face structure of the drive belt of the production line for manufacturing the steel bar with the passivation film and the thermal spray alloy corrosion protection coating of example 6.

FIG. 7 is a schematic view of the structure of the antiskid coating of the steel bar running rail of the production line for preparing the steel bar with the passivation film and the thermal spray alloy anticorrosive coating in example 6.

In the above figures, 1, a steel bar base; 3. a straightening and surface treatment section; 4. a feed conveying section; 5. rolling the thermal spraying section; 6. a passivation stage; 6-1, passivating operation area; 6-2, a drying operation area; 7. a packaging section; 8. running the track; 8-1, running a track substrate; 8-2, an anti-slip coating; 9. hot spraying the pre-coated steel bar; 10. thermally spraying the steel bar; 11. after passivation, the steel bar is provided with a thermal spraying alloy anticorrosive coating; 12. a production line steel beam; 13. aligning the sand blasting machine set; 14. hot spraying a spray gun group; 15. a rolling drive unit; 16. a high pressure atomizing spray gun group; 17. an atomization recovery device; 18. a dry hot air spray gun group; 19. a conveyor set; 20. a conveyor belt; 21. supporting the steel bar running track; 22. a thermal spraying dust recovery device; 23. a thermal spray gun; 24. a main drive wheel; 25. a drive belt; 25-1, a soft surface layer; 25-2, driving the belt substrate; 26. a driven wheel; 27. rotating the press roll; 28. the axial direction of the jet flow of the spray gun; a. distance between surfaces of the steel bars; alpha, the included angle between the jet axis of the thermal spraying spray gun and the horizontal plane of the steel bar production line; r, radius of the rebar.

Detailed Description

The invention is illustrated below with reference to specific examples. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

The experimental procedures in the following examples are conventional unless otherwise specified. The raw materials and reagent materials used in the following examples are all commercially available products unless otherwise specified. Wherein, the purchase conditions of partial reagents and raw materials are as follows:

sodium molybdate: suzhou Peng chemical industry technology, Inc., Industrial grade;

potassium molybdate: hubei Xin Rundchemical Co., Ltd, technical grade;

sodium fluoride: southwest aventurine fluorochemical ltd, industrial grade;

potassium fluoride: southwest aventurine fluorochemical ltd, industrial grade;

sodium dodecylbenzenesulfonate: shandong Hengli auxiliary agent, Inc., chemically pure;

sodium lauryl sulfate: chemical corporation of Changzhou Baiyurt, chemical purity;

water-dispersible nanosilicon dioxide: nanometer silicon dioxide water slurry of Shanghai ink high and new materials science and technology Limited, and the mark MG-Si 024A;

water-dispersible nano cerium oxide: shenzhen crystal material chemical industry Co., Ltd, the average grain diameter is 30-40 nm, and the product is industrial grade;

cerium nitrate: hubei Wangyi pharmaceuticals, Inc., chemically pure;

cerium acetate: changsha market success rare earth chemical industry limited liability commune, industrial purity

The polyaniline solutions used in the following examples were prepared as follows: respectively weighing 79 parts of deionized water, 14 parts of phytic acid and 1 part of p-phenylenediamine in parts by weight, placing the materials into a three-neck flask, stirring and mixing the materials, respectively adding 1 part of aniline and 5 parts of ammonium persulfate, stirring and mixing the materials, and placing the materials into an ice-water bath at 0 ℃ for treatment for 3 hours to obtain a polyaniline solution with the water content of more than 80%.