High-precision control method for stainless steel casting

Abstract

The invention relates to the technical field of precision casting, and discloses a high-precision control method for stainless steel castings, which comprises the following steps: preparing raw materials, recording component characteristics of the raw materials, designing a formula proportion of the raw materials, carrying out pouring process design, and setting a parameter control system in each link of pouring, according to the shape of the needed stainless steel casting, mold design and manufacturing and mold quality control are carried out, grinding tool design parameters are recorded, a stainless steel casting solidification process simulation model is established according to raw material component characteristics, a raw material formula proportion, a designed pouring process and the mold design parameters, and the casting solidification process is simulated in the model. The method comprises the following steps: predicting a defect area in a casting production process, carrying out advanced prevention and optimization treatment on the defect area according to the predicted defect area in the casting production process, strengthening a refining degassing operation in a casting process, further carrying out a metal solution purification step after refining degassing, and demolding the casting, and the mold is cleaned, checked and maintained in time.

Description

Technical Field

[0001] The present invention relates to the technical field of precision casting, and particularly to a method for high-precision control of stainless steel castings. Background Art

[0002] In the production process of stainless steel castings, shrinkage cavities and sand holes and other porosity defects are key factors affecting the quality of castings. These defects not only reduce the structural strength of the castings, but also cause cracks or fractures in the castings during use, thus seriously affecting their service life and safety. Therefore, predicting and controlling shrinkage cavities and sand hole porosity defects is an important means to improve the precision of stainless steel castings.

[0003] A shrinkage cavity refers to a spherical or elliptical pit formed inside the casting due to volume shrinkage during the solidification of stainless steel. This defect usually occurs in the last solidified area of the casting, especially in parts with a large wall thickness or poor heat dissipation conditions. The formation of shrinkage cavities is closely related to insufficient feeding of the molten metal. When the casting solidifies, the liquid metal cannot be fully replenished to the solidified area, resulting in the formation of cavities.

[0004] A sand hole refers to a depression or hole on the surface or inside of the casting, mainly caused by reasons such as sand core shrinkage marks and poor gas discharge. During the casting process, if the molding sand contains gas-generating substances, or the gas cannot be discharged in time before the molten metal enters the cavity, sand holes may be formed. In addition, insufficient strength or damage of the sand core will also cause the molten metal to penetrate into the sand core, forming sand eyes. Summary of the Invention

[0005] (I) Technical Problems to be Solved

[0006] In view of the deficiencies of the prior art, the present invention provides a method for high-precision control of stainless steel castings, which has the advantages of early prediction and precision improvement, and solves the problem of being unable to predict and control shrinkage cavities and sand hole porosity defects in the production process of stainless steel castings in advance.

[0007] (II) Technical Solutions

[0008] To achieve the above object, the present invention provides the following technical solution: A method for high-precision control of stainless steel castings, comprising the following steps:

[0009] Step 1. Raw material control: Prepare raw materials, record the composition characteristics of the raw materials, and design the raw material formula ratio;

[0010] Step 2. Design the pouring process and control system: Design the pouring process, and at the same time set up a parameter control system for each link of pouring;

[0011] Step 3. Mold parameter control: Design and manufacture the mold according to the shape of the required stainless steel casting, control the mold quality, and record the mold design parameters;

[0012] Step 4. Simulation of the casting solidification process and defect prediction: Establish a simulation model of the stainless steel casting solidification process based on the raw material composition characteristics, raw material formula ratio, designed gating system, and mold design parameters. Simulate the casting solidification process in the model to predict the defect areas during the casting production process;

[0013] Step 5. Casting production process: According to the predicted defect areas during the casting production process, take preventive and optimization measures for the defect areas in advance;

[0014] Step 6. Refining and degassing: During the casting process, strengthen the refining and degassing operations;

[0015] Step 7. Metal solution purification: After refining and degassing, further implement the metal solution purification step;

[0016] Step 8. Mold maintenance and servicing: After the casting is formed and cooled for 3 - 5 hours, after the casting is demolded, clean, inspect, and maintain the mold in a timely manner.

[0017] Preferably, the raw material formula of the stainless steel casting is: 60 - 72 parts by mass of carbon steel; 8 - 10 parts by mass of chromium; 5 - 7 parts by mass of nickel; 1 - 3 parts by mass of copper; 0.009 - 0.02 parts by mass of titanium; 1.5 - 2.3 parts by mass of silicon powder.

[0018] Preferably, the gating system design in Step 2 includes: According to the shape, size, and wall thickness of the required stainless steel casting, plan the sprue layout and pouring speed curve, and set up a parameter control system in each link of the casting to monitor the pouring temperature, pressure, and flow rate parameters in real time. When the monitored parameters deviate from the preset range, it can immediately adjust automatically or issue an alarm.

[0019] Preferably, the mold design parameters in Step 3 include: parting surface position, draft angle, and cooling water channel layout.

[0020] Preferably, the model in Step 4 includes: Simulate the effects of heat conduction, convection, and latent heat release during solidification on the casting solidification process in the model to predict the defect areas during the casting production process. At the same time, combine the effects that will be generated by the raw material composition characteristics, raw material formula ratio, designed gating system, and mold design parameters to judge the positions where shrinkage cavities and sand hole porosity will appear in the existing preparation process.

[0021] Preferably, the casting production process in Step 5 is as follows: After adding carbon steel, chromium, nickel, copper, titanium and silicon powder of the raw material formula into the melting furnace, initially control the melting temperature between 1400 - 1500 °C, and then combine with the parts predicted to have shrinkage cavities in the casting production process in Step 4, adjust the feeding channel of the gating system to between 10 - 25 mm, increase the riser size to between 50 - 100 mm or add chill blocks to adjust the temperature field distribution of the casting, so that the finally controlled melting temperature is between 1500 - 1600 °C. After melting is completed, prepare for ladle vacuuming.

[0022] Preferably, the refining and degassing process in Step 6 is as follows: Perform vacuum treatment on the ladle, then purge the ladle with nitrogen with a content of more than 99%, control the ladle vacuum degree between 15 - 30 Pa, control the gas flow rate between 10 - 15 m 3 / h, and control the purging time between 30 - 45 min.

[0023] Preferably, the metal solution purification process in Step 7 is as follows: After refining and degassing, combine the ceramic filtration technology with the electromagnetic stirring technology, optimize the pore size parameter of the ceramic filter to 10 - 15 μm and the layer number parameter to 4 - 6 layers. Input the optimized pore size and layer number parameters into the control interface of the ceramic filter, pass the metal solution through the ceramic filter, set the frequency parameter of electromagnetic stirring to 50 - 100 Hz and the intensity parameter to 0.5 - 1.5 T during the metal solution filtration process, stir and filter the molten steel simultaneously. When the inclusion content of the molten steel is finally lower than 0.008%, it enters the mold for shaping.

[0024] Preferably, for the maintenance and upkeep of the mold in Step 8: After the casting is formed and cooled for 3 - 5 h, after the casting is demolded, clean, inspect and maintain the mold, repair and polish the worn parts, and perform rust prevention treatment on the mold regularly.

[0025] Preferably, the finished product dimensional tolerance of the stainless steel casting is controlled within ±0.08 mm, and the surface roughness is controlled within Ra0.65 μm.

[0026] Compared with the prior art, the present invention provides a high-precision control method for stainless steel castings, having the following beneficial effects:

[0027] 1. The present invention optimizes the feeding channels and riser sizes to make them larger, so as to more effectively compensate for the shrinkage of the casting during solidification, reduce the occurrence of shrinkage cavity defects, improve the density and structural integrity of the casting. At the same time, according to the parts where shrinkage cavities will occur predicted by the model and combined with the real-time monitoring equipment for each link, the melting temperature during the casting production process is maintained between 1500 - 1600 °C, which helps the full melting of the metal solution and homogenizes the raw material components to ensure that the components in the raw materials can be fully mixed, thus avoiding casting quality problems caused by insufficient melting. By controlling the ladle vacuum degree between 15 - 30 Pa, the gases in the metal solution can be more effectively removed, reducing the formation of porosity defects, further enhancing the density of the casting, making it more wear-resistant and impact-resistant during use, and thus improving the overall precision of the casting.

[0028] 2. The present invention adopts a composite purification technology combining a ceramic filter and electromagnetic stirring, which can thoroughly remove non-metallic inclusions in the metal solution to improve the purity of the solution. This composite purification technology can give full play to the advantages of the two technologies. The ceramic filter intercepts larger inclusions through its pore structure, while electromagnetic stirring makes fine inclusions migrate and separate through the generated electromagnetic force. Finally, the inclusion content in the molten steel is lower than 0.008%. The casting formed during the solidification of the metal solution purified by this method has a more uniform and fine internal structure and a more dense grain structure, which helps to improve the tensile strength, yield strength and toughness of the casting, enabling it to withstand greater loads and stresses. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flowchart of the steps of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figure 1 , a high-precision control method for stainless steel castings, comprising the following steps:

[0032] Step 1. Raw material control: Prepare raw materials, record the component characteristics of the raw materials, and design the raw material formula ratio;

[0033] Step 2. Design the pouring process and control system: Design the pouring process, and at the same time set up a parameter control system for each link of pouring;

[0034] Step 3. Mold parameter control: Design and manufacture the mold according to the shape of the required stainless steel casting, control the mold quality, and record the mold design parameters;

[0035] Step 4. Simulation of the casting solidification process and defect prediction: Establish a simulation model of the stainless steel casting solidification process based on the raw material composition characteristics, raw material formula ratio, designed gating system, and mold design parameters. Simulate the casting solidification process in the model to predict the defect areas during the casting production process;

[0036] Step 5. Casting production process: According to the predicted defect areas during the casting production process, take preventive and optimization measures in advance for the defect areas to avoid shrinkage cavities and sand hole porosity defects;

[0037] Step 6. Refining and degassing: During the casting process, strengthen the refining and degassing operations;

[0038] Step 7. Metal solution purification: After refining and degassing, further implement the metal solution purification step;

[0039] Step 8. Maintenance and servicing of the mold: After the casting is formed and cooled for 3 - 5 hours, after the casting is demolded, clean, inspect, and maintain the mold in a timely manner.

[0040] Specifically, the raw material formula of the stainless steel casting is: 60 - 72 parts by mass of carbon steel; 8 - 10 parts by mass of chromium; 5 - 7 parts by mass of nickel; 1 - 3 parts by mass of copper; 0.009 - 0.02 parts by mass of titanium; 1.5 - 2.3 parts by mass of silica powder.

[0041] Specifically, the gating system design in Step 2 includes: According to the shape, size, and wall thickness of the required stainless steel casting, plan the gating layout and pouring speed curve, and set up a parameter control system at each link of the casting to monitor the pouring temperature, pressure, and flow rate parameters in real time. When the monitored parameters deviate from the preset range, it can immediately adjust automatically or issue an alarm to ensure the stability and controllability of the pouring process. Through sensor technology and automation control software, realize the intelligent management of the pouring process.

[0042] Specifically, the mold design parameters in Step 3 include: parting surface position, draft angle, and cooling water channel layout, providing a basis for subsequent mold maintenance, improvement, and quality traceability.

[0043] Specifically, the model in Step 4 includes: simulating the effects of heat conduction, convection, and latent heat release during solidification on the solidification process of the casting to predict the defective areas during the casting production process. At the same time, considering the effects of raw material composition characteristics, raw material formula ratios, designed pouring processes, and mold design parameters, it is used to judge the positions and severity of shrinkage cavities and sand hole looseness in the existing preparation process, providing an intuitive visual reference for process optimization in advance.

[0044] Specifically, the casting production process in Step 5 is as follows: After adding carbon steel, chromium, nickel, copper, titanium, and silicon powder in the raw material formula to the melting furnace, initially control the melting temperature between 1400 - 1500 °C. Then, combined with the positions of shrinkage cavities predicted in Step 4 during the casting production process, adjust the feeding channel of the gating system to be between 10 - 25 mm, increase the riser size to be between 50 - 100 mm, or add chill blocks to adjust the temperature field distribution of the casting, so that the finally controlled melting temperature is between 1500 - 1600 °C. After melting is completed, prepare for ladle vacuum to avoid the problems of shrinkage cavities and sand hole looseness defects. At the same time, during the production process, operate according to the established process specifications in Step 2 to ensure the stability of parameters in each link, monitor the forming quality of the casting in real time, and finally enter the ladle link.

[0045] Specifically, the refining and degassing process in Step 6 is as follows: Vacuum-treat the ladle, then purge the ladle with nitrogen with a content of more than 99%. Control the ladle vacuum degree between 15 - 30 Pa, control the gas flow rate between 10 - 15 m 3 / h, and control the purging time between 30 - 45 min to effectively remove hydrogen and oxygen dissolved gases in the molten metal, further reduce the formation of pores, improve the density and strength of the casting. The composition changes of the molten metal are monitored throughout the refining process to ensure that the refining effect reaches the expected goal.

[0046] Specifically, the purification process of the metal solution in Step 7 is as follows: After refining and degassing, the ceramic filtration technology is combined with the electromagnetic stirring technology to further implement the metal solution purification step. The non-metallic inclusions in the metal solution are removed through the pore structure of the ceramic filter to improve the purity of the solution. The pore size parameter of the ceramic filter is optimized to be 10 - 15 μm (the pore size determines the interception ability of the filter for inclusions. A smaller pore size can effectively remove finer inclusions, but too small a pore size will also increase the filtration resistance. Therefore, a balance needs to be found between the filtration effect and the filtration resistance. The increase in the number of layers can improve the filtration efficiency, but it will also increase the filtration resistance and cost. The number of layers needs to be reasonably selected according to the actual production requirements), the number of layers parameter is 4 - 6 layers, and the optimized pore size and number of layers parameters are input into the ceramic filter control interface (to ensure that the filter can operate according to the set parameters in actual operation, so as to achieve the best filtration effect). The metal solution is passed through the ceramic filter (when the metal solution is passed through the ceramic filter, the non-metallic inclusions in the solution will be intercepted by the pore structure of the filter, thus achieving purification. During the filtration process, the flow rate of the solution needs to be controlled. Too fast a flow rate may cause the inclusions to penetrate the filter and reduce the purification effect). During the filtration of the metal solution, the frequency parameter of the electromagnetic stirring is set to 50 - 100 Hz, and the intensity parameter is 0.5 - 1.5 T (the increase in frequency can increase the number of times of the electromagnetic force action, which is helpful for the migration and separation of inclusions. The increase in intensity can enhance the electromagnetic force and more effectively promote the migration of inclusions). The molten steel is filtered while being stirred. Finally, when the inclusion content of the molten steel is lower than 0.008%, it enters the mold for forming;

[0047] The advantages are as follows: In actual operation, the ceramic filter is combined with the electromagnetic stirring technology. First, most of the non-metallic inclusions are removed through the ceramic filter, and then the electromagnetic stirring is used to further remove the fine inclusions. This composite purification technology can give full play to the advantages of the two methods, improve the purification efficiency and effect, and finally intercept the micro-inclusions to the greatest extent, laying a foundation for obtaining high-quality castings. The purified metal solution needs to be sampled and tested to ensure that the inclusion content is lower than 0.008% and meets the specified standards.

[0048] Specifically, for the maintenance and upkeep of the mold in Step 8: After the casting is formed and cooled for 3 - 5 h, after the casting is demolded, the mold is cleaned, inspected, and maintained to remove the residual casting materials, oxides and other impurities on the mold surface, check the wear condition of the mold, especially the key mating parts and the forming surface, repair and polish the worn parts to ensure that the mold can still maintain high precision and good demolding performance in the next production cycle, and perform anti-rust treatment on the mold regularly to extend the service life of the mold and reduce the production cost.

[0049] Specifically, the finished product dimensional tolerance of the stainless steel casting is controlled within ±0.08 mm, and the surface roughness is controlled within Ra0.65 μm.

[0050] A certain factory applied the raw material formula of the present invention, as well as the preparation process and high-precision control method, to Examples 1-3, and at the same time carried out Comparative Examples 1-3 of the corresponding traditional methods for comparison. The data are as follows:

[0051] Example 1

[0052] Raw material formula: 68 parts by mass of carbon steel, 9 parts by mass of chromium, 6 parts by mass of nickel, 2 parts by mass of copper, 0.015 parts by mass of titanium, and 2 parts by mass of silicon powder.

[0053] Parameter control of the preparation process:

[0054] Feeding channel of the gating system: 15 mm;

[0055] Riser size: 70 mm;

[0056] Melting temperature: 1550 °C;

[0057] Vacuum degree of refining and degassing: 20 Pa;

[0058] Purification of the metal solution: The pore diameter of the ceramic filter is 12 μm and the number of layers is 5 layers, the electromagnetic stirring frequency is 75 Hz and the intensity is 1 T.

[0059] Finished product parameters of the obtained stainless steel casting:

[0060] Dimensional tolerance: ±0.07 mm;

[0061] Surface roughness: Ra 0.6 μm.

[0062] Comparative Example 1

[0063] Raw material formula: 65 parts by mass of carbon steel, 8 parts by mass of chromium, 5 parts by mass of nickel, 1 part by mass of copper, 0.01 parts by mass of titanium, and 1.8 parts by mass of silicon powder.

[0064] Parameter control of the preparation process:

[0065] Feeding channel of the gating system: 8 mm;

[0066] Riser size: 40 mm;

[0067] Melting temperature: 1450 °C;

[0068] Vacuum degree of refining and degassing: 35 Pa;

[0069] Purification of the metal solution: Only use a ceramic filter with a pore diameter of 20 μm and 3 layers.

[0070] Finished product parameters of the obtained stainless steel casting:

[0071] Finished product dimensional tolerance: ±0.1 mm

[0072] Surface roughness: Ra 0.8 μm

[0073] Example 2

[0074] Raw material formula: 70 parts by mass of carbon steel, 9.5 parts by mass of chromium, 6.5 parts by mass of nickel, 2.5 parts by mass of copper, 0.018 parts by mass of titanium, 2.1 parts by mass of silicon powder.

[0075] Parameter control during the preparation process:

[0076] Feeding channel of the gating system: 20 mm;

[0077] Riser size: 90 mm;

[0078] Melting temperature: 1580 °C;

[0079] Vacuum degree of refining and degassing: 18 Pa;

[0080] Purification of the metal solution: The pore size of the ceramic filter is 14 μm and the number of layers is 6 layers, the electromagnetic stirring frequency is 90 Hz and the intensity is 1.2 T.

[0081] Finished product parameters of the obtained stainless steel casting:

[0082] Finished product dimensional tolerance: ±0.06 mm;

[0083] Surface roughness: Ra 0.55 μm.

[0084] Comparative example 2

[0085] Raw material formula: 63 parts by mass of carbon steel, 7.5 parts by mass of chromium, 4.5 parts by mass of nickel, 0.8 parts by mass of copper, 0.009 parts by mass of titanium, 1.6 parts by mass of silicon powder.

[0086] Parameter control during the preparation process:

[0087] Feeding channel of the gating system: 10 mm;

[0088] Riser size: 55 mm;

[0089] Melting temperature: 1420 °C;

[0090] Vacuum degree of refining and degassing: 40 Pa;

[0091] Purification of the metal solution: Only electromagnetic stirring is used, with a frequency of 60 Hz and an intensity of 0.8 T.

[0092] Finished product parameters of the obtained stainless steel casting:

[0093] Finished product dimensional tolerance: ±0.12 mm;

[0094] Surface roughness: Ra 0.9 μm;

[0095] Example 3

[0096] Raw material formula: 65 parts by mass of carbon steel, 8.5 parts by mass of chromium, 5.5 parts by mass of nickel, 1.8 parts by mass of copper, 0.012 parts by mass of titanium, 1.9 parts by mass of silicon powder.

[0097] Parameter control in the preparation process:

[0098] Feeding channel of gating system: 18 mm;

[0099] Riser size: 80 mm;

[0100] Melting temperature: 1520 °C;

[0101] Vacuum degree of refining and degassing: 22 Pa;

[0102] Purification of molten metal: Pore size of ceramic filter is 13 μm, number of layers is 5 layers, electromagnetic stirring frequency is 85 Hz, intensity is 1.1 T.

[0103] Finished product parameters of the obtained stainless steel casting:

[0104] Finished product dimensional tolerance: ±0.075 mm;

[0105] Surface roughness: Ra 0.62 μm.

[0106] Comparative example 3

[0107] Raw material formula: 60 parts by mass of carbon steel, 7 parts by mass of chromium, 4 parts by mass of nickel, 0.5 parts by mass of copper, 0.008 parts by mass of titanium, 1.5 parts by mass of silicon powder.

[0108] Parameter control in the preparation process:

[0109] Feeding channel of gating system: 6 mm;

[0110] Riser size: 45 mm;

[0111] Melting temperature: 1380 °C;

[0112] Vacuum degree of refining and degassing: 45 Pa;

[0113] Purification of molten metal: No purification measures.

[0114] Finished product parameters of the obtained stainless steel casting:

[0115] Finished product dimensional tolerance: ±0.15 mm;

[0116] Surface roughness: Ra 1.0 μm.

[0117] The comparative analysis between the examples and the comparative examples is as follows:

[0118] Raw material formula: In the raw material formulas of Examples 1-3 of the present invention, the proportions of carbon steel, chromium, nickel, copper, titanium and silicon powder are relatively high and more precise, which can better meet the performance requirements of stainless steel castings. However, the formula proportions of the traditional invention are lower and less precise, which will lead to unstable casting performance.

[0119] Parameter control in the preparation process: The feeding channels and riser sizes of the present invention are larger, which can more effectively compensate for the shrinkage of the casting during solidification and reduce the occurrence of shrinkage cavity defects. However, the sizes of the traditional invention are smaller and the feeding effect is poor; the melting temperature of the present invention is controlled between 1500-1600 °C, which is conducive to the full melting of the metal solution and the homogenization of the composition. However, the temperature of the traditional invention is lower, which will lead to insufficient melting and affect the quality of the casting; the vacuum degree of the present invention is controlled between 15-30 Pa, which can more effectively remove the gas in the metal solution and reduce the porosity defects. However, the vacuum degree of the traditional invention is higher and the degassing effect is poor; the present invention adopts a composite purification technology combining a ceramic filter and electromagnetic stirring, which can more thoroughly remove the inclusions in the metal solution and improve the purity of the solution. However, the purification measures of the traditional invention are single and the purification effect is poor.

[0120] Due to the above raw material formula and parameter control in the preparation process, the final finished product size tolerance and surface roughness of the present invention are controlled more strictly and can meet higher precision requirements. However, the raw material formula and parameter control in the preparation process of the traditional invention are not precise enough, resulting in larger tolerances and roughness, thus reducing the casting precision.

[0121] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-precision control method for stainless steel castings, characterized in that: The following steps are involved: Step 1: Raw material control: prepare raw materials, record raw material composition characteristics, and design raw material formula ratio; Step 2: Design the pouring process and control system: Design the pouring process and set up a parameter control system at every step of the pouring process; Step 3: Mold parameter control: Design and manufacture the mold according to the required shape of the stainless steel casting, control the mold quality, and record the mold design parameters; Step 4: Casting solidification process simulation and defect prediction: A stainless steel casting solidification process simulation model is established based on the raw material composition characteristics, raw material formula ratio, designed pouring process and mold design parameters. The casting solidification process is simulated in the model to predict the defect area in the casting production process; Step 5: Casting production process: Based on the predicted defect areas in the casting production process, prevent and optimize the defect areas in advance; Step 6: Refining and degassing: During the casting process, strengthen the refining and degassing operation; Step 7: Metal solution purification: After refining and degassing, the metal solution purification step is further performed; Step 8. Mold maintenance: After the casting is formed, cool it for 3-5 hours. After the casting is demoulded, clean, inspect and maintain the mold in time.

2. A high-precision control method for stainless steel castings according to claim 1, characterized in that: The raw material formula of the stainless steel casting is: 60-72 parts by mass of carbon steel; 8-10 parts by mass of chromium; 5-7 parts by mass of nickel; 1-3 parts by mass of copper; 0.009-0.02 parts by mass of titanium; and 1.5-2.3 parts by mass of silicon powder.

3. A high-precision control method for stainless steel castings according to claim 1, characterized in that: The pouring process design in step 2 includes: planning the runner layout and pouring speed curve according to the shape, size and wall thickness of the required stainless steel casting, and establishing a parameter control system at each link of the casting to monitor the pouring temperature, pressure and flow rate parameters in real time. When the parameters are detected to deviate from the preset range, they can be automatically adjusted or an alarm can be issued immediately.

4. A high-precision control method for stainless steel castings according to claim 1, characterized in that: The mold design parameters in step three include: parting surface position, demoulding slope and cooling water channel layout.

5. A high-precision control method for stainless steel castings according to claim 1, characterized in that: The model in step 4 includes: simulating the effects of heat conduction, convection, and latent heat release of solidification on the solidification process of the casting in the model to predict the defective areas in the casting production process, and combining the raw material composition characteristics, raw material formula ratio, designed casting process, and mold design parameters to determine the locations where shrinkage holes and sand hole looseness will appear in the existing preparation process.

6. A high-precision control method for stainless steel castings according to claim 1, characterized in that: The casting production process in step 5 is as follows: after adding carbon steel, chromium, nickel, copper, titanium and silicon powder of the raw material formula into the smelting furnace, the smelting temperature is initially controlled between 1400-1500° C., and then, based on the predicted location of shrinkage holes in the casting production process in step 4, the shrinkage feeding channel of the pouring system is adjusted to between 10-25 mm, the riser size is increased to between 50-100 mm or a chiller is added to adjust the temperature field distribution of the casting, so that the final controlled smelting temperature is between 1500-1600° C. After the smelting is completed, the ladle vacuum preparation is performed.

7. A high-precision control method for stainless steel castings according to claim 6, characterized in that: The refining and degassing process in step 6 is: subjecting the ladle to vacuum treatment, and then purging the ladle with nitrogen with a content of more than 99%, controlling the vacuum degree of the ladle between 15-30Pa, and controlling the gas flow rate between 10-15m 3 / h, and control the purge time between 30-45min.

8. A high-precision control method for stainless steel castings according to claim 7, characterized in that: The metal solution purification process in step seven is as follows: after refining and degassing, the ceramic filtration technology is combined with the electromagnetic stirring technology, the pore size parameter of the ceramic filter is optimized to be 10-15 μm, and the layer number parameter is 4-6 layers, the optimized pore size and layer number parameters are input into the ceramic filter control interface, the metal solution is passed through the ceramic filter, and the frequency parameter of the electromagnetic stirring is set to 50-100 Hz and the intensity parameter is set to 0.5-1.5 T during the filtration process of the metal solution, the molten steel is filtered while being stirred, and finally the molten steel enters the mold for forming when the inclusion content of the molten steel is less than 0.008%.

9. A high-precision control method for stainless steel castings according to claim 8, characterized in that: Maintenance and care of the mold in step eight: Cool the casting for 3-5 hours after molding, demould the casting, clean, inspect and maintain the mold, repair and polish the worn parts, and regularly perform rust prevention on the mold.

10. A high-precision control method for stainless steel castings according to claim 9, characterized in that: The finished product size tolerance of the stainless steel casting is controlled within ±0.08mm and the surface roughness is controlled within Ra0.65μm.

Images