A high-cleanliness lubricating leveling fluid for continuous annealing lines and its preparation method

Abstract

This application relates to the field of leveling process technology, and discloses a high-cleanliness lubricating leveling fluid for continuous annealing lines and its preparation method. The high-cleanliness lubricating leveling fluid for continuous annealing lines comprises the following components by mass percentage: rust inhibitor 21%-30%, lubricant 2-3%, pH adjuster 2-5%, cleaning agent 3-5%, and water as the balance. The high-cleanliness lubricating leveling fluid provided in this application optimizes the cleanliness of the leveling fluid by combining cationic and nonionic surfactants to produce an additive synergistic effect, significantly reducing the surface tension of the leveling fluid and optimizing the dispersibility of iron powder. This is beneficial in application for improving the surface cleanliness of strip steel (reducing residual iron), maintaining the cleanliness of the rolling mill stand, solving the problem of most leveling fluids on the market easily clogging nozzles and roll holes, and enabling its widespread application in continuous annealing production lines.

Description

Technical Field

[0001] This application relates to the field of leveling process technology, and mainly to a high-cleanliness lubricating leveling fluid for continuous annealing lines and its preparation method. Background Technology

[0002] Leveling is a process technology that further rolls cold-rolled steel sheets after continuous or bell-type annealing to achieve the target elongation. Currently, there are two main methods in this process: dry leveling and wet leveling. Wet leveling is gaining popularity due to its low dust levels and the special morphology and matte finish it produces on the steel sheet. Typically, wet-leveled steel sheets are used directly as substrates for tin or chromium plating, which directly impacts their rust resistance. However, annealed substrates have high surface activity and rapid corrosion rates, requiring processing media to enhance rust resistance. Considering both high production efficiency and cost savings, using a leveling solution in the wet leveling process to improve substrate rust resistance is the most economical and feasible approach.

[0003] The continuous annealing line is characterized by its continuous production process, resulting in high efficiency and the ability to meet the demands of mass production. The leveling machine, on the other hand, works by using the squeezing action of upper and lower rollers to achieve a smoothing effect on strips or plates. Specifically, the leveling machine uses a working mechanism consisting of two rollers covered with abrasive belts. During operation, the plate is deburred and leveled by the abrasive belts. If the roller gap is too tight, the roller press cannot accurately press the material or thin plate, leading to unsatisfactory results. Furthermore, in current leveling processes, the leveling machine's plate and roller conveyors must adhere to clean production procedures. Before production, the leveling fluid nozzles must be inspected; the emulsion nozzles in the middle of the strip must not be clogged. The leveling fluid must be sprayed in a fan shape onto the gap between the upper and lower working rollers without clogging. Therefore, a qualified leveling fluid needs, on the one hand, suitable lubrication performance and friction coefficient to ensure high-speed and stable rolling of the steel strip and reduce wear between the steel plate and the rollers; on the other hand, it also needs excellent cleaning performance to improve the surface cleanliness of the steel plate.

[0004] Several leveling fluids have been publicly disclosed. For example, Chinese invention patent CN114480007A describes a wet leveling fluid using borate esters and borates as composite rust inhibitors; Chinese invention patent CN102286749A introduces a wet leveling fluid that uses organic acids and organic amines to achieve rust prevention; and Chinese invention patent CN102199478A discloses a method for preparing an anti-yellowing, environmentally friendly wet leveling fluid. However, to date, none of the reported wet leveling fluid patents have optimized their cleaning performance, thus limiting the use of wet leveling processes. Furthermore, existing commercially available wet leveling fluids generally focus more on their rust-preventing properties, neglecting the cleanliness of the rolling mill. During application, phosphate esters, which are prone to residue, are often added to ensure lubrication. However, after a period of use, the nozzles and roller holes of the rolling mill are easily clogged, leading to excessively tight roller gaps. If the leveling fluid lacks self-cleaning properties and mixes with iron powder, remaining in the roller holes, the gaps cannot be widened, affecting the normal operation of the machine and significantly reducing production efficiency, potentially failing to meet the demands of large-scale production on continuous annealing lines. Therefore, to solve this problem, workers often need to frequently clean and maintain the roller holes, and downtime for cleaning significantly reduces the efficiency of continuous annealing lines. Therefore, to reduce roller hole clogging, it is necessary to provide a method for preparing a highly clean, lubricating leveling fluid suitable for continuous annealing lines, and to study its performance to meet the requirements of leveling processing. Thus, existing technologies require further improvement and development. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a high-cleanliness lubricating leveling fluid for continuous annealing lines and its preparation method, aiming to solve the problem of insufficient cleaning performance of existing leveling fluids.

[0006] The technical solution of this application is as follows:

[0007] In a first aspect, this application provides a high-cleanliness lubricating leveling fluid for continuous annealing lines, wherein, by mass percentage, it comprises the following components:

[0008] Rust inhibitor 21%-30%, lubricant 2-3%, pH adjuster 2-5%, cleaning agent 3-5%, water balance.

[0009] Furthermore, the rust inhibitor is one or more of the following: a rust inhibitor composed of ethanolamine and acid, a polyol ester rust inhibitor, a self-assembled rust inhibitor, a silane coupling rust inhibitor, or a vapor phase rust inhibitor.

[0010] Furthermore, the rust inhibitor is a rust inhibitor composed of ethanolamine and acid, wherein the mass ratio of ethanolamine to acid is 7:4.

[0011] Furthermore, the ethanolamine is a combination of monoethanolamine and triethanolamine, wherein the mass ratio of monoethanolamine to triethanolamine is 1:1;

[0012] The acid is a combination of dicarboxylic acid C21 and mixed dicarboxylic acid GM1, and the mass ratio of dicarboxylic acid C21 to mixed dicarboxylic acid GM1 is 5:3.

[0013] Furthermore, the cleaning agent is a combination of tallow amine polyoxyethylene ether T05 and polyether L-62, with a mass ratio of tallow amine polyoxyethylene ether T05 to polyether L-62 of 1:2.

[0014] Furthermore, the pH adjuster is boric acid.

[0015] Furthermore, the lubricant is one of the following: fatty alcohol ether phosphate MOA-3P, phosphate ester NP-10, and neodecanoic acid 685-2.

[0016] Furthermore, the lubricant is phosphate ester NP-10.

[0017] Secondly, this application also provides a method for preparing the high-cleanliness lubricating leveling fluid for continuous annealing lines as described in the first aspect, comprising the following steps:

[0018] At 35-45℃, the rust inhibitor, cleaning agent, lubricant, pH adjuster and water are added to the container in sequence according to the ratio. After stirring for 1-2 hours, stirring and heating are stopped to obtain the high-cleanliness lubricating continuous stripping line leveling liquid.

[0019] Furthermore, after stopping stirring and heating, let it stand for 1-2 hours.

[0020] Beneficial effects: The high-cleanliness lubricating leveling fluid for continuous annealing lines provided in this application optimizes the cleanliness of the leveling fluid by combining cationic and nonionic surfactants to produce an additive synergistic effect, which greatly reduces the surface tension of the leveling fluid and optimizes the dispersibility of iron powder. In application, this is beneficial to improve the surface cleanliness of strip steel (reduce residual iron), maintain the cleanliness of the rolling mill stand, solve the problem that most leveling fluids on the market are prone to clogging nozzles and roll holes, and enable its widespread application in continuous annealing production lines. Attached Figure Description

[0021] Figure 1 The results are the iron powder dispersibility test results of Examples 1, 2, 3, 4, Comparative Examples 1-1, 1-2 and 1-3 of this application.

[0022] Figure 2 The results are the iron powder dispersibility test results of Examples 1, 5, 6 and Comparative Example 2-1 of this application.

[0023] Figure 3 The results of the iron powder dispersibility test for a certain imported brand leveling fluid and a certain domestic brand leveling fluid are shown in Example 1 of this application. Detailed Implementation

[0024] This application provides a clean, lubricating, continuous line leveling fluid and its preparation method. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following provides a more detailed description. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit the scope of this application.

[0025] This application provides a high-cleanliness lubricating leveling fluid for continuous annealing lines, wherein, by mass percentage, it comprises the following components:

[0026] Rust inhibitor 21%-30%, lubricant 2-3%, pH adjuster 2-5%, cleaning agent 3-5%, water balance.

[0027] The high-cleanliness lubricating leveling fluid for continuous annealing lines provided in this application optimizes the cleanliness of the leveling fluid by combining cationic and nonionic surfactants to produce an additive synergistic effect, which greatly reduces the surface tension of the leveling fluid and optimizes the dispersion of iron powder. This is beneficial for improving the surface cleanliness of strip steel (reducing residual iron) and maintaining the cleanliness of the rolling mill stand. It solves the problem that most leveling fluids on the market are prone to clogging nozzles and roll holes, and enables its widespread application in continuous annealing production lines.

[0028] Specifically, the high-cleanliness lubricating continuous annealing line leveling fluid provided in this application, as the stock solution, needs to be diluted with water before use. The mass percentage of the stock solution in the diluted solution is 1-5%. Deionized water can be used.

[0029] Furthermore, the rust inhibitor is one or more of the following: a rust inhibitor compounded with ethanolamine and acid, a polyol ester rust inhibitor, a self-assembled rust inhibitor, a silane coupling rust inhibitor, or a vapor-phase rust inhibitor. Specifically, wet leveling solutions require water as a carrier for dilution before use, but the presence of water is a major cause of metal corrosion. Therefore, a relatively large amount of rust inhibitor needs to be added to the stock solution of the wet leveling solution to meet the rust prevention requirements. The selected rust inhibitors compounded with ethanolamine and acid, polyol ester rust inhibitors, self-assembled rust inhibitors, silane coupling rust inhibitors, and vapor-phase rust inhibitors, as environmentally friendly water-based rust inhibitors, have excellent metal rust prevention effects.

[0030] Preferably, the rust inhibitor is a combination of ethanolamine and acid, with a mass ratio of ethanolamine to acid of 7:4. Studies have shown that rust prevention is related to the length of the alkyl chain and the type and number of polar groups in the molecule. In this application, the ethanolamine in the preferred rust inhibitor combination can combine with a diacid to form an organic carboxylic acid ethanolamine salt, which can keep steel products rust-free for 48 hours at a low concentration.

[0031] More specifically, the ethanolamine is a combination of monoethanolamine and triethanolamine, with a mass ratio of monoethanolamine to triethanolamine of 1:1, and the acid is a combination of diacid and mixed diacid, with a mass ratio of diacid to mixed diacid of 5:3. The diacid can be diacid C21, and the mixed diacid can be mixed diacid GM1. In this application, the monoethanolamine, triethanolamine, diacid, and mixed diacid are used in combination. The monoethanolamine and triethanolamine react with the carboxyl groups in the diacid and mixed diacid to form an amide, which is also a very effective rust inhibitor. This forms a very dilute alkylolamide, which can prevent steel from rusting even at low concentrations and has good hydrolysis resistance. It also thickens the rust inhibitor, thus preventing the rust inhibitor from flowing off the metal surface and ensuring its firm adhesion to the metal surface. Moreover, the nitrogen and oxygen atoms in the generated organic carboxylic acid alcohol amine salts and alkyl alcohol amide molecules have lone pairs of electrons, which can interact with metal surfaces with empty orbitals, such as iron, to form a complex film, preventing oxygen, water and other molecules from contacting the metal surface, thus further ensuring the anti-rust effect.

[0032] Specifically, surface treatment cleaning agents work by using surfactants and other chemical substances in their components to adsorb and disperse surface dirt, causing it to detach from the surface and form a foam or suspension. Finally, the dirt on the object's surface is thoroughly cleaned through rinsing or suction of the cleaning solution. Water-based cleaning agents in leveling solutions mainly consist of surfactants and cleaning aids. Most commercially available wet leveling solutions use nonionic surfactants with strong cleaning capabilities, but using only one type of nonionic surfactant is insufficient for dispersing iron powder.

[0033] To address this issue, the cleaning agent is further described as a combination of tallow amine polyoxyethylene ether T05 and polyether L-62, with a mass ratio of tallow amine polyoxyethylene ether T05 to polyether L-62 of 1:2. In this application, by using a combination of nonionic and cationic surfactants, high lubricity is ensured while achieving stronger cleaning performance than using a single surfactant, even with the same amount of rust inhibitor, lubricant, and pH adjuster. This not only improves the cleanliness of the steel plate but also effectively removes residual substances from the roll gap. Tallow amine polyoxyethylene ether T05 is a cationic surfactant obtained by polymerizing tallow amine and a low amount of ethylene oxide. The low EO number of tallow amine polyoxyethylene ether T05 results in low surface tension, strongly reducing the surface tension of the leveling solution dilution, thereby improving the dispersibility of iron powder. Polyether L-62 is a nonionic surfactant. When tallow amine polyoxyethylene ether T05 and polyether L-62 are compounded in the provided ratio, the surface tension of the mixed micelles in the compound system at the critical micelle concentration is lower than that of either one alone, resulting in a positive additive and synergistic effect. This is the result of the interaction between the ionic groups of tallow amine polyoxyethylene ether T05 and the polar polyoxyethylene groups of polyether L-62, which is beneficial to further improve the dispersion and cleaning performance of the leveling solution.

[0034] Furthermore, the pH adjuster is boric acid. Specifically, since iron hydroxide is insoluble in alkaline solutions, a thin protective film can be formed on the metal surface, slowing down the corrosion rate of steel plates in alkaline solutions compared to acidic solutions. Alkaline solutions are also more conducive to degreasing and cleaning of steel strip surfaces; therefore, leveling solutions are mostly alkaline. However, the alkalinity of wet leveling solutions should not be too high, as excessively high pH values ​​not only harm human skin and are detrimental to the ecological environment but also corrode the coated metal. This application uses a certain amount of boric acid as a pH adjuster in the wet leveling solution to adjust the pH value within a suitable range. The selected boric acid, as a weak acid, is less harmful to human skin and the environment and also has certain anti-corrosion properties, making it suitable for use in leveling processes.

[0035] Specifically, in the leveling process of cold-rolled steel sheets, a rolling process with a reduction rate of 0.3% to 3.0% is generally involved, and some cold-rolled steel sheets require a higher reduction rate to maintain flatness. Therefore, introducing an appropriate water-soluble lubricant into the wet leveling fluid formulation can give the leveling fluid suitable lubrication performance, reduce the rolling force of the rolls, reduce roll wear, and enable the steel sheet surface to obtain a stable and uniform elongation, thereby preventing over-lubrication and slippage. Preferably, the lubricant is one of fatty alcohol ether phosphate ester MOA-3P, phosphate ester NP-10, or neodecanoic acid 685-2. Neodecanoic acid is generally used in metal extractants, lubricating oils, and cosmetics, and as an effective metal extractant, it can also be used as a synthetic ester lubricant. This application selects neodecanoic acid 685-2 as a lubricant because, due to the highly branched structure of the α-carbon tertiary carbide, it has better hydrolysis resistance and corrosion resistance compared to the linear secondary carbide structure. The selected fatty alcohol ether phosphate esters MOA-3P and NP-10 both possess excellent water solubility, detergency, emulsification, lubrication, cleaning, dispersion, antistatic, and rust-preventing properties, as well as excellent electrolyte compatibility and stability to heat and alkalis. They are resistant to acids, alkalis, hard water, inorganic salts, and high temperatures, while also exhibiting good biodegradability, low irritation, and strong degreasing power.

[0036] Preferably, the lubricant is NP-10 phosphate ester. Specifically, most phosphate esters currently on the market are prone to residue and have weak detergency, failing to meet high cleanliness requirements. This application investigates the dosage and type of phosphate ester to address this problem, and subsequently selects NP-10 phosphate ester as the preferred choice. The selected NP-10 phosphate ester is anionic, exhibiting high activity and stability in a system environment with a pH of 9-10 in the working solution (diluent) of the leveling solution, which matches the pH range of this product. Furthermore, by controlling the addition of NP-10 phosphate ester at 2-3%, both lubricity and high cleanliness of the leveling solution can be ensured. Exceeding the recommended addition amount of NP-10 phosphate ester can easily cause residue, affecting the cleanliness of the leveling solution; while adding less than the recommended amount cannot guarantee sufficient lubrication.

[0037] The high-cleanliness lubricating leveling fluid for continuous annealing lines provided in this application optimizes the cleanliness of the leveling fluid by combining cationic and nonionic surfactants to produce an additive synergistic effect, which greatly reduces the surface tension of the leveling fluid and optimizes the dispersion of iron powder. This is beneficial for improving the surface cleanliness of strip steel (reducing residual iron) and maintaining the cleanliness of the rolling mill stand. It solves the problem that most leveling fluids on the market are prone to clogging nozzles and roll holes, and enables its widespread application in continuous annealing production lines.

[0038] This application also provides a method for preparing the high-cleanliness lubricating leveling fluid for continuous annealing lines as described above, comprising the following steps:

[0039] At 35-45℃, rust inhibitor, cleaning agent, lubricant, pH adjuster and water are added to the container in sequence according to the ratio. After stirring for 1-2 hours, stirring and heating are stopped to obtain a high-cleanliness lubricating continuous stripping line leveling fluid.

[0040] Specifically, the container can be a water bath, and the resulting high-cleanliness lubricating continuous stripping line leveling liquid is a transparent light yellow liquid.

[0041] Furthermore, after stopping stirring and heating, allow it to stand for 1-2 hours. This cooling and standing process improves compatibility and enhances the stability of the resulting high-cleanliness, lubricating, continuous-line leveling fluid.

[0042] The following specific examples provide further details.

[0043] 1. Some of the raw materials used in the embodiments of this application are from the following sources:

[0044] Monoethanolamine: Junyan New Materials Technology (Shanghai) Co., Ltd.;

[0045] Triethanolamine: Tianjin Yitaicheng Chemical Technology Co., Ltd.;

[0046] Dicarboxylic acid C21: Guangzhou Mickey Chemical Co., Ltd.;

[0047] Mixed dicarboxylic acid GM1: Shandong Kaisai Biotechnology Materials Co., Ltd.;

[0048] Boric acid: Tianjin Haoruisen Chemical Trading Co., Ltd.;

[0049] Polyether L-62: Sanda Chemical Co., Ltd.;

[0050] PE6100: Sanda Chemical Co., Ltd.;

[0051] Tallow amine polyoxyethylene ether T10: Shanghai Wenpu Chemical Technology Co., Ltd.;

[0052] Tallow amine polyoxyethylene ether T05: Shanghai Wenpu Chemical Technology Co., Ltd.;

[0053] MOA-3P (Fat Alcohol Ether Phosphate): Haian Petrochemical Plant, Jiangsu Province;

[0054] Phosphate NP-10: Xingtai Xinlanxing Technology Co., Ltd.;

[0055] Neodecanoic acid 685-2: Guangzhou Fufeng Chemical Technology Co., Ltd.

[0056] 2. The preparation method of the high-cleanliness lubricating continuous annealing line leveling fluid in the embodiments of this application includes the following steps:

[0057] The water bath was heated to 40°C. Rust inhibitor, cleaning agent, lubricant, pH adjuster, and water were added sequentially according to the specified proportions, stirring for 2 hours. Stirring and heating were then stopped, and the mixture was allowed to stand for 1.5 hours to obtain the high-cleanliness lubricating continuous stripping line leveling fluid of each embodiment. All the obtained high-cleanliness lubricating continuous stripping line leveling fluids were transparent pale yellow liquids.

[0058] 3. The testing method of the embodiments of this application.

[0059] The test subjects in this application are the various high-cleanliness lubricating continuous annealing line leveling fluids in the embodiments:

[0060] (1) Appearance, determined by visual inspection.

[0061] (2) The test method for lubrication performance is to determine the pB value of the original sample solution according to GB / T 3142 "Test Method for Lubricant Carrying Capacity (Four-Ball Method)" and judge the quality of the lubrication performance of the sample by the pB value. Tester model: Xiamen Tianji MS-10A.

[0062] (3) The surface tension was tested using the OCA15EC video optical contact angle measuring instrument developed by Dataphysics GmbH in Germany.

[0063] (4) Test method for iron powder dispersion performance: Dilute the original solution of the leveling solution with deionized water to a concentration of 5%, take 100ml of solution into a stoppered graduated cylinder, add 2g of iron powder, shake up and down for 30s (about 60 times), and observe the dispersion of iron powder.

[0064] (5) The cleaning performance test shall be conducted in accordance with JB / T 4323.2-1999 "Test Methods for Water-based Metal Cleaning Agents", and the cleaning efficiency of the leveling liquid dilution shall be determined by the oil washing rate.

[0065] (6) Rust prevention test method: Wash 2g of rust-free cast iron filings twice with No. 120 solvent gasoline, drain and then quickly dry with hot air. Then spread them evenly on a petri dish with filter paper with a 30mm×30mm grid in the middle placed at the bottom. Use a pipette to draw the test solution (1%, 3%, and 5% concentration leveling solution dilution) and evenly drip it onto the iron filings. Cover the petri dish and place it at room temperature for 72 hours to observe the rusting of the iron filings. Then quickly rinse the iron filings on the filter paper with tap water, dry the filter paper, and observe the rusting on the filter paper.

[0066] Using the above preparation method, leveling solutions for Examples 1, 2, 3, 4, Comparative Example 1-1, Comparative Example 1-2, and Comparative Example 1-3 were prepared according to the component ratios in Table 1. The component ratios are shown in Table 1.

[0067] Table 1

[0068] Example 1 Example 2 Example 3 Example 4 Comparative Example 1-1 Comparative Examples 1-2 Comparative Examples 1-3 monoethanolamine 7% 7% 7% 7% 3.5% 7% 7% Triethanolamine 7% 7% 7% 7% 7% 7% 7% Dicarboxylic acid C21 5% 5% 5% 5% 5% 5% 5% Mixed dicarboxylic acid GM1 3% 2% 3% 3% 3% 3% 3% boric acid 3% 3% 3% 3% 2% 3% 3% PE6100 - - 3% - - 3% - Polyether L-62 3% 3% - 3% 3% - 3% Neodecanoic acid 685-2 - - 3% - - 3% - MoA-3P (Fat Alcohol Ether Phosphate) - - - 2% - - 2% Phosphate NP-10 2% 2% - - 2% - - Tallow amine polyoxyethylene ether T05 1.5% 1.5% 1.5% - 1.5% 3% - Tallow amine polyoxyethylene ether T10 - - - 1.5% - - 3% water 68.5% 69.5% 67.5% 68.5% 73% 66% 67%

[0069] Basic performance index tests were conducted on Examples 1, 2, 3, 4, Comparative Examples 1-1, 1-2, and 1-3. P B Surface tension and cleaning properties were tested using the undiluted solution, while rust prevention was tested by diluting the solution to 5%, 3%, and 1% by mass, respectively. The test results are shown in Table 2.

[0070] Table 2

[0071] Test Project Example 1 Example 2 Example 3 Example 4 Comparative Example 1-1 Comparative Examples 1-2 Comparative Examples 1-3 <![CDATA[P B ,Kg]]> 40 40 40 40 40 40 40 Surface tension, mN / m 5.2 5.2 5.4 10.1 5.3 5.5 10.9 Cleanability (oil removal rate), % 98.8 94.3 96.5 93.1 95.5 96.5 92.2 Rust prevention (5% dilution, 72h) Rust-free Rust-free Rust-free Rust-free Rusty Rust-free Rust-free Rust prevention (3% dilution, 72h) Rust-free Rusty Rust-free Rust-free Rusty Rust-free Rust-free Rust prevention (1% dilution, 72h) Rust-free Rusty Rust-free Rust-free Rusty Rust-free Rust-free

[0072] The test results of Examples 1, 2 and Comparative Example 1-1 show that reducing the ratio of organic acid and organic base has a significant impact on the rust prevention performance of the leveling liquid system. Therefore, the preferred ratio of organic base to organic acid in the rust inhibitor is 7:4.

[0073] The test results of Examples 1, 3 and Comparative Examples 1-2 show that: (1) Using NP-10 phosphate ester and 685-2 neodecanoic acid as lubricants for leveling fluid, both can achieve excellent lubrication performance in this system. However, under the condition that PB is 40Kg, the amount of NP-10 phosphate ester added is lower than that of 685-2 neodecanoic acid. Therefore, it is preferable to select NP-10 phosphate ester as lubricant in this system. (2) By selecting different cationic and nonionic compounding agents, it can be found that the surface cleaners selected by T05 and PE6100 and the surface cleaners selected by T05 and polyether L-62 have excellent cleaning performance. However, the surface cleaners selected by T05 and polyether L-62 have slightly better cleaning performance than those selected by T05 and PE6100. It was also found that increasing the amount of T05 compounding did not significantly improve the cleaning performance. Therefore, it is preferable to select the surface cleaners selected by T05 and polyether L-62 in this system with a compounding ratio of 1:2.

[0074] The test results of Examples 1, 4 and Comparative Examples 1-3 show that: (1) When NP-10 phosphate ester, 685-2 neodecanoic acid, or MOA-3P fatty alcohol ether phosphate ester are selected as lubricants for leveling fluid, they can all achieve excellent lubrication performance in this system; (2) It was found that the cleaning performance of surface cleaners with T05 and polyether L-62 and surface cleaners with T10 and polyether L-62 is significantly different, which proves that the surface tension of tallow amine polyoxyethylene ether with low EO number is low, which can reduce the surface tension of the leveling fluid dilution and has good iron powder dispersibility. Therefore, it is preferable to use surface cleaners with T05 and polyether L-62.

[0075] The iron powder dispersibility test results for Examples 1, 2, 3, 4, Comparative Examples 1-1, 1-2, and 1-3 are as follows: Figure 1 As shown (from left to right: Example 1, Comparative Example 1-1, Example 2, Comparative Example 1-2, Example 3, Comparative Example 1-3, Example 4), the comparative test results show that Example 1 uses a surface cleaning agent composed of cationic and nonionic surfactants in the leveling liquid, and the iron powder in the emulsion has good dispersion and the iron powder is dispersed relatively evenly.

[0076] Using the above preparation method, leveling solutions for Examples 1, 5, 6, and Comparative Example 2-1 were prepared according to the component ratios in Table 3. The component ratios are shown in Table 3.

[0077] Table 3

[0078] Example 1 Example 5 Example 6 Comparative Example 2-1 monoethanolamine 7% 7% 7% 7% Triethanolamine 7% 7% 7% 7% Dicarboxylic acid C21 5% 5% 5% 5% Mixed dicarboxylic acid GM1 3% 3% 3% 3% boric acid 3% 3% 3% 3% PE6100 - 4.5% - 3% Polyether L-62 3% - 4.5% 3% Phosphate NP-10 2% 2% 2% 2% Tallow amine polyoxyethylene ether T05 1.5% - - - Tallow amine polyoxyethylene ether T10 - - - - water 68.5% 68.5% 68.5% 67%

[0079] The basic performance test results of the stock solutions of Examples 1, 5, 6 and Comparative Example 2-1 are shown in Table 4:

[0080] Table 4

[0081] Test Project Example 1 Example 5 Example 6 Comparative Example 2-1 Surface tension, mN / m 5.2 15.3 12.5 10.4 Cleanability (oil removal rate), % 98.8 90.5 91.1 94.5

[0082] The iron powder dispersibility test results of Examples 1, 5, 6 and Comparative Example 2-1 are as follows: Figure 2 As shown (from left to right, they are Example 1, Example 5, Example 6 and Comparative Example 2-1). The test results of the basic performance indicators of Example 1, Example 5, Example 6 and Comparative Example 2-1 are as follows: (1) In terms of surface tension test results, the effect of using a single nonionic surfactant and using a combination of nonionic surfactants to reduce surface tension is not as good as using the low EO number cationic surfactant T05 combined with a nonionic surfactant applied to the leveling liquid; (2) In terms of cleaning performance, the surface tension of the leveling liquid directly affects the cleaning performance. The lower the surface tension, the better the cleaning performance of the leveling liquid; (3) In terms of iron powder dispersion performance, Example 1 with low surface tension has more uniform iron powder dispersion than Example 5, Example 6 and Comparative Example 2-1.

[0083] Basic performance indicators of a certain imported brand leveling fluid and a certain domestic brand leveling fluid were tested in Example 1. P B Surface tension and cleaning properties were tested using the undiluted solution, while rust prevention was tested using diluted solutions at concentrations of 5%, 3%, and 1% by mass. The test results are shown in Table 5.

[0084] Table 5

[0085] Test Project Example 1 A certain imported brand of leveling fluid A domestic brand of leveling fluid <![CDATA[P B ,Kg]]> 40 30 26 Surface tension, mN / m 5.2 12.9 20.1 Cleanability (oil removal rate), % 98.8 89.5 77 Rust prevention (5% dilution, 72h) Rust-free Rust-free Rust-free Rust prevention (3% dilution, 72h) Rust-free Rust-free Rust-free Rust prevention (1% dilution, 72h) Rust-free Rust-free Rust-free

[0086] The iron powder dispersibility test results of Example 1, an imported brand leveling fluid, and a domestic brand leveling fluid are as follows: Figure 3 As shown (from left to right: Example 1, a domestic brand leveling fluid, and an imported brand leveling fluid). The test results of Example 1, the imported brand leveling fluid, and the domestic brand leveling fluid illustrate that: the imported brand, as a major international brand, uses a single surface cleaner, resulting in high surface tension and slightly inferior lubricity and cleaning properties compared to the leveling fluid of this invention. The domestic brand leveling fluid also uses a single surface cleaner, but its cleaning, lubricity, and iron filings dispersion are far inferior to those of this invention. This application uses a cleaning agent composed of a low-EO number cationic surfactant and a nonionic surfactant, which can significantly improve the cleaning properties of the leveling fluid, effectively reduce and remove residues clogging nozzles and roller holes, improve production efficiency, and meet the needs of large-scale production on continuous annealing lines.

[0087] The high-cleanliness lubricating leveling fluid for continuous annealing lines provided in this application optimizes cleanliness by combining low-EO-number cationic surfactants with nonionic surfactants to create an additive synergistic effect, forming a novel surface treatment cleaning agent. This significantly reduces the surface tension of the leveling fluid and optimizes the dispersion of iron powder. In application, this is beneficial for improving the surface cleanliness of strip steel (reducing residual iron) and maintaining the cleanliness of the rolling mill stand. It can solve the problem that most leveling fluids on the market are prone to clogging nozzles and roll holes, and enable its widespread application in continuous annealing production lines.

[0088] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. A high-cleanliness lubricating leveling fluid for continuous annealing lines, characterized in that, Calculated by mass percentage, it includes the following components: Rust inhibitor 21%-30%, lubricant 2-3%, pH adjuster 2-5%, cleaning agent 3-5%, water balance; The cleaning agent is a combination of tallow amine polyoxyethylene ether T05 and polyether L-62, and the mass ratio of tallow amine polyoxyethylene ether T05 to polyether L-62 is 1:

2. The lubricant is one of fatty alcohol ether phosphate MOA-3P or phosphate ester NP-10.

2. The high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 1, characterized in that, The rust inhibitor is one or more of the following: ethanolamine and acid compound rust inhibitor, polyol ester rust inhibitor, and silane coupling rust inhibitor.

3. The high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 2, characterized in that, The rust inhibitor is a rust inhibitor composed of ethanolamine and acid, and the mass ratio of ethanolamine to acid is 7:

4.

4. The high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 3, characterized in that, The ethanolamine is a combination of monoethanolamine and triethanolamine, and the mass ratio of monoethanolamine to triethanolamine is 1:

1.

5. The high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 1, characterized in that, The pH adjuster is boric acid.

6. The high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 1, characterized in that, The lubricant is NP-10 phosphate ester.

7. A method for preparing a high-cleanliness lubricating leveling fluid for continuous annealing lines as described in any one of claims 1-6, characterized in that, Includes the following steps: At 35-45℃, the rust inhibitor, cleaning agent, lubricant, pH adjuster and water are added to the container in sequence according to the ratio. After stirring for 1-2 hours, stirring and heating are stopped to obtain the high-cleanliness lubricating continuous stripping line leveling liquid.

8. The method for preparing the high-cleanliness lubricating leveling fluid for continuous annealing lines according to claim 7, characterized in that, After stopping stirring and heating, let it stand for 1-2 hours.

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