Electromagnetic valve seat machining method based on electrothermal upsetting

Abstract

The application discloses a kind of electromagnetic valve seat processing methods based on electrothermal upsetting, comprising the following steps: step 1: selecting cylindrical bar stock, using electrothermal upsetting to carry out phased processing on cylindrical bar stock in stages, to obtain intermediate structural member, intermediate structural member includes stem, one end of stem is provided with convex portion in the shape of garlic head, the size of convex portion is greater than stem;Step 2: heated intermediate structural member is placed in mould, and is forged and formed to obtain blank, the convex portion includes a counterbore, the counterbore is located in the extension direction of stem;Step 3: the magnetic property annealing of blank is carried out, magnetic property annealing;Step 4: the finish machining of blank is turned, to obtain electromagnetic valve seat finished product.The application can greatly utilize blank material, reduce consumables, and also because of this, processing time is less than traditional processing mode, material utilization is high, with better microstructure streamline and dense grain size.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of part processing, and particularly relates to a machining method of an electromagnetic valve seat based on electric heating upsetting. BACKGROUND

[0002] Most of the materials of the electromagnetic valve seat are 00Cr18Si2Mo2 electromagnetic steel, and the existing machining method for forming the electromagnetic valve seat mainly comprises turning machining of a cylindrical bar material with a diameter of 30 mm and a length of 29 mm and made of 00Cr18Si2Mo2 electromagnetic steel. The existing machining method mainly comprises two steps, i.e., first turning machining of the cylindrical bar material to obtain a rough machining blank, and then finishing machining of the rough machining blank to obtain the final electromagnetic valve product.

[0003] The existing machining method of the electromagnetic valve seat mainly has the following deficiencies and defects:

[0004] 1. In order to obtain the cylindrical bar material with a diameter of 30 mm and ensure that the microcrystalline grain size of the cylindrical bar is about 8-9 levels (average 10 um), a cast blank with a diameter of 100-120 mm needs to be forged, and after forging, hot drawing is performed, and finally the cylindrical bar material with a diameter of 30 mm is obtained by grinding. The larger the diameter of the cast blank, the larger the tonnage of the required smelting equipment and forging equipment, and at the same time, it also causes the material rejection rate to increase.

[0005] 2. The cylindrical bar material with a diameter of 30 mm and a length of 29 mm has a weight of about 160 g, and the formed blank has a weight of about 56 g, that is, the material loss of the cylindrical bar material after turning machining is about 100 g, and the material utilization rate is low.

[0006] 3. Since the processing material has a large amount of excess material from the raw material to the cylindrical bar material and then to the blank, the processing time is also long. At a feeding speed of 20 m / min, i.e., 0.3 m / s, a rough turning feeding amount of 0.2-0.3 mm / r, a finishing turning amount of 0.15 mm / r, and a processing amount of 8 mm on a single side, it needs to process 266 process parameters, and the processing time is about 130-150 seconds.

[0007] 4. During the direct turning machining of the cylindrical bar material to form the blank, the microstructure flow lines in the blank are discontinuous, and the corner position of the blank will cause the tendency of strengthening cracking. SUMMARY

[0008] In view of the deficiencies of the prior art, the present application aims to provide a machining method of an electromagnetic valve seat based on electric heating upsetting, which can solve the problems described in the background.

[0009] The technical scheme for achieving the object of the present application is as follows: a method for processing a solenoid valve seat based on electric upsetting, comprising the following steps:

[0010] Step 1: selecting a cylindrical bar stock, performing stage-by-stage processing on the cylindrical bar stock by using electric upsetting to obtain an intermediate structural member, the intermediate structural member comprising a rod portion, one end of the rod portion being provided with a garlic-shaped protruding portion, the size of the protruding portion being greater than that of the rod portion;

[0011] Step 2: placing the heated intermediate structural member into a die for performing forging and pressing forming to obtain a blank, the protruding portion comprising a counterbore, the counterbore being located in the extension direction of the rod portion;

[0012] Step 3: performing magnetic property annealing on the blank;

[0013] Step 4: performing turning finish machining on the blank to obtain a solenoid valve seat finished product.

[0014] Further, in Step 1, the cylindrical bar stock with a diameter of 11.7 mm and a length of 260 mm is selected.

[0015] Further, in Step 1, the processing on the cylindrical bar stock by using electric upsetting to obtain the intermediate structural member is specifically implemented by the following steps:

[0016] The cylindrical bar stock is heated by using the high electrical resistance property of the cylindrical bar stock itself, the heating temperature is maintained at 900-1120°C, and a deformation force is applied to the cylindrical bar stock during the heating process, so that the one end of the cylindrical bar stock is formed into a garlic shape, thereby obtaining the intermediate structural member.

[0017] Further, the forging and pressing forming specifically comprises the following steps:

[0018] Step 41: electric upsetting preheating stage: the cylindrical bar stock is preheated by passing current, and the anvil of the electric upsetting equipment is preheated by the thermal radiation of the cylindrical bar stock; in this stage, the upsetting cylinder pressure of the electric upsetting equipment is set to 5-10 kN, the displacement is 0 mm, and the current is 2000-5000 A; the preheating temperature of the heating zone where the cylindrical bar stock portion between the electrode and the anvil of the electric upsetting equipment is located reaches 200-500°C, and the holding time is 2-5 s; the anvil is synchronously preheated by heat conduction, and the heating zone where the cylindrical bar stock portion between the electrode and the anvil of the electric upsetting equipment is located is the bar stock heating zone;

[0019] Step 42: initial electric upsetting stage, i.e. initial deformation, the bar stock is preliminarily preformed by reaching the deformation temperature through the bar stock heating zone, and cooperating with the upsetting cylinder displacement and pressure, and the anvil back-off;

[0020] In the initial electric upsetting stage, the heating current and the pressure are equivalent to the current and the pressure in the preheating stage, or the difference is within a preset threshold range, the upsetting cylinder sequentially performs two straight-line displacements in the direction of the anvil, the sum of the displacement amounts of the two straight-line displacements is within [50, 70] mm, and the displacement amount of the first straight-line displacement is less than the displacement amount of the second straight-line displacement; the initial electric upsetting stage includes two different upsetting pressures, the first-stage upsetting pressure is [11, 15] kN, the second-stage upsetting pressure is [13, 17] kN, and two different upsetting currents, the first-stage upsetting current is [2700, 3100] A, and the second-stage upsetting current is [2900, 3300] A, so as to gradually increase the temperature of the bar heating zone to 900-1120°C to reach the required temperature range for deformation; and by gradually increasing the applied pressure, the deformation part of the cylindrical bar gradually accelerates the metal aggregation into a micro-drum shape, accompanied by the start of the upsetting of the cylindrical bar, the anvil also starts to retreat synchronously with the cylindrical bar while upsetting, and during the anvil retreat operation, 3-4 displacement stages are set, each stage has a different retreat speed, so that the garlic head-shaped protrusion formed after the upsetting of the cylindrical bar is smooth and meets the requirements,

[0021] If four displacement stages are set, the anvil retreat speed is gradually decreased, and the four displacement stages correspond to the retreat speeds of 1.3 mm / s, 1.1 mm / s, 0.8 mm / s, and 0.6 mm / s, respectively. During the four displacement stages of the anvil retreat, the intermediate structure has a preset protrusion height of 44 mm, and the four displacement distances are [5, 15] mm, [15, 25] mm, [25, 35] mm, and [35, 45] mm, respectively.

[0022] Step 43: enter the middle upsetting stage, that is, rapid deformation, by increasing the pressure and current of the upsetting cylinder, the cylindrical bar in the bar heating zone is rapidly deformed into a round drum shape;

[0023] In the middle upsetting stage, the intermediate structure is sequentially subjected to three straight-line displacements, the sum of the displacement amounts of the three straight-line displacements is within [100, 140] mm, and the displacement amount of the first straight-line displacement is less than the displacement amount of the second straight-line displacement, which is less than the displacement amount of the third straight-line displacement; the heating current in the middle upsetting stage is greater than the heating current in the preheating stage, and 3-5 stage displacements are set, the heating current is gradually increased, and the increment of the heating current in each stage is within 150-250 A, the forging pressure in the middle upsetting stage is greater than the forging pressure in the initial electric upsetting stage, and 3-5 stage forging pressures are set, which are also gradually increased by 0.5-5 kN, so that the deformation resistance of the cylindrical bar gradually increases during the rapid deformation;

[0024] Step 44: Enter the final upsetting stage. By increasing the pressure and current of the upsetting cylinder and gradually slowing down or stopping the anvil retraction speed, the intermediate structural parts continue to gather and gradually solidify.

[0025] In the final upsetting stage, the anvil retraction displacement is 40-60mm. By adjusting the upsetting displacement, it is ensured that the intermediate structural parts can be placed into the die for forging to meet the blank size requirements. The corresponding current and upsetting pressure are greater than those in the middle upsetting stage, with the current increasing by 150-250A and the forging pressure increasing by 0.5-5kN.

[0026] Step 45: Enter the necking stage, gradually transforming the cylindrical bar in the bar heating zone from a rounded, bulging shape into a garlic-shaped bar with a smooth transition, so that the head of the blank and the rod section can be easily forged into the correct position during the transition stage.

[0027] During the necking stage, the displacement of the upsetting cylinder is 5-15mm. The pressure of the upsetting cylinder in the middle upsetting stage is greater than that in the necking stage, which is greater than that in the initial electrothermal upsetting stage. The upsetting current in the middle upsetting stage is greater than that in the necking stage, which is greater than that in the initial electrothermal upsetting stage. The anvil retraction is then restarted at a speed of 1.5-6mm / s and a distance of 5-10mm. The necking is maintained for 2-6 seconds.

[0028] Furthermore, the magnetic properties are annealed at a temperature of 850-980℃ for 2 hours, followed by water cooling after removal from the furnace.

[0029] The beneficial effects of the present invention are: the present invention can make great use of raw materials, reduce material consumption, have less excess material, and therefore, the processing time is shorter than that of traditional processing methods, the material utilization rate is high, and it has better microstructure flow lines and dense grain size. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the process of the present invention;

[0031] Figure 2 This is a structural diagram of the intermediate structural component;

[0032] Figure 3 This is a structural schematic diagram of a finished solenoid valve seat;

[0033] In the diagram, 1 – rod, 2 – protrusion, 3 – countersunk hole. Detailed Implementation

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0035] like Figures 1-3 As shown, a method for machining an electromagnetic valve seat based on electro-forging includes the following steps:

[0036] Step 1: Select a cylindrical bar with a diameter of 11.7 mm and a length of 260 mm, and process the cylindrical bar by electric upsetting to obtain an intermediate structural member, which includes a rod portion 1, and one end of the rod portion 1 includes a convex portion 2 which is larger in size than the rod portion 1 and has a garlic head shape.

[0037] In an optional embodiment, the intermediate structural member is obtained by processing the cylindrical bar by electric upsetting, and the specific implementation process includes the following steps:

[0038] The cylindrical bar is heated by electric conduction, and the temperature formed by heating is maintained at 800-1020°C. During the heating process, a deformation force is applied to the cylindrical bar, so that one end of the cylindrical bar forms a ball head (also known as a garlic head), thereby obtaining the intermediate structural member.

[0039] Step 2: Place the heated intermediate structural member into a die and perform forging and pressing forming in stages to obtain a blank, and the obtained blank includes the convex portion 2 and the rod portion 1, the convex portion 2 includes a counterbore 3, the convex portion 2 is larger in size than the rod portion 1, and the counterbore 3 is located in the extension direction of the rod portion 1.

[0040] Reference Figure 2 , Figure 2 Figure 3 is a structural schematic diagram of the intermediate structural member, one end of which is formed into a ball head by forging and pressing forming, the intermediate part of the ball head is formed into a counterbore 3 by forging and pressing forming, and the other part of the intermediate structural member constitutes a rod portion 1.

[0041] In an optional embodiment, the forging and pressing forming in stages specifically includes the following steps:

[0042] Step 41: Electric upsetting preheating stage: the cylindrical bar is preheated by electric conduction, and the anvil of the electric upsetting equipment is preheated by heat radiation of the cylindrical bar; in this stage, the upsetting cylinder pressure of the electric upsetting equipment is set to 5-10 kN, the displacement is 0 mm, and the current is 2000-5000 A; the preheating temperature of the heating zone where the cylindrical bar part between the electrode and the anvil of the electric upsetting equipment is located reaches 200-500°C, and the holding time is 5-10 s, that is, the preheating temperature of the heater where the cylindrical bar part is located needs to be maintained at 200-500°C for 5-10 s; the anvil is preheated by synchronous temperature rise by heat conduction, and the heating zone of the cylindrical bar part between the electrode and the anvil of the electric upsetting equipment is the bar heating zone;

[0043] Step 42: initial electric upsetting stage, also known as initial deformation, the cylindrical bar is preliminarily preformed by the combined action of the deformation temperature reached by the bar heating zone, the upsetting cylinder displacement and pressure, and the anvil backoff.

[0044] In the initial electric upsetting stage, the heating current and the pressure are the same as the current and the pressure in the preheating stage, or the difference is within a preset threshold range, the upsetting cylinder sequentially performs two straight-line displacements in the direction of the anvil, the sum of the displacement amounts of the two straight-line displacements is 50-70 mm (including the end values), and the displacement amount of the first straight-line displacement is < the displacement amount of the second straight-line displacement; the initial electric upsetting stage includes two different upsetting pressures, the upsetting pressure of the first section is 11-15 kN (including the end values), and the upsetting pressure of the second section is 13-17 kN (including the end values), and the upsetting current is different during the two displacement processes, the upsetting current during the first displacement process is 2700-3100 A (including the end values), and the upsetting current during the second displacement process is 2900-3300 A (including the end values), so as to gradually increase the temperature of the bar heating zone to 900-1120°C, thereby reaching the required temperature range for deformation; and by gradually increasing the applied pressure, the deformation part of the cylindrical bar gradually accelerates the metal aggregation into a micro-drum shape. As the cylindrical bar begins to upset, the anvil also begins to retreat synchronously with the cylindrical bar. And during the anvil retreat operation, 3-4 displacements are set, each displacement performs different retreat speeds, so that the garlic-shaped protrusions formed after the cylindrical bar is upset are smooth and meet the requirements. If 4 displacements are set, the retreat speed of the anvil decreases from fast to slow (i.e. gradually decreases), and the retreat speeds corresponding to the 4 displacements are 1.3 mm / s, 1.1 mm / s, 0.8 mm / s, and 0.6 mm / s. During the 4 displacement processes of the anvil retreat, the intermediate structure has a preset protrusion height of 44 mm, and the 4 displacement distances are [5, 15] mm, [15, 25] mm, [25, 35] mm, and [35, 45] mm.

[0045] Step 43: enter the middle upsetting stage, that is, rapid deformation, by increasing the pressure and displacement of the upsetting cylinder, the cylindrical bar in the bar heating zone is rapidly deformed into a round drum shape;

[0046] During the intermediate upsetting stage, the intermediate structural component undergoes three to five linear displacements sequentially. The total displacement of the three linear displacements is 100-140 mm (including the end value), and the displacement of the first linear displacement is less than that of the second linear displacement, which is less than that of the third linear displacement. The heating current for the cylindrical bar stock during the intermediate upsetting stage is greater than that during the electric upsetting preheating stage. The current gradually increases at each stage, with an increment of 150-250 A (including the end value) to ensure that the current can maintain the temperature of the bar stock's heating zone within the deformation temperature range during the rapid deformation process of the intermediate upsetting stage. The forging pressure in the intermediate upsetting stage is greater than that in the initial electric heating upsetting stage. The intermediate upsetting stage is set to include 3-5 different forging pressures. The forging pressure in each stage increases gradually. Starting from the first stage, the forging pressure in each stage increases by 0.5-5 kN. This is to ensure that the deformation resistance of the cylindrical bar gradually increases during rapid deformation, and the pressure of the upsetting cylinder is increased simultaneously to ensure that the deformation meets the requirements.

[0047] Step 44: Enter the final upsetting stage. By increasing the pressure and current of the upsetting cylinder and gradually slowing down or stopping the anvil retraction speed, the intermediate structural parts continue to gather and gradually take shape.

[0048] In the final upsetting stage, the anvil retraction displacement is 50±10mm. By adjusting the upsetting displacement, it is ensured that the intermediate structural parts can be placed into the mold for forging to meet the blank size requirements. The corresponding current and upsetting pressure are greater than those in the middle upsetting stage, with the current increasing by 200A±50A and the forging pressure also increasing by 0.5-5kN.

[0049] Step 45: Enter the necking stage, gradually transforming the cylindrical bar in the bar heating zone from a bulge shape into a smooth, rounded garlic-shaped bar.

[0050] During the necking stage, the displacement of the upsetting cylinder is 5-15mm. The pressure of the upsetting cylinder in the intermediate upsetting stage is greater than that in the necking stage, which is greater than that in the initial electrothermal upsetting stage. Similarly, the upsetting current in the intermediate upsetting stage is greater than that in the necking stage, which is greater than that in the initial electrothermal upsetting stage. At the same time, the anvil retraction is restarted and should be performed quickly at a speed of 1.5-6mm / s and a distance of 5-10mm. The necking is maintained for 2-6 seconds.

[0051] In step 45, that is, in the necking stage, since the upsetting cylinder stops moving, that is, the cylindrical bar stock is no longer fed into the bar stock heating zone, and the anvil continues to retract, the round drum shape is elongated. As a result, while ensuring the pressure of the upsetting cylinder, the part that is first elongated is the part of the round drum shape near the electrode position, thus forming a garlic head shape.

[0052] Step 3: magnetic property annealing is performed on the blank, and the magnetic property annealing is performed in stages.

[0053] Step 4: finish turning is performed on the blank to obtain the electromagnetic valve seat product.

[0054] Reference Figure 3 , Figure 3 is a structural schematic view of the electromagnetic valve seat product. Through the processing of the above steps, the diameter of the blank rod part 1 can be close to the required φ11.3, and the garlic-shaped protruding part 2 can be forged by electrothermal upsetting to obtain a shape structure of the counterbore 3 with an outer diameter of φ28.7 and an inner diameter of φ19.7, so that the blank material can be largely utilized, the material consumption is reduced, the excess amount is small, and therefore, the processing time is less than that of the traditional processing mode.

[0055] The present application can largely utilize the blank material, reduce the material consumption, have a small excess amount, and therefore, the processing time is less than that of the traditional processing mode, the material utilization rate is high, has better microstructure streamline and compact grain size.

[0056] The embodiments disclosed in the specification are only an example of the one-sided features of the present application, and the protection scope of the present application is not limited to this embodiment. Any other functionally equivalent embodiments fall within the protection scope of the present application. For those skilled in the art, other various corresponding changes and modifications can be made according to the above-described technical solutions and concepts, and all these changes and modifications should belong to the protection scope of the claims of the present application.

Claims

1. A method of machining an electromagnetic valve seat based on electrothermal upsetting, characterized in that, The method comprises the following steps: Step 1: selecting a cylindrical bar, and adopting electric upsetting to process the cylindrical bar in stages to obtain an intermediate structural part, the intermediate structural part comprising a rod portion, and a convex portion in the shape of a garlic head provided at one end of the rod portion, the convex portion having a size greater than that of the rod portion; Step 2: placing the heated intermediate structural part into a die to perform forging forming to obtain a blank, the convex portion comprising a counterbore, and the counterbore being located in the extension direction of the rod portion; Step 3: performing magnetic property annealing on the blank, and the magnetic property annealing being performed in stages; Step 4: performing turning finish machining on the blank to obtain an electromagnetic valve seat finished product, The forging forming specifically comprises the following steps: Step 41: electric upsetting preheating stage: the cylindrical bar is preheated by being electrified, and the anvil of the electric upsetting equipment is preheated by heat radiation of the cylindrical bar; in this stage, the upsetting cylinder pressure of the electric upsetting equipment is set to 5-10 kN, the displacement is 0 mm, and the current is 2000-5000 A; the preheating temperature of the heating zone in which the portion of the cylindrical bar between the electrode and the anvil of the electric upsetting equipment is located reaches 200-500 DEG C, and the holding time is 2-5 s; the anvil is synchronously preheated by heat conduction, and the heating zone in which the portion of the cylindrical bar between the electrode and the anvil of the electric upsetting equipment is located is the bar heating zone; Step 42: initial electric upsetting stage, that is, initial deformation, the bar heating zone reaches the deformation temperature, and the cylindrical bar is initially preformed under the combined action of the upsetting cylinder displacement and pressure and the anvil back-off; In the initial electric upsetting stage, the heating current and the pressure are equivalent to or have a difference within a preset threshold range from the current and the pressure in the preheating stage, the upsetting cylinder sequentially performs two straight-line displacements in the direction of the anvil, the sum of the displacement amounts of the two straight-line displacements is within [50, 70] mm, and the displacement amount of the first straight-line displacement is less than that of the second straight-line displacement; the initial electric upsetting stage comprises two different upsetting pressures, the first-stage upsetting pressure is [11, 15] kN, and the second-stage upsetting pressure is [13, 17] kN; and two different upsetting currents, the first-stage upsetting current is [2700, 3100] A, and the second-stage upsetting current is [2900, 3300] A, to gradually increase the temperature of the bar heating zone to 900-1120 DEG C to reach the required temperature range for deformation; and by gradually increasing the applied pressure, the deformation part of the cylindrical bar gradually accelerates the metal aggregation to form a micro-drum shape, accompanied by the cylindrical bar starting to upset, the anvil also starts to synchronously retreat with the cylindrical bar while the cylindrical bar is upsetting, and during the anvil back-off operation, 3-4 segments of displacement are set, each segment of back-off performs different back-off speeds, so that the garlic head-shaped convex portion formed after the cylindrical bar is upset is smooth and sufficient to meet the requirements. If the displacement is set to 4 segments, the anvil back-off speed is gradually reduced, and the 4 segment displacements correspond to the back-off speeds of 1.3 mm / s, 1.1 mm / s, 0.8 mm / s, and 0.6 mm / s, respectively. In the 4 segment displacement process of the anvil back-off, the intermediate structural member has a preset protrusion height of 44 mm, and the 4 segment displacement distances are [5, 15] mm, [15, 25] mm, [25, 35] mm, and [35, 45] mm, respectively. Step 43: enter the middle stage of upsetting, that is, rapid deformation, by increasing the pressure and current of the upsetting cylinder, the cylindrical bar in the bar heating zone is rapidly deformed into a round drum shape. In the middle stage of upsetting, the intermediate structural member is subjected to three straight-line displacements, the sum of the displacement amounts of the three straight-line displacements is in the range of [100, 140] mm, and the displacement amount of the first straight-line displacement is less than that of the second straight-line displacement, which is less than that of the third straight-line displacement. The heating current in the middle stage of upsetting is greater than that in the initial electro-upsetting preheating stage, and 3-5 stage displacements are set accordingly, the heating current is gradually increased, and the increment of the heating current in each stage is in the range of 150-250 A. The forging pressure in the middle stage of upsetting is greater than that in the initial electro-upsetting stage, and 3-5 stage forging pressures are set accordingly, which are also gradually increased by 0.5-5 kN, so that the deformation resistance of the cylindrical bar gradually increases during the rapid deformation process. Step 44: enter the final stage of upsetting, by increasing the pressure and current of the upsetting cylinder, and gradually slowing down or stopping the anvil back-off speed, so that the intermediate structural member continues to gather and gradually shape. In the final stage of upsetting, the displacement amount of the anvil back-off is 40-60 mm, and the upsetting displacement amount is adjusted to ensure that the intermediate structural member can be placed into the die for forging to meet the blank size requirements. The corresponding current and upsetting pressure are greater than those in the middle stage of upsetting, the current is increased by 150-250 A, and the forging pressure is also increased by 0.5-5 kN. Step 45: enter the necking stage, so that the cylindrical bar in the bar heating zone gradually deforms into a garlic-shaped shape that is smoothly connected to the cylindrical bar, so that the head and rod of the blank are easily forged in place. In the necking stage, the displacement amount of the upsetting cylinder is 5-15 mm, the upsetting cylinder pressure in the middle stage of upsetting is greater than that in the necking stage, which is greater than that in the initial electro-upsetting stage, the upsetting current in the middle stage of upsetting is greater than that in the necking stage, which is greater than that in the initial electro-upsetting stage, and the anvil back-off is restarted, the back-off speed is 1.5-6 mm / s, the back-off distance is 5-10 mm, and the necking is maintained for 2-6 seconds.

2. The hot upset based solenoid valve seat machining method according to claim 1, characterized by, In step 1, a cylindrical bar with a diameter of 11.7 mm and a length of 260 mm is selected.

3. The hot upset based solenoid valve seat machining method according to claim 2, characterized by, In step 1, the cylindrical bar is processed by electro-upsetting in stages to obtain an intermediate structural member, and the specific implementation process includes the following steps: The cylindrical rod is heated by using the high resistance characteristic of the cylindrical rod itself, the heating temperature is maintained at 900-1120 DEG C, and a deformation force is given to the cylindrical rod during the heating process, so that the one end of the cylindrical rod is formed into a garlic head shape, thereby obtaining the intermediate structural part.

4. The hot upset based solenoid valve seat machining method according to claim 1, characterized by The magnetic performance is annealed, the annealing temperature is 850-980 DEG C, the annealing holding time is 2 hours, and water cooling is performed after discharging.

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