Machine tool structural part casting machining method
By optimizing metal raw materials and process parameters, combining digital analog design and non-destructive testing, defects such as pores and sand holes in machine tool structural parts casting are solved, the quality and production efficiency of castings are improved, and the costs are reduced.
Patent Information
- Application Number
- CN202510473302.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-11
AI Technical Summary
There are defects such as pores and sand holes in the casting processing of existing machine tool structural parts, poor product consistency, difficult to accurately control process parameters, cumbersome processing processes, low production efficiency and high cost.
The optimization of metal raw material composition is adopted, combined with electromagnetic stirring and ultrasonic vibration treatment, and the mold is designed using digital simulation, vacuum low-pressure casting and rapid solidification composite process is implemented, thermal aging and vibration aging treatment is carried out, and non-destructive testing technology is combined to ensure the quality and dimensional accuracy of the castings.
It significantly reduces the internal defect rate of the casting, improves the degree of grain refinement and mechanical properties, improves the strength and toughness of the casting, shortens the machining time, reduces production costs and scrap rates, and enhances the reliability and production efficiency of machine tool structural parts.
Smart Images
Figure CN120286682A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of machine tool manufacturing, and particularly relates to a casting and processing method for machine tool structural parts. Background Art
[0002] In the machine tool manufacturing industry, machine tool structural parts, as the basic support and carrier of key operating components of machine tools, their quality directly affects the overall performance, accuracy retention, and service life of machine tools.
[0003] In the existing casting and processing methods for machine tool structural parts, defects such as pores and sand holes are likely to occur inside the castings, resulting in a reduction in the strength of the structural parts; it is difficult to precisely control the process parameters during the casting process, and the product consistency is poor; moreover, the processing procedures are cumbersome, the production efficiency is low, and the cost is relatively high. Therefore, an efficient and high-quality casting and processing method for machine tool structural parts is needed. Summary of the Invention
[0004] The purpose of the present invention is to solve the deficiencies existing in the prior art and propose a casting and processing method for machine tool structural parts.
[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A casting and processing method for machine tool structural parts, including the following steps: Raw material optimization and pretreatment step: Select high-quality metal raw materials within a specific composition range. For cast iron, select pig iron with low sulfur, low phosphorus, and a carbon equivalent controlled within 3.8% - 4.2%. Sulfur and phosphorus impurities will seriously deteriorate the mechanical properties of cast iron, reducing its toughness and strength, while an appropriate carbon equivalent plays a decisive role in the graphitization process and final microstructure of cast iron; at the initial stage of melting, a combined treatment of electromagnetic stirring and ultrasonic vibration is adopted. The electromagnetic stirring intensity is 50A - 100A, forming a corresponding magnetic field in the melting furnace to promote strong convection of the molten metal and achieve compositional homogenization. The ultrasonic vibration frequency is 20kHz - 30kHz. Utilize the cavitation effect and mechanical effect of ultrasound to break up gas bubbles and inclusion aggregates in the molten metal. The treatment duration is 15 - 20 minutes to remove gases and inclusions in the molten metal and significantly improve the purity of the molten metal; Mold design and manufacturing steps: Use digital simulation technology such as ProCAST software to simulate and analyze the casting process. Based on complex physical models and algorithms, this software can accurately predict the flow and solidification behavior of molten metal in the mold cavity, as well as the distribution of temperature and stress fields, and design an integrated mold with conformal cooling water channels accordingly; the mold is made of high-strength, high-thermal-conductivity hot-working die steel, such as H13 steel, that has undergone special heat treatment and has a hardness of HRC48-52; the special heat treatment process includes multiple processes such as quenching and tempering to optimize the internal structure of the steel, giving it excellent thermal fatigue performance, toughness and wear resistance; the mold is manufactured using a five-axis CNC machining center to ensure that the mold cavity size accuracy reaches ±0.03mm; Casting process steps: adopt vacuum low-pressure casting and rapid solidification composite process, inject the smelted molten metal into the mold cavity preheated to 300℃-400℃ at a low pressure of 0.03MPa-0.08MPa under a vacuum environment of 10-50Pa. The vacuum environment can reduce the solubility of gas in the molten metal and reduce the possibility of pore defects; low-pressure filling can control the flow rate of the molten metal, avoid turbulence and air entrainment, and ensure complete and accurate filling of complex-shaped structural parts; at the same time, a forced cooling device is set outside the mold to make the cooling rate of the casting surface reach 50℃ / s-100℃ / s. The rapid solidification process refines the casting grains. According to the solidification theory, rapid cooling increases the number of crystal cores and reduces the grain size, thereby significantly improving the mechanical properties of the casting, such as strength, hardness and toughness; Stress relief and dimensional accuracy control steps: After the casting solidifies, it is first subjected to heat aging treatment. The casting is heated to 500℃-600℃ and kept warm for 2-3 hours. During the heat aging process, the residual stress inside the casting gradually relaxes under the action of high temperature, and the organizational structure tends to be stable. Then, vibration aging equipment is used to vibrate for 30-60 minutes at a frequency of 20Hz-50Hz and an exciting force of 5kN-10kN. Vibration aging causes the casting to resonate, causing the internal microstructure to undergo plastic deformation, further reducing residual stress, and accurately controlling dimensional accuracy. The aging temperature, holding time, frequency and exciting force of vibration aging can be optimized and adjusted according to the material, shape and residual stress distribution of the casting. For large castings with complex structures and uneven residual stress distribution, such as large machine tool columns, the thermal aging temperature can be appropriately increased to 580℃-600℃, which is close to the upper limit, and the holding time can be extended to 2.5-3 hours. In the vibration aging process, according to the residual stress in different parts of the casting, the vibration frequency and exciting force are adjusted in a targeted manner. In the stress concentration area, a higher exciting force and appropriate frequency are used to promote full stress release and homogenization. Post - processing and quality inspection steps: The machined structural parts of the machine tool that have been cast and stress - relieved are subjected to surface shot peening to make the surface roughness reach Ra0.8 - Ra1.6μm. Non - destructive testing techniques such as X - ray flaw detection, ultrasonic flaw detection, and electronic speckle pattern interferometry are used to conduct a comprehensive quality inspection of the castings. X - ray flaw detection uses X - rays to penetrate the castings and detects internal defects based on the difference in the degree of X - ray absorption by different materials. Ultrasonic flaw detection emits and receives ultrasonic waves and judges the internal defect situation based on the propagation characteristics of the waves. Electronic speckle pattern interferometry is based on the principle of optical interference and conducts high - precision detection of surface deformation and defects of the castings.
[0006] As a further description of the above technical solution: In the raw material optimization and pretreatment steps, for different types of machine - tool structural parts, the specific composition range of pig iron or other metal raw materials can be adjusted accordingly according to their material requirements.
[0007] As a further description of the above technical solution: In the mold design and manufacturing steps, the path of the conformal cooling channels is designed individually according to the digital simulation results to adapt to different - shaped machine - tool structural parts and ensure uniform cooling of each part of the casting.
[0008] As a further description of the above technical solution: In the mold design and manufacturing steps, a ceramic coating with a thickness of 0.05 - 0.1mm, which has high temperature resistance and low friction coefficient, is coated on the mold surface. The coating materials are usually zirconia, alumina, etc. This coating is coated by advanced technologies such as plasma spraying or physical vapor deposition. It can effectively resist high - temperature erosion, extend the service life of the mold, reduce the friction force between the molten metal and the mold cavity wall during the filling process of the molten metal, reduce the surface roughness of the casting, and improve the surface quality of the casting.
[0009] As a further description of the above technical solution: After the stress relief and dimensional accuracy control steps, an additional dimensional accuracy re - measurement process is added. A high - precision laser measuring instrument is used to re - measure the key dimensions of the casting. If the dimensional deviation exceeds the IT6 - IT7 level accuracy range, a numerical control grinding machine is used for micro - grinding correction to ensure that the dimensional accuracy of the final product meets the requirements.
[0010] As a further description of the above technical solution: In the post - processing and quality inspection steps, the non - destructive testing techniques can be selected one or more in combination according to the specific requirements and quality standards of the machine - tool structural parts to ensure the comprehensiveness and accuracy of the inspection.
[0011] As a further description of the above technical solution: In the raw material optimization and pretreatment step, an intermediate frequency induction furnace with precise temperature control function is used as the melting equipment, and the temperature control accuracy can reach ±5°C, ensuring that the metal raw materials are always in a suitable and stable temperature environment during the melting process, providing high-quality molten metal for the subsequent casting process.
[0012] As a further description of the above technical solution: In the post-treatment and quality inspection step, the shot used for surface shot peening treatment is cast steel shot with a hardness of HRC40 - 50, and the diameter of the shot is between 0.5 - 1.5 mm. By adjusting the shot peening angle and shot peening speed of the shot peening equipment, uniform shot peening treatment of the surfaces of machine tool structural parts with different shapes is achieved. Shot peening causes plastic deformation on the surface, increasing the surface roughness to Ra0.8 - Ra1.6 μm, and enhancing the surface hardness and fatigue strength.
[0013] The present invention has the following beneficial effects: In the present invention, through raw material pretreatment, composite casting process, and strict post-treatment, the defect rates such as internal pores and sand holes in the casting are reduced to less than 0.5%, the grain size is refined by 30% - 50%, the tensile strength is increased by 25% - 35%, and the hardness is increased by 20% - 25%. This effectively improves the quality and reliability of the machine tool structural parts, enabling them to better meet the usage requirements of the machine tool under high-speed, high-precision, and high-load working conditions.
[0014] In the present invention, the innovative mold design and stress control method, combined with the size precision remeasurement and correction process, significantly improve the dimensional accuracy of the casting, reduce the subsequent machining allowance, and shorten the machining time by 40% - 50%. This not only improves the production efficiency, but also reduces the material waste and cost increase caused by machining, improves the economic benefits of the enterprise, and the improvement of production efficiency, reduction of scrap rate, and reduction of machining cost comprehensively reduce the production cost by 30% - 40%. Description of the Drawings
[0015] Figure 1 It is a flow block diagram of a casting and processing method for a machine tool structural part proposed by the present invention. Detailed Embodiments
[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the 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.
[0017] Refer to Figure 1, an embodiment provided by the present invention: A casting processing method for a machine tool structural part, comprising the following steps: Raw material optimization and pretreatment step: Select high-quality metal raw materials within a specific composition range. For cast iron, select pig iron with low sulfur, low phosphorus, and a carbon equivalent controlled between 3.8% and 4.2%. Sulfur and phosphorus impurities will seriously deteriorate the mechanical properties of cast iron, reducing its toughness and strength, while the appropriate carbon equivalent plays a decisive role in the graphitization process and final microstructure of cast iron; In the initial stage of melting, a combined treatment of electromagnetic stirring and ultrasonic vibration is adopted. The electromagnetic stirring intensity is 50A - 100A, the ultrasonic vibration frequency is 20kHz - 30kHz, and the treatment duration is 15 - 20 minutes to remove gases and inclusions in the molten metal. Mold design and manufacturing step: Use digital simulation technology such as ProCAST software to simulate and analyze the casting process. This software is based on complex physical models and algorithms, and can accurately predict the flow, solidification behavior, and temperature field and stress field distribution of the molten metal in the mold cavity. Based on this, design an integrated mold with conformal cooling channels; The mold is made of high-strength and high-thermal conductivity hot work die steel with a hardness of HRC48 - 52 after special heat treatment, such as H13 steel; The special heat treatment process includes multiple processes such as quenching and tempering, optimizing the internal microstructure of the steel, and enabling it to have excellent thermal fatigue performance, toughness, and wear resistance; The mold is manufactured by a five-axis linkage CNC machining center to ensure that the dimensional accuracy of the mold cavity reaches ±0.03mm. Casting process step: Adopt a composite process of vacuum low-pressure casting and rapid solidification. Inject the melted molten metal into the mold cavity preheated to 300℃ - 400℃ under a low pressure of 0.03MPa - 0.08MPa in an environment with a vacuum degree of 10 - 50Pa. The vacuum environment can reduce the solubility of gases in the molten metal and reduce the possibility of porosity defects; Low-pressure filling can control the flow rate of the molten metal, avoid turbulent flow and gas entrainment phenomena, and ensure the complete and accurate filling of complex-shaped structural parts; At the same time, a forced cooling device is set outside the mold to make the surface cooling rate of the casting reach 50℃ / s - 100℃ / s. The rapid solidification process refines the grains of the casting. According to the solidification theory, rapid cooling increases the number of crystallization nuclei, making the grain size smaller, thus significantly improving the mechanical properties of the casting, such as strength, hardness, and toughness. Stress relief and dimensional accuracy control steps: After the casting solidifies, it is first subjected to heat aging treatment. The casting is heated to 500℃-600℃ and kept warm for 2-3 hours. During the heat aging process, the residual stress inside the casting gradually relaxes under the action of high temperature, and the organizational structure tends to be stable. Then, vibration aging equipment is used to vibrate for 30-60 minutes at a frequency of 20Hz-50Hz and an exciting force of 5kN-10kN. Vibration aging causes the casting to resonate, causing the internal microstructure to undergo plastic deformation, further reducing residual stress, and accurately controlling dimensional accuracy. The aging temperature, holding time, frequency and exciting force of vibration aging can be optimized and adjusted according to the material, shape and residual stress distribution of the casting. For large castings with complex structures and uneven residual stress distribution, such as large machine tool columns, the thermal aging temperature can be appropriately increased to 580℃-600℃, which is close to the upper limit, and the holding time can be extended to 2.5-3 hours. In the vibration aging process, according to the residual stress in different parts of the casting, the vibration frequency and exciting force are adjusted in a targeted manner. In the stress concentration area, a higher exciting force and appropriate frequency are used to promote full stress release and homogenization. Post-processing and quality inspection steps: Shot blasting treatment is performed on the surface of the machine tool structural parts that have been cast and stress-relieved to make the surface roughness reach Ra0.8-Ra1.6μm; non-destructive testing technologies such as X-ray flaw detection, ultrasonic flaw detection and electronic speckle pattern interferometry are used to conduct comprehensive quality inspection of castings. X-ray flaw detection uses X-rays to penetrate castings and detect internal defects based on the difference in the degree of X-ray absorption by different materials; ultrasonic flaw detection determines the internal defects by emitting and receiving ultrasonic waves based on the propagation characteristics of the waves; electronic speckle pattern interferometry is based on the principle of optical interference and performs high-precision detection of surface deformation and defects of castings.
[0018] In the raw material optimization and pretreatment step, for different types of machine tool structural parts, the specific composition range of pig iron or other metal raw materials can be adjusted accordingly according to their material requirements; In the mold design and manufacturing steps, the path of the conformal cooling water channel is individually designed according to the digital simulation results to adapt to machine tool structural parts of different shapes and ensure uniform cooling of all parts of the casting; In the mold design and manufacturing steps, a layer of high-temperature resistant, low-friction ceramic coating with a thickness of 0.05-0.1mm is applied to the mold surface. The coating material is usually zirconium oxide, aluminum oxide, etc. The coating is applied by advanced technologies such as plasma spraying or physical vapor deposition. It can effectively resist high-temperature erosion and extend the service life of the mold. At the same time, it reduces the friction between the metal liquid and the mold cavity wall during mold filling, reduces the surface roughness of the casting, and improves the surface quality of the casting; After the stress relief and dimensional accuracy control steps, an additional dimensional accuracy re-measurement process is added. A high-precision laser measuring instrument is used to re-measure the key dimensions of the casting. If the dimensional deviation exceeds the IT6 - IT7 accuracy range, a numerical control grinding machine is used for micro-grinding correction to ensure that the dimensional accuracy of the final product meets the requirements; In the post-treatment and quality inspection steps, non-destructive testing techniques can be selected one or more in combination according to the specific requirements and quality standards of the machine tool structural parts to ensure the comprehensiveness and accuracy of the inspection; In the raw material optimization and pre-treatment steps, an intermediate frequency induction furnace with precise temperature control function is used as the melting equipment, and the temperature control accuracy can reach ±5°C, ensuring that the metal raw materials are always in a suitable and stable temperature environment during the melting process, providing high-quality molten metal for the subsequent casting process; In the post-treatment and quality inspection steps, the shot used for surface shot peening treatment is cast steel shot with a hardness of HRC40 - 50, and the shot diameter is between 0.5 - 1.5 mm. By adjusting the shot blasting angle and shot blasting speed of the shot blasting equipment, uniform shot peening treatment of the surfaces of machine tool structural parts with different shapes is achieved. Shot peening causes plastic deformation on the surface, increasing the surface roughness to Ra0.8 - Ra1.6 μm and enhancing the surface hardness and fatigue strength.
[0019] Working steps: Implementation method for casting processing of small machine tool skateboards: 100kg of high-quality gray cast iron that meets the standards is selected and placed in a medium-frequency induction furnace with a precise temperature control function of ±5℃ for smelting. During the smelting period, 25kHz ultrasonic vibration and 80A electromagnetic stirring are applied for 18 minutes to purify the molten metal, remove gas and inclusions, and improve purity; the casting process is simulated with the help of ProCAST software to design an integrated mold; the mold is made of H13 steel with a hardness of HRC50 that has undergone special heat treatment and is processed by a five-axis linkage CNC machining center to ensure that the mold cavity size accuracy reaches ±0.03mm; using plasma spraying technology, a 0.07mm thick zirconium oxide ceramic coating is applied on the mold surface, and then the mold is preheated to 350℃; in a 30Pa vacuum environment, the pretreated molten metal is injected into the preheated mold cavity at a low pressure of 0.05MPa, and at the same time, liquid nitrogen spraying is started on the outside of the mold for forced cooling The cooling device is used to make the surface cooling rate of the casting reach 70℃ / s. Before the molten metal is injected, it is first filtered through a filter device with an aperture of 0.5mm to further filter out inclusions. After the casting solidifies, it is first subjected to heat aging treatment at 550℃ for 2.5 hours to eliminate most of the residual stress, and then treated with a vibration aging device with a frequency of 30Hz and an excitation force of 8kN for 45 minutes to stabilize the internal structure. After the stress is eliminated, a high-precision laser measuring instrument is used to re-measure the key dimensions of the skateboard, such as the spacing between mounting holes and flatness. If the dimensional deviation exceeds the IT6 level accuracy range, a CNC grinder is used for micro-grinding correction. Cast steel shots with a hardness of HRC45 and a diameter of 1mm are used for shot blasting of the casting. The projectile angle and speed of the shot blasting equipment are adjusted to make the surface of the skateboard evenly blasted. The surface roughness after treatment reaches Ra1.2μm, which improves the surface hardness and fatigue strength. Ultrasonic flaw detection is used to detect the internal quality of the casting to ensure that there are no defects and meet the requirements for the use of small machine tool skateboards.
[0020] The implementation method for casting processing of large machine tool bed is as follows: prepare 5000kg of high-quality alloy cast steel, melt it in a medium-frequency induction furnace, apply 22kHz ultrasonic vibration and 60A electromagnetic stirring during melting, process for 20 minutes, and precisely control the temperature within the accuracy range of ±5℃. According to the characteristics of alloy cast steel, adjust the electromagnetic stirring and ultrasonic vibration parameters, purify the molten metal, and provide high-quality raw materials for subsequent casting; use ProCAST software to simulate the casting process and design an integrated mold with conformal cooling water channel. The mold material is H13 steel with a hardness of HRC52 that has undergone special heat treatment. It is manufactured by a five-axis linkage CNC machining center to ensure the dimensional accuracy of the complex shape of the mold cavity. According to the simulation results, optimize the conformal cooling water channel path, increase the cooling water flow rate and flow rate in the thick-walled part of the bed, and adjust the thin-walled part appropriately to ensure uniform cooling. Physical vapor deposition technology is used to coat the mold surface with a 0.08mm thick alumina ceramic coating to improve the mold's high temperature resistance and wear resistance. The mold is preheated to 380°C; under a 20Pa vacuum environment, the molten metal is injected into the preheated mold at a low pressure of 0.06MPa, and a circulating water cooling system is used as a forced cooling device to make the casting surface cooling rate reach 80°C / s. The molten metal is first filtered through a multi-layer filter, and the filter aperture is gradually reduced from 1mm to 0.1mm to effectively remove various inclusions; after the casting solidifies, it is heated to 600°C for 3 hours of heat aging treatment, and then a vibration aging equipment with a frequency of 40Hz and an excitation force of 10kN is used for vibration treatment for 60 minutes. According to the structural characteristics of the bed and the simulated distribution of residual stress, the heat aging and vibration aging parameters are optimized to ensure that the stress is fully eliminated. Use a laser measuring instrument to re-measure the key dimensions of the bed, such as the straightness of the guide rail mounting surface, the position accuracy of each mounting hole, etc. If the dimensional deviation exceeds the IT7 level accuracy range, use a CNC grinder to accurately grind and correct it; use cast steel shots with a hardness of HRC48 and a diameter of 1.2mm to shot blast the bed, adjust the shot blasting parameters, and achieve uniform shot blasting on the complex surface of the bed. The surface roughness after shot blasting reaches Ra1.0μm. Use a variety of non-destructive testing technologies such as X-ray flaw detection, ultrasonic flaw detection, and electronic speckle interferometry to conduct a comprehensive quality inspection of the bed to ensure that there are no internal defects and the surface quality meets the high standard requirements for large machine tool beds.
[0021] The machine tool structural parts casting processing method provided by the present invention has shown excellent performance in the production of different types of machine tool structural parts, effectively solved many problems existing in the traditional casting processing method, and has extremely high promotion and application value. In the actual production process, various process parameters can be appropriately adjusted and optimized according to the specific material, shape and performance requirements of the machine tool structural parts to achieve the best casting processing effect.
[0022] All the electrical components appearing in this text are electrically connected to the external main controller and the 220V mains power supply. Moreover, the main controller can be a conventional known device such as a computer for control. In the specific implementation manners of this disclosure, the detailed descriptions of known functions and known components are omitted. To ensure the compatibility of the device, all the operation means adopted are consistent with the parameters of commercial instruments.
[0023] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A casting and machining method for a machine tool structural part, characterized in that It includes the following steps: Raw material optimization and pretreatment step: Select high-quality metal raw materials within a specific composition range. For cast iron, choose pig iron with low sulfur, low phosphorus, and a carbon equivalent controlled between 3.8% - 4.2%. In the initial stage of melting, use a combined treatment of electromagnetic stirring and ultrasonic vibration. The electromagnetic stirring intensity is 50A - 100A, the ultrasonic vibration frequency is 20kHz - 30kHz, and the treatment duration is 15 - 20 minutes; Mold design and manufacturing step: Use digital simulation technology such as ProCAST software to simulate and analyze the casting process, and accordingly design an integrated mold with conformal cooling channels; The mold is made of high-strength, high-thermal conductivity hot work die steel that has undergone special heat treatment and has a hardness of HRC48 - 52; Manufacture the mold through a five-axis linkage CNC machining center to ensure that the dimensional accuracy of the mold cavity reaches ±0.03mm; Casting process step: Adopt a composite process of vacuum low-pressure casting and rapid solidification. Inject the melted metal liquid into the mold cavity preheated to 300℃ - 400℃ under a low pressure of 0.03MPa - 0.08MPa in an environment with a vacuum degree of 10 - 50Pa; At the same time, set a forced cooling device outside the mold to make the surface cooling rate of the casting reach 50℃ / s - 100℃ / s; Stress relief and dimensional accuracy control step: After the casting solidifies, first perform thermal aging treatment, heat the casting to 500℃ - 600℃, and keep it warm for 2 - 3 hours. Subsequently, use a vibration aging device to perform vibration treatment for 30 - 60 minutes under the conditions of a frequency of 20Hz - 50Hz and an exciting force of 5kN - 10kN; Post-treatment and quality inspection step: Perform surface shot peening treatment on the machined tool structure parts that have been cast and stress-relieved to make the surface roughness reach Ra0.8 - Ra1.6μm; Use non-destructive testing techniques such as X-ray flaw detection, ultrasonic flaw detection, and electronic speckle pattern interferometry to conduct a comprehensive quality inspection of the casting.
2. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the raw material optimization and pretreatment step, for different types of machine tool structure parts, the specific composition range of pig iron or other metal raw materials can be adjusted accordingly according to their material requirements.
3. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the mold design and manufacturing step, the path of the conformal cooling channels is designed individually according to the digital simulation results to adapt to different-shaped machine tool structure parts.
4. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the mold design and manufacturing step, apply a ceramic coating with a thickness of 0.05 - 0.1mm on the mold surface, which has high temperature resistance and a low friction coefficient.
5. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: After the stress relief and dimensional accuracy control step, add a re-measurement process for dimensional accuracy. Use a high-precision laser measuring instrument to re-measure the key dimensions of the casting. If the dimensional deviation exceeds the IT6 - IT7 level accuracy range, use a CNC grinding machine for micro-grinding correction to ensure that the dimensional accuracy of the final product meets the requirements.
6. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the post-treatment and quality inspection step, the non-destructive testing techniques can be selected individually or in combination according to the specific requirements and quality standards of the machine tool structure parts to ensure the comprehensiveness and accuracy of the inspection.
7. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the raw material optimization and pretreatment step, the melting equipment uses an intermediate frequency induction furnace with an accurate temperature control function, and the temperature control accuracy can reach ±5℃.
8. A method for casting and machining a machine tool structural part according to claim 1, characterized in that: In the post-treatment and quality inspection steps, the shot used for surface shot peening is cast steel shot with a hardness of HRC 40 - 50, and the diameter of the shot is between 0.5 and 1.5 mm.