Electrolytic plasma heat treatment method and device for artillery barrel

Abstract

The invention discloses an electrolytic plasma heat treatment method and device for an artillery barrel, and belongs to the technical field of heat treatment. The device comprises an electrolyte supply system for treatment, an electrolyte supply system for cooling, an electrolyte recovery water tank and a positioner, the position of an artillery barrel is fixed and adjusted through a positioner, electrolyte is sprayed to the inner surface of the artillery barrel through an electrolyte nozzle of an electrolyte supply system for treatment, after electrification, the electrolyte nozzle and the electrolyte on the surface to be treated form current, plasma is induced, and heating of the surface to be treated is achieved. External cooling is achieved through a spraying device of the electrolyte supply system for cooling, and supply circulation of the electrolyte is achieved through the electrolyte recycling water tank. Compared with a traditional method, the method is higher in efficiency, simpler in technological process, intelligent in control mode and good in hardening effect; the problem of highly toxic pollution of a traditional chromium plating process is solved through an electrolytic plasma heat treatment technology, and meanwhile high temperature resistance and impact resistance are provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of heat treatment, and particularly relates to a gun barrel electrolytic plasma heat treatment method and device. BACKGROUND

[0002] As a key component in modern artillery equipment, the inner surface of the gun barrel is subjected to multiple severe challenges under extreme working conditions: during the firing process, the instantaneous temperature in the bore can exceed 3000 DEG C, the pressure can be as high as 500-800 MPa, and the projectile rubs the inner wall at a speed of more than 1500 m / s. These extreme physical and chemical environments together cause serious ablation, high-temperature fatigue cracks and chemical corrosion on the inner surface of the barrel, significantly reducing the service life and firing accuracy of the weapon.

[0004] Although the currently widely used chrome plating process can enhance the surface hardness and wear resistance to some extent, the hexavalent chromium generated in the production process causes serious pollution to the environment and human health, and the environmental protection compliance cost increases year by year; while the laser cladding technology can realize high-performance coating, but it is limited by high equipment cost and complex process, especially it is difficult to achieve uniform coverage in complex inner cavity structures such as deep holes and variable diameters, which easily causes barrel deformation, subsequent processing difficulty, and low overall applicability.

[0005] Therefore, it is an urgent need to develop a new type of gun barrel surface treatment technology to balance high performance, low pollution, good process adaptability and economy, in order to improve the reliability and service life of the gun system in China. SUMMARY

[0006] In view of the deficiencies of the prior art, the purpose of the present application is to provide a gun barrel electrolytic plasma heat treatment method and device.

[0007] The purpose of the present application is achieved by the following technical solution: a gun barrel electrolytic plasma heat treatment method, comprising the following steps: Step one, pretreating the surface of the gun barrel; Step two, fixing the pretreated gun barrel on the chuck of the rotary indexing machine on the electrolytic plasma equipment, and adjusting the center line of the gun barrel to the horizontal position; Step three, setting the single-point process parameters of the electrolyte nozzle in the electrolytic plasma equipment, and moving the electrolyte nozzle to a suitable distance position from the surface of the gun barrel; Step four, starting the power supply and the water pump, spraying the working electrolyte on the inner surface of the gun barrel through the electrolyte nozzle, using the high-low voltage and cooling voltage mode to act on the electrolyte to induce plasma to release heat, and heat treating the inner surface of the gun barrel; spraying the cooling electrolyte on the outer surface of the gun barrel through the spraying device to realize the cooling of the gun barrel and avoid the overall temperature rise of the gun barrel from affecting the product quality.

[0008] Further, the electrolyte is a sodium carbonate solution with a concentration of 10-22wt%.

[0009] Further, the flow of the cooling electrolyte is controlled at 35-40ml / s, and the flow of the working electrolyte is controlled at 17-20ml / s.

[0010] Further, the high-low voltage and cooling voltage mode is specifically: sequentially using high voltage, low voltage, high voltage, low voltage, high voltage and cooling voltage for heat treatment.

[0011] Further, the single-point process parameters are specifically: the high voltage is 300-340V, the high voltage action time is 3-8s; the low voltage is 260-300V, the low voltage action time is 4-12s; the cooling voltage is 1-10V, and the cooling voltage action time is 5-10s.

[0012] Further, the diameter of the electrolyte nozzle is 10-30mm; during the working process, the nozzle mouth must be upward, and the sprayed electrolyte is controlled to just contact the inner surface of the gun barrel.

[0013] Further, the rotary positioner is provided with a leveling hand wheel, and the angle of the gun barrel can be adjusted by rotating the hand wheel; when the inner surface of the gun barrel needs to be heat treated to enter the next to-be-treated point, the gun barrel can be rotated according to the program or the electrolyte nozzle can be moved to the next treatment point.

[0014] Further, the step three further comprises: starting the electrolytic plasma equipment, not running the program, observing whether the electrolyte flow is appropriate and whether the interval meets the plasma triggering condition, if the condition is not met, adjusting the single-point process parameters or the interval position again, and if all conditions are met, performing step four.

[0015] The application further provides a gun barrel electrolytic plasma heat treatment device, which comprises an electrolyte supply system, a rotary positioner and an electrolyte recovery tank; the electrolyte supply system and the rotary positioner are arranged in the electrolyte recovery tank. The electrolyte supply system comprises a spraying device and an electrolyte nozzle, the spraying device is used for spraying electrolyte to cool down the gun barrel, the electrolyte is supplied by a single water pump and finally flows to an electrolyte recovery tank, and the electrolyte in the electrolyte recovery tank is drawn back to an electrolyte pool by an air pump; the electrolyte nozzle comprises a mesh anode, there is a gap between the electrolyte nozzle and the surface to be treated of the gun barrel, and after being electrified, the electrolyte nozzle and the electrolyte of the surface to be treated form an electric current and induce plasma, so that the surface to be treated is heated, the electrolyte of the water inlet of the electrolyte nozzle is supplied by the electrolyte pool, and finally flows to the electrolyte recovery tank, and the electrolyte in the electrolyte recovery tank is drawn back to the electrolyte pool by the air pump, so that the supply cycle is realized; The electrolyte nozzle is fixed in the gun barrel by a rotary positioner and can move to a target point on the inner wall of the gun barrel. The rotary positioner is used for rotating the gun barrel, and the gun barrel is fixed by a positioner chuck.

[0016] Further, the spraying device is provided with a baffle for shielding the splashed electrolyte.

[0017] The present application has the following beneficial effects: (1) The electrolytic plasma heat treatment gun barrel is simpler in process flow compared with the traditional chrome plating process, and completely solves the possibility of micro-cracks in the chromium layer and peeling of the chromium layer from the brush under high temperature and high pressure gas.

[0018] (2) The electrolytic plasma heat treatment gun barrel uses safe, stable and environmentally friendly electrolyte as an energy generating medium to generate plasma between the cathode and the anode, rapidly heats the work surface through high-energy plasma, and thus obtains a hardened layer, and the technology has an advantage in environmental protection and safety.

[0019] (3) The plasma heat treatment gun barrel heats the workpiece surface by spraying electrolyte through a plasma torch, the nozzle diameter can be selected, and the small-diameter nozzle has a small heat-affected zone and generates less stress.

[0020] (4) A cooling system is added to the outside of the gun barrel to accelerate the cooling speed, so that the gun barrel can complete rapid heating and rapid cooling in tens of seconds to obtain a good hardened layer, and the initial temperature consistency of each processing point during heat treatment can also be ensured, so that the quality stability goal is achieved.

[0021] (5) By optimizing the voltage process parameters, using high voltage, low voltage, high voltage, low voltage, high voltage and cooling voltage for heat treatment, first using high voltage to rapidly heat to the phase transition temperature, low voltage to maintain the temperature above the phase transition temperature for a period of time to ensure that the heat is transferred from the surface to the inside, and the high-low voltage cycle is beneficial to avoid the ablation and remelting damage of the inner surface of the gun barrel due to rapid heating, and the cooling voltage is low enough to generate plasma, which realizes rapid cooling of the treated part and is beneficial to the formation of hardened structure without affecting the electrolyte concentration.

[0022] In summary, the present application provides a gun barrel inner wall processing method with higher efficiency, simpler process flow, intelligent control mode and good hardening effect. By introducing electrolytic plasma heat treatment technology, the problem of toxic pollution in traditional chrome plating process is revolutionarily solved. The hardened layer after electrolytic plasma treatment has no risk of falling off, and can also provide considerable high temperature resistance and impact resistance, realizing the manufacturing goal of longer service life, higher performance and more green and environmental protection of the gun barrel, and closely following the theme of green, efficient and intelligent development of the times. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0024] Figure 1 The figure is a schematic diagram of the device of the present application; Figure 2 The figure is a comparison diagram of the modified layer and the matrix after processing of the gun steel material; In the figure: baffle 1, electrolyte nozzle 2, gun barrel 3, rotary positioner 4, positioner chuck 5, mesh anode 6, cooling spray device 7, electrolyte recovery water tank 8, electrolyte 9. DETAILED DESCRIPTION

[0025] In order to make those skilled in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art should belong to the scope of protection of the present application.

[0026] In the description of the present application, the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and are not required to be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. The terms "connected", "connected", "provided" used in the present application should be understood broadly, for example, can be fixed connection, can also be detachable connection, can be directly connected, can also be indirectly connected through intermediate parts, can be wired electrical connection, wireless electrical connection, or wireless communication signal connection, and the specific meaning of the above terms can be understood by the person skilled in the art according to the specific situation.

[0027] As shown in Figure 1 The present application provides a kind of cannon barrel electrolytic plasma heat treatment device, and arrowhead is replaced in pipe section electrolyte 9 in figure, arrowhead direction is electrolyte 9 flow direction, including: electrolyte supply system, rotary positioner 4 and electrolyte recovery water tank 8;Electrolyte supply system and rotary positioner 4 are located in electrolyte recovery water tank 8.

[0028] Electrolyte supply system includes spraying device 7 and electrolyte nozzle 2, the spraying device 7 is used to spray electrolyte 9 for cannon barrel 3 cooling, the electrolyte 9 is supplied by single water pump, finally flows to electrolyte recovery tank 8, and electrolyte 9 in electrolyte recovery tank 8 is drawn into electrolyte pool by air pump;Electrolyte nozzle 2 includes mesh anode 6, electrolyte nozzle 2 and the surface to be treated of cannon barrel 3 exist gap, after electrification, electrolyte 9 of electrolyte nozzle 2 and the surface to be treated forms electric current, and induces plasma, realizes the heating of the surface to be treated, the electrolyte 9 of electrolyte nozzle 2 inlet is supplied by electrolyte pool, finally flows to electrolyte recovery tank 8, and electrolyte in electrolyte recovery tank 8 is drawn into electrolyte pool by air pump, realizes supply cycle.

[0029] Electrolyte nozzle 2 is fixed in cannon barrel 3 by rotary positioner 4, and can be moved to target point in cannon barrel 3 inner wall.

[0030] Rotary positioner 4 is used to rotate cannon barrel 3, and the cannon barrel 3 is fixed by positioner chuck 5.

[0031] Among them, the spraying device 7 is provided with baffle 1, for shielding splashed electrolyte.

[0032] The embodiment of the present application also provides a kind of cannon barrel electrolytic plasma heat treatment method, comprising the following steps: Step one, the surface of cannon barrel 3 is pretreated.

[0033] Step two, the pre-processed gun barrel 3 is fixed on the electrolytic plasma device through the displacement chuck 5 of the rotary displacement machine 4, and the center line of the barrel is adjusted to the horizontal position.

[0034] Step three, the single-point process parameters of the electrolyte nozzle 2 in the electrolytic plasma device are set, and the electrolyte nozzle 2 is moved to a suitable interval position from the surface of the gun barrel 3.

[0035] Step four, the power supply and the water pump are started, the electrolyte nozzle 2 sprays working electrolyte 9 on the inner surface of the gun barrel 3, and the electrolyte 9 is acted on by high and low voltages and cooling voltages to induce plasma to release heat, so as to perform heat treatment on the inner surface of the gun barrel 3; the spraying device 7 sprays cooling electrolyte 9 on the outer surface of the gun barrel 3 to realize the cooling of the gun barrel 3.

[0036] Example 1 Based on the heat treatment method provided in the present application, the following experiments are carried out, specifically, a 100mmx100mmx20mm gun steel material plate is used to simulate the strengthening effect of the barrel, and the composition of the barrel is the same as that of the gun barrel, which includes 0.38%C, 0.30%Si, 0.35%Mn, 0.030%S, 0.030%P, 1.50%Cr, 0.8%Ni, 0.3%Mo, 0.25%V, 0.20%Cu, including the following steps: (1) The gun steel material is polished and cleaned with alcohol to ensure that the surface rust, dirt and oxides are removed, and finally it is fixed on the fixed support of the electrolytic plasma device.

[0037] (2) Set the single-point process parameters of the anode nozzle in the electrolytic plasma device, wherein the high voltage is 330V, the high voltage time is 4s, the low voltage is 285V, the low voltage time is 8s, the cooling voltage is 5V, the cooling pressure time is 10s, the electrolyte is a sodium carbonate solution with a concentration of 13.5wt%, the electrolyte flow is 22ml / s, the cooling electrolyte flow is 40ml / s, the nozzle d diameter is 12mm, and the distance d between the electrolyte nozzle and the inner surface of the simulated gun barrel of the medium carbon steel plate is 2.5mm; (3) Start the electrolytic plasma device, do not give the electrical test run program, observe whether the electrolyte flow is appropriate, and whether the interval meets the plasma triggering condition.

[0038] (4) Open the electrolyte water valve, open the cooling electrolyte water valve, run the program, and the electrolyte sprayed by the anode nozzle impacts on the surface of the cathode steel plate to be treated, after the high voltage power supply is powered on, the electrolyte between the anode nozzle and the inner surface of the gun barrel forms an electric current and induces plasma to release the heat required for heat treatment, and finally the heat treatment is completed.

[0039] (5) After the gun steel material is cooled, the bolts are loosened, and the gun steel material is removed from the fixture.

[0040] (6) Five spot samples are taken, and each of the five samples is polished, inlaid, polished, polished, alcohol cleaned, hardness tested, and metallographically observed. The average surface hardness of the gun steel material obtained by this method is 650.4HV, the hardened depth above 600HV is 1.2mm, and the average matrix hardness is 325.1HV.

[0041] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no electrolyte cooling system is provided and no cooling voltage is added, and the rest of the parameters and equipment are the same.

[0042] Five spot samples are taken, and each of the five samples is polished, inlaid, polished, polished, alcohol cleaned, hardness tested, and metallographically observed. The average surface hardness of the gun steel material obtained by this method is 530.5HV, the hardened depth above 500HV is 0.8mm, and the average matrix hardness is 323.6HV.

[0043] After comparing Example 1 and Comparative Example 1, the results of the gun steel material processing are that the average surface hardness and the average hardened depth of Example 1 are both higher than those of Comparative Example 1.

[0044] Example 2 Based on the heat treatment method provided, the following experiments are conducted. The simulated circular tube used for the gun barrel has a diameter of 150mm x 3500mm, and the material composition includes 0.38%C, 0.30%Si, 0.35%Mn, 0.030%S, 0.030%P, 1.50%Cr, 0.8%Ni, 0.3%Mo, 0.25%V, and 0.20%Cu. The following steps are included: (1) The simulated gun barrel circular tube is polished and cleaned to remove surface rust, oil, and oxides, and is finally fixed on the positioner of the electrolytic plasma device.

[0045] (2) The single-point process parameters of the anode nozzle in the electrolytic plasma device are set, including a high voltage of 330V, a high voltage time of 4s, a low voltage of 285V, a low voltage time of 8s, a cooling voltage of 5V, a cooling voltage time of 10s, an electrolyte of a sodium carbonate solution with a concentration of 13.5wt%, an electrolyte flow rate of 22ml / s, a cooling electrolyte flow rate of 40ml / s, a nozzle d diameter of 12mm, and a distance d between the electrolyte nozzle and the inner surface of the simulated gun barrel circular tube of 2.5mm.

[0046] (3) The electrolytic plasma device is started, and the run program is not given a voltage. The electrolyte flow rate is observed to determine whether it is appropriate, and the distance is observed to determine whether it meets the plasma triggering condition.

[0047] (4) open the electrolyte outlet valve for discharging, open the electrolyte outlet valve for cooling, run the program, the electrolyte sprayed by the anode nozzle impacts on the inner surface of the simulated gun barrel of the cathode pipe, and the high-voltage power supply passes electricity to the electrolyte, and the electrolyte between the anode nozzle and the inner surface of the gun barrel forms an electric current and induces plasma to release the heat required during heat treatment, and finally completes the heat treatment.

[0048] (5) after the pipe simulated gun barrel material is cooled, the locking device of the positioner is loosened, and the pipe simulated gun barrel material is detached from the clamp.

[0049] (6) five spot samples are taken, and the five samples are polished, inlaid, polished, polished, alcohol cleaned, hardness tested, and metallographic observed, so that the average surface hardness of the gun steel material is 651.7HV, the hardness is greater than 600HV, the hardened depth is 1.1mm, the average hardness of the matrix is 325.2HV, and the metallographic structure is as shown in Figure 2 .

[0050] As shown in Figure 2 , from the microstructure diagram, it can be seen that the modified layer and the matrix structure are obviously different, the upper layer of the boundary line is the modified layer, the structure is obviously refined, the corrosion resistance is also better than the matrix, the refined structure is more uniform, and the hardness is higher than the matrix.

[0051] In summary, by introducing the electrolytic plasma heat treatment technology, the electrolyte flow, the treatment process parameters and the configuration of the cooling system are optimized, so that these factors form a synergistic effect in the heat treatment process, and the distribution and intensity of heat input are jointly controlled. The synergistic mechanism realizes the accurate control of the depth and surface performance of the gun barrel, effectively controls the heat input while meeting the material performance requirements, thereby significantly reducing the deformation of the workpiece in the heat treatment process. The method improves the strengthening of the inner surface of the gun barrel, the surface hardness is 650HV, the matrix hardness is 325HV, the hardness performance is doubled, and the wear resistance and corrosion resistance are increased. It has strong process adaptability and controllability, improves the heat treatment quality and efficiency, and has high industrial application value.

[0052] The above examples only illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method of electrochemical plasma heat treatment of a gun barrel, characterized in that, The method comprises the following steps: Step 1: pretreating the surface of the gun barrel; Step 2: fixing the pretreated gun barrel on the chuck of the rotary positioner and adjusting the center line of the gun barrel to the horizontal position; Step 3: setting the single-point process parameters of the electrolyte nozzle in the electrolytic plasma device and moving the electrolyte nozzle to a position with a proper distance from the surface of the gun barrel; Step 4: starting the power supply and the water pump, spraying the working electrolyte on the inner surface of the gun barrel through the electrolyte nozzle, and using the high-low voltage and cooling voltage to induce the release of heat by the plasma to heat treat the inner surface of the gun barrel; Spraying the cooling electrolyte on the outer surface of the gun barrel through the spraying device to cool the gun barrel.

2. The method of claim 1, wherein, The electrolyte is a sodium carbonate solution with a concentration of 10-22wt%.

3. The method of claim 1, wherein, The flow rate of the cooling electrolyte is controlled to be 35-40ml / s, and the flow rate of the working electrolyte is controlled to be 17-20ml / s.

4. The method of claim 1, wherein, The high-low voltage and cooling voltage are used in sequence, i.e., high voltage, low voltage, high voltage, low voltage, high voltage, and cooling voltage.

5. The method of claim 1, wherein, The single-point process parameters are as follows: the high voltage is 300-340V, the high voltage action time is 3-8s; the low voltage is 260-300V, the low voltage action time is 4-12s; the cooling voltage is 1-10V, and the cooling voltage action time is 5-10s.

6. The method of claim 1, wherein, The diameter of the electrolyte nozzle is 10-30mm; during the working process, the nozzle opening faces upward, and the sprayed electrolyte is controlled to just contact the inner surface of the gun barrel.

7. The method of claim 1, wherein, The rotary positioner is provided with a leveling hand wheel, and the angle of the gun barrel can be adjusted by rotating the hand wheel; when the inner surface of the gun barrel needs to be heated to the next treatment point, the gun barrel can be rotated according to the program or the electrolyte nozzle can be moved to the next treatment point.

8. The method of claim 1, wherein, Step 3 further comprises: starting the electrolytic plasma device, not running the program, observing whether the electrolyte flow rate is appropriate and whether the distance meets the plasma triggering condition, readjusting the single-point process parameters or the distance position if the conditions are not met, and performing step 4 if all conditions are met.

9. An electrolytic plasma heat treatment device for a gun barrel, characterized by comprising: The method comprises the following steps: The electrolyte supply system, the rotary positioner (4), and the electrolyte recovery tank (8); the electrolyte supply system and the rotary positioner (4) are arranged in the electrolyte recovery tank (8). The electrolyte supply system comprises a spraying device (7) for spraying electrolyte (9) to cool the gun barrel (3), the electrolyte (9) being supplied by a separate water pump and finally flowing into an electrolyte recovery tank (8), the electrolyte (9) in the electrolyte recovery tank (8) being pumped back into the electrolyte pool by an air pump; the electrolyte nozzle (2) comprises a mesh anode (6), the electrolyte nozzle (2) and the surface to be treated of the gun barrel (3) having a gap, the electrolyte nozzle (2) and the electrolyte (9) of the surface to be treated forming an electric current after being electrified and inducing plasma to heat the surface to be treated, the electrolyte (9) at the water inlet of the electrolyte nozzle (2) being supplied by the electrolyte pool and finally flowing into the electrolyte recovery tank (8), the electrolyte in the electrolyte recovery tank (8) being pumped back into the electrolyte pool by the air pump to realize the supply cycle; The electrolyte nozzle (2) is fixed in the gun barrel (3) by a rotary positioner (4) and can move to a target point on the inner wall of the gun barrel (3); The rotary positioner (4) is used to rotate the gun barrel (3), and the gun barrel (3) is fixed by a positioner chuck (5).

10. The apparatus of claim 9, wherein, The spraying device (7) is provided with a baffle (1) for shielding the splashed electrolyte.

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