Multipurpose overspeed quenching oil and preparation method thereof

Abstract

The invention relates to the technical field of metal heat treatment, and discloses multipurpose overspeed quenching oil and a preparation method thereof.The multipurpose overspeed quenching oil is prepared from, by weight, 85-94 parts of three-class hydroisomerization base oil, 2-8 parts of main cooling accelerant, 2-4 parts of over-base magnesium stearate serving as a synergistic coolant and 0.5-1.5 parts of boric acid ester serving as a latent demulsifier, and 0.1-0.6 part of an amine compound as a hydrolysis activator. The preparation method adopts a step-by-step cooling and feeding process, the coolant is added at 85-95 DEG C, the hydrolysis activator is added after the temperature is reduced to 60-68 DEG C, and finally the latent demulsifier is added after the temperature is reduced to 40-45 DEG C. According to the invention, demulsification separation and failure self-indication are realized during water pollution by utilizing a water-induced inactivation mechanism of the latent demulsifier and the activating agent; and meanwhile, a thixotropic network is constructed by utilizing the main cooling accelerant and the synergistic coolant, and multipurpose cooling is realized by regulating and controlling the shearing rate.

Description

Technical Field

[0001] This invention relates to the field of metal heat treatment technology, and in particular to a multi-purpose high-speed quenching oil and its preparation method. Background Technology

[0002] Quenching oil is a widely used cooling medium in the heat treatment process of metal workpieces, and its cooling performance plays a decisive role in the final microstructure and mechanical properties of the workpiece. Ultra-fast quenching oil, due to its extremely rapid cooling rate at high temperatures, can effectively improve the hardenability of steel and is often used for the heat treatment of high-alloy steel, large-section workpieces, or steels with low hardenability.

[0003] However, in industrial applications, existing high-speed quenching oils generally face a serious problem: they are highly sensitive to moisture contamination. Moisture can originate from workpiece carryover, air condensation, or leaks in the cooling system. When moisture mixes into conventional quenching oils, additives in the oil (such as cooling accelerators or dispersants) often act as emulsifiers, causing the oil to emulsify rapidly and form a stable oil-water emulsion.

[0004] Oil emulsification can have serious consequences. First, the cooling properties of emulsified oil become extremely unstable and uncontrollable. When high-temperature workpieces are immersed in the oil, an uneven vapor film easily forms on the surface, leading to uneven cooling and causing soft spots, deformation, or quenching cracks. Second, the presence of emulsion significantly increases operational safety risks. Furthermore, once emulsification occurs, oil-water separation becomes extremely difficult, often requiring the entire tank of oil to be discarded, resulting in significant economic losses and production interruptions.

[0005] Furthermore, conventional high-speed quenching oils typically have a fixed cooling profile. Their cooling characteristics are optimized to achieve the maximum cooling rate, but this limits their application scenarios. When the production line needs to process different steel grades or workpieces with strict requirements for deformation control (e.g., requiring medium-speed cooling), the quenching medium must be changed or different quenching tanks must be used, which restricts the flexibility of the production process.

[0006] Therefore, developing a quenching oil that can effectively manage water pollution, avoid emulsification failure, and has adjustable cooling characteristics to meet the needs of multiple applications is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide a multi-purpose high-speed quenching oil, which aims to overcome the technical defects of existing high-speed quenching oils, such as sensitivity to moisture contamination, easy emulsification failure, and single cooling mode.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a multi-purpose high-speed quenching oil composition comprising the following components in parts by weight:

[0010] Group III hydroisomerized base oils: 85–94 parts;

[0011] Main cooling accelerator: 2-8 parts;

[0012] Magnesium stearate with a high alkalinity as a synergistic coolant: 2-4 parts;

[0013] Borate ester as a latent demulsifier: 0.5–1.5 parts;

[0014] Amine compounds used as hydrolysis activators: 0.1 to 0.6 parts.

[0015] By adopting the above technical solution, the composition of the present invention achieves multiple technical effects through the synergistic design of specific components:

[0016] First, the composition uses a Group III hydroisomerized base oil. This type of base oil has a high flash point and low evaporation loss, which can significantly reduce oil evaporation and oil fume generation when the workpiece is quenched at high temperatures, such as when it enters the cleaning tank.

[0017] Secondly, the composition possesses rheological regulation properties. This property depends on the primary cooling promoter and the superbasic magnesium stearate as a synergistic coolant. Together, they form a thixotropic colloidal network structure in the base oil. Specifically, under low shear rates such as static conditions or weak stirring, this network structure remains intact, resulting in a high apparent viscosity of the oil, corresponding to an ultra-fast cooling mode. However, when the oil flows through high-shear stress areas such as those experienced by powerful pumping or specific valve groups, the network structure is temporarily disrupted by mechanical shear forces, causing shear thinning of the oil and a decrease in apparent viscosity. In this state, the vapor film stage on the workpiece surface is prolonged, the peak cooling rate decreases, and the oil transitions from an ultra-fast cooling mode to a medium-fast cooling mode. Therefore, by adjusting the shear intensity of the fluid circulation system, switching between different cooling modes can achieve multi-purpose cooling.

[0018] Furthermore, the composition possesses water-induced deactivation and demulsification properties. This property relies on the synergistic effect of borate ester latent demulsifier, amine compound hydrolytic activator, and superbasic magnesium stearate as a co-coolant.

[0019] (1) In the dry state, borate esters and amine compounds coexist stably in oil, and the composition provides efficient cooling performance by relying on the main cooling promoter and superbasic magnesium stearate.

[0020] (2) When water invades the oil, the hydrolysis activator acts as a catalyst, significantly accelerating the hydrolysis reaction of the latent demulsifier. This reaction consumes the invading water and borate esters, and generates acidic hydrolysis products such as boric acid and alcohols.

[0021] (3) Basic amine compounds immediately undergo acid-base neutralization or complexation reactions with the generated acidic hydrolysis products.

[0022] (4) The complex generated in step (3) acts as a flocculant, which will destroy or neutralize the colloidal core of the superalkaline magnesium stearate, which is the main emulsifier in the system, resulting in the irreversible destruction of the original emulsification stability of the system.

[0023] (5) The flocculation process eventually causes the oil to lose its emulsifying ability and transform into a strong demulsifier, which promotes rapid separation of oil and water.

[0024] This water-induced deactivation mechanism makes it easy for the mixed water to be removed through sedimentation and physical separation, thus enabling the regeneration and reuse of the oil. On the other hand, because the hydrolysis and flocculation reactions consume the superbasic magnesium stearate, which is a cooling functional component, the cooling performance of the separated oil is significantly reduced. This performance reduction can serve as an indicator signal that the oil has been contaminated and has failed, preventing the continued use of emulsified oil with uncontrollable performance and ensuring production safety and process consistency.

[0025] Preferably, the composition comprises the following components in parts by weight: Group III hydroisomerized base oil: 88-91 parts; main cooling accelerator: 3-5 parts; superbasic magnesium stearate: 2.5-3.5 parts; borate ester: 0.8-1.2 parts; amine compound: 0.5-0.7 parts.

[0026] By adopting the above technical solution, a good balance can be achieved between the cooling performance and water-induced deactivation responsiveness of the composition.

[0027] Preferably, the primary cooling promoter is pentaerythritol tetraoleate.

[0028] By adopting the above technical solution, pentaerythritol tetraoleate, as the main cooling promoter, can provide excellent high-temperature heat transfer performance, and synergistically with superbasic magnesium stearate to construct an effective thixotropic network.

[0029] Preferably, the latent demulsifier is triisopropyl borate or tri-n-butyl borate; and / or, the hydrolysis activator is oleylamine or oleyl imidazoline.

[0030] By adopting the above technical solution, the selected borate ester has suitable hydrolysis reactivity and oil solubility; the selected amine compound, as a long-chain fatty amine or imidazoline derivative, can effectively catalyze hydrolysis, has good oil solubility, and can be used as a highly efficient flocculant component in subsequent reactions.

[0031] Preferably, the composition further comprises 0.5 to 1.5 parts by weight of a composite antioxidant, said composite antioxidant being composed of 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine.

[0032] By adopting the above technical solution, the addition of composite antioxidants can inhibit the oxidative degradation of base oil under high-temperature conditions and extend the service life of the composition.

[0033] Secondly, the present invention provides a method for preparing a multi-purpose high-speed quenching oil composition, comprising the following steps:

[0034] (a) Heat the three types of hydroisomerized base oils and mix them with a composite antioxidant;

[0035] (b) Heat to the first preset temperature, add the main cooling accelerator and superalkaline magnesium stearate in sequence, and keep warm while stirring;

[0036] (c) Cool to the second preset temperature, add the hydrolysis activator, and continue stirring;

[0037] (d) Continue cooling to the third preset temperature, add a latent demulsifier, and continue stirring, wherein the third preset temperature is lower than the second preset temperature.

[0038] By adopting the above technical solution, this preparation method employs a step-by-step cooling feeding sequence. First, the main cooling accelerator and synergistic coolant are added at a relatively high, first preset temperature to ensure that the high-viscosity component can be fully dissolved and dispersed, providing a foundation for constructing the thixotropic network structure.

[0039] Subsequently, the hydrolysis activator and the latent demulsifier are added at progressively decreasing second and third preset temperatures, respectively. The core of this process design lies in the stepwise addition of the amine compound (hydrolysis activator) and the borate ester (latest demulsifier) ​​at different and controlled lower temperatures, specifically adding the relatively thermally unstable and reactive borate ester last at the lowest third preset temperature. This controlled sequence effectively avoids unintended reactions or degradation of these two functional components during blending due to high temperatures or premature contact, thus ensuring the integrity and latency of the water-induced deactivation system in the final product.

[0040] Preferably, the first preset temperature in step (b) is 85-95°C.

[0041] By adopting the above technical solution, this temperature range helps the main cooling accelerator and superbasic magnesium stearate to disperse and dissolve rapidly and uniformly in the base oil.

[0042] Preferably, the second preset temperature in step (c) is 60-68°C; and / or, the third preset temperature in step (d) is 40-45°C.

[0043] By adopting the above technical solution, the temperature gradient provides mild process conditions for adding amine compounds and borate esters, which not only ensures the flowability and mixing efficiency of the materials, but also minimizes the premature reaction of the active components during the preparation process.

[0044] Preferably, the heat preservation and stirring time in step (b) is 40 to 60 minutes; and / or, the continued stirring time in step (d) is 30 to 40 minutes.

[0045] By adopting the above technical solution, the reasonable stirring time ensures that the components are mixed evenly at the corresponding temperature, thus guaranteeing the uniformity of the final product performance.

[0046] Preferably, the method further includes a step of filtration using a filter device with a pore size of 1 to 5 μm after step (d).

[0047] By adopting the above technical solution, the final filtration step can remove trace impurities or incompletely dispersed particles that may be generated during the blending process, ensuring the cleanliness and storage stability of the quenching oil composition.

[0048] In summary, the present invention has at least one of the following beneficial technical effects:

[0049] 1. This invention utilizes the synergistic design of a latent demulsifier and a hydrolytic activator. When oil encounters water contamination, the system is activated and triggers a chain reaction, disrupting the colloidal structure of the synergistic coolant acting as an emulsifier. This reaction transforms the oil from easily emulsifiable to strongly demulsifiable, facilitating oil-water separation and water removal. Simultaneously, the flocculation failure of the functional components leads to a significant decrease in cooling performance, providing operators with a clear signal of contamination failure and avoiding safety hazards and workpiece scrap caused by using emulsified oils with uncontrollable performance.

[0050] 2. This invention utilizes a thixotropic network structure constructed in the base oil by a primary cooling accelerator and a synergistic coolant. The oil exhibits different apparent viscosities and heat transfer characteristics under varying shear stresses. Users can switch between ultra-fast and medium-fast cooling modes by adjusting the shear rate of the fluid system, using a single oil to meet the diverse heat treatment needs of steels with different hardenability or easily cracked workpieces, thus improving process flexibility.

[0051] 3. The preparation method of the present invention adopts a step-by-step cooling feeding sequence, especially the latent demulsifier is added last at a lower third preset temperature, which effectively avoids the unexpected premature reaction or degradation of the hydrolytic activator and the latent demulsifier during the high-temperature mixing process. Detailed Implementation

[0052] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0053] The base oil used is a conventional commercially available Group 1 hydrotreated base oil (kinematic viscosity 28 mmHg at 40°C). 2 / s) and Group III hydroisomerized base oils (kinematic viscosity 22 mm at 40℃) 2 / s).

[0054] The functional additives of this invention include:

[0055] Pentaerythritol tetraoleate (CAS No.: 19321-40-5) is used as a primary cooling promoter.

[0056] Magnesium stearate, a superbasic coolant, is an oil-soluble liquid. The general chemical formula of its active ingredient is (CH3(CH2)). 16 COO)2Mg·nMgCO3, where n represents the molar ratio of magnesium carbonate to magnesium stearate; the core is a magnesium carbonate colloidal dispersion stabilized by magnesium stearate as a surfactant, with a total base number (TBN) ranging from 300 to 450 mg KOH / g; in the embodiments of the present invention, unless otherwise specified, the product with a TBN of approximately 350 mg KOH / g prepared by Preparation Example A below is used.

[0057] Triisopropyl borate (CAS No.: 5419-55-6) or tri-n-butyl borate (CAS No.: 688-74-4) are used as latent demulsifiers; oleylamine (CAS No.: 112-90-3) or oleyl imidazoline (CAS No.: 95-38-5) are used as hydrolysis activators.

[0058] The conventional additives in the comparative example include:

[0059] Calcium petroleum sulfonate (CAS No.: 61789-86-4) has a total base value of 30 mg KOH / g; polyoxyethylene polyoxypropylene ether demulsifier is a block copolymer of ethylene oxide and propylene oxide with an average molecular weight range of 2000-4000 g / mol.

[0060] In all examples and comparative examples, a composite antioxidant consisting of 2,6-di-tert-butyl-p-cresol (CAS No.: 128-37-0) and N-phenyl-1-naphthylamine (CAS No.: 90-30-2) was added.

[0061] Preparation example:

[0062] This preparation example provides a method for preparing superbasic magnesium stearate as a synergistic coolant. The method is based on the superbasic carbonation process of organic acid salts and includes the following steps:

[0063] (1) Feeding and dissolving: In a reaction vessel equipped with a mechanical stirrer, reflux condenser, thermometer and gas distributor, add 100g xylene solvent oil, 50g Group III hydroisomerized base oil as diluent, 30g analytical grade stearic acid and 10g methanol as promoter in sequence. Start the stirring device and heat the system to 45℃~50℃ to make the materials mix evenly.

[0064] (2) Neutralization and dispersion: Add 25g of highly active light magnesium oxide to the above system. Keep the system temperature at 50℃~55℃ and stir for 30 minutes. During this stage, stearic acid and some magnesium oxide undergo a neutralization reaction to generate neutral magnesium stearate, which acts as a surfactant in subsequent reactions.

[0065] (3) Carbonation of superalkali: The reaction system is heated to 65℃~75℃. Carbon dioxide gas is slowly introduced into the system using a gas distributor, with the gas flow rate controlled within a range that allows for sufficient absorption by the system. During this process, excess magnesium oxide reacts with carbon dioxide under the action of accelerators and surfactants to generate micro- and nano-sized magnesium carbonate particles. These particles are encapsulated by magnesium stearate micelles and stably suspended in the oil phase. When the amount of carbon dioxide absorbed by the reaction system reaches 85%~90% of the theoretically calculated value, the gas flow is stopped.

[0066] (4) Post-treatment: The reaction system was heated to 130℃~140℃ and kept under reduced pressure of -0.08MPa for 1 hour to remove xylene solvent oil, methanol and water generated in the reaction by distillation. Then the system was cooled to 80℃, a filter aid was added, and the system was filtered while hot to remove unreacted solid residue.

[0067] (5) Product specifications: The filtrate is collected to obtain a superalkaline magnesium stearate colloidal dispersion, which is an amber-colored, transparent, viscous liquid. Tests show that its total alkali number (TBN) is 352 mg KOH / g, and its magnesium content is approximately 9.8%.

[0068] Example 1:

[0069] This embodiment provides a method for preparing a multi-purpose high-speed quenching oil, including the following steps:

[0070] (1) Add 90.4 parts of Group III hydroisomerized base oil to a blending vessel, start stirring (150 rpm), and heat to 65°C. Add 1.0 part of a composite antioxidant obtained by mixing 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine in a mass ratio of 1:1, and keep warm and stir for 25 minutes.

[0071] (2) Raise the oil temperature in the kettle to 90°C, and add 4.0 parts of pentaerythritol tetraoleate and 3.0 parts of superalkaline magnesium stearate in sequence. Keep the mixture at this temperature and stir for 50 minutes.

[0072] (3) Stop heating, cool down to 65°C, add 0.6 parts of oleylamine, and continue stirring for 15 minutes.

[0073] (4) Continue to cool down to 45°C, add 1.0 part of triisopropyl borate, and continue stirring at this temperature for 35 minutes.

[0074] (5) After the material is finally homogenized and stirred, it is filtered using a filter device with a pore size of 5μm to obtain the quenching oil composition of this embodiment.

[0075] Example 2:

[0076] This embodiment provides a method for preparing a multi-purpose high-speed quenching oil, including the following steps:

[0077] (1) Add 88.9 parts of Group III hydroisomerized base oil to a blending vessel, start stirring (120 rpm), and heat to 68°C. Add 1.0 part of a composite antioxidant obtained by mixing 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine in a mass ratio of 1:1, and keep warm and stir for 28 minutes.

[0078] (2) Raise the oil temperature in the reactor to 92°C, and add 5.0 parts of pentaerythritol tetraoleate and 3.0 parts of superalkaline magnesium stearate in sequence. Keep the mixture at this temperature and stir for 55 minutes.

[0079] (3) Stop heating, cool down to 62°C, add 0.6 parts of oleic acid imidazoline, and continue stirring for 20 minutes.

[0080] (4) Continue to cool down to 42°C, add 1.5 parts of tributyl borate, and continue stirring at this temperature for 40 minutes.

[0081] (5) After the material is finally homogenized and stirred, it is filtered using a filter device with a pore size of 3μm to obtain the quenching oil composition of this embodiment.

[0082] Example 3:

[0083] This embodiment provides a method for preparing a multi-purpose high-speed quenching oil, including the following steps:

[0084] (1) Add 93.4 parts of Group III hydroisomerized base oil to a blending vessel, start stirring (100 rpm), and heat to 60°C. Add 1.0 part of a composite antioxidant obtained by mixing 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine in a mass ratio of 1:1, and keep warm and stir for 20 minutes.

[0085] (2) Raise the oil temperature in the kettle to 85°C, and add 2.0 parts of pentaerythritol tetraoleate and 2.0 parts of superalkaline magnesium stearate in sequence. Keep the mixture at this temperature and stir for 40 minutes.

[0086] (3) Stop heating, cool down to 60°C, add 0.1 parts of oleylamine, and continue stirring for 15 minutes.

[0087] (4) Continue to cool down to 40°C, add 0.5 parts of triisopropyl borate, and continue stirring at this temperature for 30 minutes.

[0088] (5) After the material is finally homogenized and stirred, it is filtered using a filter device with a pore size of 5μm to obtain the quenching oil composition of this embodiment.

[0089] Example 4:

[0090] This embodiment provides a method for preparing a multi-purpose high-speed quenching oil, including the following steps:

[0091] (1) Add 85.0 parts of Group III hydroisomerized base oil to a blending vessel, start stirring (200 rpm), and heat to 70°C. Add 1.0 part of a composite antioxidant obtained by mixing 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine in a mass ratio of 1:1, and keep warm and stir for 30 minutes.

[0092] (2) Raise the oil temperature in the kettle to 95°C, and add 8.0 parts of pentaerythritol tetraoleate and 4.0 parts of superalkaline magnesium stearate in sequence. Keep the mixture at this temperature and stir for 60 minutes.

[0093] (3) Stop heating, cool down to 65°C, add 0.5 parts of oleic acid imidazoline, and continue stirring for 20 minutes.

[0094] (4) Continue to cool down to 45°C, add 1.5 parts of tributyl borate, and continue stirring at this temperature for 40 minutes.

[0095] (5) After the material is finally homogenized and stirred, it is filtered using a filter device with a pore size of 1μm to obtain the quenching oil composition of this embodiment.

[0096] Comparative Example 1:

[0097] This comparative example provides a prior art ultra-fast quenching oil, the formulation of which, by weight, is: 93.0 parts of Class I hydrorefined base oil, 5.0 parts of calcium petroleum sulfonate, 1.0 part of composite antioxidant, and 1.0 part of polyoxyethylene polyoxypropylene ether demulsifier. Its preparation employs a conventional heating and blending process.

[0098] Comparative Example 2:

[0099] Compared to Example 1, the difference is that triisopropyl borate and oleylamine are not added; their mass fraction is made up from Group III hydroisomerized base oils. All other raw materials and preparation steps are the same.

[0100] Comparative Example 3:

[0101] Compared to Example 1, the difference is that oleylamine is not added, and its mass fraction is made up from three types of hydroisomerized base oils. All other raw materials and preparation steps are the same.

[0102] Comparative Example 4:

[0103] The difference from Example 1 is that triisopropyl borate is not added; its mass fraction is made up from Group III hydroisomerized base oil. All other raw materials and preparation steps are the same.

[0104] Test Example 1:

[0105] This test uses chemical analysis to verify whether the latent demulsifier and hydrolysis activator of the quenching oil composition in Example 1 undergo the expected chemical consumption under simulated water pollution conditions, and to confirm the formation of hydrolysis reaction products.

[0106] The experimental steps are as follows:

[0107] (1) Sample preparation: Take 100.0g of the new quenching oil composition prepared in Example 1 and place it in a 250mL three-necked flask. Take another 100.0g of the new oil sample from Example 1 as the original oil sample control group and seal it for preservation.

[0108] (2) Contamination simulation: Add 1.0 g of distilled water (i.e., 1.0% water content by mass) to the oil sample in the three-necked flask. Install a mechanical stirrer and a reflux condenser, and place the flask in a constant temperature magnetic stirring water bath.

[0109] (3) Reaction process: Start stirring and control the speed at 500 rpm. Set the water bath temperature to 60℃ and stir vigorously at a constant temperature for 1 hour to simulate the process of quenching oil being contaminated by water and circulating during use.

[0110] (4) Sample post-processing: After the reaction is complete, stop heating and stirring. Transfer the oil-water mixture in the flask to a 150 mL separatory funnel and let it stand for 30 minutes. After the three phases of oil, water, and flocculents (if present) are clearly separated, discard the lower aqueous phase and the solid flocculents at the interface. Take the upper oil phase, record it as the water-treated oil sample, and dehydrate it (e.g., using anhydrous sodium sulfate) before testing.

[0111] (5) Analysis of triisopropyl borate content: Gas chromatography (GC) was used for quantification using the external standard method. Chromatographic conditions: DB-5 capillary column (30m×0.25mm×0.25μm); injection port temperature 250℃; detector (FID) temperature 280℃; temperature program: column temperature 80℃ for 2 minutes, then increased to 200℃ at 15℃ / min and held for 5 minutes; carrier gas was high-purity nitrogen. The mass percentage of triisopropyl borate in the original oil sample and the water-treated oil sample was determined.

[0112] (6) Analysis of oleylamine content: Non-aqueous alkaline potentiometric titration method was used. The oil sample was weighed, dissolved in a toluene / isopropanol mixed solvent, and the content of oleylamine in the oil sample was determined using a perchloric acid-glacial acetic acid standard solution as the titrant. The results were expressed as mass percentage (wt%).

[0113] (7) Total acid value analysis: According to ASTM D664 standard (potential titration method), potassium hydroxide-isopropanol standard solution was used as titrant to determine the total acid value (TAN) of the original oil sample and the water-treated oil sample, respectively, in mgKOH / g.

[0114] The test results are shown in Table 1.

[0115] Table 1. Validation test data for water-induced reactant consumption:

[0116] Test Project Original oil sample (Example 1) Oil sample after water treatment (Example 1) Change Triisopropyl borate content (wt%) 0.98 0.17 -0.81 Oleamine content (wt%) 0.61 0.22 -0.39 Total acid number (TAN) (mgKOH / g) 0.08 0.43 0.35

[0117] Table 1 shows that after simulated water pollution, the content of triisopropyl borate, the core component of the oil sample in Example 1, dropped sharply from 0.98 wt% to 0.17 wt%, with a consumption rate of 82.7%. This confirms that triisopropyl borate, as a reactant, underwent a large-scale hydrolysis reaction under the condition of water intrusion, which is completely consistent with the design mechanism of its hydrolysis in this invention.

[0118] Meanwhile, the content of oleylamine also showed significant depletion, decreasing from 0.61 wt% to 0.22 wt%, with a depletion rate of approximately 63.9%. The reduction in oleylamine confirms its dual role in this reaction chain: firstly, as a hydrolysis activator (phase transfer catalyst or alkaline catalyst), it promotes the hydrolysis of triisopropyl borate; secondly, as an alkaline flocculant, it undergoes subsequent acid-base neutralization or complexation reactions with the acidic products of the hydrolysis reaction, thereby leading to its own depletion.

[0119] The original oil sample had a TAN content of only 0.08 mg KOH / g, indicating a weakly neutral pH. After water pollution treatment, although the reaction consumed the alkaline oleylamine, the TAN content of the system still increased by a net 0.35 mg KOH / g, rising to 0.43 mg KOH / g. This proves that after the hydrolysis of triisopropyl borate, acidic substances (i.e., boric acid B(OH)3) were indeed generated in the oil phase, and the amount of acid generated exceeded the amount neutralized by oleylamine.

[0120] In summary, the addition of water to the pollutants activated the synergistic reaction of the latent demulsifier and the hydrolysis activator, leading to the simultaneous consumption of both components and the generation of acidic hydrolysis products. This verifies that the water-induced deactivation chemical pathway designed within the present invention can be triggered when encountering water pollution, laying the foundation for subsequent flocculation and demulsification separation steps.

[0121] Test Example 2:

[0122] This test verifies, through physical separation and quantitative measurement, whether the quenching oil composition of the present invention can generate physically visible solid flocs after simulating water pollution, and compares it with a control group that does not contain key components.

[0123] The experimental steps are as follows:

[0124] (1) Sample preparation: Following the same method as steps (1) to (3) in Test Example 1, simulated water pollution treatment was performed on the virgin oil samples of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3 and Comparative Example 4 (1.0% by mass of distilled water was added and stirred at 60°C for 1 hour). The virgin oil sample of Example 1 without any treatment was taken as a blank control.

[0125] (2) Sample preparation: Take 50 mL of sample from each of the above-treated mixtures or blank control oil samples and place it in a graduated 50 mL centrifuge tube.

[0126] (3) Centrifugation: Place all centrifuge tubes symmetrically in a centrifuge and centrifuge at 4000 rpm for 15 minutes.

[0127] (4) Results observation and recording: Take out the centrifuge tube and observe it vertically in a bright place. Record the interface scales of the oil phase, water phase, emulsion layer and solid precipitate (flocculation) at the bottom of the tube, and calculate their respective volumes (mL).

[0128] The test results are shown in Table 2.

[0129] Table 2. Test data on water-induced flocculant formation and demulsification effect:

[0130] Test sample oil phase state Oil phase volume (mL) Aqueous phase volume (mL) Emulsion layer volume (mL) Volume of solid flocculants (mL) Example 1 (Original oil sample) clarify 50 0 0 0 Example 1 (after water treatment) clarify 48.2 0.5 0 1.3 Comparative Example 1 (after water treatment) turbid 0 0 49.5 0 Comparative Example 2 (after water treatment) turbid 0 0 47 0 Comparative Example 3 (after water treatment) turbid 1 0 47.5 0.1 Comparative Example 4 (after water treatment) turbid 0 0 48 0

[0131] Table 2 shows that after water treatment, the oil sample from Example 1, after centrifugation, had 1.3 mL of solid flocculent deposited at the bottom of the tube. Simultaneously, the oil phase became clear, the water phase separated, and the emulsion volume was 0.0 mL. This confirms that the final product generated by the consumption of the latent demulsifier and hydrolysis activator detected in Test Example 1 is indeed this physically existing solid flocculent.

[0132] The formation of this solid flocculant occurred simultaneously with the complete demulsification of the oil-water mixture (the emulsion layer was 0.0 mL). This indicates that the flocculation process effectively removed the emulsifying active substances in the system, namely the synergistic coolant magnesium stearate with a high alkalinity, causing the oil to lose its emulsifying ability, thereby achieving oil-water separation.

[0133] Comparative Example 2, lacking both latent demulsifier and hydrolysis activator, did not generate solid flocs after water treatment; instead, it formed a stable emulsion layer of 47.0 mL.

[0134] Comparative Example 4, which lacked a latent demulsifier, also did not produce solids, and the emulsion volume was 48.0 mL.

[0135] The results of the two comparative examples above demonstrate that the chemical mechanism of the present invention cannot be initiated without a latent demulsifier as a reactant.

[0136] In contrast, Comparative Example 3, lacking a hydrolysis activator, produced only a trace amount of solid precipitate while simultaneously forming a severely emulsified layer of 47.5 mL. This demonstrates that while slow, unactivated hydrolysis reactions may occur, their reaction rates and efficiency are far insufficient to generate enough flocculants to disrupt the emulsion system. The presence of oleylamine is crucial for driving the reaction to proceed rapidly and efficiently.

[0137] The conventional scheme in Comparative Example 1 formed a stable emulsion layer of 49.5 mL after water contamination, indicating that the conventional polyether demulsifier added was completely ineffective against the metal soap emulsifier in this system.

[0138] In summary, the technical solution of this invention, when encountering water pollution, can generate physical solid flocs through the synergistic chemical reaction of a latent demulsifier and a hydrolysis activator. The formation of these flocs is the direct cause of demulsification and oil-water separation in the system, and this effect depends on the combined action of the two key components.

[0139] Test Example 3:

[0140] This test, conducted according to ISO 9950 standard, measures and compares the cooling characteristic curves of the quenching oils in the embodiments of the present invention with those of the comparative examples, in order to evaluate their basic performance as an ultra-fast quenching medium.

[0141] The experimental steps are as follows:

[0142] (1) Sample preparation: Take 2L of oil samples from Examples 1 to 4 and Comparative Examples 1 to 4 and place them in the oil tank of the tester.

[0143] (2) Equipment and parameters: A cooling medium property tester was used. The probe was a nickel alloy probe conforming to ISO 9950 standard (12.5 mm in diameter and 60 mm in length).

[0144] (3) Oil sample isothermal: The oil sample to be tested in the oil tank is heated and kept at a constant temperature of 60℃ (±1℃).

[0145] (4) Probe heating: Heat the standard probe in a heating furnace to 850℃ (±5℃) and keep it at a uniform temperature.

[0146] (5) Quenching test: Start the test program, the probe is automatically released and vertically immersed in the constant temperature oil sample to be tested, and the immersion depth is kept constant. The data acquisition system automatically records the temperature change data of the thermocouple at the center of the probe over time (t) (i.e., the cooling curve T=f(t)).

[0147] (6) Data processing: Each oil sample was tested three times and the average value was taken. The differential of the collected temperature-time data was calculated to obtain the cooling rate-temperature (dT / dt=f(T)) curve.

[0148] (7) Index Extraction: Two evaluation indicators were extracted from the cooling rate-temperature curve:

[0149] ① Maximum cooling rate (°C / s) in the temperature range of 550°C to 650°C.

[0150] ② The total cooling time (s) required for the probe to cool from 850℃ to 200℃.

[0151] The test results are shown in Table 3.

[0152] Table 3. Test data on the cooling performance of each oil sample:

[0153] Test sample Maximum cooling rate (°C / s) in the 550°C–650°C range Cooling time (s) from 850℃ to 200℃ Example 1 152.4 8.9 Example 2 155.1 8.7 Example 3 148.9 9.3 Example 4 161.3 8.1 Comparative Example 1 145.8 9.5 Comparative Example 2 151.9 9 Comparative Example 3 152.8 8.9 Comparative Example 4 153.1 8.8

[0154] Table 3 shows that the maximum cooling rates of the oil samples in Examples 1-4 all reached a range of 148.9℃ / s to 161.3℃ / s in the range of 550℃ to 650℃ (the critical temperature range for the transformation from austenite to martensite). This range represents typical performance of ultra-fast quenching oils, and the values ​​are all higher than those of Comparative Example 1 (145.8℃ / s), which represents conventional technology.

[0155] Comparing Example 3 (low concentration, 148.9℃ / s) and Example 4 (high concentration, 161.3℃ / s), a positive correlation was found between the maximum cooling rate and the total concentration of the synergistic coolant (pentaerythritol tetraoleate and superbasic magnesium stearate). This indicates that the cooling performance of the present invention can be controlled by adjusting the additive ratio.

[0156] The key aspect of this test was comparing Example 1 (152.4 °C / s) with Comparative Examples 2 (151.9 °C / s), 3 (152.8 °C / s), and 4 (153.1 °C / s). The data showed that, under pristine, water-free conditions, Example 1, with the addition of borate ester and oleylamine, did not exhibit a significantly different maximum cooling rate compared to the comparative examples lacking one or both of these components.

[0157] The test results confirm that the quenching oil composition designed in this invention possesses highly efficient ultra-fast cooling performance. Simultaneously, the introduced water-induced deactivation system is chemically inert when the oil is in a dry state, and will not interfere with or reduce the oil's original core cooling and heat transfer characteristics.

[0158] Test Example 4:

[0159] This test, conducted according to ASTM D5800 (Noorck method), measures the evaporation loss of the embodiments of the present invention and Comparative Example 1 at high temperatures to evaluate their thermal stability and tendency to produce fumes.

[0160] The experimental steps are as follows:

[0161] (1) Instrument preparation: Use a Nowak volatile matter tester that conforms to ASTM D5800 standard.

[0162] (2) Sample weighing: Weigh the empty evaporation crucible precisely and record its mass (m0). Add about 65g of the oil sample to be tested (Example 1, Example 4 and Comparative Example 1) to the crucible, weigh it precisely again, and record its total mass (m1).

[0163] (3) Test procedure: Place the crucible containing the sample into the heating block and seal the instrument. Set and maintain the temperature of the heating block at 250℃ (±0.5℃), while applying a constant micro negative pressure of 20 mm H2O inside the crucible.

[0164] (4) Heating timing: Start timing when the temperature of the heating block reaches 249℃ and keep it at a constant temperature for 1 hour.

[0165] (5) Cooling and weighing: After heating, remove the crucible and cool it to room temperature in a desiccator. Weigh the cooled crucible precisely and record its final mass (m2).

[0166] (6) Data Calculation: Each sample was tested three times, and the average value was taken. The percentage of evaporation loss (L) was calculated using the following formula:

[0167] ;

[0168] The test results are shown in Table 4.

[0169] Table 4. Nowak Volatility Test Data:

[0170] Test sample Evaporation loss (%) Example 1 8.3 Example 4 8.1 Comparative Example 1 13.8

[0171] Table 4 shows that the evaporation losses of Examples 1 and 4 were 8.3% and 8.1%, respectively, while the evaporation loss of Comparative Example 1 was 13.8%, indicating that the evaporation loss of the embodiments of the present invention was significantly lower than that of Comparative Example 1.

[0172] The performance difference mainly stems from the type of base oil used. The Group III hydroisomerized base oil used in this invention has a high molecular structure saturation, low sulfur content, and narrow molecular weight distribution, resulting in a lower saturated vapor pressure and better thermal oxidation stability compared to the Group I hydrorefined base oil used in Comparative Example 1. Therefore, under high-temperature conditions of 250°C, the Group III base oil exhibits less volatilization loss.

[0173] Evaporation loss of oil is a direct measure of its tendency to generate oil fumes and mist under high-temperature conditions. A lower Nowachs evaporation loss value indicates that the quenching oil of this invention suffers less oil loss due to evaporation and generates less oil fumes when in contact with high-temperature workpieces. This has a direct positive effect on improving the workshop working environment, reducing fire hazards, and lowering oil consumption.

[0174] In summary, the formulation of this invention has the characteristic of low volatility, which is superior to quenching oil formulations using traditional Class I base oils.

[0175] Test Example 5:

[0176] This test, conducted in accordance with ASTM D1401, evaluates the demulsification performance, i.e., oil-water separation capability, of the oil samples in the embodiments of this invention and the comparative examples after mixing with water.

[0177] The experimental steps are as follows:

[0178] (1) Sample preparation: Take oil samples from Examples 1 to 4 and Comparative Examples 1 to 4.

[0179] (2) Instruments and reagents: An oil-water separation tester conforming to ASTM D1401 was used, including a 100mL graduated glass cylinder, a stirrer, and a 54℃ (±1℃) constant temperature water bath. The reagent was distilled water.

[0180] (3) Sample loading: Add 40 mL of the oil sample to be tested and 40 mL of distilled water to the vector cylinder in sequence.

[0181] (4) Constant temperature: Place the graduated cylinder containing the sample in a constant temperature water bath at 54℃ and keep it warm for 10 minutes.

[0182] (5) Emulsification: Insert the agitator into the measuring cylinder, ensuring that the agitator blades are at the oil-water interface. Start the agitator and control the speed at 1500 (±15) rpm for 5 minutes.

[0183] (6) Settling and observation: After stirring stops, immediately remove the stirrer, put the graduated cylinder back into the water bath, and start timing.

[0184] ① Evaluation index 1 (demulsification time): Observe the volume of oil, water, and the emulsion layer (WOE) at regular intervals. Record the time (min) required for the volume of the emulsion layer to decrease to 3 mL or less.

[0185] ② Evaluation index 2 (30-minute status): If the volume of the emulsion layer fails to decrease to below 3 mL within 30 minutes, the volumes of the oil phase, aqueous phase, and emulsion layer shall be recorded at 30 minutes.

[0186] The test results are shown in Table 5.

[0187] Table 5. Oil-water separation performance test data:

[0188] Test sample Demulsification time (min) (until emulsion layer ≤ 3 mL) State after 30 minutes (oil-water-emulsion layer) (mL) Example 1 13 (40-38-2) Example 2 11 (40-39-1) Example 3 21 (40-37-3) Example 4 9 (40-39-1) Comparative Example 1 ＞30 (33-27-20) Comparative Example 2 ＞30 (25-15-40) Comparative Example 3 ＞30 (28-18-34) Comparative Example 4 ＞30 (30-20-30)

[0189] Table 5 shows that the oil samples from Examples 1 to 4 all exhibited rapid demulsification capabilities, with demulsification times all within 30 minutes. The shortest time was only 9 minutes for Example 4, and even the lowest concentration, Example 3, required only 21 minutes. This indicates that the formulation of the present invention rapidly activates its oil-water separation capability when exposed to moisture and a certain temperature.

[0190] Comparative Example 2, lacking both a latent demulsifier and a hydrolysis activator, exhibited the worst demulsibility, still maintaining a stable emulsion layer of 40 mL after 30 minutes. This confirms that the basic cooling accelerator in the formulation itself possesses extremely strong emulsifying capabilities, and without inhibition, it will lead to severe emulsification problems upon contact with water.

[0191] Comparative Example 3, lacking a hydrolysis activator, and Comparative Example 4, lacking a latent demulsifier, also failed to demulsify, leaving emulsion layers of 34 mL and 30 mL, respectively.

[0192] Comparing Comparative Examples 2, 3, and 4 with Example 1, the results clearly indicate that both the latent demulsifier and the hydrolysis activator must be present simultaneously to achieve rapid demulsification of the system upon contact with water. Without either component, the water-induced deactivation function cannot be effectively activated.

[0193] The conventional method in Comparative Example 1 still had a 20 mL emulsion layer after 30 minutes, and its demulsification performance was far inferior to that of the embodiments of the present invention.

[0194] This test simulated an immediate water contamination process. The demulsification in the examples confirmed that the water-induced deactivation reaction chain of the present invention was effectively triggered within the standard test time. The introduction of water, heating, and stirring collectively promoted the rapid hydrolysis of the latent demulsifier under the action of the hydrolysis activator. As shown in Test Examples 1 and 2, this reaction consumed key components and generated flocculants, thereby disrupting the original emulsification equilibrium of the system and ultimately achieving rapid separation of the oil and water phases.

[0195] In summary, the water-resistant properties of the composition of the present invention stem from its unique water-sensitive reaction system, which is activated when water enters the oil, actively disrupting the emulsification of the oil and achieving oil-water separation, thereby avoiding oil emulsification failure caused by water pollution.

[0196] Test Example 6:

[0197] This test aims to evaluate the ability of the oil samples from the embodiments of the present invention and the comparative examples to retain or change their cooling performance after undergoing a severe water contamination and subsequent separation operation.

[0198] The experimental steps are as follows:

[0199] (1) Initial performance test: Take 2L of brand new oil sample from Example 1 and 2L of brand new oil sample from Comparative Example 1. Test and record the maximum cooling rate of the two oil samples before contamination according to the method of Test Example 3.

[0200] (2) Simulated contamination: Take another 2L of brand new oil sample from Example 1 and 2L of brand new oil sample from Comparative Example 1, and place them in 4L beakers respectively. Add 2% of the mass of the oil sample to each beaker of distilled water (i.e., 40g of water).

[0201] (3) Contamination process: Place the beaker in a 60°C water bath and use a mechanical stirrer to stir vigorously at 500 rpm for 1 hour to fully simulate the contamination and emulsification process.

[0202] (4) Post-contamination treatment:

[0203] ① For Example 1: After stirring was stopped, the mixture was poured into a separatory funnel and allowed to stand for 2 hours. At this time, the mixture had separated into an upper oil phase, a lower aqueous phase, and interfacial flocculants. The lower aqueous phase and flocculants were discarded, and the upper oil phase was collected and recorded as the contaminated oil sample of Example 1.

[0204] ② For Comparative Example 1: After stirring was stopped, the mixture was poured into a separatory funnel and allowed to stand for 2 hours. The mixture remained a homogeneous and stable emulsion, making oil-water separation impossible. This emulsion was taken directly and recorded as the contaminated oil sample of Comparative Example 1.

[0205] (5) Final performance test: Following the method of test example 3, test the cooling performance of the contaminated oil sample of Example 1 and the contaminated oil sample of Comparative Example 1 obtained in step (4), and record their maximum cooling rate after contamination.

[0206] (6) Data calculation: Calculate the rate of change of the maximum cooling rate of the two oil samples before and after contamination.

[0207] Change rate = [(post-pollution rate - pre-pollution rate) / pre-pollution rate] × 100%;

[0208] The test results are shown in Table 6.

[0209] Table 6. Test data on cooling performance stability after circulating contamination:

[0210] Test sample Maximum cooling rate before contamination (°C / s) (550~650°C) Post-contamination treatment methods Maximum cooling rate after contamination (°C / s) (550~650°C) Cooling rate change rate (%) Example 1 152.4 Let it stand and separate into layers, then take the upper layer of oil. 85.7 -43.8 Comparative Example 1 145.8 Unable to separate into layers, take the emulsion. 112.3 -23.0

[0211] Table 6 shows that after water contamination and separation, the maximum cooling rate of Example 1 dropped sharply from 152.4 °C / s to 85.7 °C / s. As shown in Test Examples 1 and 2, 2% water is sufficient to activate the hydrolysis reaction of the latent demulsifier under the action of the hydrolysis activator, and generate flocculants. This flocculation process removes or deactivates the synergistic coolant and the main cooling promoter from the oil phase. Therefore, the upper layer oil measured in test step (5) is an oil with ineffective functional additives, and its cooling rate drops back to a level close to that of the base oil.

[0212] Comparative Example 1 could not be separated after contamination, forming a stable emulsion (as shown in Test Example 3). Testing of this emulsion showed a 23.0% decrease in cooling rate. This decrease was due to irregular, unsteady heat transfer caused by emulsion droplets on the high-temperature probe surface. The presence of the emulsion severely interferes with the stability of the cooling process and poses a very high safety risk (such as steam explosion) in actual operating conditions.

[0213] This test confirms the versatility of the present invention. In a dry state, it is a highly efficient ultra-fast quenching oil (Example 1, 152.4℃ / s). When contaminated with water, it achieves functional self-deactivation through an active chemical reaction and removes contaminants and degraded additives through physical separation (stratification). The performance of the separated oil decreases significantly (-43.8%), providing a failure signal to on-site operators, preventing the misuse of contaminated oil, and ensuring the consistency of the quenching process. In contrast, conventional oils (Comparative Example 1) passively transform into dangerous emulsions with uncontrollable performance after contamination.

[0214] Test Example 7:

[0215] This test aims to verify whether the quenching oil composition of the present invention has shear responsiveness, that is, whether its cooling performance changes reversibly with the change of fluid shear state.

[0216] The experimental steps are as follows:

[0217] (1) Sample preparation: Take 2L of brand new oil samples from Example 1, Example 4 and Comparative Example 1, and keep them at a constant temperature of 60℃.

[0218] (2) Default performance test: Following the method in the test example, the cooling performance of the three oil samples in the standard static oil bath (low shear conditions) was tested respectively. The cooling curves under default conditions and the maximum cooling rate in the range of 550℃~650℃ were recorded.

[0219] (3) High shear treatment: Take 2L of each of the above three oil samples and pass them through a high shear circulation device (using a gear pump to drive the oil sample through a narrow valve or capillary tube to ensure that the peak shear rate experienced by the oil sample is >10,000s). -1 The oil sample temperature was maintained at 60℃ during the circulation process.

[0220] (4) Performance test after high shear: Within 60 seconds after the high shear treatment is stopped, the treated oil sample is immediately transferred to an ISO 9950 test oil bath preheated to 60°C, and the standard probe quenching test is immediately performed. Record the cooling curve after high shear and the maximum cooling rate in the range of 550°C to 650°C.

[0221] The test results are shown in Table 7.

[0222] Table 7 Comparison of cooling performance before and after rheological modulation (high shear):

[0223] Test sample Test conditions Maximum cooling rate (°C / s) in the 550°C–650°C range Example 1 Default state (low shear) 152.4 Example 1 High shear followed by (test immediately) 173.1 Example 4 Default state (low shear) 161.3 Example 4 High shear followed by (test immediately) 185.9 Comparative Example 1 Default state (low shear) 145.8 Comparative Example 1 High shear followed by (test immediately) 146.2

[0224] Table 7 shows that after high-shear treatment, the maximum cooling rate of the oil sample in Example 1 increased significantly from 152.4 °C / s to 173.1 °C / s. The high-concentration oil in Example 4 also showed the same trend, with the cooling rate increasing from 161.3 °C / s to 185.9 °C / s.

[0225] Comparative Example 1, with its conventional formulation, showed no substantial change in maximum cooling rate after undergoing the same high-shear treatment. This indicates that the shear responsiveness exhibited by the examples stems from the specific additive system of this invention, rather than the general physical properties of base oils or conventional additives.

[0226] This phenomenon reveals the synergistic cooling system of the present invention, particularly the thixotropic structure formed in oil by the colloidal dispersion of superbasic magnesium stearate and pentaerythritol tetraoleate. Under low shear or static conditions, these components may form a weak, reversible colloidal network, giving the oil a high apparent viscosity, corresponding to a rapid cooling curve (152.4 °C / s). When the oil is subjected to vigorous stirring or high-flow pumping in a simulated quenching tank, this network structure is temporarily disrupted by mechanical force, and the oil undergoes shear thinning, i.e., a decrease in apparent viscosity. The decrease in viscosity promotes more intense convective heat transfer and more stable nucleated boiling, resulting in a significant increase in the peak cooling rate (173.1 °C / s), transforming the oil into an ultra-fast cooling mode.

[0227] This test confirms the versatility of the present invention. By adjusting the hydrodynamic conditions of the quenching tank, the same oil can be switched between rapid and ultra-rapid cooling modes to adapt to the quenching process requirements of different materials or workpieces. This rheological control function is independent of its water-induced deactivation function and is another important aspect of the functionality of the composition of the present invention.

Claims

1. A multi-purpose high-speed quenching oil, characterized in that, It contains the following components in parts by weight: Group III hydroisomerized base oils: 85–94 parts; Main cooling accelerator: 2-8 parts; Magnesium stearate with a high alkalinity as a synergistic coolant: 2-4 parts; Borate ester as a latent demulsifier: 0.5–1.5 parts; Amine compounds used as hydrolysis activators: 0.1 to 0.6 parts.

2. The multi-purpose high-speed quenching oil according to claim 1, characterized in that, It contains the following components in parts by weight: Group III hydroisomerized base oils: 88–91 parts; Main cooling accelerator: 3-5 parts; Superalkaline magnesium stearate: 2.5–3.5 parts; Borate ester: 0.8–1.2 parts; Amine compounds: 0.5–0.7 parts.

3. The multi-purpose high-speed quenching oil according to claim 1, characterized in that, The main cooling accelerator is pentaerythritol tetraoleate.

4. The multi-purpose high-speed quenching oil according to claim 1, characterized in that, The latent demulsifier is triisopropyl borate or tri-n-butyl borate; and / or, the hydrolysis activator is oleylamine or oleyl imidazoline.

5. The multi-purpose high-speed quenching oil according to claim 1, characterized in that, It also contains 0.5-1.5 parts by weight of a composite antioxidant, which is composed of 2,6-di-tert-butyl-p-cresol and N-phenyl-1-naphthylamine.

6. A method for preparing the multi-purpose high-speed quenching oil according to any one of claims 1-5, characterized in that, Includes the following steps: (a) Heat the three types of hydroisomerized base oils and mix them with a composite antioxidant; (b) Heat to the first preset temperature, add the main cooling accelerator and superalkaline magnesium stearate in sequence, and keep warm while stirring; (c) Cool to the second preset temperature, add the hydrolysis activator, and continue stirring; (d) Continue cooling to the third preset temperature, add a latent demulsifier, and continue stirring, wherein the third preset temperature is lower than the second preset temperature.

7. The preparation method according to claim 6, characterized in that, The first preset temperature in step (b) is 85-95°C.

8. The preparation method according to claim 6, characterized in that, The second preset temperature in step (c) is 60-68°C; and / or the third preset temperature in step (d) is 40-45°C.

9. The preparation method according to claim 6, characterized in that, The time for heat preservation and stirring in step (b) is 40 to 60 minutes; and / or the time for continued stirring in step (d) is 30 to 40 minutes.

10. The preparation method according to claim 6, characterized in that, The method further includes a step of filtration using a filter device with a pore size of 1 to 5 μm after step (d).