An aqueous quenching agent and a method for producing the same

Abstract

The application relates to the technical field of metal heat treatment, and discloses a water-based quenching agent and a production method thereof, which comprises the following steps: mixing water, triethanolamine, a preservative and a bactericide into a first mixed solution; adding a dispersing agent into the first mixed solution to obtain a second mixed solution; and finally slowly adding a water-soluble polyurethane solution into the second mixed solution under stirring, wherein the application is characterized by specific process settings, especially the pre-addition of triethanolamine and the slow addition of the water-soluble polyurethane solution, which are used for synergistically controlling the intermolecular hydrogen bond association between the two, guiding the spontaneous assembly of components to form an ordered liquid-phase association structure, the structure has the objective attribute of gradually and uniformly redissolving with the decrease of temperature in the quenching low-temperature stage, and the technical problem that the existing quenching medium is prone to cooling out of control due to irregular peeling in the low-temperature zone, thereby causing the cracking of workpieces can be solved.

Description

Technical Field

[0001] This invention relates to a water-based quenching agent and its production method, belonging to the field of metal heat treatment technology. Background Technology

[0002] Heat treatment of metallic materials is currently a core industrial process for controlling their final performance. In the quenching process, rapid cooling through a medium is used to improve the hardness and strength of the workpiece. Among commonly used cooling media, water or brine has strong cooling capacity, but its rapid cooling at low temperatures can easily cause workpiece deformation or cracking. While mineral oil provides gentle cooling, its cooling capacity is insufficient at high temperatures, making it suitable only for a few high-alloy steels, and it also poses environmental problems. To balance the process requirements of rapid cooling at high temperatures and slow cooling at low temperatures, polymer-based water-based quenching fluids such as PAG and PVP are used. These media mainly rely on the reverse dissolution properties of polymers to form a polymer film on the surface of high-temperature workpieces to regulate heat transfer efficiency. However, in continuous heat treatment production practice, this working mechanism has inherent process problems. The core of the problem is that the quality of the polymer film formation is highly dependent on the working concentration of the quenching fluid. During production, factors such as water evaporation and workpiece carry-over inevitably cause concentration fluctuations, leading to drift in cooling performance. In the existing PAG or PVP water-based quenching fluids, the maximum cooling rate in the high-temperature zone can still be maintained when the concentration changes, but the cooling rate in the low-temperature zone will change significantly.

[0003] To improve the adaptability of single polymer films, existing technologies attempt to enhance the film-forming mechanism through multi-component composites or biomass modification. For example, Chinese invention patent application CN106916925A discloses a method for preparing a water-based quenching agent, which combines polyvinyl alcohol with desalted snail shell powder and plant mixtures. The cooling rate is adjusted by using chitosan and polyvinyl alcohol to form a network gel. Although this enhances the physical toughness of the film, it is essentially a static improvement of the physical properties of the solid film. In practical applications, the thermal shock response of complex component gel structures lacks uniformity. Especially in the low-temperature martensitic transformation stage, the stiff gel layer is difficult to smoothly dissolve and re-dissolve as the temperature decreases. It is prone to uncontrolled cooling due to local irregular cracking and peeling of the film. This uncontrollable change in the cooling rate in the low-temperature region occurs precisely in the martensitic transformation stage where the stress in the workpiece is most concentrated and most prone to cracking. This is the root cause of heat treatment failure of complex structural steel products.

[0004] Therefore, how to provide a water-based quenching agent and its production method that maintains low temperature and slow cooling when the concentration changes, and solve the cracking problem of complex structural steel products, has become the technical problem to be solved by this invention. Summary of the Invention

[0005] To address the problems mentioned in the background section, the technical solution of this invention is as follows:

[0006] A method for producing a water-based quenching agent includes the following steps:

[0007] Step 101: Add the remaining water, 0.5% to 1% by mass of triethanolamine, 0.2% by mass of preservative, and 0.1% by mass of bactericide to the reaction vessel and mix them, stirring until homogeneous to obtain the first mixture.

[0008] Step 102: While stirring, add 0.1% to 0.3% by mass of dispersant to the first mixture, mix evenly, and obtain the second mixture;

[0009] Step 103: Under continuous stirring, slowly add 5% to 12% by mass of water-soluble polyurethane solution to the second mixture, and continue stirring until homogeneous. The process settings of adding triethanolamine in step 101 and slowly adding water-soluble polyurethane solution in step 103 are used to synergistically regulate the intermolecular hydrogen bond association between water-soluble polyurethane and triethanolamine in the aqueous phase. Under the bridging of triethanolamine, the intermolecular hydrogen bond association guides the spontaneous assembly of the molecular chains of water-soluble polyurethane to form a dynamic and ordered liquid-phase association structure. During the low-temperature stage of quenching, the liquid-phase association structure gradually and uniformly redissolves as the workpiece temperature decreases, maintaining a stable liquid film boundary layer on the workpiece surface.

[0010] Preferably, the water-soluble polyurethane solution is a polyether-type water-soluble polyurethane solution. Triethanolamine, as a strong polar hydrogen bond regulator, undergoes hydrogen bond association with the urethane groups and polyether segments contained in the molecular chain of the water-soluble polyurethane solution. The slow addition of the water-soluble polyurethane solution, through kinetic control, ensures that the hydrogen bond association forms a liquid-phase associated structure under the synergistic guidance of the dispersant, and inhibits the occurrence of disordered physical entanglement.

[0011] Preferably, in step 103, the ratio of the addition rate of the water-soluble polyurethane solution to the volume of the second mixture is controlled within the range of 0.01 min⁻¹ to 0.1 min⁻¹ to ensure that the liquid-phase associated structure has sufficient time for orderly assembly.

[0012] Preferably, in step 102, the dispersant adsorbs and coats the components in the first mixture, assisting triethanolamine to play a more uniform bridging role in step 103.

[0013] Preferably, in step 101, the order of adding the components is as follows: water, triethanolamine, preservative and bactericide.

[0014] Preferably, steps 101, 102 and 103 are all carried out at a temperature of 10 degrees Celsius to 40 degrees Celsius, and the stirring rate is 100 RPM to 300 RPM.

[0015] Preferably, the mass ratio of the water-soluble polyurethane solution is 5% to 8%.

[0016] Preferably, the mass ratio of the water-soluble polyurethane solution is 9% to 12%.

[0017] Preferably, the preservative is an isothiazolinone preservative; the bactericide is a quaternary ammonium salt bactericide; used to give the water-based quenching agent prepared by the production method the ability to inhibit microorganisms.

[0018] A water-based quenching agent, characterized in that the water-based quenching agent is prepared by a method for producing water-based quenching agents.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The quenching agent, through the synergistic effect of water-soluble polyurethane solution and specific components of triethanolamine, combined with a specific preparation process, provides sufficient cooling rate in the high-temperature zone during heat treatment to ensure the hardenability of the workpiece, and provides a continuous and gradual cooling rate when the workpiece enters the low-temperature zone. This transformation of cooling characteristics is in line with the actual needs of complex structural steel products during the cooling process. After rapidly passing through the pearlite transformation zone, it slowly passes through the martensite transformation zone, releasing the internal structural stress of the workpiece and avoiding quenching cracking caused by excessively rapid local cooling and stress concentration.

[0021] 2. The order and method of slowly adding water-soluble polyurethane solution after fully mixing triethanolamine, preservative, bactericide and dispersant ensure that each component, especially water-soluble polyurethane and triethanolamine, forms a stable synergistic state in the aqueous phase, thus ensuring the process guarantee of the above-mentioned unique cooling performance and making the final performance of the quenching agent highly repeatable and stable.

[0022] 3. The cooling mechanism of the quenching agent overcomes the technical limitations of some existing water-based quenching fluids, which suffer from drastic fluctuations in cooling rate in the low-temperature zone due to changes in concentration. Through the synergistic effect of water-soluble polyurethane and triethanolamine and other components, the cooling characteristics of the quenching agent, especially the cooling rate in the critical low-temperature zone, maintain good stability within the normal fluctuation range of the concentration used, thereby improving the robustness and consistency of the heat treatment process and reducing the stringent requirements for concentration control on the production site. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the production process and liquid phase association mechanism of the water-based quenching agent of the present invention;

[0024] Figure 2 The graph shows the test data of cooling characteristics of different groups of the present invention at low temperature.

[0025] Figure 3 This is a diagram illustrating the interactive use cases for the entire process of production quality control and application of the water-based quenching agent of this invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] This invention provides a water-based quenching agent and its production method, including stages such as premixing of raw materials, addition of dispersant, and kinetically controlled addition of key polymer solutions. In the heat treatment process of metal workpieces, especially in the martensitic transformation region, high requirements are placed on the uniformity and stability of the cooling rate of the cooling medium in the low-temperature region. Existing PAG-type media mainly rely on the reverse dissolution property of the polymer, and the polymer film formed is prone to irregular peeling in the low-temperature region, leading to uncontrolled cooling and workpiece cracking. To solve this technical problem, the production method of this invention, while retaining the high-temperature reverse dissolution film-forming characteristics, avoids the traditional low-temperature disordered peeling mode. It maintains a stable liquid film boundary layer on the workpiece surface by constructing a liquid-phase association structure that gradually and uniformly redissolves as the temperature decreases during the quenching low-temperature stage. In a specific embodiment, a stirring device is provided... The reaction is carried out in a reactor with an adjustable stirring rate ranging from 100 RPM to 300 RPM and temperature control capabilities, ensuring that all steps are performed at temperatures between 10°C and 40°C. The method executes step 101, where the remaining water, 0.5% to 1% by mass of triethanolamine, 0.2% by mass of preservative, and 0.1% by mass of bactericide are added to the reactor and mixed. To ensure the uniformity and controllability of the subsequent association reaction, the specific order of addition in step 101 can be: adding water, then adding triethanolamine, preservative, and bactericide sequentially. The preservative can be an isothiazolinone preservative, and the bactericide can be a quaternary ammonium salt bactericide, used to give the final quenching agent microbial inhibitory capabilities. In step 101, the mixture is stirred at a rate of 100 RPM to 300 RPM until the first mixture is homogeneous.

[0028] In step 102, while maintaining stirring, 0.1% to 0.3% by mass of a dispersant is added to the first mixture. This dispersant is used to adsorb and coat the components in the first mixture, especially triethanolamine, in the liquid phase, assisting triethanolamine in more uniformly exerting its hydrogen bond bridging effect in subsequent steps. After stirring and mixing evenly, a second mixture is obtained. The key step of this method is step 103, where, while continuously stirring, 5% to 12% by mass of a water-soluble polyurethane solution is slowly added to the second mixture. In a specific embodiment, the water-soluble polyurethane solution is a polyether-type water-soluble polyurethane solution, and the mass ratio can be limited to 5% to 8% or... 9% to 12%; the slow addition here is a key process control point for achieving the technical effect of this invention. Kinetic control ensures that the water-soluble polyurethane molecular chain, containing urethane groups and polyether segments, undergoes sufficient and orderly hydrogen bond association with triethanolamine, acting as a strongly polar hydrogen bond regulator. Specifically, the abundant hydroxyl (-OH) and central nitrogen atom in the triethanolamine molecule give it unique zwitterionic characteristics, allowing it to act as both a hydrogen bond acceptor and donor in the system. Under the kinetic control conditions of step 103, triethanolamine utilizes this property to anchor the urethane groups distributed on the water-soluble polyurethane molecular chain. The multi-site hydrogen bonding interactions (including the group and ether bonds) do not form permanent chemical crosslinks, but rather induce the water-soluble polyurethane molecular chains to construct a thermodynamically unstable, thixotropic, and reversible network under the bridging of triethanolamine. This reversible network structure is the core of the liquid-phase association structure of this invention, ensuring that the molecular chains can undergo ordered dissociation and redissolution as the temperature decreases and shear force changes during the quenching low-temperature stage. To achieve this kinetic control, the ratio between the addition rate of the water-soluble polyurethane solution and the total volume of the second mixture already present in the reactor at the beginning of step 103 is controlled at 0.01 min. -1 up to 0.1 min -1 Within a certain range; this rate setting ensures that hydrogen bond association, under the synergistic guidance of the dispersant, has sufficient time for ordered assembly, guiding the molecular chains of water-soluble polyurethane to spontaneously assemble into a dynamic and ordered liquid-phase associated structure under the bridging of triethanolamine, and suppressing the occurrence of disordered physical entanglement; after addition, stirring continues until the system is homogeneous; thus, the production method of the present invention prepares an aqueous quenching agent, comprising a liquid-phase associated structure formed by spontaneous assembly through intermolecular hydrogen bond association, synergistically controlled by specific process settings, especially the pre-addition of triethanolamine in step 101 and the slow addition of water-soluble polyurethane solution in step 103.

[0029] Example 1: In typical heat treatment applications, it is necessary to quench a batch of precision transmission workpieces with complex geometries, especially those containing thin-walled, thick-walled junctions and sharp inner radius corners. The workpiece material is highly sensitive to stress concentration and quenching cracks. When conventional PAG quenching media based on the reverse dissolution precipitation mechanism are used to treat such workpieces, the polymer film undergoes irregular peeling during the low-temperature cooling stage, causing the cooling rate of the stress concentration area of ​​the workpiece to suddenly run out of control, resulting in uneven martensitic transformation and microcracks, leading to the scrapping of the workpiece. To address this challenge, a water-based quenching agent is prepared using a production method. The key to this method is that the pre-addition of triethanolamine in step 101 and the slow addition of water-soluble polyurethane solution in step 103, through specific process settings, synergistically regulate the intermolecular hydrogen bond association between water-soluble polyurethane and triethanolamine in the aqueous phase. The purpose of this regulation is not simply physical dissolution, but to guide the components to spontaneously assemble into an ordered liquid-phase associated structure.

[0030] When high-temperature precision transmission workpieces are immersed in this water-based quenching agent, the cooling behavior differs from that of PAG media: In the high-temperature zone, the buffer film formed on the workpiece surface by the liquid-phase association structure provides sufficient cooling capacity, allowing the entire workpiece to quickly pass through the pearlite transformation zone; as the workpiece temperature decreases and enters the low-temperature zone of martensitic transformation, which is prone to cracking, the liquid-phase association structure exhibits the key objective property already explained in the specific implementation, namely, gradual and uniform redissolution as the workpiece temperature decreases; it is precisely at the thin-walled and thick-walled junctions and inner radius corners of the workpiece that this uniform and gradual redissolution process occurs on the workpiece surface. The surface maintains a stable liquid film boundary layer, providing a continuous and gentle cooling rate in the low-temperature zone; it resolves the inherent contradiction of rapid cooling in the high-temperature zone and uncontrolled cooling in the low-temperature zone leading to cracking in traditional media; after this batch of workpieces was treated by this method, the test showed that no quenching cracks were found in any stress concentration areas, a uniform martensitic structure was obtained, and the residual stress was controlled within an acceptable range. The specific liquid phase structure formed by the dynamic regulation of the molecular forces between components provides a way to solve the deformation and cracking problems of complex workpieces in the field during heat treatment, which is different from the traditional reverse dissolution precipitation mechanism.

[0031] Example 2: This example is used to objectively verify the key process settings in the production method of the present invention, namely the slow addition in step 103 and the key component, triethanolamine, for the synergistic effect on the cooling performance of the quenching agent in the critical low-temperature zone (martensitic transformation zone) of the process, and to verify the preferred mass ratio range of the water-soluble polyurethane solution. The test adopts the field-standard quenching medium cooling characteristic test method and is performed according to the standard. The test equipment includes a temperature-controlled tube furnace with a temperature control accuracy of ±5℃ and a cooling characteristic test system. The test probe is a standard 12.5mm diameter Inconel 600 alloy probe. During the test, the probe is heated to 850℃ in the tube furnace, held at the temperature, and then quickly (within 1 second) immersed in the quenching agent sample group to be tested. The medium temperature of the quenching agent sample group is pre-constantly maintained at 30℃, the ambient temperature is 25℃, and the stirring intensity is 0m / s.

[0032] Sample groups A and B of the present invention and control groups C, D, E, F, and G were prepared. The differences in preparation process and composition of each sample group are as follows: Sample group A of the present invention: prepared according to the production method of the present invention, namely, according to steps 101 (triethanolamine mass ratio 0.5%), 102, and 103, wherein the mass ratio of water-soluble polyurethane solution in step 103 is 5%, and the addition rate is controlled at 0.05 min. -1 Sample B of this invention: The production method of this invention is the same as that of sample A, but in step 103, the mass ratio of the water-soluble polyurethane solution is 12%, and the addition rate is controlled at 0.05 min. -1 Control Group C (Out of Range - Below Lower Limit): The production method of this invention is used, with the same steps as sample group A, but the mass ratio of water-soluble polyurethane solution in step 103 is 4%; Control Group D (Out of Range - Above Upper Limit): The production method of this invention is used, with the same steps as sample group A, but the mass ratio of water-soluble polyurethane solution in step 103 is 13%; Control Group E (Process Missing): The components are exactly the same as sample group B (12% polyurethane), but the preparation method is conventional physical mixing, that is, after step 102, the 12% water-soluble polyurethane solution is quickly poured into the second mixture in one go and stirred evenly; Control Group F (Component Missing): Using the production method of this invention, the composition is basically the same as that of sample group B (12% polyurethane), but triethanolamine is not added in step 101; control group G (existing technology): commercially available PAG-type water-based quenching fluid is used to prepare a working fluid with a mass ratio of 15%; according to the above test method, the cooling characteristics of each sample group are tested, the cooling curves are recorded, and the key low-temperature cooling time data are extracted from them, namely the time to cool from high temperature to 400℃ (T400) and the time to cool to 200℃ (T200). The longer the T400 and T200 times, the smoother and more controllable the cooling rate of the quenching agent in the low-temperature region; the test data are summarized in Table 1.

[0033] Table 1: Comparison of Cooling Characteristics Data in Low Temperature Zones of Different Groups

[0034]

[0035] Data analysis is as follows: The data of control group G (PAG) (T200 of 7.9s) shows the limitations of existing technology, namely, the rapid cooling rate in the low-temperature zone easily leads to workpiece cracking; comparing sample group B (12% concentration, T200 of 27.7s) and sample group A (5% concentration, T200 of 12.7s) of the present invention: as the concentration decreases from 12% to 5%, the low-temperature cooling time T200 shows the expected physical shortening. However, even at the lower limit of 5% concentration, the T200 of sample group A (12.7s) is still significantly longer than that of control group G (7.9s). This indicates that the water-based quenching agent of the present invention can suppress low temperature cracking in a wide concentration range (5%-12%). The rapid cooling effect in the temperature range maintains a smooth cooling characteristic, avoiding the problem of the cooling rate dropping into the extremely fast danger zone (<10s) due to concentration fluctuations in conventional media. Compared with control group C (4%) and sample group A, it can be seen that when the mass ratio is less than 5%, the slow cooling effect in the low temperature zone is significantly insufficient. Compared with control group D (13%), it can be seen that when the mass ratio is greater than 12%, although the low temperature cooling time is further extended, it was observed in the experiment that the polymer film in the high temperature zone has excessive accumulation and instability, resulting in a decrease in the cooling capacity in the high temperature zone, exceeding the optimal window of the process. Compared with control groups E and F, which lack the slow addition of process or triethanolamine components, the cooling characteristics in the low temperature zone are close to those of control group G.

[0036] Example 3: This example combines Figures 1 to 3 A description of a water-based quenching agent and its production method, such as... Figure 1 As shown, the remaining water, 0.5% to 1% triethanolamine (by mass), 0.2% preservative, and 0.1% bactericide are mixed and proceeded to step 101 to prepare the first mixture. Then, 0.1% to 0.3% dispersant is added, and the mixture proceeds to step 102 to prepare the second mixture and assist in subsequent uniform bridging. Next, step 103, the critical association stage, involves slowly adding 5% to 12% water-soluble polyurethane solution to the second mixture under kinetic control, ultimately producing a product containing ordered liquid-phase associated structures. The water-based quenching agent, through the synergistic regulation of key process settings, utilizes the pre-addition of triethanolamine as a strong polar hydrogen bond regulator in step 101, combined with the slow addition of water-soluble polyurethane in step 103 to achieve kinetic control and ensure ordered assembly time. This synergistic regulation of intermolecular hydrogen bond association guides spontaneous assembly and inhibits the occurrence of disordered physical entanglement, ultimately forming an ordered liquid-phase associated structure. The structural characteristics are characterized by gradual and uniform redissolution as the temperature decreases during the quenching low-temperature stage, while maintaining a stable liquid film boundary layer.

[0037] like Figure 2As shown, the vertical axis of this bar chart represents time in seconds (s), and the horizontal axis represents seven sample groups: sample group A, sample group B, control group C, control group D, control group E, control group F, and control group G. The legend distinguishes between the time T400 for cooling to 400℃ and the time T200 for cooling to 200℃. Specifically, sample group A has a T400 of 5.1 and a T200 of 12.7; sample group B has a T400 of 6.6 and a T200 of 27.7; control group C has a T400 of 4.2 and a T200 of 9.8; control group D has a T400 of 10.5 and a T200 of 38.2; control group E has a T400 of 3.1 and a T200 of 8.5; control group F has a T400 of 3.5 and a T200 of 9.2; and control group G has a T400 of 2.8 and a T200 of 7.9. Figure 3 As shown, the production technician is responsible for executing the production method. This use case specifically includes three sub-processes: step 101 premixing, step 102 adding dispersant, and step 103 slow association. The quality control analyst is responsible for executing the two use cases of testing cooling characteristics and characterizing the liquid phase association structure. The heat treatment engineer is responsible for executing the use case of quenching complex workpieces. The above roles, by executing the corresponding process operations or testing steps, together constitute the whole-process interactive system of water-based quenching agents from production preparation, quality monitoring to final application.

[0038] Example 4: This example is used to verify the mechanism of the observed differences in cooling performance caused by different preparation methods and components from a structural level. Three key sample groups from Example 2 are selected for comparison: Sample group B of the present invention, with a water-soluble polyurethane solution mass ratio of 12%, is prepared using the method of the present invention, containing triethanolamine and added slowly; Control group E, with a water-soluble polyurethane solution mass ratio of 12%, is prepared by rapid physical mixing; Control group F, with a water-soluble polyurethane solution mass ratio of 12%, is prepared by slow addition but does not contain triethanolamine in step 101. Dynamic light scattering (DLS) analysis technology is used to characterize the hydrodynamic size distribution of the three sample groups at the same medium temperature of 30°C as in Example 2. This is used to detect the aggregation state of polymer molecular chains in the solution. Ordered associated structures will show a narrow peak distribution in a specific size range, while disordered entanglement or simple dissolution will show a broad polydisperse peak or only small molecule peaks.

[0039] DLS test results showed that sample B of this invention exhibited a single peak with a clear main peak and narrow distribution in the range of 100nm to 300nm, with an average particle size of about 180nm, indicating that relatively uniform aggregates were formed in the system. To quantify the orderliness and stability of the liquid-phase associated structure, the prepared water-based quenching agent was subjected to dynamic light scattering DLS detection at 25℃. The qualified associated structure showed a single-peak distribution, a polydispersity index (PDI) of less than 0.2, and a hydrodynamic radius concentrated in the range of 150nm to 200nm, ruling out multi-peak or broad-peak distribution caused by physical disorder entanglement. After undergoing an accelerated aging test of 168 hours of constant temperature and sealed storage at 50℃, the kinematic viscosity change rate at 40℃ and the T400 change rate after cooling to 400℃ both remained within 1.5%, confirming the formation of hydrogen bonds under specific processes. The associated structure possesses structural stability suitable for long-term industrial cyclic use. Control group E, i.e., the rapidly mixed sample group, exhibits extremely broad and amorphous polydisperse peaks from 50 nm to over 1000 nm, indicating disordered physical entanglement of the polymer. Control group F, i.e., the sample group without triethanolamine, failed to observe peaks above 100 nm, and its particle size distribution is close to that of pure water-soluble polyurethane solution, indicating that no associated structure has been formed. This structural characterization data confirms that the process setting of pre-adding triethanolamine and slowly adding water-soluble polyurethane solution, which is unique to the production method of this invention, is the direct reason for guiding the spontaneous assembly of components to form an ordered liquid-phase associated structure. The absence of this ordered structure in control groups E and F is consistent with their performance in Example 2, which exhibits rapid cooling (short T200 time) in the low-temperature region, similar to that of PAG media.

[0040] Example 5: This example provides a reproducible process control procedure for large-scale production to ensure that the production method of the present invention can stably form a liquid-phase associated structure during industrial batch production, taking 2000L as an example; the process is carried out in a 3000L capacity reactor equipped with a bottom high-speed shear stirring (set to 300RPM) and a top low-speed anchor stirring (set to 60RPM), with the reactor temperature controlled at 25°C by a jacketed water bath; according to steps 101 and 102, 1825.2L of water (balance) and 10.0L of triethanolamine (0.5% by mass) are added sequentially to the reactor. 4.0 L of preservative (0.2% by mass), 2.0 L of bactericide (0.1% by mass), and 6.0 L of dispersant (0.3% by mass) were mixed at high speed with shear for 5 minutes to obtain 1847.2 L of homogeneous second mixture. In step 103, 152.8 L of water-soluble polyurethane solution (8% by mass) was pumped into the second mixture at a constant rate of 18.47 L / min using a pre-calibrated metering pump. The ratio of this addition rate of 18.47 L / min to the existing volume of the second mixture in the reactor (1847.2 L) was calculated to be 0.01 min. -1 The ratio falls within 0.01 min. -1up to 0.1 min -1 Within the controllable range, the entire feeding process lasted approximately 8.3 minutes.

[0041] In this embodiment, the weight-average molecular weight (Mw) of the selected polyether-type water-soluble polyurethane solution is preferably limited to between 15,000 and 25,000 Daltons, and the solid content is between 30% and 35%. This specific chain length range provides sufficient ether-oxygen bond acceptors to form hydrogen bonds with triethanolamine, avoiding steric hindrance that would hinder the orderly arrangement of the associated structures due to excessively high molecular weight. In step 103, the kinetic control process determines the reaction endpoint independently of time parameters, by online monitoring of the output torque of the reactor stirrer motor. When the real-time monitored torque value experiences an upward phase and then enters a plateau phase, and the fluctuation range remains within ±2% within 10 minutes, it indicates that hydrogen bonds in the system are present. Once the network reaches thermodynamic equilibrium, the liquid-phase associative structure assembly is complete. After the water-soluble polyurethane solution is added, the high-speed bottom shear stirring is stopped, and the low-speed top anchor stirring is started. Stirring continues at a rate of 150 RPM for 30 minutes to ensure that the liquid-phase associative structure is fully formed and reaches uniform stability. After stirring, a sample is taken from the reactor, and its viscosity is measured at 25°C using a rotational viscometer. When the viscosity value stabilizes within the preset quality control window, such as 16.5 cP ± 1.0 cP, the batch of water-based quenching agent is deemed to be qualified. This viscosity value is an objective physical characterization of the liquid-phase associative structure formed at a specific concentration.

[0042] Example 6: This example provides a standardized engineering calibration procedure for determining key process parameters in the production method of the present invention, namely, the addition rate of the water-soluble polyurethane solution in step 103 and the optimal working concentrations of the key components triethanolamine and dispersant. The goal is to ensure that a liquid-phase associated structure with specific hydrodynamic dimensions and stable low-temperature cooling performance can be reproducibly formed in different production batches. The mass ratio of the water-soluble polyurethane solution is fixed at 8%, and the ambient and medium temperature is 25°C. In the first stage, the addition rate is calibrated: the mass ratio of triethanolamine is fixed at 0.8%, and the mass ratio of dispersant is 0.2%. Five sample groups are prepared using the production method of the present invention, and the addition rate in step 103 is changed and set to 0.005 min. -1 (Out of range - too slow), 0.01min -1 (Lower limit), 0.05min -1 (Median value), 0.1 min -1 (Upper limit) and 0.2min -1 (Out of range - too fast); After preparation, the low-temperature cooling time T200 of each sample group was tested according to the method of Example 2, and the average particle size of DLS was tested according to the method of Example 4; the test results showed that the rate was 0.01 min. -1 0.05min -1 and 0.1min -1The three sample groups all had a T200 that remained stable within the range of 20 to 22 seconds, and the average particle size of DLS was within a narrow distribution range of 170 nm to 190 nm, indicating that they all formed liquid-phase associated structures; the rate was 0.2 min. -1 The sample group showed a shortened T200 of 11.2 s and a DLS peak broadened to over 450 nm, indicating that insufficient assembly time led to disordered entanglement; the assembly rate was 0.005 min. -1 The sample group, whose T200 and DLS data are consistent with 0.01 min -1 There was no significant difference between the sample groups, indicating that 0.01 min -1 This is already the lower limit rate sufficient for forming an ordered structure; slower rates are not economically viable. This data confirms that 0.01 min... -1 up to 0.1 min -1 The first stage is the kinetic control window; the second stage is the calibration of the component range: the addition rate is fixed at 0.05 min. -1 (Verified rate) The mass ratio of the water-soluble polyurethane solution was fixed at 8%; multiple gradient sample groups were prepared, and the mass ratios of triethanolamine (0.3%, 0.5%, 1.0%, 1.2%) and dispersant (0.05%, 0.1%, 0.3%, 0.4%) were determined respectively; the test results showed that when the triethanolamine content was below 0.5%, the T200 was shortened to 9.5s, and no association peak was observed in DLS; when it was above 1.0%, the T200 was prolonged (23.1s), but the viscosity of the system showed uneven fluctuations; when the dispersant content was below 0.1%, the DLS peak shape was irregular, and the dispersion of the T200 data increased in repeated tests; when it was above 0.3%, the T200 no longer showed significant changes; it was confirmed that the mass ratio of triethanolamine 0.5% to 1% to dispersant 0.1% to 0.3% is the component range that synergistically forms a stable liquid-phase association structure with the process.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for producing a water-based quenching agent, characterized in that, Includes the following steps: Step 101: By mass percentage, add 0.5% to 1% triethanolamine, 0.2% preservative, 0.1% bactericide and the balance water to the reaction vessel and mix, stirring until homogeneous to obtain the first mixture. Step 102: While stirring, add 0.1% to 0.3% by mass of dispersant to the first mixture, mix evenly, and obtain the second mixture; Step 103: While continuously stirring, slowly add 5% to 12% by mass of water-soluble polyurethane solution to the second mixture, and continue stirring until homogeneous; In step 103, the ratio of the volume of the water-soluble polyurethane solution added per minute to the volume of the second mixture is controlled within the range of 0.01 to 0.1; the water-soluble polyurethane solution is a polyether-type water-soluble polyurethane solution, the weight-average molecular weight Mw of the polyether-type water-soluble polyurethane solution is limited to between 15,000 and 25,000 Daltons and the solid content is between 30% and 35%.

2. The method for producing a water-based quenching agent according to claim 1, characterized in that, In step 101, the order of adding the components is as follows: water, triethanolamine, preservative, and bactericide.

3. The method for producing a water-based quenching agent according to claim 1, characterized in that, Steps 101, 102 and 103 are all carried out at a temperature of 10 degrees Celsius to 40 degrees Celsius, and the stirring rate is 100 RPM to 300 RPM.

4. The method for producing a water-based quenching agent according to claim 1, characterized in that, The mass ratio of the water-soluble polyurethane solution is 5% to 8%.

5. The method for producing a water-based quenching agent according to claim 1, characterized in that, The mass ratio of the water-soluble polyurethane solution is 9% to 12%.

6. The method for producing a water-based quenching agent according to claim 1, characterized in that, The preservative is an isothiazolinone preservative; the bactericide is a quaternary ammonium salt bactericide.

7. A water-based quenching agent, characterized in that, The water-based quenching agent is prepared by the production method of the water-based quenching agent according to claim 1.

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