An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel and its method for determining the electrolyte composition.

Abstract

This invention discloses an electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel. Its specific composition and mass percentage content are: sodium nitrate 2wt.%-18wt.%, sodium sulfate 2wt.%-18wt.%, and deionized water 64wt.%-96wt.%. The electrolyte used in this invention is neutral, which not only avoids damage to machine tools caused by acid and alkali corrosion, but also uses readily available, economical, and easy-to-prepare chemical reagents. Ion loss during electrochemical machining is negligible, and the electrolyte can be recycled and reused, effectively reducing production costs. The electrolyte of this invention can generate a uniform and dense passivation film on the surface of 9Cr18Mo bearing steel. Compared to the base material, this passivation film has lower hardness and elastic modulus, making it easier to remove by mechanical grinding. Simultaneously, this passivation film significantly reduces uneven corrosion on the workpiece surface, greatly improving the surface quality of the machined workpiece.

Description

Technical Field

[0001] This invention relates to an electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel and a method for determining the electrolyte solution, belonging to the field of electrolytic machining technology for metal materials. Background Technology

[0002] 9Cr18Mo is a high-carbon chromium martensitic stainless steel with high hardness, high wear resistance, and good corrosion resistance. It is widely used in the manufacture of cutting tools, medical instruments, industrial cutting tools, precision parts, and bearings. During operation, the raceway surface of bearings is often subjected to complex working environments such as high speed, high temperature, and high load. Therefore, the machining quality of the raceway surface directly determines the overall performance and service life of the bearing. Currently, the machining methods for bearing raceway surfaces typically employ traditional abrasive wheel forming grinding and ultra-precision grinding (such as oilstone grinding). However, due to the high hardness and outstanding wear resistance of 9Cr18Mo bearing steel, traditional grinding methods often result in low processing efficiency and are prone to problems such as grinding burns, surface cracks, and surface hardening, severely restricting the performance improvement of bearing products.

[0003] To address these challenges, electrolytic grinding technology emerged. Electrolytic grinding is a composite machining method that organically combines electrochemical machining with mechanical grinding, demonstrating significant advantages, particularly in the precision manufacturing of difficult-to-grind materials. This technology generates a soft passivation film on the workpiece surface through electrochemical action, which is then effectively removed using mechanical grinding. This electrochemical-mechanical synergy not only significantly reduces grinding wheel wear but also improves machining efficiency and workpiece surface quality. For example, Sikorsky Aircraft in the United States successfully used electrolytic grinding technology to achieve precision machining of complex gears, greatly improving machining accuracy and economy; Manfred G. Becker in Germany developed electrolytic micro-machining technology that achieves high-precision, deformation-free fine machining; and Tridex Technology's electrolytic point grinding system has been successfully applied to the manufacture of precision needle tips for medical devices. These successful industrial cases fully demonstrate the significant advantages and broad application prospects of electrolytic grinding technology in overcoming the challenges of machining high-hardness, difficult-to-machine materials.

[0004] However, the effectiveness of electrolytic grinding is influenced by numerous factors, including cathode structure design, EDM parameters (voltage, current, electrode gap), workpiece material properties (such as electrical conductivity, chemical stability, and mechanical properties), mechanical grinding parameters (grinding wheel speed, grinding pressure), processing environment stability (machine tool vibration, temperature fluctuations), and the composition and ratio of the electrolyte. Among these, the electrolyte is one of the key factors for the success of electrolytic grinding. Optimizing the composition and ratio of the electrolyte can effectively improve machining accuracy and surface quality, increase production efficiency, and reduce processing costs.

[0005] However, there is currently a lack of clear theoretical guidance for the formulation of electrolytic grinding electrolytes specifically for certain materials (such as 9Cr18Mo), and most cases still rely on electrochemical experiments for screening and optimization. This method has significant limitations: First, most electrochemical polarization experiments are conducted in a static electrolyte environment, which differs significantly from the dynamic flow of the electrolyte during actual electrolytic grinding, making it difficult for experimental results to accurately reflect the actual processing conditions. Second, some electrolytes (such as Na2SO4) are susceptible to temperature-induced crystallization, further reducing the accuracy of the measurement data. Additionally, some electrochemical experimental setups lack strict temperature control, causing fluctuations in the electrolyte concentration gradient, making it impossible for experimental data to accurately reflect the optimal electrolyte concentration range in actual processing. Furthermore, some existing studies directly use conventional electrolytes for processing experiments, neglecting the importance of optimizing the electrolyte for specific materials, thus making it difficult to ensure optimal processing results.

[0006] For electrolytic grinding of 9Cr18Mo bearing steel, special consideration must be given to the formation and stability of the surface passivation film resulting from the material's high strength and excellent corrosion resistance. Traditional acidic or alkaline electrolytes are unable to provide a stable equilibrium environment between corrosion and passivation, easily causing damage to the passivation film structure on the workpiece surface, thereby reducing machining accuracy and surface quality. Furthermore, acidic and alkaline electrolytes are corrosive to equipment, while neutral electrolytes can mitigate this problem to some extent.

[0007] Therefore, the development of a high-performance neutral electrolyte specifically for 9Cr18Mo bearing steel is of great practical significance. Summary of the Invention

[0008] The purpose of this invention is to provide an electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel and a method for determining its formulation. This invention effectively solves the aforementioned problems and significantly improves the processing efficiency and surface quality of 9Cr18Mo bearing steel, while extending the service life of the grinding wheel. This achievement will not only further promote the application of 9Cr18Mo steel in the field of precision bearing manufacturing, but also provide important theoretical basis and practical guidance for the electrolytic grinding process of other difficult-to-grind materials, possessing broad promotion and application value.

[0009] The technical solution of the present invention is an electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, the specific composition and mass percentage content of which are: sodium nitrate 2wt.%-18wt.%, sodium sulfate 2wt.%-18wt.%, and deionized water 64wt.%-96wt.%.

[0010] The electrolyte for electrolytic grinding of 9Cr18Mo bearing steel mentioned above has the following specific composition and mass percentage content: sodium nitrate 14.356 wt.%, sodium sulfate 7.841 wt.%, and deionized water 77.803 wt.%.

[0011] A method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel.

[0012] Step 1: First, an electrochemical experiment was conducted to determine that the composite electrolyte consisted of sodium nitrate and sodium sulfate;

[0013] Step 2: Then, based on the uniform design method, the electrolytic grinding experiment was systematically planned, and the effects of changes in sodium nitrate and sodium sulfate concentrations on the processing performance of 9Cr18Mo bearing steel were comprehensively investigated. By analyzing the experimental data, a stepwise linear multiple regression model was constructed between the concentrations of the two electrolytes and the key process response indicators—material removal rate and surface roughness—to reveal the primary and secondary influence relationships of each factor on processing performance.

[0014] Step 3: The WOA-GA intelligent optimization model, constructed by fusing the whale optimization algorithm and the genetic algorithm, is used to optimize the parameters of the regression model and finally obtain a set of electrolyte composition ratios that can achieve optimal process performance while taking into account both processing efficiency and surface quality.

[0015] In the aforementioned method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel, step one specifically involves: selecting neutral electrolytes NaH2PO4·2H2O, Na2HPO4·12H2O, Na2SO4, NaNO3, NaClO3, Na2CO3, and NaCl; eliminating electrolytes with insignificant effects by performing linear sweep voltammetry experiments on the above electrolytes, each with a concentration of 10%; then combining the remaining electrolytes in pairs and performing linear sweep voltammetry and constant potential experiments on the composite electrolytes to determine the optimal electrolyte combination.

[0016] In the aforementioned method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel, steps two and three are specifically as follows: First, an electrolytic grinding experiment of 9Cr18Mo bearing steel is carried out according to the uniform design method, and the material removal rate y1 and surface roughness y2 are collected as response indicators. Then, a multiple regression model between the concentrations of sodium nitrate and sodium sulfate and the material removal rate y1 and surface roughness y2 is constructed using SPSS software. The WOA-GA intelligent optimization model, which is constructed by fusing the whale optimization algorithm and the genetic algorithm, is used to optimize the parameters of the established multiple regression model. Finally, a set of electrolyte composition ratios that can achieve optimal process performance under the premise of balancing processing efficiency and surface quality is obtained.

[0017] In the aforementioned method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel, the multiple regression model is:

[0018]

[0019] In the formula, x1 represents the concentration of sodium nitrate and x2 represents the concentration of sodium sulfate.

[0020] The beneficial effects of the present invention: Compared with the prior art, the present invention has the following obvious advantages:

[0021] (1) This study only requires basic electrochemical experiments (open circuit potential experiment, linear sweep voltammetry experiment, and constant potential experiment) to obtain basic data suitable for the selection of electrolytes for 9Cr18Mo bearing steel and other metallic materials. Based on this, a mathematical regression model is constructed using electrolytic grinding experimental data, and an advanced intelligent hybrid algorithm is used for optimization, which can achieve efficient and accurate optimization of the electrolyte composition ratio, and the results are more scientific and convincing.

[0022] (2) The electrolyte used in this invention is neutral, which not only avoids the damage to machine tool equipment caused by acid and alkali corrosion, but also the chemical reagents used are easy to purchase, economical, and easy to prepare; the ion loss during the electrochemical processing is negligible, and the electrolyte can be recycled and reused, effectively reducing production costs.

[0023] (3) The electrolyte of the present invention can generate a uniform and dense passivation film on the surface of 9Cr18Mo bearing steel. Compared with the substrate material, the passivation film has lower hardness and elastic modulus, and is therefore easier to remove by mechanical grinding. At the same time, the passivation film can significantly reduce the uneven corrosion phenomenon on the workpiece surface and greatly improve the surface quality of the workpiece after processing. Attached Figure Description

[0024] Figure 1 Linear sweep voltammetry curves for a single electrolyte;

[0025] Figure 2 The figure shows the electrochemical experimental results of the composite electrolyte. In the figure, a-linear scan voltammetry experiment, b-potential constant experiment (1-NaNO3+Na2SO4; 2-Na2SO4+NaClO3; 3-Na2SO4+Na2CO3; 4-NaNO3+NaClO3; 5-NaNO3+Na2CO3; 6-NaClO3+Na2CO3).

[0026] Figure 3 The open-circuit potentials of 9Cr18Mo bearing steel in sodium nitrate and sodium sulfate solutions, respectively;

[0027] Figure 4The anodic polarization curves of 9Cr18Mo bearing steel in a preferred electrolyte composition (14.356 wt.% sodium nitrate, 7.841 wt.% sodium sulfate, and 77.803 wt.% deionized water) are shown.

[0028] Figure 5 The microstructure of the passivation film of 9Cr18Mo bearing steel after electrolytic corrosion in a preferred composition electrolyte.

[0029] Figure 6 The surface microstructure of 9Cr18Mo bearing steel after electrolytic corrosion in a preferred composition electrolyte;

[0030] Figure 7 The microstructure of the surface of a 9Cr18Mo bearing after electrochemical machining and mechanical grinding. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0032] Example 1 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 10 wt.%, sodium sulfate 10 wt.%, and deionized water 80 wt.%.

[0033] Example 2 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 2 wt.%, sodium sulfate 8 wt.%, and deionized water 90 wt.%.

[0034] Example 3 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 14 wt.%, sodium sulfate 16 wt.%, and deionized water 70 wt.%.

[0035] Example 4 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 4 wt.%, sodium sulfate 14 wt.%, and deionized water 82 wt.%.

[0036] Example 5 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 6 wt.%, sodium sulfate 4 wt.%, and deionized water 90 wt.%.

[0037] Example 6 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 18wt.%, sodium sulfate 12wt.%, and deionized water 70wt.%.

[0038] Example 7 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 16wt.%, sodium sulfate 6wt.%, and deionized water 78wt.%.

[0039] Example 8 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 12wt.%, sodium sulfate 2wt.%, and deionized water 86wt.%.

[0040] Example 9 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that its specific composition and mass percentage content are: sodium nitrate 8 wt.%, sodium sulfate 18 wt.%, and deionized water 74 wt.%.

[0041] Example 10 of the present invention: An electrolyte suitable for electrolytic grinding of 9Cr18Mo bearing steel, the specific composition and mass percentage content are: sodium nitrate 14.356 wt.%, sodium sulfate 7.841 wt.%, deionized water 77.803 wt.%.

[0042] The above embodiments describe the method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel:

[0043] Step 1: First, an electrochemical experiment was conducted to determine that the composite electrolyte consisted of sodium nitrate and sodium sulfate;

[0044] Step Two: Then, based on the uniform design method, the electrolytic grinding experiment was systematically planned to reduce the number of experiments, improve experimental efficiency, and comprehensively investigate the effects of changes in sodium nitrate and sodium sulfate concentrations on the machinability of 9Cr18Mo bearing steel. Through analysis of the experimental data, a stepwise linear multiple regression model was constructed between the concentrations of the two electrolytes and the key process response indicators—material removal rate (MRR) and surface roughness (Ra)—to reveal the primary and secondary influence relationships of each factor on machinability.

[0045] Step 3: To achieve multi-objective optimization design of the electrolyte components, a WOA-GA intelligent optimization model, constructed by fusing the whale optimization algorithm and a genetic algorithm, was used to optimize the parameters of the regression model. This resulted in an electrolyte composition ratio that achieves optimal process performance while balancing processing efficiency and surface quality. The optimized formula is: sodium nitrate 14.356 wt.%, sodium sulfate 7.841 wt.%, and deionized water 77.803 wt.%.

[0046] Step one specifically involves the following: Since acidic and alkaline electrolytes are highly corrosive to processing equipment (such as grinding machines), neutral electrolytes are the preferred choice for electrolytic grinding of metal materials. Commonly used neutral electrolytes include Na₂SO₄, NaNO₃, NaClO₃, Na₂CO₃, and NaCl. Linear sweep voltammetry experiments (e.g., [missing information]) were performed on electrolytes with a concentration of 10% at each concentration. Figure 1 As shown in the figure, it was found that NaCl is not suitable for 9Cr18Mo bearing steel, and the black passivation film formed by it falls off directly. Since single-component electrolytes are difficult to effectively form passivation films, previous studies have shown that composite electrolytes, due to the synergistic effect between their components, can efficiently form and stably maintain the surface passivation film. Based on this, the screened electrolyte components were combined in pairs, and linear sweep voltammetry and potentiostatic experiments were used to finally determine the composite electrolyte combination with the best performance. Further, the remaining four electrolytes were combined in pairs, and linear sweep voltammetry experiments were conducted using the composite electrolytes (e.g., ...). Figure 1 (as shown) and constant potential experiments (such as) Figure 2 As shown in the figure, the results indicate that the passivation films formed by groups a1 (NaNO3+Na2SO4) and b1 (NaNO3+Na2SO4) are the densest and darkest in color, demonstrating significant effects. Therefore, NaNO3+Na2SO4 was ultimately determined to be the optimal electrolyte combination for electrolytic grinding of 9Cr18Mo bearing steel.

[0047] According to relevant literature, the commonly used electrolyte concentrations in electrolytic grinding are mainly concentrated at 10%, 15%, and 20%. Lower electrolyte concentrations are not conducive to achieving higher material removal rates, while higher concentrations may lead to increased workpiece surface roughness. Furthermore, excessively high electrolyte concentrations may cause solution saturation, resulting in incomplete electrolyte dissolution. Based on this, the ratio of sodium nitrate to sodium sulfate is selected to be between 2 wt.% and 18 wt.%.

[0048] Step 2: In the linear scanning voltammetric experiment and constant potential electrochemical test of the composite electrolyte, although 10wt.% NaNO3 and 10wt.% Na2SO4 showed better performance than other electrolytes and could generate a passivation film visible to the naked eye, it was still insufficient to determine that it was the optimal concentration combination. In order to further optimize the electrolyte formulation, the uniform design method was introduced to carry out electrolytic grinding experiments based on the above, and combined with the genetic algorithm, the optimal electrolyte concentration ratio suitable for electrolytic grinding of 9Cr18Mo bearing steel was systematically explored. Specifically, the electrolytic grinding experiment of 9Cr18Mo bearing steel was carried out according to the uniform design method (as shown in Table 1), and the material removal rate y1 (MRR) and surface roughness y2 (Ra) were collected as response indicators. The experimental data are shown in Table 1. Subsequently, the SPSS software was used to construct a multiple regression model between concentration and material removal rate and surface roughness (as shown in Equation (1)), and the WOA-GA intelligent optimization model constructed by the fusion of whale optimization algorithm and genetic algorithm was used to optimize the parameters of the established regression model. Ultimately, an electrolyte composition ratio was obtained that achieves optimal process performance while balancing processing efficiency and surface quality.

[0049] Table 1. Experimental design and results of electrolyte composition for 9Cr18Mo bearing steel.

[0050]

[0051]

[0052] To verify the effectiveness of the electrolyte composition ratio determined by the above method for optimal process performance, the following experiment was conducted:

[0053] Specific steps for implementing the experiment:

[0054] (1) Cut 9Cr18Mo bearing steel into 5mm×5mm×5mm cubic samples. Use different grit sandpaper (400#, 800#, 1200#, 1500#, 2000#) to gradually polish the sample surface until it is bright. After thoroughly cleaning with deionized water, spray 0.5μm diamond spray polishing agent on the sample surface and polish with polishing cloth. Then, use petroleum ether and anhydrous ethanol to degrease and ultrasonically clean the sample. Finally, vacuum pack it for later use.

[0055] (2) A three-electrode electrochemical testing system was used to measure the open-circuit potential of the above samples in electrolytes with different components and contents. Specifically, the sample processed in step one was used as the anode in the electrochemical experiment, a 15mm×15mm platinum sheet was used as the auxiliary electrode, and a KCl-saturated Ag / AgCl electrode was used as the reference electrode. The electrolyte temperature was strictly controlled within the range of 25±1℃ using an intelligent thermostat. The scanning time for each point was set to 1s, and the total measurement time was 7200s. The experimental results for sodium nitrate and sodium sulfate are as follows: Figure 3 As shown in the figure, in the initial stage of the experiment, the open-circuit potential of the steel in both electrolytes showed a rapid decreasing trend, indicating that a relatively violent electrochemical reaction occurred on the material surface in the early stage (such as the dissolution of the passivation film on the material surface or the rapid activation of the metal matrix), indicating that the steel has a high initial reaction sensitivity to both electrolyte environments. As time went by, the open-circuit potential tended to stabilize, indicating that the material surface gradually reached a dynamic equilibrium state. In Na2SO4, the open-circuit potential stabilized at a low level (about -445mV), indicating that the formation or stability of the passivation film on the steel surface was poor, and the material remained in a highly active state, which was not conducive to the formation of a dense protective film. In contrast, in NaNO3 solution, the open-circuit potential stabilized at a higher level (about -262mV), indicating that 9Cr18Mo bearing steel was more likely to form a relatively stable and dense oxide passivation film in this electrolyte environment, keeping the potential in a more positive range. This higher stable potential usually means that the surface has better electrochemical stability, which is conducive to achieving the desired surface passivation effect during electrolytic grinding. Therefore, from the perspective of electrolytic grinding process, NaNO3 electrolyte is more favorable for the formation of surface passivation film on 9Cr18Mo bearing steel, which helps to form a dense and stable passivation film and effectively improves the quality and corrosion resistance of the ground surface; while Na2SO4 environment may produce a poor surface passivation state and increase the electrochemical corrosion sensitivity of the ground surface.

[0056] (3) Using the electrolyte prepared above, electrochemical experiments were conducted in a three-electrode system to measure anodic open-circuit potential, anodic polarization, and constant potential. The polarization curves of the sample in different electrolytes were measured using a linear scanning voltammetry method in the three-electrode system. The voltage scan range was set to -0.5V to 3V, and the scan rate was 0.01V / s. The measurement results of the preferred electrolyte composition are shown below. Figure 4 The linear sweep voltammetry curve clearly shows that in a Na₂SO₄ and NaNO₃ composite electrolyte environment, 9Cr18Mo bearing steel forms a highly stable passivation film in the range of -0.5V to 1.5V (vs Ag / AgCl), while maintaining an extremely low current density (approximately 0.1 mA / cm²). 2 The passivation region is as wide as approximately 2.0V, and the electrochemical performance is stable and reliable. The breakdown potential of the passivation film clearly occurs at approximately 2.0V, and the current increases sharply to several hundred mA / cm² after breakdown.2 This composite electrolyte exhibits a very well-defined critical point. Therefore, it provides a clear and broad processing potential window (approximately 1.0V-1.8V recommended range), meeting the requirements for precise control and high-quality surface finish in electrolytic grinding processes. In summary, this composite electrolyte demonstrates significantly superior electrochemical performance compared to single electrolytes, showing great promise for practical applications and warranting further process optimization and in-depth research.

[0057] (4) The corrosion behavior of the samples under different electrolyte compositions was observed through electrochemical corrosion experiments. The anodic open-circuit potential and polarization characteristics obtained from the electrochemical corrosion experiments were analyzed, and the microstructure of the 9Cr18Mo bearing steel sample surface after electrochemical corrosion was analyzed by microscopic observation. The power supply parameters were set as follows: DC high-frequency 10V, power supply duty cycle 50%, frequency 10kHz, inter-electrode gap 0.8mm, and corrosion time 1min. The experiment showed that in the optimized electrolyte composition, a thick and uniform passivation film could be formed on the surface of 9Cr18Mo bearing steel, and the passivation effect was significant. Figure 5 and Figure 6 ).

[0058] (5) After electrolytic grinding with an optimized electrolyte, the surface of the 9Cr18Mo bearing achieves higher surface precision and a better microstructure, such as... Figure 7 As shown.

Claims

1. A method for determining the electrolyte scheme suitable for electrolytic grinding of 9Cr18Mo bearing steel, characterized in that: Step 1: First, an electrochemical experiment was conducted to determine that the composite electrolyte consisted of sodium nitrate and sodium sulfate; Step 2: Then, based on the uniform design method, the electrolytic grinding experiment was systematically planned, and the effects of changes in sodium nitrate and sodium sulfate concentrations on the processing performance of 9Cr18Mo bearing steel were comprehensively investigated. By analyzing the experimental data, a stepwise linear multiple regression model was constructed between the concentrations of the two electrolytes and the key process response indicators—material removal rate and surface roughness—to reveal the primary and secondary influence relationships of each factor on processing performance. Step 3: The WOA-GA intelligent optimization model, constructed by fusing the whale optimization algorithm and the genetic algorithm, is used to optimize the parameters of the regression model and finally obtain a set of electrolyte composition ratios that can achieve optimal process performance while taking into account both processing efficiency and surface quality.

2. The method for determining the electrolyte scheme for electrolytic grinding of 9Cr18Mo bearing steel according to claim 1, characterized in that: Step one specifically involves selecting neutral electrolytes Na2SO4, NaNO3, NaClO3, Na2CO3, and NaCl. A linear sweep voltammetry experiment is performed on each of these electrolytes (all at a concentration of 10%) to eliminate electrolytes with insignificant effects. The remaining electrolytes are then combined in pairs, and a linear sweep voltammetry and potentiostatic experiment are conducted using these composite electrolytes to determine the optimal electrolyte combination.

3. The method for determining the electrolyte scheme for electrolytic grinding of 9Cr18Mo bearing steel according to claim 1, characterized in that: Steps two and three are as follows: First, an electrolytic grinding experiment of 9Cr18Mo bearing steel is carried out according to the uniform design method, and the material removal rate y1 and surface roughness y2 are collected as response indicators. Then, a multiple regression model between the concentrations of sodium nitrate and sodium sulfate and the material removal rate y1 and surface roughness y2 is constructed using SPSS software. The WOA-GA intelligent optimization model, which is constructed by fusing the whale optimization algorithm and the genetic algorithm, is used to optimize the parameters of the established multiple regression model. Finally, a set of electrolyte composition ratios that can achieve the optimal process performance under the premise of balancing processing efficiency and surface quality is obtained.

4. The method for determining the electrolyte scheme for electrolytic grinding of 9Cr18Mo bearing steel according to claim 3, characterized in that: The multiple regression model is as follows: (1), where x1 represents the concentration of sodium nitrate and x2 represents the concentration of sodium sulfate.

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