Processing method of steel long screw rod for electrolytic cell of hydrogen production equipment

Abstract

The invention relates to the technical field of long screw rod machining, and particularly discloses a machining method of a steel long screw rod for a hydrogen production equipment electrolytic bath, which comprises the following specific steps: putting a steel rod raw material into a heating furnace for modulation treatment: quenching treatment, high-temperature tempering treatment, cooling to a specified temperature after high-temperature tempering heat preservation, and cooling to the specified temperature; the straightness is checked, the straightness is measured to be larger than 4 mm, the steel bar is in a warped state, a temperature measuring tool is adopted for measuring the warped steel bar, after the temperature reaches the straightening temperature, straightening equipment is adopted for hot correction, the straightness of the warped steel bar is corrected to 1-2 mm, air cooling is conducted after straightening is completed, and then secondary supplementary tempering is conducted; and the mechanical property of the steel bar meets the European Union CE standard and use requirements. The machining process of the steel long screw comprises the following steps of tempering and straightening, supplementary tempering, datum setting, center frame datum turning and long screw machining. The mechanical property and straightness of a steel bar can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of long screw processing, and in particular relates to a processing method of a steel long screw for an electrolytic cell of hydrogen production equipment. Background Art

[0002] The electrolyzer is the core of hydrogen production equipment. The electrolyzer usually uses long screws to assemble and connect the pole frame and the end pressure plate. It is an important structural fastener of the electrolyzer and one of the pressure-bearing parts. The reliability of the screw affects the service life of the electrolyzer and is a necessary condition for the electrolyzer to pass CE certification.

[0003] However, when ordinary forged long screws are used as the long screws of electrolytic cells for processing, the screws cannot meet the CE standard of 54J at 0°C during forging, and the plastic elongation strength Rp0.2 cannot be guaranteed at the same time, which seriously affects the life of the electrolytic cell. The finished long screw of the electrolytic cell is usually 4-13 meters in length and ∮10-∮68 in outer diameter. Under the premise of meeting the CE mechanical properties, the size requirements must be met, and the following problems usually occur when processing steel long screws: 1. After heat treatment, the bar material does not meet the standard of 54J at 0°C; 2. After heat treatment, the specified plastic extension strength Rp0.2 of the bar material does not reach 850Mpa, resulting in insufficient strength of the long screw, which is easy to cause local bending, elastic failure, and the electrolytic cell cannot be assembled normally. After forced assembly, it will cause serious deformation and cause a major risk of the electrolytic cell falling apart; 3. After heat treatment, the tensile strength of conventional long screws does not reach 950Mpa. Under extreme working conditions, there will be hidden dangers of breakage, resulting in serious damage to the electrolytic cell. bad; 4. After heat treatment, the conventional long screw is seriously warped, with a straightness of more than 4mm, and cannot be machined; 5. After being placed for a period of time, the existing long screw will have internal stress, and the warping deformation will reach 5-8mm, which will make it impossible to assemble; 6. However, when the long screw with released internal stress is turned, the processing efficiency is low, and it takes 3 normal working days to process a screw, and the tool vibration and collision phenomena occur frequently during processing, resulting in serious damage to the tool; 7. The outer diameter runout of the finished screw is 3mm and the straightness is 4mm, so it cannot meet the technical requirements for the required assembly. The screw is bent, and the technical requirements are: the runout is 1mm, and the straightness is 1mm; Therefore, it is urgently needed to invent and design a processing method for a steel long screw for an electrolyzer of hydrogen production equipment to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a method for processing a long steel screw for an electrolyzer of hydrogen production equipment, which solves the problems that the material after heat treatment mentioned above does not meet the CE standards and usage requirements, is prone to warping after heat treatment, resulting in great difficulty in processing, is prone to warping and cannot be assembled after being placed for a period of time if the internal stress is not eliminated, is prone to tool vibration and collision during processing, and is also prone to tool damage and low processing efficiency.

[0005] In order to solve the above technical problems, the present invention provides a method for processing a steel long screw for an electrolyzer of hydrogen production equipment, and the specific steps of the method are as follows: S1. Put the steel bar raw material into the heated furnace for modulation treatment. The modulation treatment method includes quenching treatment, high temperature tempering treatment, cooling to the specified temperature after high temperature tempering and heat preservation, checking the straightness, and measuring the straightness>4mm, the steel bar is in a warped state. Use a temperature measuring tool to measure the warped steel bar. When the temperature reaches the straightening temperature, use the straightening equipment for heat calibration, and calibrate the straightness of the warped steel bar to 1-2mm. After the straightening is completed, air cool; S2. After straightening, the steel bars are air-cooled to room temperature, and the bars are placed in a furnace for secondary tempering to improve the comprehensive mechanical properties of the steel bars and make them meet EU CE standards and usage requirements; S3. Use a steel rod as the long axis of the long screw, and randomly select one end of the long axis as the reference end and the other end as the non-reference end. Use a machine tool chuck to clamp the reference end of the long axis, use the reference method to drill a pinhole on the non-reference end of the long axis, and mark the best reference position for setting up the center frame at the same time. Turn the long shaft around and clamp the non-reference end with the machine chuck. Install the center frame on the machine tool, use the center frame to support the middle of the long shaft, use the reference method to drill the pinhole at the reference end of the long shaft, and mark the best reference position for setting up the center frame. S4. Change the clamping method, change the direction of the long axis, install the first ejector on the ejector seat of the machine tool, clamp a reference calibration tool in the chuck jaws of the machine tool, clamp a second ejector in the chuck jaws and locate it on the inner side of the tool, move the long axis position by adjusting the reference calibration tool, so that the first ejector and the second ejector both support the ejector holes at both ends of the long axis, rotate in the double-top state, perform external turning on the best reference position of the center frame marked, and turn out the outer circle of the long axis, and this position is used as the reference surface of the center frame; S5. Move the center frame to the center frame reference plane, hold the long axis, and perform rough turning of the outer diameter, semi-finishing of the outer diameter, turning of the non-reference end face, finishing of the outer diameter, and processing of threads at both ends of the long axis. The outer diameter is then polished to complete the processing of the long screw, so that the technical parameters of the long screw are within the specified requirements, and the performance of the long screw is tested.

[0006] Furthermore, the steel bar raw material in S1 is fastener alloy steel that complies with EU Directive 2014 / 68 / EU.

[0007] Furthermore, the quenching treatment in S1: heating the furnace to 920±50°C to heat the steel bar raw material, the heating rate is 50°C~200°C / h, and then keeping it warm for 1-4 hours, and then cooling it with oil; high temperature tempering treatment: heating the temperature to 600±50°C, keeping it warm for 2-8 hours, and then air cooling it to a temperature of 250°C±20°C; oil cooling oil temperature is controlled at 20~50°C, and the cooling rate is 50°C~200°C / h.

[0008] Furthermore, the temperature measuring tool in S1 is a temperature measuring gun, and the specified temperature and the straightening temperature in S1 are both 250°C±20°C.

[0009] Furthermore, the room temperature in S2 is 0-30°C, the secondary tempering temperature is 400±150°C, and the comprehensive mechanical properties improved in S2 are the strength, hardness and toughness of the steel bar.

[0010] Furthermore, the reference setting method in S3 is as follows: use a machine tool chuck to clamp the reference end or non-reference end of the long axis, install a center frame on the machine tool, use the center frame to support the middle of the long axis, rotate the long axis, measure the end runout of the long axis, install a center drill on the thimble seat of the machine tool, drill the thimble hole at the non-reference end or the reference end of the long axis that meets the minimum end runout requirement of the long axis, replace the center drill with a first thimble, support the thimble hole at the non-reference end or the reference end with the first thimble, move the center frame away from the middle, and rotate the long axis, and mark the best reference position for setting up the center frame at the location with larger runout deviation in the middle of the long axis.

[0011] Furthermore, the margin left for the outer diameter in the rough turning in S3 is 6-7 mm.

[0012] Furthermore, the width of the center frame reference plane in S4 is 18-25 mm.

[0013] Furthermore, the reference calibration tool in S4 includes a ring sleeve and four adjustment bolts evenly distributed on the ring sleeve, and the ring sleeve can be installed in the chuck jaws of the machine tool. The four adjustment bolts are threadedly connected to the ring sleeve, and the inner walls of the four adjustment bolts are used to adjust the position of the long axis.

[0014] Furthermore, the technical parameters of the long screw in S5 specify the requirements: outer diameter runout ≤ 2mm, straightness ≤ 2mm, and the performance of the long screw tested in S5: under 0°C environment, the steel rod impact test reaches ≥90KV2 (J), the plastic extension strength Rp0.2 ≥ 850Mpa, the tensile strength Rm ≥ 950Mpa, and the elongation after fracture A ≥ 15%.

[0015] Beneficial effects of the present invention: The processing flow of the steel long screw of the present invention is as follows: quenching and straightening process → supplementary tempering process → reference setting process → center frame reference process → long screw processing process, which can effectively improve the mechanical properties and straightness of the steel bar, and also solve the problems of tool vibration and tool collision during processing, improve processing efficiency, and at the same time can make the size meet the technical parameter requirements of outer diameter runout ≤2mm and straightness ≤2mm; The quenching and straightening process can heat treat the steel bar raw material. After the heat treatment, the warped steel bar is heat straightened at a specified temperature to make the straightness of the steel bar reach 1-2mm. After straightening, it is air-cooled to ensure the straightness of the steel bar and solve the serious warping problem of the long screw to meet the requirements of mechanical processing and assembly. In the supplementary tempering process, secondary tempering can not only improve the comprehensive mechanical properties of the steel rod, but also solve the problem that the steel rod cannot reach the 54J standard at 0℃ after heat treatment. At the same time, it can also solve the problem that the existing rod material is insufficient in strength and easily leads to local bending, elastic failure and the electrolytic cell cannot be assembled normally. It can prevent the hidden dangers of steel rod breakage and serious damage to the electrolytic cell in the extreme working environment after heat treatment, and also prevent the electrolytic cell from breaking. The benchmark process uses the method of measuring the end jump of the long axis to screen out qualified long axes, and drills ejector holes on the reference end and non-reference end of the long axis, and marks the best reference position of the center frame placed twice to improve the accuracy of the center frame reference surface, so as to avoid the problem of frequent tool collision caused by serious deviation of the ejector hole position; The center frame datum process uses a datum calibration tool to adjust the relative position of the long axis and the second ejector, and marks and machines the center frame datum surface in the double ejection state of the first ejector and the second ejector to balance the deviations on both sides of the center frame datum surface in the middle of the long axis and reduce the difference in cutting allowances at both ends to solve the problem of easy tool vibration during processing; The long screw processing technology uses a center frame to support the center frame reference surface and balance the deviations on both sides of the center frame reference surface in the middle of the long shaft, so that the allowance can be evenly arranged during rough turning, so that the outer diameter of the semi-finishing turning and the outer diameter of the finishing turning can be fully turned out in the later stage, so as to avoid the problem of the outer diameter not being round due to the inability to turn out the outer diameter. At the same time, the allowance can also be turned out in steps to reduce the problem of tool vibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a front view of a machine tool for a method of processing a steel long screw for an electrolyzer of hydrogen production equipment according to the present invention; Figure 2 The invention discloses a method for processing a steel long screw for an electrolytic cell of hydrogen production equipment. Figure 1 A magnified view of middle; Figure 3 It is a cross-sectional view of a reference calibration tool for a method of processing a long steel screw for an electrolyzer of hydrogen production equipment according to the present invention; Figure 4 It is a schematic diagram of an ideal state and an actual state of a long axis of a method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to the present invention; In the figure: 1-machine tool, 2-center frame, 3-reference calibration tool, 4-long axis, 5-thimble seat, 11-chuck, 12-claw, 13-first thimble, 14-second thimble, 41-center frame reference surface, 31-ring sleeve, 32-adjusting bolt. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings of the present invention specification to clearly and completely describe the technical solutions in the embodiments of the invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In a specific embodiment of the present invention, Figure 1-Figure 4 As shown, a method for processing a steel long screw for an electrolyzer of hydrogen production equipment is specifically disclosed, and the specific steps of the method are as follows: Tempering and straightening process: The steel bar raw material must comply with the fastener alloy steel of EU Directive 2014 / 68 / EU. The steel bar raw material is placed in a heated furnace for tempering treatment. The tempering treatment method is as follows: Quenching treatment: Heat the furnace to 920±50℃ to heat the steel bar raw material, the heating rate is 50℃~200℃ / h, and then keep it warm for 1-4 hours. After keeping warm, cool it with oil, the oil temperature is controlled at 20~50℃, and the cooling rate is 50℃~200℃ / h; High temperature tempering treatment: heat the temperature to 600±50℃, keep it warm for 2-8 hours, and then air cool it to 250℃±20℃; After high-temperature tempering and heat preservation, cool to the specified temperature, check the straightness, and if the measured straightness is greater than 4mm, the steel bar is in a warped state. Use a temperature measuring tool to measure the warped steel bar. When the temperature reaches the straightening temperature, use the straightening equipment for heat calibration to calibrate the straightness of the warped steel bar to 1-2mm. After the straightening is completed, air cool; After high-temperature tempering and heat preservation, it is cooled to 250℃±20℃, and the straightness is checked by visual inspection. The measured straightness is>4mm, and the steel bar is in a warped state. A temperature measuring tool is used to measure the warped steel bar. In this embodiment, the temperature measuring tool is a temperature measuring gun. In other embodiments, it can be other measuring tools. When the temperature reaches 250℃±20℃, a straightening device is used for heat calibration to calibrate the straightness of the warped steel bar to 1-2mm, and air cool after straightening.

[0020] Supplementary tempering process: air-cool the straightened steel bars to room temperature, which is 0-30°C, and put the bars into the furnace for secondary tempering treatment, with the secondary tempering temperature being 400±150°C, to improve the comprehensive mechanical properties, which include the strength, hardness and toughness of the steel bars, so that the steel bars meet the EU CE standards and usage requirements; Reference setting process: a steel rod is used as the long axis 4 of the long screw, and one end of the long axis 4 is randomly selected as the reference end and the other end is used as the non-reference end. The reference end of the long axis 4 is clamped by the chuck 11 of the machine tool 1. The reference end of the long axis 4 is clamped by the chuck 11 of the machine tool 1. A center frame 2 is installed on the machine tool 1. The middle part of the long axis 4 is supported by the center frame 2. The long axis 4 is rotated, and the end runout of the long axis 4 is measured. A center drill is installed on the ejector seat 5 of the machine tool 1. For the long axis 4 that meets the minimum end runout requirement of the long axis 4, an ejector hole at the non-reference end is drilled. The center drill is replaced with a first ejector 13. The first ejector 13 is supported by the ejector hole at the non-reference end. The center frame 2 is moved away from the middle part, and the long axis 4 is rotated. The best reference position for setting up the center frame 2 is marked at the part with large runout deviation in the middle part of the long axis 4. Turn the long axis 4 around and clamp the non-reference end with the chuck 11 of the machine tool 1, install the center frame 2 on the machine tool 1, and use the center frame 2 to support the middle of the long axis 4, use the chuck 11 of the machine tool 1 to clamp the non-reference end of the long axis 4, install the center frame 2 on the machine tool 1, and use the center frame 2 to support the middle of the long axis 4, rotate the long axis 4, measure the end runout of the long axis 4, install the center drill on the thimble seat 5 of the machine tool 1, drill the thimble hole of the reference end of the long axis 4 that meets the minimum end runout requirement of the long axis 4, replace the center drill with the first thimble 13, and use the first thimble 13 to support the thimble hole of the reference end, move the center frame 2 away from the middle, and rotate the long axis 4, and mark the best reference position for setting up the center frame 2 at the position with large runout deviation in the middle of the long axis 4; Turning center frame reference process: change the clamping mode, change the direction of the long axis 4, install the first ejector 13 on the ejector seat 5 of the machine tool 1, clamp the reference calibration tool 3 in the jaws 12 of the chuck 11 of the machine tool 1, clamp the second ejector 14 in the jaws of the chuck 11 and located on the inner side of the tool, move the position of the long axis 4 by adjusting the reference calibration tool 3, so that the first ejector 13 and the second ejector 14 both support the ejector holes at both ends of the long axis 4, rotate in the double-top state, and perform external turning on the best reference position of the marked center frame 2 to turn out the outer circle of the long axis 4. This position is used as the center frame reference surface 41. In this embodiment, the width of the turned center frame reference surface 41 is 20 mm; Long screw processing technology: move the center frame 2 to the center frame reference plane 41, hold the long axis 4, and rough turn the outer diameter of the long axis 4, leaving a margin of 6-7mm for rough turning of the outer diameter; semi-finish turning the outer diameter, turn the non-reference end face, finish turning the outer diameter and process the threads at both ends of the long axis 4, and grind the outer diameter to complete the processing of the long screw, so that the technical parameters of the long screw are within the specified requirements. The technical parameters of the long screw specify requirements: outer diameter runout ≤2mm, straightness ≤2mm, and test the performance of the long screw. Test the performance of the long screw: at 0℃ environment, the steel bar impact test reaches ≥90KV2 (J), and the specified plastic extension strength Rp0.2≥850Mpa, tensile strength Rm≥950Mpa, and elongation after fracture A≥15%.

[0021] The reference calibration tool 3 includes a ring sleeve 31 and four adjustment bolts 32 evenly distributed on the ring sleeve 31. The ring sleeve 31 can be installed in the jaws 12 of the chuck 11 of the machine tool 1. The four adjustment bolts 32 are threadedly connected to the ring sleeve 31, and the inner walls of the four adjustment bolts 32 are used to adjust the position of the long axis 4.

[0022] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for processing a steel long screw for an electrolyzer of hydrogen production equipment, characterized in that: The specific steps of the method are as follows: S1. The steel bar raw material is subjected to conditioning treatment. After the treatment, the straightness is checked. If the straightness is measured to be greater than 4mm, the steel bar is in a warped state. The warped steel bar is measured using a temperature measuring tool. When the temperature reaches the straightening temperature, a heat calibration is performed to calibrate the straightness of the warped steel bar to 1-2mm. S2. After straightening, the steel bar is air-cooled to room temperature and subjected to secondary tempering treatment; S3. Use a steel rod as the long axis of the long screw, one end of the long axis as the reference end, and the other end as the non-reference end. The machine tool chuck clamps the reference end of the long axis, and uses the reference method to drill a pinhole on the non-reference end of the long axis, and at the same time mark the best reference position for setting up the center frame; Turn the long shaft around and clamp the non-reference end, install a center frame on the machine tool, use the center frame to support the middle of the long shaft, use the reference method to drill the ejector hole at the reference end of the long shaft, and mark the best reference position for setting up the center frame at the same time; S4, change the clamping mode, change the direction of the long axis, clamp a reference calibration tool in the jaws of the machine tool chuck, move the long axis position by adjusting the reference calibration tool, and rotate in the double-top state of the first ejector and the second ejector, and perform external turning on the best reference position of the marked center frame to turn out the outer circle of the long axis, and this position is used as the reference surface of the center frame; S5. Move the center frame to the center frame reference plane, hold the long axis, and perform rough turning of the outer diameter, semi-finishing of the outer diameter, turning of the non-reference end face, finishing of the outer diameter, and processing of the threads at both ends of the long axis to complete the processing of the long screw.

2. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The steel bar material in S1 is fastener alloy steel that complies with EU Directive 2014 / 68 / EU.

3. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The modulation treatment method in S1 includes quenching treatment and high-temperature tempering treatment. Quenching treatment: heating the furnace to 920±50℃ to heat the steel bar raw material, the heating rate is 50℃~200℃ / h, and then keeping it warm for 1-4 hours. After keeping warm, cooling with oil, the oil temperature of the oil cooling is controlled at 20~50℃, and the cooling rate is 50℃~200℃ / h; high-temperature tempering treatment: heating the temperature to 600±50℃, keeping warm for 2-8 hours, air cooling to a temperature of 250℃±20℃ after keeping warm, cooling to a specified temperature after high-temperature tempering and keeping warm, and the specified temperature is 250℃±20℃.

4. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The temperature measuring tool in S1 is a temperature measuring gun, and the straightening temperature in S1 is 250°C±20°C.

5. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The room temperature in S2 is 0-30°C, and the secondary tempering temperature is 400±150°C. After the secondary tempering treatment, the comprehensive mechanical properties of the steel bar are improved, and the comprehensive mechanical properties include the strength, hardness and toughness of the steel bar. At the same time, the steel bar meets the EU CE standards and usage requirements.

6. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The room temperature in S2 is 0-30°C, and the secondary tempering temperature is 400±150°C. After the secondary tempering treatment, the comprehensive mechanical properties of the steel bar are improved, and the comprehensive mechanical properties include the strength, hardness and toughness of the steel bar. At the same time, the steel bar meets the EU CE standards and usage requirements.

7. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The allowance for the outer diameter in the rough turning of S3 is 6-7mm.

8. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The first ejector and the second ejector in S4 are installed in the following manner: the first ejector is installed on the ejector seat of the machine tool, a reference calibration tool is clamped in the chuck jaws of the machine tool, and the second ejector is clamped in the chuck jaws and is located on the inner side of the tool; The width of the center frame reference surface in S4 is 18-25mm.

9. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The reference calibration tool in S4 includes a ring sleeve and four adjustment bolts evenly distributed on the ring sleeve. The ring sleeve can be installed in the chuck jaws of the machine tool. The four adjustment bolts are threadedly connected to the ring sleeve, and the inner walls of the four adjustment bolts are used to adjust the position of the long axis.

10. The method for processing a steel long screw for an electrolyzer of hydrogen production equipment according to claim 1, characterized in that: The technical parameter requirements met by the long screw in S5 are: outer diameter runout ≤ 2mm, straightness ≤ 2mm. The performance of the long screw in S5 is: under 0°C environment, the steel bar impact test reaches ≥90KV2 (J), the specified plastic extension strength Rp0.2 ≥850Mpa, the tensile strength Rm ≥950Mpa, and the elongation after fracture A ≥15%.

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