Refrigerant valve and manufacturing process thereof

Abstract

The refrigerant valve comprises a valve seat, the crystal phase organization of the valve seat is in equiaxed grain distribution, and the forming process of the valve seat comprises a warm upsetting process. The forming process of the valve seat in the refrigerant valve comprises the warm upsetting process. The warm upsetting process can make the base body of the valve seat deform plastically, close the cracks around the inclusions in the base body, and further reduce the leakage of the refrigerant in the refrigerant valve.

Description

Technical Field

[0001] This application belongs to the field of fluid control device technology, specifically relating to a refrigerant valve and its manufacturing method. Background Technology

[0002] Refrigerant valves are essential multi-functional and reliable flow control devices in industrial applications. Components in refrigerant valves that come into contact with the refrigerant, such as valve seats, valve pads, valve cores, etc., typically withstand high pressure during internal operation and require high airtightness. However, in related technologies, these components themselves often have numerous cracks caused by inclusions, leading to refrigerant valve leakage. Summary of the Invention

[0003] The purpose of this application is to provide a refrigerant valve, including a valve seat, wherein the crystalline phase morphology of the valve seat exhibits an equiaxed grain distribution; the forming process of the valve seat includes a warm forging process.

[0004] This application includes a warm forging process in the forming process of the valve seat in the refrigerant valve. The warm forging process can cause the base of the valve seat to undergo large plastic deformation, which closes the cracks around the inclusions in the base, thereby reducing the leakage of refrigerant in the refrigerant valve.

[0005] This application also provides a method for manufacturing a refrigerant valve, including a valve seat, the manufacturing method comprising the following steps:

[0006] Provide the valve seat bar stock;

[0007] The valve seat bar is placed in a mold and warm-forged to form a valve seat blank.

[0008] In this application, the valve seat bar is warm-forged to form a valve seat blank. Warm-forging can cause the valve seat matrix to undergo large plastic deformation, which closes the cracks around the inclusions in the matrix, thereby reducing the leakage of refrigerant in the refrigerant valve. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the overall structure of the refrigerant valve in one embodiment of this application;

[0010] Figure 2 for Figure 1 Cross-sectional structural diagram of the refrigerant valve;

[0011] Figure 3 for Figure 1 Explosion-proof diagram of the intermediate refrigerant valve;

[0012] Figure 4 This is a morphological diagram of the crystal phase structure of the valve seat in Example 1;

[0013] Figure 5The image shows the crystalline phase structure of the valve seat in Comparative Example 1.

[0014] Figure 6 The image shows the crystalline phase structure of the valve seat in Comparative Example 2.

[0015] Figure 7 This is a microscopic morphology diagram of the valve seat surface in Example 1;

[0016] Figure 8 This is a microscopic image of the surface morphology of the valve seat in Comparative Example 1. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described below in conjunction with the embodiments of this application.

[0018] Currently, pressure-bearing components inside refrigerant valves are typically formed using bar stock and machining, such as valve seats in solenoid valves, electronic expansion valves, and needle valves. Due to incomplete deoxidation or incomplete floating of inclusions to the surface of the base material during the refining process of the bar stock, inclusions such as chromium oxide, silicates, and composite silicates will be generated in the base material. At the same time, microcracks generally exist around the inclusions and inside the material. These valve seats typically withstand a certain high pressure of refrigerant during operation and have high requirements for airtightness. The presence of internal inclusions and surrounding cracks can cause refrigerant leakage in the refrigerant valve to a certain extent.

[0019] Figures 1 to 3 The image shows a refrigerant valve conforming to this application, including a valve seat, wherein the crystalline phase morphology of the valve seat exhibits an equiaxed grain distribution; the forming process of the valve seat includes a warm forging process.

[0020] This application includes a warm forging process in the forming process of the valve seat in the refrigerant valve. The warm forging process can cause the base of the valve seat to undergo large plastic deformation, which closes the cracks around the inclusions in the base, thereby reducing the leakage of refrigerant in the refrigerant valve.

[0021] In some embodiments, the valve seat is made of stainless steel; further, the stainless steel may be selected from at least one of ferritic stainless steel, austenitic stainless steel, and martensitic stainless steel; specifically, the stainless steel may be selected from 00Cr. 18 At least one of Si2Mo2 stainless steel, 304 stainless steel and 430 stainless steel.

[0022] In some implementations, the refrigerant valve operates at a pressure range of 0-3.1 MPa.

[0023] In some embodiments, the refrigerant valve includes, but is not limited to, solenoid valves, expansion valves, and large-diameter needle valves, as well as other refrigerant valves whose internal structure includes a stainless steel valve seat; it should be noted that the valve seat in this application is a component that bears the pressure from the refrigerant, and the valve seat blank refers to the valve seat without annealing or machining, and only refers to the valve seat after preliminary forming.

[0024] This application also provides a method for manufacturing a refrigerant valve, the refrigerant valve including a valve seat, the manufacturing method comprising the following steps:

[0025] Valve seat bar stock is available;

[0026] The valve seat bar is placed in a mold and warm-forged to form a valve seat blank.

[0027] In some embodiments, the method of manufacturing a refrigerant valve includes step S1 of providing a valve seat bar stock, the valve seat bar stock being selected from stainless steel materials; further, the stainless steel material may be selected from at least one of ferritic stainless steel and austenitic stainless steel.

[0028] In some embodiments, the method for manufacturing a refrigerant valve includes step S2, which involves feeding a valve seat bar into at least three consecutive dies for at least three warm upsetting processes to obtain a valve seat blank, according to the required shape of the valve seat. Further, according to the required shape of the valve seat, a first die is provided, and the bar is fed into the first die for a first warm upsetting process to form a first blank; a second die is provided, and the first blank is fed into the second die for a second warm upsetting process to form a second blank; a third die is provided, and the second blank is fed into the second die for a third warm upsetting process to form a valve seat blank.

[0029] In some embodiments, the warm upsetting step further includes a fourth warm upsetting process, which can be performed between the first and second warm upsetting processes, or between the second and third warm upsetting processes; and so on. The warm upsetting step can also include a fifth, sixth, or even more warm upsetting processes. That is, the valve seat blank can undergo three, four, or even more warm upsetting processes.

[0030] Furthermore, in some embodiments, the first mold is a first deformation mold, the second mold includes at least one intermediate deformation mold, and the third mold is a tail deformation mold; the first warm upsetting process is the first deformation process, the second warm upsetting process includes at least one intermediate deformation process, and the third warm upsetting process is the tail deformation process; the deformation amount of each process is defined as the larger of the upsetting ratio and the reduction of area in each process; the deformation amount of the first deformation process is less than the deformation amount of the intermediate deformation process, and the deformation amount of the intermediate deformation process is less than the deformation amount of the tail deformation process. Based on the deformation amount of each warm upsetting process and the material composition, the deformation amounts of the first deformation process, the intermediate deformation process, and the tail deformation process are adjusted to achieve plastic deformation of the grain structure, thereby closing inclusion cracks in the material, improving the compactness of the internal structure of the valve seat, and thus reducing refrigerant valve leakage.

[0031] Furthermore, in some embodiments, the deformation amount in the first deformation step is ≤5%, the deformation amount in the middle deformation step ranges from 10-40%, and the deformation amount in the final deformation step is >40%. Setting the deformation amount in the warm upsetting process in this way can achieve a denser grain structure, meet sealing requirements, and further improve corrosion resistance while maintaining good magnetic properties. In this application, the deformation amount in each deformation step is determined by the upsetting ratio or the reduction of area, calculated using the following formula.

[0032] Upsetting ratio = (original height of blank before upsetting - height of workpiece after upsetting) / original height of blank before upsetting * 100%.

[0033] Reduction of area = (Cross-sectional area of ​​blank - Cross-sectional area of ​​workpiece after cold heading) / Cross-sectional area of ​​blank * 100%.

[0034] Furthermore, the intermediate deformation mold includes a first intermediate deformation mold, a second intermediate deformation mold, a third intermediate deformation mold, and a fourth intermediate deformation mold. The intermediate deformation process includes a first intermediate deformation process, a second intermediate deformation process, a third intermediate deformation process, and a fourth intermediate deformation process. The deformation amount of the first intermediate deformation process is controlled to be 35-40%, the deformation amount of the second intermediate deformation process is 18-21%, the deformation amount of the third intermediate deformation process is 15-18%, and the deformation amount of the fourth intermediate deformation process is 8-12%.

[0035] It should be noted that the first deformation process shapes the bar stock into a blank, the middle deformation process reduces the diameter of the blank, and controls the amount of deformation to achieve the diameter reduction of the blank while avoiding cracks; the tail deformation process performs hole drawing, hole stretching, and surface shaping on the blank to make the blank more consistent with the target fixed valve seat structure and reduce subsequent finishing.

[0036] Specifically, in some embodiments, the first, second, third, and fourth intermediate deformation processes correspond to warm upsetting deformation in the first, second, third, and fourth intermediate deformation molds, respectively. The deformation amount in the first intermediate deformation process is the reduction of area, while the deformation amounts in the second, third, and fourth intermediate deformation processes are the upsetting rates. Furthermore, in one specific embodiment, the deformation amounts in the first and final deformation processes are the upsetting rates.

[0037] In some embodiments, before placing the valve seat bar stock in the mold for warm upsetting, step S2 further includes heating the valve seat bar stock to 200-500°C, which can be selected from 210°C, 230°C, 250°C, 270°C, 290°C, 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 410°C, 430°C, 450°C, 470°C, 490°C, or other values ​​within this range, without limitation here. Specifically, heating the valve seat bar stock to 200-500°C can improve the plasticity of the valve seat bar stock. Then, the heated valve seat bar stock is sent into the first deformation mold for upsetting to perform the first deformation process, and then sequentially sent into the first intermediate deformation mold, the second intermediate deformation mold, the third intermediate deformation mold, and the fourth intermediate deformation mold for upsetting to perform the second deformation process, respectively. The process involves four stages of deformation: a first stage, a second stage, a third stage, and a fourth stage. The material is then fed into a tail-end deformation die for final deformation, forming the valve seat blank. The upsetting temperature is 200-500℃, and each die is used for 1-2 seconds to minimize heat loss. The heated valve seat bar is then fed sequentially into six consecutive dies for rapid upsetting to the desired shape, forming the valve seat blank. This warm upsetting process (200-500℃) allows for significant plastic deformation of the bar matrix, closing cracks around inclusions and resulting in an equiaxed grain structure, reducing valve seat leakage and consequently refrigerant leakage in the refrigerant valve. Furthermore, warm upsetting reduces machining time, significantly lowering production costs.

[0038] In some embodiments, the pressure of warm upsetting is 4.5-5.5 kg / cm, and the warm upsetting time is 1-3 seconds. It should be noted that the pressure range of each warm upsetting process is 4.5-5.5 kg / cm, and the warm upsetting time refers to the time required to complete all warm upsetting processes. The crystal phase morphology of the valve seat blank shows a banded grain distribution and a small number of microcracks.

[0039] In some embodiments, the manufacturing method of the refrigerant valve further includes step S3 of annealing and machining the valve seat blank; further, in some embodiments, the annealing temperature is 600-900°C and the annealing time is 30-60 min.

[0040] refer to Figure 1 and Figure 3 As shown, in some embodiments, the refrigerant valve includes a core assembly 1, a mounting base 2, and a coil component 3. The mounting base 2 has a first receiving cavity 21 and an inlet channel 23 and an outlet channel 24 communicating with the first receiving cavity. Part of the core assembly 1 is located in the first receiving cavity 21, and the core assembly 1 is fixedly connected to the mounting base 2.

[0041] In some embodiments, the core assembly 1 includes a cylindrical portion 11 and a valve seat 12. The valve seat 12 has at least one portion with an outer diameter larger than that of the cylindrical portion 11, and the valve seat 12 has a surface perpendicular to the axial direction of the cylindrical portion 11. The stationary core portion 112 is located at the lower end of the sleeve 111, and the valve seat 12 and the stationary core portion 112 are integrally formed. A moving core (not shown) is disposed inside the sleeve 111. A coil component 3 is sleeved on the outer periphery of a portion of the cylindrical portion 11. When the coil component 3 is energized or de-energized, the moving core moves, thereby opening and closing the valve port of the solenoid valve to control the flow of refrigerant fluid. Along the axial direction of the cylindrical portion 11, the valve seat 12 is integrally formed with one end of the cylindrical portion 11, and a snap-fit ​​component 5 is fixedly connected to the other end of the cylindrical portion 11. The snap-fit ​​component 5 can axially limit the movement of the coil component 3. In other embodiments of the cylindrical portion 11, the valve seat 12 may also be fixedly connected to one end of the cylindrical portion 11. The cylindrical part 11 includes a sleeve 111 of the solenoid valve and a stationary iron core part 112. The stationary iron core part 112 is located at the upper end of the sleeve 111, that is, the stationary iron core part 112 is separate from the valve seat 12. The snap-fit ​​part 5 is fixedly connected to the stationary iron core part 112. The refrigerant valve also includes a pad 4, an elastic element 6, and a snap-fit ​​part 5 for fixing the coil component 3. The elastic element 6 is located between the coil component 3 and the valve seat 12, and the elastic element 6 abuts against the valve seat 12 and the coil component 3.

[0042] In some embodiments, the coil component 3 includes a magnetic conductor 7 located on its outer periphery. The magnetic conductor 7 has an axially extending extension 71 extending from the coil component 3 toward the mounting base 2. The mounting base 2 has a second groove 22 corresponding to the extension 71, at least a portion of the extension 71 being located in the second groove 22, thereby achieving circumferential positioning of the coil component 3. The extension 71 can be formed by bending a portion of the magnetic conductor 7. When installing the coil component 3, the extension 71 can be inserted axially into the second groove 22. This circumferential positioning structure is relatively simple, easy to install, and occupies less space on the mounting base 2, which is beneficial for further miniaturization of the mounting base 2. It is suitable for situations where there is a large height difference between the main body of the magnetic conductor 7 and the mounting base 2. In different solenoid valves, the coil component 3 needs to be designed with different circumferential rotation directions. The circumferential positioning of the coil component 3 can be achieved by setting the second groove 22 at different positions on the mounting base 2 without changing the structure of the coil component 3.

[0043] In some embodiments, the coil component 3 includes a magnetic conductor 7 located on its outer periphery. The magnetic conductor 7 has an axially extending extension 71 extending from the coil component 3 toward the mounting base 2. The mounting base 2 has a first groove 22 corresponding to the extension 71, and at least a portion of the extension 71 is located in the first groove 22, thereby achieving circumferential positioning of the coil component 3. The extension 71 can be formed by bending a portion of the magnetic conductor 7. When installing the coil component 3, the extension 71 can be axially inserted into the second groove 22. This circumferential positioning structure is relatively simple, easy to install, and occupies less space on the mounting base 2, which is beneficial for further miniaturization of the mounting base 2. It is suitable for situations where there is a large height difference between the main body of the magnetic conductor 7 and the mounting base 2. In different solenoid valves, the coil component 3 needs to be designed with different circumferential rotation directions. The circumferential positioning of the coil component 3 can be achieved by setting the first groove 22 at different positions on the mounting base 2 without changing the structure of the coil component 3.

[0044] It should be noted that the refrigerants mentioned in this application include, but are not limited to, R22, R32, R290, R410A, etc.

[0045] The manufacturing method of the refrigerant valve in this application will be described below with reference to specific embodiments.

[0046] Example 1

[0047] A method for manufacturing a refrigerant valve includes the following steps:

[0048] S1. Provide valve seat bar stock, wherein the material of the bar stock is 00Cr. 18Si2Mo2 stainless steel comprises: 0.015 wt% carbon (C), 1.5 wt% silicon (Si), 0.25 wt% manganese (Mn), 0.02 wt% phosphorus (P), 0.005 wt% sulfur (S), 17.5 wt% chromium (Cr), 1.3 wt% molybdenum (Mo) and balance iron (Fe);

[0049] S2. First, heat the valve seat bar stock to 350℃ to improve its plasticity. Then, according to the required shape of the valve seat, sequentially feed the valve seat bar stock into the first deformation die for upsetting, performing the first deformation process at a pressure of 4.5 kg / cm. The deformation amount in the first deformation process is controlled at an upsetting rate of 5%. Next, feed it into the first intermediate deformation die for upsetting, performing the first intermediate deformation process at a pressure of 5.2 kg / cm. The deformation amount in the first intermediate deformation process is controlled at a reduction of area of ​​35%. Finally, feed it into the second intermediate deformation die for upsetting, performing the second intermediate deformation process at a pressure of 5.0 kg / cm. The deformation amount in the second intermediate deformation process is controlled at... The upsetting ratio is 25%, then it is fed into the third intermediate deformation mold for upsetting and forging in the third intermediate deformation process. The pressure is 4.8 kg / cm, and the deformation amount in the third intermediate deformation process is controlled at an upsetting ratio of 15%. Then it is fed into the fourth intermediate deformation mold for upsetting and forging in the fourth intermediate deformation process. The pressure is 4.7 kg / cm, and the deformation amount in the fourth intermediate deformation process is controlled at an upsetting ratio of 10%. Finally, it is fed into the tail deformation mold for tail deformation process. The pressure is 5.4 kg / cm, and the deformation amount in the tail deformation process is controlled at an upsetting ratio of 45%, which is warm upsetting. The entire warm upsetting time is 2 seconds, and the valve seat blank is obtained.

[0050] S3. Anneal the above valve seat blank at a temperature of 850°C for 60 minutes, then machine it to form a valve seat, and assemble the various components to obtain a refrigerant valve.

[0051] Example 2

[0052] A method for manufacturing a refrigerant valve, which differs from Example 1, is as follows:

[0053] In step S2, the valve seat bar stock is first heated to 450°C. Then, according to the required shape of the valve seat, the valve seat bar stock is sequentially fed into the first deformation mold, the first intermediate deformation mold, the second intermediate deformation mold, the third intermediate deformation mold, the fourth intermediate deformation mold, and the tail deformation mold for upsetting. The first deformation process, the first intermediate deformation process, the second intermediate deformation process, the third intermediate deformation process, the fourth intermediate deformation process, and the tail deformation process are carried out respectively. That is, after warm upsetting, the valve seat blank is obtained.

[0054] All other steps are the same as in Example 1.

[0055] Example 3

[0056] A method for manufacturing a refrigerant valve, which differs from Example 1, is as follows:

[0057] In step S3, the valve seat blank is annealed at a temperature of 870°C for 60 minutes, and then machined to form the valve seat. The various components are then assembled to obtain the refrigerant valve, i.e., the expansion valve.

[0058] All other steps are the same as in Example 1.

[0059] Comparative Example 1

[0060] A method for manufacturing a refrigerant valve includes the following steps:

[0061] S1. Provide valve seat bar stock, wherein the material of the bar stock is 00Cr. 18 Si2Mo2 stainless steel comprises: 0.015 wt% carbon (C), 1.5 wt% silicon (Si), 0.25 wt% manganese (Mn), 0.02 wt% phosphorus (P), 0.005 wt% sulfur (S), 17.5 wt% chromium (Cr), 1.3 wt% molybdenum (Mo) and balance iron (Fe);

[0062] S2. The valve seat bar is machined according to the required shape of the valve seat to obtain the valve seat, and the various components are assembled to obtain the refrigerant valve.

[0063] Comparative Example 2

[0064] A method for manufacturing a refrigerant valve includes the following steps:

[0065] S1. Provide valve seat bar stock, wherein the material of the bar stock is 00Cr. 18 Si2Mo2 stainless steel comprises: 0.015 wt% carbon (C), 1.5 wt% silicon (Si), 0.25 wt% manganese (Mn), 0.02 wt% phosphorus (P), 0.005 wt% sulfur (S), 17.5 wt% chromium (Cr), 1.3 wt% molybdenum (Mo) and balance iron (Fe);

[0066] S2. According to the required shape of the valve seat, the valve seat bar is placed in a hot forging equipment for forging. The inner cavity of the equipment is adapted to the outer shape of the valve seat. The temperature during the hot forging process is 950℃, and a valve seat blank is obtained.

[0067] S3. The valve seat blank is annealed at a temperature of 900℃ for 60 minutes, then machined to form the valve seat. The refrigerant valve is obtained by assembling the various components.

[0068] Experimental example:

[0069] 1. The test method for using a cut section of the valve seat as a test sample to test various performance characteristics is as follows:

[0070] ① The hardness of the sample shall be tested in accordance with GB / T 4340.1-2009 Metallic Materials Vickers Hardness Test Part 1: Test Method.

[0071] ② The average grain size of the metal shall be determined according to the intercept point method in GB / T 6394-2017;

[0072] ③ Magnetic properties were determined in accordance with GB / T 13012-2008.

[0073] The performance standards required for industrial applications are shown in Table 1.

[0074] Table 1 Performance Standards Required by Industry

[0075]

[0076] The test results of the valve seat samples in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 are shown in Table 2.

[0077] Table 2 Performance test results of samples in each embodiment and comparative example

[0078]

[0079] As can be seen from Table 2, the hardness, grain size and magnetic properties of the samples in Examples 1, 2 and 3 all meet the requirements for industrial use, and the hardness is higher than that of Comparative Example 1 and Comparative Example 2, indicating that the valve seat made by warm forging in this application has excellent mechanical properties and magnetic properties, and meets the requirements for industrial use.

[0080] 2. Salt spray resistance test

[0081] The sample of the solenoid valve without the coil was placed in a salt spray chamber, and the results were recorded every 24 hours. After 1000 hours, the surface of the valve seat was observed to see if red rust was generated. The test results are shown in Table 3.

[0082] Table 3 shows the salt spray resistance test results of the samples.

[0083] Group Salt spray test results Example 1 No red rust Example 2 No red rust Example 3 No red rust Comparative Example 1 Red rust forms after 500 hours Comparative Example 2 Red rust forms after 720 hours.

[0084] As can be seen from Table 3, no red rust was generated on the surface of the valve seat in Examples 1, 2 and 3, while red rust was generated in Comparative Example 1 after 500 hours and in Comparative Example 2 after 720 hours. This indicates that the valve seat made by the warm forging process in this application, and thus the solenoid valve, has excellent salt spray corrosion resistance.

[0085] 3. Leakage test

[0086] Helium and water leak tests were used to perform external leakage tests on the refrigerant valves of Example 1 and Comparative Example 1. The refrigerant valves in this application are selected from solenoid valves, and the specific requirements are as follows:

[0087] ① Helium testing requirements: At room temperature, apply 2.0-2.3 MPaG of helium gas to the outlet of the solenoid valve, with a helium concentration of not less than 80%; the product itself must have a concentration of <2 g / y (@2.0 MPaG, R134a); the test method is as follows:

[0088] A. The solenoid valve is not equipped with a coil, and its inlet and outlet are connected to the tooling of the helium detection equipment.

[0089] B. At room temperature, the equipment automatically evacuates the solenoid valve and the test chamber, and fills the inlet and outlet of the solenoid valve with high-purity nitrogen gas at a pressure of 2.0-2.3 MPaG to conduct a large leak test. If it fails, the equipment will alarm.

[0090] C. If qualified (the equipment does not alarm), the equipment will automatically evacuate the solenoid valve and the test chamber, and then charge the solenoid valve with helium gas at a pressure of 0.5-0.6 MPaG and a concentration of not less than 80% for a leak test. If it fails, the equipment will alarm.

[0091] D. If it passes (the equipment does not alarm), the equipment continues to charge the solenoid valve with 2.0-2.3 MPaG of helium gas with a concentration of not less than 80% for micro-leakage testing. If it fails, the equipment will alarm.

[0092] ② Water test requirements: Apply 3.0-3.3 MPaG of dry air to the inlet of the solenoid valve and maintain the pressure for 60 seconds. No air bubbles should be generated at any sealing connection points of the solenoid valve. The test method is as follows:

[0093] A. The solenoid valve is not equipped with a coil, and the inlet is connected to the water testing bench fixture (air enters at both the inlet and outlet simultaneously);

[0094] B. At room temperature, air at 3.0-3.3 MPaG is introduced through the inlet;

[0095] C. Immerse the entire valve in water and maintain pressure for 60 seconds. Observe that no air bubbles are generated at the sealing connection parts of the solenoid valve.

[0096] 1000 solenoid valves from Example 1 and 1000 solenoid valves from Comparative Example 1 were randomly selected for helium and water testing. The test results are shown in Table 4.

[0097] Table 4 Comparison of leakage tests of the solenoid valves in Example 1 and Comparative Example 1

[0098] Group Leakage Leakage rate / % Example 1 0 0 Comparative Example 1 101 1.01

[0099] As can be seen from Table 3, no leakage was found in the solenoid valve of Example 1 after helium and water tests, while the leakage rate of Comparative Example 1 was 1.01%. This shows that the valve seat made by the warm forging process in this application and then assembled into a solenoid valve can make the internal structure of the valve seat more compact and significantly reduce the leakage rate of the solenoid valve.

[0100] The tissue morphology of the valve seats in Example 1, Comparative Example 1, and Comparative Example 2 was observed using an electron scanning microscope. Figure 4 , Figure 5 and Figure 6 The images shown are tissue morphology diagrams from Example 1, Comparative Example 1, and Comparative Example 2, respectively. Figure 4 It can be seen that the crystal structure of the valve seat in Example 1 almost exhibits an equiaxed grain distribution, composed of... Figure 5 It can be seen that the crystal phase morphology of Comparative Example 1 exhibits an irregular lamellar distribution, which is caused by... Figure 6 It can be seen that the crystal phases in Comparative Example 2 are not uniform in size and are unevenly distributed. Furthermore, according to the OM optical microscope, the σ phase with a particle size of 2μm or larger precipitates in the matrix of the valve seat sample in Example 1 at a density of 13 particles / (30μm×30μm), while the σ phase with a particle size of 2μm or larger precipitates in the matrix of the valve seat sample in Comparative Example 2 at a density of 34 particles / (30μm×30μm), which is higher than that in Example 1. The proportion of σ precipitates in the matrix of the valve seat in the refrigerant valve of this application is relatively small, which makes the refrigerant valve have excellent corrosion resistance, mechanical properties and magnetic properties, while reducing the leakage of refrigerant in the refrigerant valve.

[0101] In addition, scanning electron microscopy was used to observe the surface microstructure of the valve seats in Example 1 and Comparative Example 1. Figure 7 This is a microscopic image of the surface morphology of the valve seat in Example 1. Figure 8 This is a microscopic image of the surface morphology of the valve seat in Comparative Example 1, created by... Figure 7 As can be seen, in Example 1, only inclusions were observed, while no obvious cracks were observed around the inclusions. Figure 8 As can be seen, the valve seat surface in Comparative Example 1 has inclusions and cracks around it. Therefore, it can be concluded that the valve seat obtained by the warm forging process in this application can reduce the cracks caused by inclusions in the valve seat matrix, thereby reducing the leakage of the refrigerant valve.

Claims

1. A refrigerant valve, characterized in that, The refrigerant valve includes a valve seat, characterized in that the crystal phase morphology of the valve seat exhibits an equiaxed grain distribution; The forming process of the valve seat includes a warm forging process.

2. The refrigerant valve according to claim 1, characterized in that, The valve seat is made of stainless steel.

3. The refrigerant valve according to claim 1 or 2, characterized in that, The refrigerant valve includes at least one of a solenoid valve, an electronic expansion valve, and a needle valve.

4. A method for manufacturing a refrigerant valve, the refrigerant valve comprising a valve seat, characterized in that, The manufacturing method includes preparing a valve seat, which includes the following steps: Supply bar stock; The bar stock is placed in a mold and warm-forged to form a valve seat blank.

5. The manufacturing method according to claim 4, characterized in that, Before placing the bar stock in the mold for warm upsetting, the method further includes the following steps: The bar stock is heated to 200-500℃.

6. The manufacturing method according to claim 4 or 5, characterized in that, The step of placing the bar stock in a mold for warm upsetting includes: A first mold is provided, and the bar stock is placed into the first mold for a first temperature upsetting process to form a first blank; A second mold is provided, and the first blank is placed into the second mold to perform a second temperature upsetting process to form the second blank; A third mold is provided, and the second blank is placed into the second mold for a third temperature upsetting process to form a valve seat blank.

7. The manufacturing method according to claim 6, characterized in that, The pressure for warm upsetting is 4.5-5.5 kg / cm, and the warm upsetting time is 1-3 seconds.

8. The manufacturing method according to claim 6, characterized in that, The first mold is a first deformation mold, the second mold includes at least one intermediate deformation mold, and the third mold is a tail deformation mold. The first warm upsetting process is a first deformation process, the second warm upsetting process includes at least one intermediate deformation process, and the third warm upsetting process is a tail deformation process. The deformation amount of each process is defined as the larger of the upsetting ratio and the reduction of area in each process. The deformation amount of the first deformation process is less than the deformation amount of the intermediate deformation process, and the deformation amount of the intermediate deformation process is less than the deformation amount of the tail deformation process.

9. The manufacturing method according to claim 4, 5, 7 or 8, characterized in that, After the bar stock is placed in a mold and warm-forged, the process further includes the following steps: The valve seat blank is annealed and machined.

10. The manufacturing method according to claim 9, characterized in that, The annealing temperature is 600-900℃, and the annealing time is 30-60 minutes.

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