Highly lubricating and dispersing water-based steel cold rolling liquid and its preparation method

Abstract

The application provides a high-lubricating high-dispersing water-based steel cold rolling liquid and a preparation method thereof. The high-lubricating high-dispersing water-based steel cold rolling liquid comprises base oil, a composite emulsifier, extreme pressure agent, antioxidant and deionized water, and the composite emulsifier is composed of Span-60, sodium dodecyl sulfate and cosolvent n-butanol. The application adds the composite emulsifier with specific components into the water-based steel cold rolling liquid, and through specific pre-combination process of the composite emulsifier and the extreme pressure agent and microemulsion and dynamic emulsification process of the rolling liquid, the finally obtained rolling liquid has better lubricating performance (surface roughness Ra is less than or equal to 0.085 mu m) and good dispersing performance (the rolling liquid can be kept for 30 days without sedimentation and oil phase separation).

Description

Technical Field

[0001] This invention relates to the field of lubrication and cooling materials for metal processing, specifically to a highly lubricating and highly dispersible water-based rolling fluid suitable for cold rolling processes of steel and its preparation method. Background Technology

[0002] In the cold rolling process of steel, rolling fluid, as a core functional material, directly affects the surface quality, dimensional accuracy, and production efficiency of strip steel. Currently, the mainstream rolling fluid products are water-based emulsified rolling fluids, which typically contain base oil, emulsifiers, lubricants, extreme pressure agents, rust inhibitors, corrosion inhibitors, and water.

[0003] Compared to traditional oil-based rolling fluids, water-based steel cold rolling fluids offer several advantages. From a safety perspective, water-based rolling fluids are less flammable and less explosive than oil-based fluids, significantly reducing the risk of fires and explosions on the production site and providing strong protection for safe production. In terms of cooling performance, water's high specific heat capacity and thermal conductivity allow water-based rolling fluids to quickly and effectively absorb and remove the large amount of heat generated during rolling, preventing deformation of the rolls and steel due to excessive temperature. This helps maintain the accuracy of rolled dimensions and the mechanical properties of the steel. Furthermore, water-based rolling fluids are relatively cheaper and easier to treat environmentally than oil-based fluids, aligning with the trend of green development in modern industry. They also have better cleaning properties, leaving less residue on the surface of the rolled steel, reducing the workload of subsequent cleaning processes. However, existing water-based steel cold rolling fluids still have some significant shortcomings. In terms of lubrication performance, under high-speed, high-reduction cold rolling conditions, their lubrication performance often falls short of ideal levels. Because water itself has poor lubricity, even with the addition of lubricants and extreme pressure agents, the oil film is prone to rupture under extreme conditions, leading to direct contact between metal surfaces and generating significant friction and wear. This not only causes defects such as scratches and pitting on the steel surface, affecting the product's appearance quality and surface finish, but also accelerates roll wear, shortens roll life, and increases production costs. Regarding dispersibility, some components in existing water-based rolling fluids exhibit poor dispersion stability in water, easily leading to agglomeration and sedimentation. This results in uneven component distribution in the rolling fluid, causing differences in performance at different locations during use and affecting the consistency of rolling results. Furthermore, agglomerated particles may clog nozzles and other equipment components, hindering the normal spraying and recycling of the rolling fluid.

[0004] To address the aforementioned problems in existing technologies, there is an urgent need to develop a highly lubricating and highly dispersible water-based steel cold rolling fluid and its preparation method. This rolling fluid should possess excellent lubrication properties to meet the requirements of high-speed, high-reduction cold rolling processes, effectively reducing steel surface defects and roll wear; simultaneously, it should have good dispersibility to ensure uniform and stable dispersion of all components in water, avoiding agglomeration and sedimentation. Summary of the Invention

[0005] To address the shortcomings of the existing technology, one objective of this invention is to provide a highly lubricating and highly dispersible water-based steel cold rolling fluid and its preparation method. This aims to solve the technical problems of insufficient lubrication and poor dispersibility in existing water-based steel cold rolling fluids.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first objective of this invention is to provide a highly lubricating and highly dispersible water-based steel cold rolling fluid, comprising the following components and their mass fractions: 40-95 parts base oil 3-8 parts of compound emulsifier Extreme pressure agent 2-4 parts Antioxidant 0.5-1.5 parts 20-50 parts deionized water; The base oils include natural oils and synthetic esters; The natural oils are selected from one or more of palm oil, coconut oil, castor oil, tallow, and lard; The synthetic ester is selected from one or more of pentaerythritol oleate, pentaerythritol stearate, trimethylolpropane oleate, trimethylolpropane lauryl ester, isooctyl stearate, and palm oil isooctyl ester; The mass ratio of the natural oils to the synthetic esters is (2-5):1; The composite emulsifier is composed of Span-60, sodium dodecyl sulfate, and the cosolvent n-butanol; Preferably, the mass ratio of Span-60, sodium dodecyl sulfate, and the cosolvent n-butanol is (3-5):2:1; The extreme pressure agent is selected from one or more of sulfur esters, alkyl polysulfides, and phosphate esters; Preferably, the extreme pressure agent is oleyl alcohol polyoxyethylene ether phosphate; The antioxidant is selected from one or more of phenolic antioxidants, amine antioxidants, and sulfur-phosphorus compound antioxidants; Preferably, the phenolic antioxidant is selected from one or both of T501 or Irganox L135; Preferably, the amine antioxidant is selected from Irganox L57 or Irganox L06; Preferably, the sulfur-phosphorus composite antioxidant is selected from T309 or ZDDP; The second objective of this invention is to provide a method for preparing a highly lubricating and highly dispersible water-based steel cold rolling fluid, comprising the following steps: S1, Pre-composite of extreme pressure agent and emulsifier: ① Primary composite: Mix 50wt%-60wt% of extreme pressure agent with Span-60 and n-butanol, and stir for 15-20 minutes at a temperature of 40-45℃ and a stirring speed of 1000-1200r / min to form a primary composite system; ② Deep composite: Add the remaining extreme pressure agent and sodium dodecyl sulfate to the primary composite system, heat to 50-55℃, increase the stirring speed to 1300-1500 r / min, and continue stirring for 20-25 min to allow the extreme pressure agent molecules to be fully adsorbed on the surface of the emulsifier micelles, forming a pre-composite system; S2, Oil phase preparation: Heat the base oil to 50-60℃, add it to the pre-composite system of step S1, stir evenly to form an oil phase; S3. Aqueous phase preparation: Adjust the pH of the system to 7.5-8.5 by adding 1%-5% sodium hydroxide or potassium hydroxide solution to deionized water. S4. Microemulsion and Dynamic Emulsification: A two-step preparation process of "ultrasonic emulsification + high-pressure homogenization" is adopted. First, the oil phase is slowly added to the water phase and the oil phase is initially dispersed by ultrasound. Then, high-pressure homogenization is used to obtain a water-based cold rolling fluid for steel with high lubricity and high dispersibility.

[0007] Preferably, the ultrasonic power is 800-1000W and the ultrasonic time is 20-30min; Preferably, the high-pressure homogenization is performed at a pressure of 40-60 MPa for 3-5 cycles.

[0008] The third objective of this invention is to provide an application of a highly lubricating and highly dispersible water-based steel cold rolling fluid in improving the lubrication and dispersibility of the rolling fluid.

[0009] Compared with the prior art, the present invention has the following advantages: This invention creatively incorporates a composite emulsifier with specific components into water-based cold rolling fluid for steel, and employs a specific pre-composite process of the composite emulsifier and extreme pressure agent, as well as a microemulsion and dynamic emulsification process for the rolling fluid. On one hand, the extreme pressure agent is composited with Span-60 and sodium dodecyl sulfate in stages to form a mixed micelle structure of "hydrophobic chain entanglement + electrostatic adsorption". In the initial composite stage, the oleoyl alcohol chain of the extreme pressure agent combines with the hydrophobic chain of Span-60, and the polyoxyethylene ether chain interacts with n-butanol through hydrogen bonding, initially anchoring the active sites; in the deep composite stage, the phosphate ester groups interact with the sodium dodecyl sulfate... This structure fosters electrostatic synergy, enhancing the surface charge of the micelles. It inhibits particle agglomeration through the steric hindrance of the polyoxyethylene ether chains while ensuring uniform distribution of the extreme pressure agent, laying the foundation for subsequent lubricant film formation. Furthermore, the use of an "ultrasonic emulsification + high-pressure homogenization" process—emphasizing ultrasonic dispersion at 800-1000W and high-pressure refinement at 40-60MPa—ensures uniform distribution of oil phase particles. Alkalinity adjustment promotes hydroxylation of the metal surface, enhancing lubricant film adhesion. This results in a final rolling fluid with excellent lubrication performance (surface roughness Ra≤0.085μm) and good dispersion properties (maintaining no sedimentation or oil phase precipitation even after 30 days of standing). Detailed Implementation

[0010] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0011] Unless otherwise specified, the terms used in this specification have the same meaning as those commonly understood by those skilled in the art; however, in the event of any conflict, the definitions in this specification shall prevail.

[0012] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0013] The raw materials are selected as follows: Palm oil: Yihai Kerry, 24° refined palm oil; Pentaerythritol oleate: Haian Petrochemical Plant, Jiangsu Province, Seaweed, PETO; Oleyl alcohol polyoxyethylene ether phosphate: Solvay, LUBRHOPHOS LB-400; Example 1 A highly lubricating and highly dispersible water-based steel cold rolling fluid comprises the following components and their mass fractions: 40 parts palm oil 20 parts pentaerythritol oleate 6 parts of compound emulsifier Extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate 2 parts Antioxidant Irganox L57 1 part 50 parts deionized water; The composite emulsifier is composed of Span-60, sodium dodecyl sulfate, and the cosolvent n-butanol in a mass ratio of 3:2:1. The specific preparation method includes the following steps: S1, Pre-composite of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate with emulsifier: ① Primary composite: Mix 50wt% of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate with Span-60 and n-butanol, and stir for 20min at 40℃ and 1000 r / min to form a primary composite system; ② Deep composite: Add the remaining extreme pressure agent and sodium dodecyl sulfate to the primary composite system, heat to 50°C, increase the stirring speed to 1300 r / min, and continue stirring for 25 min to allow the extreme pressure agent molecules to be fully adsorbed on the surface of the emulsifier micelles, forming a pre-composite system; S2, Oil phase preparation: Palm oil and pentaerythritol oleate are mixed to form a base oil, heated to 50°C, added to the pre-composite system of step S1, and stirred evenly to form an oil phase; S3. Aqueous phase preparation: Add 1% sodium hydroxide solution to deionized water to adjust the pH of the system to 7.5; S4. Microemulsion and Dynamic Emulsification: A two-step preparation process of "ultrasonic emulsification + high-pressure homogenization" is adopted. First, the oil phase is slowly added to the aqueous phase, and then ultrasonically treated at 800W for 20 minutes. Then, it is subjected to high-pressure homogenization at 40MPa for 3 cycles to obtain a water-based cold rolling fluid for steel with high lubricity and high dispersibility.

[0014] Example 2 A highly lubricating and highly dispersible water-based steel cold rolling fluid comprises the following components and their mass fractions: 50 parts palm oil 10 parts pentaerythritol oleate 6 parts of compound emulsifier Extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate 2 parts Antioxidant Irganox L57 1 part 50 parts deionized water; The composite emulsifier is composed of Span-60, sodium dodecyl sulfate, and the cosolvent n-butanol in a mass ratio of 3:2:1. The specific preparation method includes the following steps: S1, Pre-composite of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate with emulsifier: ① Primary composite: Mix 50wt% of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate with Span-60 and n-butanol, and stir for 20min at 40℃ and 1000 r / min to form a primary composite system; ② Deep composite: Add the remaining extreme pressure agent and sodium dodecyl sulfate to the primary composite system, heat to 50°C, increase the stirring speed to 1300 r / min, and continue stirring for 25 min to allow the extreme pressure agent molecules to be fully adsorbed on the surface of the emulsifier micelles, forming a pre-composite system; S2, Oil phase preparation: Palm oil and pentaerythritol oleate are mixed to form a base oil, heated to 50°C, added to the pre-composite system of step S1, and stirred evenly to form an oil phase; S3. Aqueous phase preparation: Add 1% sodium hydroxide solution to deionized water to adjust the pH of the system to 7.5; S4. Microemulsion and Dynamic Emulsification: A two-step preparation process of "ultrasonic emulsification + high-pressure homogenization" is adopted. First, the oil phase is slowly added to the aqueous phase, and then ultrasonically treated at 800W for 20 minutes. Then, it is subjected to high-pressure homogenization at 40MPa for 3 cycles to obtain a water-based cold rolling fluid for steel with high lubricity and high dispersibility.

[0015] Example 3 The mass ratio of Span-60, sodium dodecyl sulfate, and cosolvent n-butanol in the composite emulsifier of Example 1 was modified to 5:2:1, while other aspects remained the same as in Example 1, to obtain the high lubricity and high dispersibility water-based steel cold rolling fluid of Example 3.

[0016] Example 4 The amount of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate in the primary composite of Example 1 was adjusted to 60wt%, while other aspects remained the same as in Example 1, to obtain the high lubricity and high dispersibility water-based steel cold rolling fluid of Example 4.

[0017] Comparative Example 1 The mass ratio of Span-60, sodium dodecyl sulfate, and cosolvent n-butanol in the composite emulsifier of Example 1 was modified to 2:2:1, while other aspects remained the same as in Example 1, to obtain the water-based cold rolling fluid for steel in Comparative Example 1.

[0018] Comparative Example 2 The mass ratio of Span-60, sodium dodecyl sulfate, and cosolvent n-butanol in the composite emulsifier of Example 1 was modified to 6:2:1, while other aspects remained the same as in Example 1, to obtain the water-based cold rolling fluid for steel in Comparative Example 2.

[0019] Comparative Example 3 The amount of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate in the primary composite of Example 1 was adjusted to 40 wt%, while other aspects remained the same as in Example 1, to obtain the water-based steel cold rolling fluid of Comparative Example 3.

[0020] Comparative Example 4 The amount of extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate in the primary composite of Example 1 was adjusted to 70 wt%, while other aspects remained the same as in Example 1, to obtain the water-based steel cold rolling fluid of Comparative Example 4.

[0021] Comparative Example 5 Step S1 in the specific preparation method of Example 1 is modified as follows: "S1, the extreme pressure agent oleyl alcohol polyoxyethylene ether phosphate is mixed with Span-60, sodium dodecyl sulfate and n-butanol in one step, and stirred for 40 minutes at a temperature of 50°C and a stirring speed of 1300 r / min to form a pre-composite system." Everything else remains the same as in Example 1.

[0022] Comparative Example 6 Step S4 in the specific preparation method of Example 1 is modified as follows: "S4, Microemulsion preparation: First, the oil phase is slowly added to the aqueous phase, and then ultrasonically treated at 800W for 30 minutes to obtain a water-based steel cold rolling fluid." Everything else remains the same as in Example 1.

[0023] Performance testing: 1. Dispersion performance characterization 30-day static stability test: Test steps: (1) Take 50 mL of the rolling liquid sample and put it into a stoppered graduated cylinder, and mark the initial liquid level height; (2) Place the graduated cylinder in a constant temperature chamber at 25℃ and let it stand for 30 days without shaking it; (3) Observe whether the sample shows stratification, agglomeration or precipitation, and record the volume percentage of the upper oil phase precipitation.

[0024] 2. Characterization of lubrication performance Surface roughness Ra value test: Stainless steel was rolled using a reversible rolling mill from I2S Corporation of the United States, with a reduction rate of 30% and a rolling speed of 800 m / min. After 50 consecutive rolling passes, the surface roughness of the obtained stainless steel was tested using a stylus profilometer.

[0025] The test results are shown in Table 1 below: Table 1

[0026] Comparing Examples 1-4 and Comparative Examples 1-6 in Table 1, it can be seen that the present invention, by adding a composite emulsifier with specific components to the water-based steel cold rolling fluid, and through a specific pre-composite process of the composite emulsifier and extreme pressure agent, as well as the microemulsion and dynamic emulsification process of the rolling fluid, results in a final rolling fluid with better lubrication performance (surface roughness Ra≤0.085μm) and good dispersion performance (the rolling fluid can remain stationary for 30 days without sedimentation or oil phase precipitation).

[0027] Comparing Examples 1-4 and Comparative Examples 1-6 in Table 1, it can be seen that when the amount of Span-60 added to the composite emulsifier of the rolling fluid or the initial amount of extreme pressure agent added is different from the content specified in this invention, or when the two-step pre-composite process and the high-pressure homogenization process are not used, the performance of the final rolling fluid will have a certain negative impact.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A highly lubricating and highly dispersible water-based steel cold rolling fluid, characterized in that, Includes the following components and their mass fractions: Base oil 40-95 parts; 3-8 parts of compound emulsifier; Extreme pressure agent 2-4 parts; Antioxidant 0.5-1.5 parts; 20-50 parts deionized water; The composite emulsifier is composed of Span-60, sodium dodecyl sulfate, and the cosolvent n-butanol; The mass ratio of Span-60, sodium dodecyl sulfate, and cosolvent n-butanol is (3-5):2:1; The highly lubricating and highly dispersible water-based steel cold rolling fluid is prepared by the following method, including the following steps: S1, Pre-compounding of extreme pressure agent and emulsifier: ① Primary composite: Mix 50wt%-60wt% of extreme pressure agent with Span-60 and n-butanol, and stir for 15-20 minutes at a temperature of 40-45℃ and a stirring speed of 1000-1200r / min to form a primary composite system; ② Deep composite: Add the remaining extreme pressure agent and sodium dodecyl sulfate to the primary composite system, heat to 50-55℃, increase the stirring speed to 1300-1500 r / min, and continue stirring for 20-25 min to allow the extreme pressure agent molecules to be fully adsorbed on the surface of the emulsifier micelles, forming a pre-composite system; S2, Oil phase preparation: Heat the base oil to 50-60℃, add it to the pre-composite system of step S1, stir evenly to form an oil phase; S3. Aqueous phase preparation: Adjust the pH of the system to 7.5-8.5 by adding 1%-5% sodium hydroxide or potassium hydroxide solution to deionized water. S4. Microemulsion and Dynamic Emulsification: A two-step preparation process of "ultrasonic emulsification + high-pressure homogenization" is adopted. First, the oil phase is slowly added to the water phase and the oil phase is initially dispersed by ultrasound. Then, high-pressure homogenization is used to obtain a water-based cold rolling fluid for steel with high lubricity and high dispersibility.

2. The high-lubricity, high-dispersibility water-based steel cold rolling fluid according to claim 1, characterized in that, The base oil includes natural oils and synthetic esters; the extreme pressure agent is selected from one or more of sulfurized esters, alkyl polysulfides and phosphate esters; the antioxidant is selected from one or more of phenolic antioxidants, amine antioxidants and sulfur-phosphorus compound antioxidants.

3. The high-lubricity, high-dispersibility water-based steel cold rolling fluid according to claim 2, characterized in that, The natural oils are selected from one or more of palm oil, coconut oil, castor oil, tallow, and lard; The synthetic ester is selected from one or more of pentaerythritol oleate, pentaerythritol stearate, trimethylolpropane oleate, trimethylolpropane lauryl ester, and isooctyl stearate; The mass ratio of the natural oils to the synthetic esters is (2-5):1; The extreme pressure agent is oleyl alcohol polyoxyethylene ether phosphate; The phenolic antioxidant is selected from one or both of T501 or Irganox L135; the amine antioxidant is selected from Irganox L57 or Irganox L06; and the sulfur-phosphorus compound antioxidant is selected from T309 or ZDDP.

4. A method for preparing a high-lubricity, high-dispersibility water-based steel cold rolling fluid according to any one of claims 1-3, characterized in that, Includes the following steps: S1, Pre-composite of extreme pressure agent and emulsifier: ① Primary composite: Mix 50wt%-60wt% of extreme pressure agent with Span-60 and n-butanol, and stir for 15-20 minutes at a temperature of 40-45℃ and a stirring speed of 1000-1200r / min to form a primary composite system; ② Deep composite: Add the remaining extreme pressure agent and sodium dodecyl sulfate to the primary composite system, heat to 50-55℃, increase the stirring speed to 1300-1500 r / min, and continue stirring for 20-25 min to allow the extreme pressure agent molecules to be fully adsorbed on the surface of the emulsifier micelles, forming a pre-composite system; S2, Oil phase preparation: Heat the base oil to 50-60℃, add it to the pre-composite system of step S1, stir evenly to form an oil phase; S3. Aqueous phase preparation: Adjust the pH of the system to 7.5-8.5 by adding 1%-5% sodium hydroxide or potassium hydroxide solution to deionized water. S4. Microemulsion and Dynamic Emulsification: A two-step preparation process of "ultrasonic emulsification + high-pressure homogenization" is adopted. First, the oil phase is slowly added to the water phase and the oil phase is initially dispersed by ultrasound. Then, high-pressure homogenization is used to obtain a water-based cold rolling fluid for steel with high lubricity and high dispersibility.

5. The method for preparing the high-lubricity, high-dispersibility water-based steel cold rolling fluid according to claim 4, characterized in that, In step S4, the ultrasonic power is 800-1000W and the ultrasonic time is 20-30min; the high-pressure homogenization pressure is 40-60MPa, and the cycle is 3-5 times.

6. The application of a high-lubricating and high-dispersibility water-based steel cold rolling fluid according to any one of claims 1-3 or a high-lubricating and high-dispersibility water-based steel cold rolling fluid obtained by the preparation method according to any one of claims 4-5 in improving the lubrication and dispersion properties of rolling fluids.

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