Laboratory silicon steel plasma nitriding equipment and control method thereof

Abstract

The invention relates to the technical field of plasma nitriding, in particular to laboratory silicon steel plasma nitriding equipment and a control method thereof. Through reasonable arrangement of the vacuumizing system, the gas input system, the nitriding chamber, the pulse power supply system, the control system and matched components, the whole structure is compact, parameter regulation and control are accurate, operation is convenient and fast, fine control over the silicon steel nitriding process can be achieved, complex manual intervention is not needed, and the experiment efficiency can be greatly improved; the electric sliding rail drives the discharge electrode to move so as to adjust the distance between the discharge electrode and a silicon steel sample, multi-parameter cooperative regulation and control in the silicon steel nitriding process can be achieved in combination with a nitriding parameter closed-loop control algorithm and high-precision gas proportion control, and then the uniformity and stability of a nitriding layer are effectively improved; the device can meet the nitriding requirements of silicon steel of different specifications, is suitable for multi-working-condition research of silicon steel surface modification in a laboratory, and is wide in application prospect and easy to popularize.

Description

Technical Field

[0001] This invention relates to the field of plasma nitriding technology, specifically to a laboratory silicon steel plasma nitriding device and its control method. Background Technology

[0002] Silicon steel, as an important soft magnetic material, possesses characteristics such as high magnetic permeability and low iron loss, and is widely used in the manufacture of cores for power equipment such as transformers, motors, and generators. To further improve the wear resistance, corrosion resistance, and magnetic stability of silicon steel, surface modification treatment is necessary. Plasma nitriding is a commonly used surface strengthening technique. By generating a high-voltage discharge between the positive and negative electrodes, plasma is produced that impacts the workpiece surface, allowing nitrogen atoms to diffuse into the silicon steel surface to form a nitrided layer. This can improve surface hardness and corrosion resistance without significantly reducing its magnetic properties.

[0003] While there have been preliminary studies on plasma nitriding technology for silicon steel, most of these studies focus on initial explorations of industrial applications, with a lack of systematic research at the laboratory level. The nitriding process for silicon steel is inherently complex: its silicon content directly affects the formation rate and microstructure of the nitrided layer, and the nitriding effect is far more sensitive to process parameters (such as electrode spacing, temperature, and gas ratio) than that of ordinary steel. Therefore, current plasma nitriding equipment for silicon steel cannot meet the core laboratory needs for studying the mechanism and optimizing the process of plasma nitriding for silicon steel.

[0004] Therefore, developing a laboratory silicon steel plasma nitriding equipment and control method with precisely adjustable electrode spacing, stable temperature control, accurate gas ratio, and high degree of integration is of great significance for promoting laboratory research on silicon steel surface modification technology. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a laboratory silicon steel plasma nitriding equipment and its control method, which has a compact structure, precise parameter control, and convenient operation, and can realize the fine control of the silicon steel nitriding process, thereby improving the uniformity and stability of the nitrided layer.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: This invention provides a laboratory silicon steel plasma nitriding device, which mainly includes: a vacuum system 1, a gas input system 2, a nitriding chamber 3, a pulse power supply system 4, and a control system 5. The gas input system 2 is connected to a gas source device for nitrogen, ammonia, and hydrogen respectively at its inlet end, and the gas output end of the gas input system 2 is connected to the inlet of the nitriding chamber 3. A silicon steel sample 6 is provided in the middle of the nitriding chamber 3. Movable discharge electrodes 7 are provided on both sides of the silicon steel sample 6, and the discharge electrodes 7 on both sides are connected to the positive terminal of the pulse power system 4. The silicon steel sample 6 is connected to the negative terminal of the pulse power system 4. The nitriding chamber 3 is equipped with a temperature control system 11. The vacuum system 1, gas input system 2, pulse power supply system 4 and temperature control system 11 are all electrically connected to the control system 5.

[0007] Preferably, the silicon steel sample 6 is fixedly installed on the sample placement rack 10 in the middle of the nitriding chamber 3, and the discharge electrodes 7 are all installed on the corresponding electric slide rails 12. The discharge electrodes 7 are moved by the electric slide rails 12 to adjust the distance between the discharge electrodes 7 and the silicon steel sample 6.

[0008] Preferably, the top of the nitriding chamber 3 is provided with a pressure gauge 8 and an exhaust port 9. The exhaust port 9 is provided with an exhaust solenoid valve and is connected to the waste gas treatment system through an exhaust pipe. The vacuum system 1 is connected to the vacuum exhaust port of the nitriding chamber 3 through an exhaust pipe.

[0009] Preferably, the gas input system 2 is provided with three independent gas branches, and each gas branch is equipped with a mass flow controller and a one-way valve. The ends of the three gas branches converge at the mixing tank and are connected to the air inlet of the nitriding chamber 3.

[0010] Preferably, the temperature control system 11 includes a temperature detection unit and a heating unit. The temperature detection unit is a temperature sensor, and the heating unit is a resistance heater surrounding the inner wall of the nitriding chamber 3.

[0011] Preferably, the sample holder 10 is made of alumina ceramic material, and the surface of the sample holder 10 is provided with a mounting slot that is compatible with the silicon steel sample 6.

[0012] Preferably, the control system 5 includes a PLC controller, a touch screen, and a data storage module. The touch screen is used for setting nitriding process parameters and displaying various monitoring data in real time during the nitriding process.

[0013] Based on the same inventive concept, the present invention also provides a control method for the laboratory silicon steel plasma nitriding equipment as described above, which mainly includes the following steps: S1, Sample pretreatment: After the silicon steel sample 6 is successively ground, cleaned and dried, it is fixed on the sample placement rack 10. S2, Pre-vacuuming: Start the vacuuming system 1 and monitor the vacuum level in the nitriding chamber 3 in real time. When the real-time vacuum level is lower than the preset vacuum level Z1, continue the vacuuming action for a preset time T1 to ensure that the vacuum level requirement during the nitriding test is met. S3, Parameter initialization setting: According to the preset test conditions, the nitriding process parameters are set through the touch screen of the control system 5, including: preset nitriding time, output parameters of pulse power supply, preset flow ratio of nitrogen, ammonia and hydrogen, target distance between discharge electrode and silicon steel sample, target gas pressure value and target nitriding temperature value in nitriding chamber. S4, Gas input and pressure regulation: Start the gas input system 2 to input a mixture of nitrogen, ammonia and hydrogen into the nitriding chamber 3 according to the preset flow ratio, and monitor the gas pressure in the nitriding chamber 3 in real time through the pressure gauge 8. When the real-time gas pressure reaches the target gas pressure value, execute the gas pressure adaptive control. S5: Electrode spacing adjustment: The control system 5 starts the stepper motor of the electric slide rail 12, driving the discharge electrodes 7 on both sides to move to the preset spacing position relative to the silicon steel sample 6, and the stepper motor locks after it is in place. S6: Temperature control and plasma nitriding: After the heating unit of the temperature control system 11 is activated to raise the temperature in the nitriding chamber 3 to the target nitriding temperature value, the pulse power system 4 is turned on to perform plasma nitriding. During the nitriding process, the temperature detection unit of the temperature control system 11 provides real-time feedback of the temperature data in the nitriding chamber 3 and performs temperature stability control. S7: Nitriding End and Post-processing: After the preset nitriding time is reached, the control system 5 sequentially shuts down the pulse power system 4, the gas input system 2, and the temperature control system 11, and restarts the vacuum system 1 to perform the vacuuming action for a preset time T2. After the temperature inside the nitriding chamber 3 cools down to room temperature, nitrogen gas is introduced into the nitriding chamber 3 through the gas input system 2 until the pressure inside the nitriding chamber 3 rises to atmospheric pressure. The nitriding chamber 3 is then opened and the silicon steel sample 6 is taken out.

[0014] Preferably, in step S4, the pressure adaptive control includes: 1) When (real-time air pressure value - target air pressure value) > target air pressure value × 0.5%, shut down the gas input system and open the exhaust port solenoid valve to the preset opening degree to reduce the real-time air pressure to the target air pressure value; 2) When (real-time air pressure value - target air pressure value) < target air pressure value × -0.5%, close the exhaust port solenoid valve and open the gas input system to continue to input mixed gas into the nitriding chamber at the preset flow ratio, so that the real-time air pressure rises to the target air pressure value.

[0015] Preferably, in step S6, the temperature stability control includes: S61 provides real-time feedback of temperature data within the nitriding chamber via a temperature detection unit; S62, the heating unit of the temperature control system dynamically adjusts the heating power based on the real-time temperature feedback value in the nitriding chamber, so that -5℃≤(real-time temperature feedback value-target nitriding temperature value)≤5℃; S63: When the real-time temperature feedback value is detected to be greater than the preset safe temperature threshold, the temperature control system issues an alarm signal and immediately shuts down the heating unit.

[0016] Compared with the prior art, the present invention has the following main advantages: 1. This invention, through the rational arrangement of the vacuum system, gas input system, nitriding chamber, pulse power supply system, control system and supporting components, has a compact overall structure, precise parameter control and convenient operation. It can achieve fine control of the silicon steel nitriding process without complicated manual intervention, which can greatly improve experimental efficiency. 2. This invention uses an electric slide rail to drive the discharge electrode to move in order to adjust the distance between it and the silicon steel sample. Combined with a closed-loop control algorithm for nitriding parameters and high-precision gas ratio control, it can realize multi-parameter coordinated control of the silicon steel nitriding process, thereby effectively improving the uniformity and stability of the nitrided layer. 3. This invention can adapt to the nitriding requirements of silicon steel of different specifications by adjusting process parameters such as gas ratio, discharge parameters, and temperature. It is suitable for multi-condition research on silicon steel surface modification in the laboratory, and has broad application prospects and is easy to promote. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the laboratory silicon steel plasma nitriding equipment in an embodiment of the present invention; Figure 2 This is a schematic diagram of the silicon steel sample and the discharge electrode in an embodiment of the present invention; Figure 3 This is an overall flowchart of the control method in an embodiment of the present invention.

[0018] In the diagram: 1-Vacuum system; 2-Gas input system; 3-Nitriding chamber; 4-Pulse power supply system; 5-Control system; 6-Silicon steel sample; 7-Discharge electrode; 8-Gas pressure gauge; 9-Exhaust port; 10-Sample rack; 11-Temperature control system; 12-Electric slide rail. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0021] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0022] Example 1: This example provides a laboratory silicon steel plasma nitriding device, such as... Figures 1-2 As shown, it mainly includes: vacuum system 1, gas input system 2, nitriding chamber 3, pulse power supply system 4, and control system 5; The gas input system 2 has its inlet connected to nitrogen, ammonia and hydrogen gas source devices respectively, and its outlet connected to the inlet of the nitriding chamber 3. A silicon steel sample 6 is provided in the middle of the nitriding chamber 3. Movable discharge electrodes 7 are provided on both sides of the silicon steel sample 6, and the discharge electrodes 7 on both sides are connected to the positive terminal of the pulse power system 4. The silicon steel sample 6 is connected to the negative terminal of the pulse power system 4. The nitriding chamber 3 is equipped with a temperature control system 11. The vacuum system 1, gas input system 2, pulse power supply system 4 and temperature control system 11 are all electrically connected to the control system 5.

[0023] Furthermore, the silicon steel sample 6 is fixedly installed on the sample placement rack 10 in the middle of the nitriding chamber 3, and the discharge electrodes 7 are all installed on the corresponding electric slide rails 12. The discharge electrodes 7 are moved by the electric slide rails 12 to adjust the distance between the discharge electrodes 7 and the silicon steel sample 6.

[0024] Furthermore, a pressure gauge 8 and an exhaust port 9 are provided on the top of the nitriding chamber 3. The exhaust port 9 is equipped with an exhaust solenoid valve and is connected to the waste gas treatment system through an exhaust pipe. The vacuum system 1 is connected to the vacuum exhaust port of the nitriding chamber 3 through an exhaust pipe.

[0025] Furthermore, the gas input system 2 is provided with three independent gas branches, and each gas branch is equipped with a mass flow controller and a one-way valve. The ends of the three gas branches converge at the mixing tank and are connected to the air inlet of the nitriding chamber 3.

[0026] Furthermore, the temperature control system 11 includes a temperature detection unit and a heating unit. The temperature detection unit is a temperature sensor, and the heating unit is a resistance heater surrounding the inner wall of the nitriding chamber 3.

[0027] Furthermore, the sample holder 10 is made of alumina ceramic material, and the surface of the sample holder 10 is provided with a mounting slot that is compatible with the silicon steel sample 6.

[0028] Furthermore, the control system 5 includes a PLC controller, a touch screen, and a data storage module. The touch screen is used for setting nitriding process parameters and displaying various monitoring data in real time during the nitriding process.

[0029] Example 2: This example provides a laboratory silicon steel plasma nitriding device. The pulse power system 4 is equipped with a rectifier (converting AC to DC), a step-up transformer, and connecting wires. The positive and negative terminals of the pulse power system 4 are respectively connected to the discharge electrode 7 and the silicon steel sample 6. Furthermore, the control system is used to coordinate the control of parameters such as the proportion and flow rate of the input gas, the output voltage and current of the pulse power supply, the temperature and vacuum degree in the nitriding chamber, the distance between the discharge electrode and the sample, and the nitriding time. Furthermore, the sample placement rack is used to place silicon steel samples, the vacuum system is used to extract air from the nitriding chamber to form a vacuum, the pressure gauge is used to observe the vacuum level of the nitriding chamber in real time, and the exhaust port is used to discharge gas from the nitriding chamber.

[0030] Furthermore, when the electric slide rail 12 is arranged laterally, it can drive the discharge electrode 7 to move laterally (along...). Figure 2 (The direction of movement in the middle) to adjust the distance between the discharge end and the silicon steel sheet; When the electric slide rail 12 is arranged longitudinally, it can drive the discharge electrode 7 to move longitudinally (perpendicular to) Figure 2 (The direction of movement in the middle) to gradually adjust the overlap area between the electrode plate and the silicon steel sheet to achieve gradient nitriding; Furthermore, the lateral and longitudinal movement speeds of the discharge electrode 7 are both adjustable.

[0031] Example 3: Based on the same inventive concept, this example also provides a control method for the laboratory silicon steel plasma nitriding equipment as described above, such as... Figure 3 As shown, the main steps include the following: Step S1, Sample pretreatment: After the silicon steel sample 6 is successively ground, cleaned and dried, it is fixed on the sample placement rack 10. Step S2, Pre-vacuuming: Start the vacuuming system 1 and monitor the vacuum level in the nitriding chamber 3 in real time. When the real-time vacuum level is lower than the preset vacuum level Z1, continue the vacuuming action for a preset time T1 to ensure that the vacuum level requirement during the nitriding test is met. Step S3, parameter initialization setting: According to the preset test conditions, the nitriding process parameters are set through the touch screen of the control system 5, including: preset nitriding time, output parameters of the pulse power supply, preset flow ratio of nitrogen, ammonia and hydrogen, target distance between the discharge electrode and the silicon steel sample, target gas pressure value and target nitriding temperature value in the nitriding chamber. Step S4, Gas Input and Pressure Regulation: Start the gas input system 2 to input a mixture of nitrogen, ammonia and hydrogen into the nitriding chamber 3 according to the preset flow ratio, and monitor the gas pressure in the nitriding chamber 3 in real time through the pressure gauge 8. When the real-time gas pressure reaches the target gas pressure value, execute the gas pressure adaptive control. Step S5: Electrode spacing adjustment: The control system 5 starts the stepper motor of the electric slide rail 12, driving the discharge electrodes 7 on both sides to move to the preset spacing position relative to the silicon steel sample 6, and the stepper motor locks after it is in place. Step S6: Temperature control and plasma nitriding: After the heating unit of the temperature control system 11 is activated to raise the temperature in the nitriding chamber 3 to the target nitriding temperature value, the pulse power system 4 is turned on to perform plasma nitriding. During the nitriding process, the temperature detection unit of the temperature control system 11 provides real-time feedback of the temperature data in the nitriding chamber 3 and performs temperature stability control. Step S7: Nitriding End and Post-processing: After the preset nitriding time is reached, the control system 5 sequentially shuts down the pulse power system 4, the gas input system 2, and the temperature control system 11, and restarts the vacuum system 1 to perform the vacuuming action for a preset time T2. After the temperature inside the nitriding chamber 3 cools down to room temperature, nitrogen gas is introduced into the nitriding chamber 3 through the gas input system 2 until the pressure inside the nitriding chamber 3 rises to atmospheric pressure. The nitriding chamber 3 is then opened and the silicon steel sample 6 is taken out.

[0032] Furthermore, in step S4, the pressure adaptive control includes: 1) When (real-time air pressure value - target air pressure value) > target air pressure value × 0.5%, shut down the gas input system and open the exhaust port solenoid valve to the preset opening degree to reduce the real-time air pressure to the target air pressure value; 2) When (real-time air pressure value - target air pressure value) < target air pressure value × -0.5%, close the exhaust port solenoid valve and open the gas input system to continue to input mixed gas into the nitriding chamber at the preset flow ratio, so that the real-time air pressure rises to the target air pressure value.

[0033] Furthermore, in step S6, the temperature stability control includes: S61 provides real-time feedback of temperature data within the nitriding chamber via a temperature detection unit; S62, the heating unit of the temperature control system dynamically adjusts the heating power based on the real-time temperature feedback value in the nitriding chamber, so that -5℃≤(real-time temperature feedback value-target nitriding temperature value)≤5℃; S63: When the real-time temperature feedback value is detected to be greater than the preset safe temperature threshold, the temperature control system issues an alarm signal and immediately shuts down the heating unit.

[0034] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0035] In summary: 1. This invention, through the rational arrangement of the vacuum system, gas input system, nitriding chamber, pulse power supply system, control system and supporting components, has a compact overall structure, precise parameter control and convenient operation. It can achieve fine control of the silicon steel nitriding process without complicated manual intervention, which can greatly improve experimental efficiency. 2. This invention uses an electric slide rail to drive the discharge electrode to move in order to adjust the distance between it and the silicon steel sample. Combined with a closed-loop control algorithm for nitriding parameters and high-precision gas ratio control, it can realize multi-parameter coordinated control of the silicon steel nitriding process, thereby effectively improving the uniformity and stability of the nitrided layer. 3. This invention can adapt to the nitriding requirements of silicon steel of different specifications by adjusting process parameters such as gas ratio, discharge parameters, and temperature. It is suitable for multi-condition research on silicon steel surface modification in the laboratory, and has broad application prospects and is easy to promote.

[0036] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0037] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0038] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laboratory silicon steel plasma nitriding device, characterized in that, include: The system includes a vacuum system (1), a gas input system (2), a nitriding chamber (3), a pulse power supply system (4), and a control system (5). The gas input system (2) is connected to a gas source device for nitrogen, ammonia, and hydrogen, respectively, and the gas output system (2) is connected to the gas inlet of the nitriding chamber (3). The nitriding chamber (3) has a silicon steel sample (6) in the middle. The silicon steel sample (6) has movable discharge electrodes (7) on both sides. The discharge electrodes (7) on both sides are connected to the positive terminal of the pulse power system (4). The silicon steel sample (6) is connected to the negative terminal of the pulse power system (4). The nitriding chamber (3) is equipped with a temperature control system (11), and the vacuum system (1), gas input system (2), pulse power supply system (4) and temperature control system (11) are all electrically connected to the control system (5).

2. The laboratory silicon steel plasma nitriding equipment according to claim 1, characterized in that, The silicon steel sample (6) is fixedly installed on the sample placement rack (10) in the middle of the nitriding chamber (3). The discharge electrodes (7) are all installed on the corresponding electric slide rails (12). The discharge electrodes (7) are moved by the electric slide rails (12) to adjust the distance between the discharge electrodes (7) and the silicon steel sample (6).

3. The laboratory silicon steel plasma nitriding equipment according to claim 2, characterized in that, The top of the nitriding chamber (3) is equipped with a pressure gauge (8) and an exhaust port (9). The exhaust port (9) is equipped with an exhaust solenoid valve and is connected to the waste gas treatment system through an exhaust pipe. The vacuum system (1) is connected to the vacuum exhaust port of the nitriding chamber (3) through an exhaust pipe.

4. The laboratory silicon steel plasma nitriding equipment according to claim 1, characterized in that, The gas input system (2) is equipped with three independent gas branches, and each gas branch is equipped with a mass flow controller and a one-way valve. The ends of the three gas branches converge in the mixing tank and are connected to the inlet of the nitriding chamber (3).

5. A laboratory silicon steel plasma nitriding device according to claim 1, characterized in that, The temperature control system (11) includes a temperature detection unit and a heating unit. The temperature detection unit is a temperature sensor, and the heating unit is a resistance heater surrounding the inner wall of the nitriding chamber (3).

6. The laboratory silicon steel plasma nitriding equipment according to claim 1, characterized in that, The sample holder (10) is made of alumina ceramic material, and the surface of the sample holder (10) is provided with mounting slots that are compatible with the silicon steel sample (6).

7. A laboratory silicon steel plasma nitriding device according to claim 1, characterized in that, The control system (5) includes a PLC controller, a touch screen and a data storage module. The touch screen is used for setting nitriding process parameters and displaying real-time monitoring data during the nitriding process.

8. A control method for a laboratory silicon steel plasma nitriding apparatus as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1, Sample pretreatment: After the silicon steel sample (6) is successively ground, cleaned and dried, it is fixed on the sample placement rack (10); S2, Pre-vacuuming: Start the vacuuming system (1) and monitor the vacuum level in the nitriding chamber (3) in real time. When the real-time vacuum level is lower than the preset vacuum level Z1, continue to perform the vacuuming action for a preset time T1 to ensure that the vacuum level requirement in the nitriding test process is met. S3, parameter initialization setting: According to the preset test conditions, the nitriding process parameters are set through the touch screen of the control system (5), including: preset nitriding time, output parameters of pulse power supply, preset flow ratio of nitrogen, ammonia and hydrogen, target distance between discharge electrode and silicon steel sample, target gas pressure value and target nitriding temperature value in nitriding chamber. S4, Gas input and pressure regulation: Start the gas input system (2) to input a mixture of nitrogen, ammonia and hydrogen into the nitriding chamber (3) according to the preset flow ratio, and monitor the gas pressure in the nitriding chamber (3) in real time through the pressure gauge (8). When the real-time gas pressure reaches the target gas pressure value, perform gas pressure adaptive control. S5: Electrode spacing adjustment: The control system (5) starts the stepper motor of the electric slide rail (12) and drives the discharge electrodes (7) on both sides to move to the preset spacing position relative to the silicon steel sample (6). After the position is reached, the stepper motor locks. S6: Temperature control and plasma nitriding: After the heating unit of the temperature control system (11) is activated to raise the temperature in the nitriding chamber (3) to the target nitriding temperature value, the pulse power system (4) is turned on to perform plasma nitriding. During the nitriding process, the temperature data in the nitriding chamber (3) is fed back in real time through the temperature detection unit of the temperature control system (11), and temperature stability control is performed. S7: Nitriding End and Post-processing: After the preset nitriding time is reached, the control system (5) sequentially shuts down the pulse power system (4), the gas input system (2) and the temperature control system (11), and restarts the vacuum system (1) to perform the vacuum action for a preset time T2. After the temperature inside the nitriding chamber (3) cools down to room temperature, nitrogen gas is introduced into the nitriding chamber (3) through the gas input system (2) until the pressure inside the nitriding chamber (3) rises to normal pressure. The nitriding chamber (3) is then opened and the silicon steel sample (6) is taken out.

9. The control method according to claim 8, characterized in that... In step S4, the adaptive pressure control includes: 1) When (real-time air pressure value - target air pressure value) > target air pressure value × 0.5%, shut down the gas input system and open the exhaust port solenoid valve to the preset opening degree to reduce the real-time air pressure to the target air pressure value; 2) When (real-time air pressure value - target air pressure value) < target air pressure value × -0.5%, close the exhaust port solenoid valve and open the gas input system to continue to input mixed gas into the nitriding chamber at the preset flow ratio, so that the real-time air pressure rises to the target air pressure value.

10. The control method according to claim 8, characterized in that... In step S6, the temperature stability control includes: S61 provides real-time feedback of temperature data within the nitriding chamber via a temperature detection unit; S62, the heating unit of the temperature control system dynamically adjusts the heating power based on the real-time temperature feedback value in the nitriding chamber, so that -5℃≤(real-time temperature feedback value-target nitriding temperature value)≤5℃; S63, when the real-time temperature feedback value is detected to be greater than the preset safe temperature threshold, the temperature control system issues an alarm signal and immediately shuts down the heating unit.

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