Rolling mill sliding plate heat treatment method

Abstract

The invention provides a rolling mill sliding plate heat treatment method which comprises the following steps: spraying an electrolyte on the surface of a rolling mill sliding plate, and meanwhile, using a high-voltage power supply to act on the electrolyte to induce plasma to release heat so as to perform heat treatment on the surface of the rolling mill sliding plate. The electrolytic plasma heat treatment technology is introduced, the distance control system is adopted for high-precision measurement and control over the target position or distance, product consistency and quality stability are improved, and the reject ratio is reduced; the rolling mill sliding plate clamp with a specific structure is adopted to quickly and accurately position and adjust the rolling mill sliding plate, and the deformation of the rolling mill sliding plate in the heat treatment process is reduced by rigid constraints in the transverse and longitudinal directions, so that the deformation of the rolling mill sliding plate after heat treatment is reduced by 80%, and the product stability is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of metal heat treatment, in particular to a rolling mill slide plate heat treatment method. Background Art

[0002] As a key component of rolling mill equipment, the main function of the rolling mill slide is to protect the key components such as the mill arch, the working roll and the bearing seat of the support roll from wear and corrosion, and ensure the stable operation of the rolling mill. With the rapid development of the steel industry, the performance requirements of rolling mill equipment are increasing day by day, and the technical requirements for rolling mill slides are also increasing. At present, rolling mill slides are mostly made of high-strength, high-temperature resistant and corrosion-resistant materials, and their dimensional accuracy and surface quality are ensured through precise processing technology.

[0003] However, rolling mill slides still face some challenges and problems. Traditional heat treatment methods still have defects such as complicated procedures, failure to meet performance requirements, or short service life. First, due to the harsh working environment of the rolling mill, the high temperature, high pressure and strong friction and wear generated during the rolling process cause serious wear of the slide plate, which needs to be replaced regularly, increasing maintenance costs and workload. Secondly, some slide plate materials are difficult to meet the requirements under extreme working conditions, such as poor thermal shock resistance, high expansion coefficient and other problems, which affect the service life and performance stability of the slide plate. In addition, the replacement process of the slide plate is often complicated and time-consuming, especially when the space of the rolling mill is limited, the replacement is more difficult.

[0004] At present, the material of rolling mill slide plate is generally medium carbon low alloy steel, which is laser quenched or induction quenched to increase the surface wear resistance. The hardened layer after laser quenching is thin, and the hardening depth is insufficient after post-processing to remove the surface deformation layer, and the wear resistance is poor; after induction quenching, there is a large deformation, and the surface will produce an ablation oxide layer, resulting in a large amount of removal in post-processing, which increases the difficulty of correction.

[0005] The Chinese patent literature discloses "a laser cladding rolling mill skateboard and its processing method", and its publication number is CN115961206A. The invention welds the skateboard base material with a base plate of comparable size - laser cladding - stress relief annealing - plasma cutting to separate the base plate - water jet cutting - grinding - polishing - milling the edge of the plate. The method of the invention is relatively cumbersome, time-consuming, and has high manpower and material costs. The powder used in the laser cladding method greatly increases the processing material cost of the skateboard. The uniformity and stability of the cladding layer may also be affected by many factors (such as laser power, cladding speed, etc.), requiring high-precision and expensive laser equipment and professional operators, and powder dust is harmful to a certain extent.

[0006] In summary, the traditional method of processing rolling mill slides has problems such as large deformation, short service life, and low performance. The non-traditional technology of laser surface cladding of rolling mill slides still needs to pay attention to the complexity of processing technology, uniformity of laser cladding layer, long processing time and high cost of processing materials in practical applications, and there is a lot of room for optimization. Summary of the invention

[0007] In view of the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a rolling mill slide heat treatment method for solving the problems of large deformation, short service life and low performance of the rolling mill slide treated by the traditional method.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention provides a rolling mill slide heat treatment method, which sprays electrolyte on the surface of the rolling mill slide and simultaneously uses a high-voltage power supply to act on the electrolyte to induce plasma to release heat, thereby heat treating the surface of the rolling mill slide.

[0009] The present application provides a method for heat treatment of the surface of a rolling mill slide with low cost, high efficiency, good hardening effect, convenient operation, uniform hardening layer and stable quality. By introducing electrolytic plasma heat treatment technology, the electrolyte is used as an energy generation medium, which has the advantages of stable composition, non-volatility, low cost, no environmental pollution, and reusability. This technology can achieve rapid quenching temperature on the surface of the rolling mill slide and then rapid cooling, obtain sufficient surface hardness and hardening depth, thereby improving its wear resistance under the premise of small deformation.

[0010] Preferably, the electrolyte is a sodium carbonate solution with a concentration of 8-18wt%.

[0011] Preferably, during the spraying process, the flow rate of the electrolyte is controlled to be 15-25 ml / s.

[0012] In the above technical solution of the present application, the appropriate electrolyte concentration and flow rate are one of the key factors in determining how much heat energy is released by the generated plasma when other conditions are the same.

[0013] Preferably, the heat treatment is performed in sequence using high voltage, medium voltage, high voltage, medium voltage, high voltage and low voltage.

[0014] In the prior art, when the electrolytic plasma heat treatment technology uses a high voltage power supply to act on the electrolyte to induce plasma to release heat, the voltage is usually treated in a high voltage-low voltage manner. When it is directly applied to the heat treatment of the rolling mill slide, there are defects such as the surface layer heating up too quickly and ablation and the internal hardening depth is insufficient. The present application optimizes the voltage process parameters and uses high voltage, medium voltage, high voltage, medium voltage, high voltage and low voltage for heat treatment. First, high voltage is used to quickly heat up to the phase change temperature, and medium voltage is used to maintain the temperature above the phase change temperature and keep the temperature constant for a period of time to ensure that heat is transferred from the surface to the inside. The high-medium voltage cycle method is beneficial to the surface of the slide to avoid the situation of ablation and remelting damage due to excessive heating, and low voltage can achieve the effect of rapid cooling because the voltage is too low to generate plasma, which is beneficial to the formation of hardened structure and does not affect the concentration of the electrolyte.

[0015] Preferably, the high voltage is 300-340V, and the high voltage action time is 2-10s; the medium voltage is 260-300V, and the medium voltage action time is 4-15s; the low voltage is 10-30V, and the low voltage action time is 3-10s.

[0016] The main reasons for adopting the pressure within the above parameter range in the present application are as follows: if the high voltage is too low, the surface of the mill slide cannot reach the phase change temperature in a short time, affecting the efficiency; if the high voltage is too high, the surface temperature will be too high in a short time, resulting in serious ablation and damage to the mill slide. The high voltage action time should not be too long, because if the high voltage action time is too long, the surface temperature of the mill slide will be too high, resulting in serious ablation and remelting, thereby damaging the mill slide; if the medium voltage is too low, the temperature will drop sharply or even fall below the phase change temperature; if the medium voltage is too high, the temperature will continue to rise after the high voltage, and the heat cannot be evenly transferred to the depth, and there is a risk of serious ablation and damage to the mill slide. The setting of the medium voltage action time is based on the heat transfer efficiency to ensure that the heat can be effectively transferred to the inside; if the low voltage is controlled within the range of 10-30V, plasma cannot be generated and the surface of the slide cannot be heated, thereby forming a convenient cooling effect. This method ensures that the surface of the slide can achieve rapid cooling and that the coolant does not affect the concentration of the electrolyte. The setting of the low voltage action time is based on the time required for the surface of the mill slide to cool. Based on the above, the high, medium and low voltage levels and times during heat treatment also need to be adjusted in combination with the thickness of the slide, the size of the rolling mill slide, the elemental composition and the required hardened layer depth.

[0017] Preferably, the electrolyte is sprayed using a spot trajectory.

[0018] More preferably, the spot running track presents two identical or similar modes on the left and right sides.

[0019] Preferably, the electrolyte is sprayed by plasma electrolysis equipment, which includes at least two electrolyte nozzles, an electrolyte supply system and a voltage regulation system, and the diameter of the electrolyte nozzle is 10~60mm; during the spraying process, the distance d between the electrolyte nozzle and the surface of the rolling mill slide is controlled to be 1.5~3mm.

[0020] In the above technical solution of the present application, the plasma electrolysis equipment adopts at least two electrolyte nozzles, which are symmetrically distributed on the left and right sides according to the spot operation trajectory, and are started and coordinated with each other for processing. The working efficiency is more than twice the original, and multiple trajectory operation modes can be realized to reduce deformation during the heat treatment process.

[0021] Preferably, the electrolyte nozzle is provided with a spacing control system, which includes a laser spacing sensor, a control unit and a positioner, the positioner is provided with a fixed arm corresponding to the electrolyte nozzle, the laser spacing sensor has a laser emitting and receiving surface, the laser spacing sensor is used to send a laser signal to the surface of the rolling mill slide, the laser spacing sensor receives the laser signal through the laser emitting and receiving surface, and feeds the data back to the control unit, the control unit is used to analyze and process the data, exchange data, and feed back the execution signal to the positioner, and the positioner drives the electrolyte nozzle to adjust the spacing of each processing point according to the execution signal.

[0022] The laser transmitting and receiving surface is the key part of the laser spacing sensor for sending and receiving laser signals. It calculates the distance d from the nozzle to the surface to be processed of the rolling mill slide through the relationship between the position of the electrolyte nozzle and the position of the rolling mill slide and mathematical formulas.

[0023] When measuring the distance d between the electrolyte nozzle and the surface of the rolling mill slide, the distance d will be displayed on the operation panel to facilitate obtaining the distance information. The distance control system will adjust the distance for each processing point. This solution can ensure the accurate spacing of each spot during continuous operation.

[0024] Preferably, during the heat treatment process, the rolling mill slide is fixed by a rolling mill slide clamp, and the rolling mill slide clamp includes clamping brackets arranged at intervals and a fixing plate arranged above the clamping brackets, and the fixing plate is used to fix the rolling mill slide horizontally between the clamping brackets and expose the side of the rolling mill slide to be heat treated.

[0025] In the above technical scheme of the present application, during the heat treatment process, it is ensured that one side of the rolling mill slide to be heat treated is exposed and corresponds to the electrolyte nozzle. The present application quickly and accurately positions and adjusts the rolling mill slide by adopting a rolling mill slide clamp with a specific structure, and the rigid constraints in the horizontal and vertical directions reduce the deformation of the rolling mill slide during the heat treatment process, so that the deformation of the rolling mill slide after heat treatment is reduced by 80%, thereby ensuring product stability. The rolling mill slide after heat treatment has no obvious deformation, and simple treatment can meet the use requirements; in addition, the use of a specific rolling mill slide clamp can reduce losses caused by operating errors and human factors, thereby saving equipment maintenance costs, extending the service life of equipment, saving production costs and time, simplifying post-processing procedures, and improving production efficiency while ensuring heat treatment processing accuracy.

[0026] More preferably, the thickness of the fixing plate is 1 to 2 times the thickness of the rolling mill slide plate, ensuring that the fixing plate can provide sufficient rigidity constraints to the rolling mill slide plate and reduce the deformation of the rolling mill slide plate during heat treatment.

[0027] Preferably, the fixed plate includes a center plate arranged along the length direction and a plurality of fixed ribs symmetrically and parallelly distributed along the center plate, the fixed ribs are provided with a first adjustment groove perpendicular to the center plate, the clamping bracket is provided with a second adjustment groove along the length direction, and after the first adjustment groove partially overlaps with the second adjustment groove, the fixed plate is fixed to the clamping bracket by a first fastener, and the rolling mill slide plate is provided with a plurality of countersunk holes corresponding to the first adjustment groove along the circumferential direction, and after the countersunk holes partially overlap with the first adjustment groove, the rolling mill slide plate is fixed to the fixed plate by a second fastener.

[0028] The design of the first adjustment groove and the second adjustment groove ensures that the rolling mill slide clamp can be suitable for fixing rolling mill slides of different sizes. This can be achieved by adjusting the size of the area where the first adjustment groove partially overlaps with the second adjustment groove and the size of the area where the countersunk hole partially overlaps with the first adjustment groove.

[0029] More preferably, the second fastener is a countersunk bolt. The countersunk bolt is used to form a flat surface through the mutual cooperation of the countersunk holes on the mill slide, and the mill slide is connected to the special clamp as a whole. This fixing method ensures that the nozzle trajectory of the surface to be processed is not affected by the clamp when adjusting.

[0030] As described above, the rolling mill slide heat treatment method of the present invention has the following beneficial effects: (1) By introducing electrolytic plasma heat treatment technology, the electrolyte, as an energy generation medium, has the advantages of stable composition, non-volatility, low cost, no environmental pollution, and reusability. This technology can achieve rapid quenching temperature on the surface of the rolling mill slide and then rapid cooling to obtain sufficient surface hardness and hardening depth, thereby improving its wear resistance under the premise of small deformation; (2) By optimizing the electrolyte flow rate, spot running trajectory, etc., the heat input during the heat treatment of the rolling mill slide is coordinated and regulated, so as to achieve the control of different hardening effects at different hardening depths. Under the premise of meeting the performance requirements, the heat input is controlled to achieve the purpose of reducing deformation; (3) The use of a spacing control system can achieve high-precision measurement and control of the target position or distance, reducing the errors caused by human operation. Through its precise control, the consistency and quality stability of the product are greatly improved, the failure rate is reduced, and the competitiveness is enhanced; (4) The rolling mill slide plate is positioned and adjusted quickly and accurately by using a specifically structured rolling mill slide plate fixture. The rigid constraints in the horizontal and vertical directions reduce the deformation of the rolling mill slide plate during the heat treatment process, reducing the deformation of the rolling mill slide plate by 80% after heat treatment, thus ensuring product stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram showing the relative positions of the plasma electrolysis equipment and the rolling mill slide.

[0032] Figure 2 Shown is one of the schematic diagrams of the installation structure of the rolling mill slide clamp and the rolling mill slide.

[0033] Figure 3 Schematic diagram showing the mill slide after heat treatment.

[0034] Figure 4 Shown is a schematic diagram of the spot running trajectory of Example 1.

[0035] Figure 5 Shown is a schematic diagram of the spot running trajectory of Example 2.

[0036] Figure 6 Shown is a schematic diagram of the spot running trajectory of Example 3.

[0037] Figure 7 Shown is a schematic diagram of the spot running trajectory of Example 4.

[0038] Figure 8 Shown is a schematic diagram of the spot running trajectory of Example 5.

[0039] Fig. 9 Shown is a schematic diagram of the spot running trajectory of Example 6.

[0040] Explanation of the accompanying drawings: electrolyte nozzle 1, laser spacing sensor 2, laser emitting and receiving surface 21, fixed arm 3, clamping bracket 4, second adjustment groove 41, fixed plate 5, center plate 51, fixed rib 52, first adjustment groove 521, first fastener 53, second fastener 54, rolling mill slide plate 6, countersunk hole 61. DETAILED DESCRIPTION

[0041] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0042] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0043] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; it should also be understood that the combination connection relationship between one or more devices / apparatuses mentioned in the present invention does not exclude the existence of other devices / apparatuses before or after the combination device / apparatus or the insertion of other devices / apparatuses between these explicitly mentioned two devices / apparatuses, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0044] The relative positions of the plasma electrolysis equipment and the rolling mill slide used in the following embodiments of the present application are as follows: Figure 1 As shown, the plasma electrolysis equipment includes two electrolyte nozzles 1, an electrolyte supply system and a voltage regulation system. The electrolyte nozzle is provided with a spacing control system, and the spacing control system includes a laser spacing sensor 2, a control unit and a positioner. The positioner is provided with a fixed arm 3 corresponding to the electrolyte nozzle, and the electrolyte nozzle is fixed on the fixed arm; the laser spacing sensor has a laser emitting and receiving surface 21, and the laser spacing sensor is used to send a laser signal to the surface of the rolling mill slide. The laser spacing sensor receives the laser signal through the laser emitting and receiving surface and feeds the data back to the control unit. The control unit is used to analyze and process the data, exchange data, and feed back the execution signal to the positioner. The positioner drives the electrolyte nozzle to adjust the spacing of each processing point according to the execution signal.

[0045] The installation structure of the rolling mill slide plate fixture and the rolling mill slide plate in the following embodiments of the present application is as follows Figure 2As shown, the rolling mill slide clamp includes a clamping bracket 4 arranged at intervals and a fixed plate 5 arranged above the clamping brackets, the fixed plate is used to fix the rolling mill slide horizontally between the clamping brackets, and makes the side of the rolling mill slide to be heat treated exposed downward, so that the side of the rolling mill slide to be heat treated is arranged opposite to the electrolyte nozzle; the fixed plate includes a center plate 51 arranged along the length direction and a plurality of fixed ribs 52 symmetrically and parallelly distributed along the center plate, the fixed rib is provided with a first adjustment groove 521 perpendicular to the center plate, the clamping bracket is provided with a second adjustment groove 41 along the length direction, the first adjustment groove is partially overlapped with the second adjustment groove, and the fixed plate is fixed to the clamping bracket by a first fastener 53, the rolling mill slide is provided with a plurality of countersunk holes 61 corresponding to the first adjustment groove along the circumferential direction, and the countersunk holes are partially overlapped with the first adjustment groove, and the rolling mill slide is fixed to the fixed plate by a second fastener 54.

[0046] Example 1 The present application provides a method for heat treatment of a rolling mill slide plate, specifically using a 100mm×200mm×20mm medium carbon steel plate to simulate a slide plate, the composition of which is the same as that of the rolling mill slide plate, including 0.38% C, 0.60% Si, 0.80% Mn, 0.035% S, 0.035% P, 13.5% Cr, and 0.4% Ni, comprising the following steps: (1) Fixing a medium carbon steel plate simulated slide plate on a rolling mill slide plate fixture so that the side of the medium carbon steel plate simulated slide plate to be heat treated is exposed downward; the roughness of the medium carbon steel plate simulated slide plate is within Ra3.2, and the flatness is less than 0.1 mm; (2) Reference Figure 4 The spot running trajectory is to set the single-point process parameters of the anode nozzle of the plasma electrolysis equipment and the spot running trajectory, wherein the high voltage is 330V, the high voltage time is 5s, the medium voltage is 295V, the medium voltage time is 10s, the low voltage is 10V, the low voltage time is 10s, the electrolyte is a sodium carbonate solution with a concentration of 13.5wt%, the electrolyte flow rate is 22ml / s, the diameter of the electrolyte nozzle d is 20mm, and the distance d from the electrolyte nozzle to the surface of the medium carbon steel plate simulating the skateboard is 2mm; (3) Import the electrolyte nozzle movement trajectory into the control cabinet respectively, turn on the spacing control system to test run the nozzle movement trajectory separately, observe whether the spacing control system is calibrated for the spacing, ensure the operation process is complete, and the spacing between all treatment points and the simulated skateboard treatment surface of the medium carbon steel plate is accurate. After it is correct, return the electrolyte nozzle to the program origin; the laser transmitting and receiving surface is the key part of the laser spacing sensor to send and receive laser signals. It calculates the spacing d from the nozzle to the surface to be treated of the mill skateboard through the relationship between the electrolyte nozzle position and the rolling mill skateboard position and the mathematical formula; when measuring the spacing d between the electrolyte nozzle and the surface of the rolling mill skateboard, the distance d will be displayed on the operation panel, which is convenient for obtaining the spacing information. The spacing control system will adjust the distance for each treatment point. This solution can ensure the accuracy of the spacing of each spot during continuous operation; (4) Turn on the plasma electrolysis equipment, refer to Figure 4 The spot running track is program-runned, and the electrolyte nozzle moves to the specified position and the set distance with the running program. The electrolyte sprayed from the anode nozzle just impacts the point to be treated on the surface of the cathode steel plate. After the high-voltage power supply is energized to the electrolyte, a current is formed in the electrolyte between the anode nozzle and the rolling mill slide, and plasma is induced to release the heat required for the medium carbon steel plate to simulate the slide heat treatment, and finally the heat treatment is completed. The schematic diagram of the rolling mill slide after heat treatment is shown in FIG. Figure 3 As shown, the through holes and countersunk holes of the slide plate are the structures of the rolling mill slide plate itself, which are used to be installed and used in conjunction with relevant equipment in specific application scenarios. The rolling mill slide plate clamp of the present application is a special clamp set based on the structure of the rolling mill slide plate itself. During the fixing process, countersunk bolts and countersunk holes can be used to form a flat surface, and the rolling mill slide plate and the special clamp are connected as a whole. This fixing method ensures that the nozzle trajectory of the surface to be processed is not affected by the clamp when adjusting; (5) After the medium carbon steel plate simulated slide plate has cooled down, loosen the bolts and remove the medium carbon steel plate simulated slide plate from the rolling mill slide plate fixture.

[0047] Example 2 The difference between Example 2 and Example 1 is that the spot running track is different. Figure 5 , the rest of the equipment and process parameters are exactly the same.

[0048] Example 3 The difference between Example 3 and Example 1 is that the spot movement trajectory is different. Figure 6 , the rest of the equipment and process parameters are exactly the same.

[0049] Example 4 The difference between Example 4 and Example 1 is that the spot running track is different. Figure 7 , the rest of the equipment and process parameters are exactly the same.

[0050] Example 5 The difference between Example 5 and Example 1 is that the spot movement trajectory is different. Figure 8 , the rest of the equipment and process parameters are exactly the same.

[0051] Example 6 The difference between Example 6 and Example 1 is that the spot movement trajectory is different. Fig. 9 , the rest of the equipment and process parameters are exactly the same.

[0052] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the electrolyte nozzle is not provided with a spacing control system, and the remaining equipment, spot running trajectory and process parameters are exactly the same.

[0053] The flatness of the simulated skateboard of the medium carbon steel plate after heat treatment in Examples 1 to 6 and Comparative Example 1 was measured, and the average value was 0.35 mm, the minimum value was 0.12 mm, and the maximum value was 0.63 mm. The deformation was less than that of laser heat treatment and laser cladding. A professional leveling method was used to level the simulated skateboard of the medium carbon steel plate with a large deformation, and the flatness was controlled within 0.2 mm.

[0054] Five spot sections were randomly cut from the simulated skateboard of the medium carbon steel plate after heat treatment in the measurement examples 1 to 6 and the comparative example 1, and the sections were grinded, mounted, polished, cleaned with alcohol, tested for hardness, and observed in metallographic structure. Through the above test, the test data under the five spots were averaged to obtain the hardening depth. The specific data are shown in Table 1. The average hardening depth of the part greater than 50HRC is 1.81mm, and the average hardening depth of the part greater than 50HRC without grinding can reach 1.9-2.0mm.

[0055] Table 1. Test data of simulated skateboard of medium carbon steel plate after heat treatment of Examples 1 to 6 and Comparative Example 1 It can be seen from Table 1 that the flatness of the simulated skateboard of the carbon steel plate after heat treatment in Example 1 is 0.12mm, the deformation is significantly reduced, and the surface hardness and hardening depth are uniform, and the average values ​​are better than the total average value. The surface hardness and hardening depth of the simulated skateboard of the carbon steel plate after heat treatment in Comparative Example 1 are uneven, resulting in low average hardness and average hardening depth. The surface hardness is 4.5HRC different from the total average hardness, and the hardening depth is 0.3mm different from the total average. The simulated skateboards of the carbon steel plates after heat treatment in Examples 1 to 6 are relatively uniform, with hardness fluctuations of plus or minus 0.5HRC and hardening depth fluctuations of plus or minus 0.2mm.

[0056] Example 7 The present application embodiment provides a method for heat treatment of a rolling mill slide plate. The specific rolling mill slide plate used has a size of 670 mm×420 mm×20 mm and is made of carbon chromium steel. The material composition includes 0.38% C, 0.60% Si, 0.80% Mn, 0.035% S, 0.035% P, 13.5% Cr, and 0.4% Ni. The method includes the following steps: Step 1: Grind and clean the mill slide, whose roughness is less than Ra3.2 and flatness is less than 0.1mm, and fix it on the mill slide fixture so that the surface to be processed faces the nozzle downwards, fix the mill slide on the fixture through countersunk bolts and countersunk holes, and fix the mill slide fixture on the support frame with nuts to ensure that it does not slide; Step 2: Set the single-point process parameters and spot running trajectory, including the electrolyte flow rate and the distance d from the electrolyte nozzle to the rolling mill slide; the high voltage is 335V, the high voltage time is 4s, the medium voltage is 295V, the medium voltage time is 8s, the low voltage is 15V, the low voltage time is 6s, the electrolyte concentration is 13.5wt%, the electrolyte flow rate is 22ml / s, the nozzle diameter is 30mm, and the distance d from the nozzle to the slide is 2mm; Step 3: When the rolling mill slide is running, the nozzle travels along the track Figure 4 Import the track shown in the figure into the control cabinet, turn on the spacing control system and test run the nozzle travel track separately, observe whether the laser spacing control system has calibrated the spacing, ensure the running process is complete, and the spacing between all processing points and the processing surface of the rolling mill slide is accurate. After it is correct, return the nozzle to the program origin; Step 4: Turn on the electrolytic plasma equipment, start the program, the nozzle moves to the specified position with the running program, the spacing control system is adjusted to the set distance, the electrolyte sprayed from the anode nozzle just impacts the point to be treated on the surface of the cathode rolling mill slide, and after the high-voltage power supply is energized to the electrolyte, a current is formed in the electrolyte between the anode nozzle and the rolling mill slide, and plasma is induced to release the heat required for the heat treatment of the rolling mill slide, and finally the heat treatment is completed; Step 5: After the rolling mill slide plate cools down, loosen the bolts and remove the rolling mill slide plate from the fixture; Step 6: Measure the flatness of the rolling mill slide plate to be about 0.08mm. After the entire process of surface heat treatment, almost no deformation can be achieved; Step 7: Finely grind the mill slide to meet the roughness and flatness requirements during use, and the total removal amount is controlled within 0.1mm; Step 8: Test the surface hardness of the ground rolling mill slide using a portable hardness tester. The average Rockwell hardness of the treated surface converted from ten test results is 57.1HRC, the minimum hardness is 52.1HRC, and the maximum hardness can reach over 60HRC.

[0057] In summary, the present invention introduces electrolytic plasma heat treatment technology, optimizes the spot running trajectory, electrolyte flow rate, etc. to ensure that the heat input during the heat treatment of the rolling mill slide plays a mutually coordinated and mutually regulated relationship, thereby realizing the control of different hardening effects at different hardening depths, and controlling the heat input to achieve the purpose of reducing deformation under the premise of meeting performance requirements; the spacing control system is used to measure and control the target position or distance with high precision, which improves the consistency of products and the stability of quality, and reduces the unqualified rate; the rolling mill slide fixture with a specific structure is used to quickly and accurately position and adjust the rolling mill slide, and the rigid constraints in the horizontal and vertical directions reduce the deformation of the rolling mill slide during the heat treatment process, so that the deformation of the rolling mill slide after heat treatment is reduced by 80%, ensuring product stability. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A rolling mill slide heat treatment method, characterized in that: Electrolyte is sprayed on the surface of the rolling mill slide, and a high voltage power supply is used to act on the electrolyte to induce plasma to release heat, so as to perform heat treatment on the surface of the rolling mill slide.

2. The rolling mill slide plate heat treatment method according to claim 1, characterized in that: The electrolyte is a sodium carbonate solution with a concentration of 8-18wt%.

3. The rolling mill slide plate heat treatment method according to claim 1, characterized in that: During the spraying process, the flow rate of the electrolyte is controlled at 15~25ml / s.

4. The rolling mill slide plate heat treatment method according to claim 1, characterized in that: The heat treatment is carried out in sequence using high voltage, medium voltage, high voltage, medium voltage, high voltage and low voltage.

5. The rolling mill slide plate heat treatment method according to claim 4, characterized in that: The high voltage is 300~340V, and the high voltage action time is 2~10s; the medium voltage is 260~300V, and the medium voltage action time is 4~15s; the low voltage is 10~30V, and the low voltage action time is 3~10s.

6. The rolling mill slide plate heat treatment method according to claim 1, characterized in that: The electrolyte is sprayed using a spot running trajectory.

7. The method for heat treatment of a rolling mill slide plate according to any one of claims 1 to 6, characterized in that: Plasma electrolysis equipment is used to spray electrolyte, the plasma electrolysis equipment comprising at least two electrolyte nozzles (1), an electrolyte supply system and a voltage regulation system, the diameter of the electrolyte nozzle being 10 to 60 mm; During the spraying process, the distance d between the electrolyte nozzle and the surface of the rolling mill slide plate (6) is controlled to be 1.5-3 mm.

8. The rolling mill slide plate heat treatment method according to claim 7, characterized in that: The electrolyte nozzle is provided with a spacing control system, which includes a laser spacing sensor (2), a control unit and a positioner, wherein the positioner is provided with a fixed arm (3) corresponding to the electrolyte nozzle, and the electrolyte nozzle is fixed on the fixed arm; the laser spacing sensor has a laser emitting and receiving surface (21), and the laser spacing sensor is used to send a laser signal to the surface of the rolling mill slide, and the laser spacing sensor receives the laser signal through the laser emitting and receiving surface, and feeds back the data to the control unit, and the control unit is used to analyze and process the data, exchange data, and feed back an execution signal to the positioner, and the positioner drives the electrolyte nozzle according to the execution signal to adjust the spacing of each processing point.

9. The rolling mill slide plate heat treatment method according to claim 1, characterized in that: During the heat treatment process, the rolling mill slide is fixed by a rolling mill slide clamp, the rolling mill slide clamp comprising clamping brackets (4) arranged at intervals and a fixing plate (5) arranged above the clamping brackets, the fixing plate being used to fix the rolling mill slide horizontally between the clamping brackets and to expose the side of the rolling mill slide to be heat treated; the thickness of the fixing plate is 1 to 2 times the thickness of the rolling mill slide.

10. The rolling mill slide plate heat treatment method according to claim 9, characterized in that: The fixed plate comprises a center plate (51) arranged along the length direction and a plurality of fixed ribs (52) symmetrically and parallelly distributed along the center plate. The fixed rib is provided with a first adjustment groove (521) perpendicular to the center plate. The clamping bracket is provided with a second adjustment groove (41) along the length direction. After the first adjustment groove and the second adjustment groove are partially overlapped, the fixed plate is fixed to the clamping bracket by a first fastener (53). The rolling mill slide is provided with a plurality of countersunk holes (61) corresponding to the first adjustment groove along the circumferential direction. After the countersunk holes and the first adjustment groove are partially overlapped, the rolling mill slide is fixed to the fixed plate by a second fastener (54).

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