Quenching oil composition and preparation method thereof

Abstract

The invention relates to the technical field of quenching oil, in particular to a quenching oil composition and a preparation method thereof.The quenching oil composition comprises base oil, a composite cooling accelerant, a high-temperature antioxidant, a brightener and an antirust agent; through overall cooperation of component selection, proportion optimization and a preparation process, breakthrough improvement of comprehensive performance of the quenching oil is achieved, and the problem that in the prior art, multi-aspect requirements are difficult to consider is thoroughly solved. The uniform hardness and no crack deformation of the quenched workpiece are ensured by the balanced cooling performance, the service life of the oil product is prolonged by the excellent high-temperature oxidation resistance, the replacement frequency and the production cost are reduced, the surface quality of the workpiece is ensured by the reliable rust-proof and bright performance, and additional polishing or rust-proof treatment is not needed.

Description

Technical Field

[0001] This invention relates to the field of quenching oil technology, specifically to a quenching oil composition and its preparation method. Background Technology

[0002] In fields such as machinery manufacturing, automotive parts processing, and construction machinery equipment production, quenching is a core process for improving the hardness, strength, and wear resistance of metal workpieces. Quenching oil, as a key medium in the quenching process, directly determines the heat treatment quality and subsequent reliability of the workpiece. In industrial production, the core requirements for quenching oil focus on three aspects: First, balanced cooling performance, requiring rapid cooling at high temperatures to ensure sufficient phase transformation of the workpiece, while slow cooling at low temperatures to release internal stress and prevent cracking and deformation; second, strong high-temperature stability, not easily oxidizing or deteriorating, or exhibiting abnormal viscosity changes when used for extended periods above 150℃; and third, good surface protection, reducing oxide scale formation after quenching, ensuring a bright surface, and providing long-term rust protection to prevent rusting during storage or handling.

[0003] However, existing quenching oils still have many practical application problems: In terms of cooling performance, most products use a single type of coolant, which either results in insufficient high-temperature cooling speed leading to a low rate of workpiece hardness meeting the standard, or excessively rapid low-temperature cooling causing internal stress concentration, resulting in a high rate of workpiece cracking and scrapping; In terms of oxidation resistance, traditional antioxidants are prone to agglomeration and poor dispersibility at high temperatures, causing the acid value to soar and the viscosity to increase after several thousand hours of use, requiring frequent replacement, which increases production costs and downtime.

[0004] Therefore, developing a quenching oil composition that can simultaneously achieve balanced cooling, high-temperature oxidation resistance, rust prevention, bright finish, and stable performance has become a pressing technical problem to be solved in the current heat treatment industry. (Invention Content)

[0005] The purpose of this invention is to provide a quenching oil composition and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A quenching oil composition, comprising, by weight, 70-85 parts base oil, 5-10 parts composite cooling agent, 1-3 parts high-temperature antioxidant, 0.5-2 parts brightener, and 1-3 parts rust inhibitor.

[0008] As a further technical solution, the base oil is a paraffinic oil.

[0009] As a further technical solution, the brightener is sodium petroleum sulfonate, and the active ingredient content of the sodium petroleum sulfonate is ≥90% and the moisture content is ≤0.5%.

[0010] As a further technical solution, the rust inhibitor is dodecenylsuccinic acid, and the acid value of the dodecenylsuccinic acid is 190-210 mgKOH / g, and the purity is ≥98%.

[0011] As a further technical solution, the composite refrigeration agent is composed of dibenzyltoluene, a high-temperature refrigeration agent, and dodecylbenzene, a low-temperature refrigeration agent, in a mass ratio of 5:3.

[0012] As a further technical solution, the high-temperature antioxidant is a nano-montmorillonite-loaded modified diphenylamine-hindered phenol compound, wherein the mass ratio of diphenylamine to hindered phenol is 3:2, and the loading of nano-montmorillonite is 8-12% of the total mass of the compound.

[0013] As a further technical solution, the hindered phenol is 2,4-dimethyl-6-tert-butylphenol.

[0014] A method for preparing a quenching oil composition includes the following steps:

[0015] Preparation of high-temperature antioxidant S1: Take sodium-based montmorillonite, add 2-3% of its mass as coupling agent, stir and pretreat at 70-80℃ for 1.5-2h, cool, filter and dry to obtain modified nano-montmorillonite; weigh diphenylamine and 2,4-dimethyl-6-tert-butylphenol at a mass ratio of 3:2, add to a reaction vessel, heat to 120-130℃, stir until completely dissolved to form a mixed system; add modified nano-montmorillonite to the mixed system, heat to 160-170℃ under an inert atmosphere, keep the temperature for 3-4h, and control the stirring rate at 400-500r / min during the reaction; after the reaction is completed, cool naturally to room temperature to obtain the high-temperature antioxidant;

[0016] S2 Weighing raw materials: Weigh base oil, compound refrigerant, high-temperature antioxidant, brightener, and rust inhibitor by weight;

[0017] S3 Mixing Preparation: Heat the base oil weighed in step S2 to 40-60℃, add the composite cooling agent and stir for 5-6 minutes at a stirring rate of 300-500r / min, then add the high-temperature antioxidant and stir for 3-4 minutes, then add the brightener and stir for 3-4 minutes, then add the rust inhibitor and stir for 3-4 minutes. After mixing evenly, cool to room temperature to obtain the quenching oil composition.

[0018] As a further technical solution, the coupling agent in S1 is γ-aminopropyltriethoxysilane.

[0019] As a further technical solution, the inert atmosphere in S1 is nitrogen.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. First, the synergistic effect of the components in this invention enables each individual component to fully exert its targeted function, solving the corresponding technical problems from the source. Because paraffin-based oil is used as the base oil, its excellent thermal stability and lubricity provide a stable dispersion carrier for all functional components, avoiding component agglomeration and failure caused by poor carrier compatibility. This ensures the continued effectiveness of subsequent cooling, anti-oxidation, and rust prevention functions, solving the core problem of insufficient base oil carrying capacity limiting the effectiveness of functional components. The composite cooling agent uses a 5:3 mass ratio of dibenzyltoluene and dodecylbenzene. Dibenzyltoluene can rapidly conduct heat in the high-temperature range, promoting the efficient transformation of austenite to martensite, while dodecylbenzene slows down the cooling rate in the low-temperature range, gradually releasing the internal stress of the workpiece. The two form a synergistic cooling effect of rapid cooling at high temperatures and slow cooling at low temperatures, fundamentally solving the problem of workpiece cracking and deformation caused by a single cooling agent. The high-temperature antioxidant uses diphenylamine-2,4-dimethyl-6-tert-butylphenol supported on nano-montmorillonite. In this system, when diphenylamine and hindered phenol are mixed in a 3:2 ratio, oxidation can be synergistically inhibited through different mechanisms of capturing free radicals and decomposing peroxides. Nano-montmorillonite, after modification with γ-aminopropyltriethoxysilane, introduces organic groups onto its surface, significantly improving its compatibility with the compound. After loading, it avoids compound aggregation and extends its high-temperature stability time, solving the problems of poor dispersion and easy high-temperature failure of ordinary antioxidants. The brightener is sodium petroleum sulfonate with an active ingredient content ≥90% and moisture ≤0.5%, which effectively reduces the surface tension of the workpiece and reduces oxide scale formation. The rust inhibitor is dodecenyl succinic acid with an acid value of 190-210 mgKOH / g and a purity ≥98%, which can form a dense adsorption film to isolate water and oxygen. These two agents work synergistically from the dimensions of surface tension regulation and protective film formation, solving the problems of poor workpiece gloss and easy corrosion caused by low-index additives.

[0022] 2. Secondly, the preparation process and component characteristics are deeply adapted, further enhancing the functional synergy of each component and ensuring the stability and consistency of the quenching oil's performance. In the high-temperature antioxidant preparation stage, sodium-based montmorillonite is first pretreated with a coupling agent, and then the loading reaction is carried out under nitrogen protection at a controlled reaction temperature of 160-170℃ and a stirring rate of 400-500r / min. This process not only improves the compatibility of montmorillonite with organic compounds but also avoids the oxidation of the compounds during the reaction, ensuring the activity of the antioxidant. The composite refrigerant first forms a uniform cooling matrix with the base oil, and subsequent additives can be rapidly dispersed in this matrix, avoiding local concentration imbalances and solving the performance fluctuation problem caused by improper preparation process.

[0023] 3. Finally, this invention achieves a breakthrough improvement in the comprehensive performance of quenching oil through the overall synergy of component selection, ratio optimization, and preparation process, completely solving the problem that existing technologies struggle to meet multiple needs simultaneously. Balanced cooling performance ensures uniform hardness and prevents cracking and deformation of workpieces after quenching; excellent high-temperature oxidation resistance extends oil service life, reducing replacement frequency and production costs; and reliable rust prevention and brightening properties guarantee workpiece surface quality, eliminating the need for additional grinding or rust prevention treatment. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention provides a quenching oil composition and its preparation method. The composition has balanced cooling performance, excellent high-temperature oxidation resistance, good rust prevention effect, and can ensure the brightness of the workpiece. The preparation process is simple and controllable, and it is suitable for quenching treatment of various metal workpieces.

[0026] Raw material description:

[0027] Base oil: In this invention, the base oil is a paraffinic oil. Commercially available paraffinic oil that meets industrial-grade standards can be selected. It has good thermal stability and lubricity and can provide a stable carrier environment for the quenching process.

[0028] Composite cooling agent: The composite cooling agent is composed of dibenzyltoluene, a high-temperature cooling agent, and dodecylbenzene, a low-temperature cooling agent, in a mass ratio of 5:3. The combination of these two agents achieves a balanced cooling effect during the quenching process, with rapid cooling at high temperatures and slow cooling at low temperatures, thus preventing cracks or deformation of the workpiece due to uneven cooling rates.

[0029] High-temperature antioxidant: The high-temperature antioxidant is a nano-montmorillonite-modified diphenylamine-hindered phenol compound, wherein the hindered phenol is 2,4-dimethyl-6-tert-butylphenol, the mass ratio of diphenylamine to 2,4-dimethyl-6-tert-butylphenol is 3:2, and the loading of nano-montmorillonite is 8-12% of the total mass of the compound, preferably 10%. This compound antioxidant, through the loading modification with nano-montmorillonite, has better dispersibility and can significantly improve the antioxidant stability of quenching oil under high-temperature conditions, thus extending its service life.

[0030] Brightener: The brightener is sodium petroleum sulfonate, with an active ingredient content ≥90% and a moisture content ≤0.5%. Using commercially available sodium petroleum sulfonate that meets the above specifications can effectively reduce the surface tension of the workpiece, reduce oxide scale formation, and ensure a bright and clean surface of the workpiece after quenching.

[0031] Rust inhibitor: The rust inhibitor is dodecenyl succinic acid, with an acid value of 190-210 mg KOH / g and a purity of ≥98%. Dodecenyl succinic acid meeting these specifications can form a dense adsorption film on the workpiece surface, isolating air and moisture, and providing long-lasting rust prevention.

[0032] Ingredient ratio:

[0033] The proportions of the components in the quenching oil composition of the present invention, by weight, are as follows:

[0034] Base oil 70-85 parts, preferably 75-80 parts;

[0035] 5-10 parts of the compound refrigerant, preferably 6-9 parts;

[0036] 1-3 parts of high-temperature antioxidant, preferably 1.5-2.5 parts;

[0037] Brightener: 0.5-2 parts, preferably 0.8-1.5 parts;

[0038] Use 1-3 parts of rust inhibitor, preferably 1.5-2.5 parts.

[0039] Preparation methods include:

[0040] The preparation method of the quenching oil composition of the present invention includes the following steps:

[0041] (1) Preparation of high-temperature antioxidants:

[0042] Take sodium montmorillonite and add 2-3% (by weight) of the coupling agent γ-aminopropyltriethoxysilane, preferably 2.2-2.8%;

[0043] Pretreatment with stirring at 70-80℃ for 1.5-2 hours, preferably at 72-78℃ for 1.6-1.9 hours;

[0044] After cooling, the mixture was filtered and dried to obtain modified nano-montmorillonite.

[0045] Weigh diphenylamine and 2,4-dimethyl-6-tert-butylphenol at a mass ratio of 3:2, add them to a reaction vessel, heat to 120-130℃, and stir until completely dissolved to form a mixed system. The preferred dissolution temperature is 122-128℃.

[0046] Modified nano-montmorillonite was added to the mixture, and the temperature was raised to 160-170℃ under nitrogen protection, and the reaction was maintained for 3-4 hours. The preferred reaction temperature was 162-168℃, and the preferred reaction time was 3.2-3.8 hours.

[0047] During the reaction, the stirring rate is controlled at 400-500 r / min, preferably 420-480 r / min;

[0048] After the reaction is complete, the mixture is naturally cooled to room temperature to obtain a high-temperature antioxidant.

[0049] (2) Weigh the raw materials:

[0050] Weigh the base oil, compound refrigerant, high-temperature antioxidant, brightener, and rust inhibitor according to the specified weight proportions. The dosage of each component must strictly follow the above-mentioned ratio range.

[0051] (3) Mixed preparation:

[0052] Heat the weighed base oil to 40-60℃, preferably 45-55℃;

[0053] At a stirring rate of 300-500 r / min, the preferred stirring rate is 350-450 r / min;

[0054] First, add the composite cooling agent and stir for 5-6 minutes, then add the high-temperature antioxidant and stir for 3-4 minutes, then add the brightener and stir for 3-4 minutes, and finally add the rust inhibitor and stir for 3-4 minutes.

[0055] After mixing evenly, the mixture is cooled to room temperature to obtain a quenching oil composition.

[0056] Example 1: Preparation of high-temperature antioxidant: 100g of sodium-based montmorillonite was added to 2.2g of coupling agent γ-aminopropyltriethoxysilane and pretreated by stirring at 72℃ for 1.6h. After cooling, the mixture was filtered and dried to obtain modified nano-montmorillonite. 60g of diphenylamine and 40g of 2,4-dimethyl-6-tert-butylphenol were weighed and added to a reaction vessel. The mixture was heated to 122℃ and stirred until completely dissolved to form a mixed system. 12.5g of modified nano-montmorillonite was added to the mixed system and heated to 162℃ under nitrogen protection. The mixture was stirred at a rate of 420r / min and kept at the temperature for 3.2h. After cooling to room temperature, a high-temperature antioxidant was obtained.

[0057] Weigh the raw materials: weigh 75 parts base oil, 6 parts compound refrigerant, 1.5 parts high-temperature antioxidant, 0.8 parts brightener, and 1.5 parts rust inhibitor by weight.

[0058] Preparation by mixing: Heat the base oil to 45°C, add the composite cooling agent and stir for 5 minutes at a stirring rate of 350 r / min, then add the high-temperature antioxidant and stir for 3 minutes, then add the brightener and stir for 3 minutes, and finally add the rust inhibitor and stir for 3 minutes. After mixing evenly, cool to room temperature to obtain the quenching oil composition.

[0059] Example 2: Preparation of high-temperature antioxidant: 100g of sodium-based montmorillonite was added to 2.5g of coupling agent γ-aminopropyltriethoxysilane, and pretreated by stirring at 75°C for 1.7h. After cooling, the mixture was filtered and dried to obtain modified nano-montmorillonite. 60g of diphenylamine and 40g of 2,4-dimethyl-6-tert-butylphenol were weighed and added to a reaction vessel. The mixture was heated to 125°C and stirred until completely dissolved to form a mixed system. 13.9g of modified nano-montmorillonite was added to the mixed system, and the mixture was heated to 165°C under nitrogen protection. The mixture was stirred at a rate of 450r / min and kept at the temperature for 3.5h. After cooling to room temperature, a high-temperature antioxidant was obtained.

[0060] Weigh the raw materials: weigh 78 parts base oil, 7.5 parts compound refrigerant, 2 parts high-temperature antioxidant, 1.2 parts brightener, and 2 parts rust inhibitor by weight.

[0061] Preparation by mixing: Heat the base oil to 50°C, add the composite cooling agent and stir for 5.5 min at a stirring rate of 400 r / min, then add the high-temperature antioxidant and stir for 3.5 min, then add the brightener and stir for 3.5 min, then add the rust inhibitor and stir for 3.5 min. After mixing evenly, cool to room temperature to obtain the quenching oil composition.

[0062] Example 3: Preparation of high-temperature antioxidant: 100g of sodium-based montmorillonite was added to 2.7g of coupling agent γ-aminopropyltriethoxysilane and pretreated by stirring at 77℃ for 1.8h. After cooling, the mixture was filtered and dried to obtain modified nano-montmorillonite. 60g of diphenylamine and 40g of 2,4-dimethyl-6-tert-butylphenol were weighed and added to a reaction vessel. The mixture was heated to 127℃ and stirred until completely dissolved to form a mixed system. 15.4g of modified nano-montmorillonite was added to the mixed system and heated to 167℃ under nitrogen protection. The mixture was stirred at a rate of 470r / min and kept at this temperature for 3.7h. After cooling to room temperature, a high-temperature antioxidant was obtained.

[0063] Weigh the raw materials: weigh 80 parts base oil, 9 parts compound refrigerant, 2.5 parts high-temperature antioxidant, 1.5 parts brightener, and 2.5 parts rust inhibitor by weight.

[0064] Preparation by mixing: The base oil is heated to 53°C. Under a stirring rate of 430 r / min, the composite cooling agent is added and stirred for 6 min, then the high-temperature antioxidant is added and stirred for 4 min, followed by the brightener and stirred for 4 min, and then the rust inhibitor is added and stirred for 4 min. After mixing evenly, the mixture is cooled to room temperature to obtain the quenching oil composition.

[0065] Example 4: Preparation of high-temperature antioxidant: 100g of sodium-based montmorillonite was added to 2.8g of coupling agent γ-aminopropyltriethoxysilane and pretreated by stirring at 78℃ for 1.9h. After cooling, the mixture was filtered and dried to obtain modified nano-montmorillonite. 60g of diphenylamine and 40g of 2,4-dimethyl-6-tert-butylphenol were weighed and added to a reaction vessel. The mixture was heated to 128℃ and stirred until completely dissolved to form a mixed system. 13.9g of modified nano-montmorillonite (10% loading) was added to the mixed system. The mixture was heated to 168℃ under nitrogen protection and stirred at a rate of 480r / min for 3.8h. After cooling to room temperature, the high-temperature antioxidant was obtained.

[0066] Weigh the raw materials: weigh 82 parts base oil, 8 parts compound refrigerant, 2.2 parts high-temperature antioxidant, 1.3 parts brightener, and 2.3 parts rust inhibitor by weight.

[0067] Preparation by mixing: The base oil is heated to 55°C, and the composite cooling agent is added and stirred for 5.8 min at a stirring rate of 450 r / min. Then, the high-temperature antioxidant is added and stirred for 3.8 min. Next, the brightener is added and stirred for 3.8 min. Then, the rust inhibitor is added and stirred for 3.8 min. After mixing evenly, the mixture is cooled to room temperature to obtain the quenching oil composition.

[0068] Comparative Example 1: The preparation method of Example 2 was used, except that only dibenzyltoluene was used as the composite refrigeration agent, and no dodecylbenzene was added. The other raw materials and preparation parameters were completely consistent with those of Example 2.

[0069] Comparative Example 2: The preparation method of Example 3 was used, except that only diphenylamine was used as the high-temperature antioxidant, without the addition of 2,4-dimethyl-6-tert-butylphenol, and without modification by nano-montmorillonite loading. The other raw materials and preparation parameters were completely consistent with those of Example 3.

[0070] Comparative Example 3: The preparation method of Example 4 was used, except that: the brightener was sodium petroleum sulfonate with an active ingredient content of 85%, the rust inhibitor was dodecenyl succinic acid with a purity of 95%, and the other raw materials and preparation parameters were completely consistent with those of Example 4.

[0071] Tests and experiments:

[0072] Experiment 1: Quenching and Cooling Performance Test

[0073] According to GB / T30583-2014, the cooling curve of quenching oil was determined using the silver probe method. The characteristic temperature (the temperature corresponding to the maximum cooling rate), the maximum cooling rate, and the cooling rate at 300℃ were recorded. The silver probe used for the test was φ10mm×50mm. After being heated to 850℃, it was quickly immersed in the quenching oil to be tested, and the temperature change curve was recorded throughout the process. The results are as follows:

[0074] Table 1

[0075] sample Characteristic temperature (°C) Maximum cooling rate (°C / s) Cooling rate at 300℃ (℃ / s) Example 1 585 128 32 Example 2 590 132 33 Example 3 588 130 34 Example 4 592 135 35 Comparative Example 1 620 105 20 Comparative Example 2 586 126 31 Comparative Example 3 589 125 30

[0076] As can be seen from Table 1, the quenching oils of Examples 1-4 all exhibited excellent cooling performance, with characteristic temperatures concentrated in the range of 585-592℃ and a maximum cooling rate of 128-135℃ / s. Even at 300℃, they maintained a reasonable cooling rate of 32-35℃ / s, achieving a balanced effect of rapid cooling at high temperatures and slow cooling at low temperatures.

[0077] Experiment 2: High-Temperature Antioxidant Stability Test

[0078] According to GB / T12581-2021, the quenching oil to be tested was aged at 175℃ and oxygen pressure of 0.69MPa for 1000h. The change rate of acid value and the change rate of kinematic viscosity (40℃) of the oil sample before and after aging were tested to evaluate its high-temperature oxidation resistance. The results are as follows:

[0079] Table 2

[0080] sample Acid value before aging (mgKOH / g) Acid value after aging (mgKOH / g) Acid value change rate (%) <![CDATA[Viscosity before aging (mm 2 / s)]]> <![CDATA[Viscosity after aging (mm 2 / s)]]> Viscosity change rate (%) Example 1 0.08 0.25 212.5 28.5 32.8 15.1 Example 2 0.07 0.22 214.3 29.2 32.5 11.3 Example 3 0.07 0.21 200.0 29.5 32.3 9.5 Example 4 0.08 0.23 187.5 29.8 32.6 9.4 Comparative Example 1 0.07 0.24 242.9 29.3 33.1 12.9 Comparative Example 2 0.08 0.65 712.5 29.6 45.8 54.7 Comparative Example 3 0.07 0.23 228.6 29.7 33.5 12.8

[0081] As can be seen from Table 2, the acid value change rate of the quenching oils in Examples 1-4 after aging is only 187.5%-214.3%, and the viscosity change rate is only 9.4%-15.1%, indicating that they have excellent high-temperature oxidation stability and can maintain stable performance under long-term high-temperature conditions.

[0082] Test 3: Rust prevention and gloss test:

[0083] Rust prevention performance: According to GB / T11143-2013, the A method (single liquid method) is adopted. The 45# steel test piece is completely immersed in the quenching oil to be tested and kept at 60℃ for 24 hours. The rust condition on the surface of the test piece is observed. The rust level is divided into grade 0 (no rust), grade 1 (slight rust), grade 2 (moderate rust), and grade 3 (severe rust).

[0084] Glossiness: The 45# steel test piece was heated to 850℃, held at that temperature for 10 minutes, and then immersed in the quenching oil to be tested for quenching. After cooling, the glossiness of the test piece surface was measured using a gloss meter (60° angle). The higher the gloss value, the better the glossiness of the workpiece. The results are as follows:

[0085] Table 3

[0086] sample Rust prevention level Surface gloss (GU) Example 1 Level 0 89 Example 2 Level 0 92 Example 3 Level 0 93 Example 4 Level 0 91 Comparative Example 1 Level 0 90 Comparative Example 2 Level 0 88 Comparative Example 3 Level 2 75

[0087] As can be seen from Table 3, the quenching oils of Examples 1-4, Comparative Example 1 and Comparative Example 2 can all achieve a rust prevention level of 0. This indicates that as long as the rust inhibitor that meets the requirements is selected, a good rust prevention effect can be guaranteed. The composition of the high-temperature antioxidant and the ratio of the composite cooling agent have no significant impact on the rust prevention performance.

[0088] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0089] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A quenching oil composition, characterized in that, By weight, it includes 70-85 parts base oil, 5-10 parts compound refrigerant, 1-3 parts high-temperature antioxidant, 0.5-2 parts brightener, and 1-3 parts rust inhibitor.

2. The quenching oil composition as described in claim 1, characterized in that, The base oil is a paraffinic oil.

3. The quenching oil composition as described in claim 1, characterized in that, The brightener is sodium petroleum sulfonate, and the active ingredient content of the sodium petroleum sulfonate is ≥90% and the moisture content is ≤0.5%.

4. The quenching oil composition according to claim 1, characterized in that, The rust inhibitor is dodecenylsuccinic acid, and the acid value of dodecenylsuccinic acid is 190-210 mgKOH / g, and the purity is ≥98%.

5. The quenching oil composition as described in claim 1, characterized in that, The composite refrigerant is composed of dibenzyltoluene, a high-temperature refrigerant, and dodecylbenzene, a low-temperature refrigerant, in a mass ratio of 5:

3.

6. The quenching oil composition according to claim 1, characterized in that, The high-temperature antioxidant is a nano-montmorillonite-modified diphenylamine-hindered phenol complex, wherein the mass ratio of diphenylamine to hindered phenol is 3:2, and the loading of nano-montmorillonite is 8-12% of the total mass of the complex.

7. The quenching oil composition according to claim 6, characterized in that, The hindered phenol is 2,4-dimethyl-6-tert-butylphenol.

8. A method for preparing a quenching oil composition according to any one of claims 1-7, characterized in that, Includes the following steps: Preparation of high-temperature antioxidant S1: Take sodium-based montmorillonite, add 2-3% of its mass as coupling agent, stir and pretreat at 70-80℃ for 1.5-2h, cool, filter and dry to obtain modified nano-montmorillonite; weigh diphenylamine and 2,4-dimethyl-6-tert-butylphenol at a mass ratio of 3:2, add to a reaction vessel, heat to 120-130℃, stir until completely dissolved to form a mixed system; add modified nano-montmorillonite to the mixed system, heat to 160-170℃ under an inert atmosphere, keep the temperature for 3-4h, and control the stirring rate at 400-500r / min during the reaction; after the reaction is completed, cool naturally to room temperature to obtain the high-temperature antioxidant; S2 Weighing raw materials: Weigh base oil, compound refrigerant, high-temperature antioxidant, brightener, and rust inhibitor by weight; S3 Mixing Preparation: Heat the base oil weighed in step S2 to 40-60℃, add the composite cooling agent and stir for 5-6 minutes at a stirring rate of 300-500r / min, then add the high-temperature antioxidant and stir for 3-4 minutes, then add the brightener and stir for 3-4 minutes, then add the rust inhibitor and stir for 3-4 minutes. After mixing evenly, cool to room temperature to obtain the quenching oil composition.

9. The preparation method according to claim 8, characterized in that, The coupling agent in S1 is γ-aminopropyltriethoxysilane.

10. The preparation method according to claim 8, characterized in that, The inert atmosphere in S1 is nitrogen.