Vacuum diffusion welding type regular arch rupture disk and manufacturing process thereof

Abstract

The invention discloses a vacuum diffusion welding type regular-arch-shaped rupture disk and a manufacturing process thereof, and the vacuum diffusion welding type regular-arch-shaped rupture disk comprises an upper-layer rupture disk and a lower-layer rupture disk which are mutually overlapped and fixed; a cross-shaped weakening groove penetrating through the thickness direction of the upper-layer rupture disk is formed in the arc-shaped surface of the upper-layer rupture disk, and the end part of the weakening groove is in smooth transition; the upper layer rupture disk is further provided with four air holes which are evenly distributed, and the diameter of each air hole is smaller than 0.1 time of the diameter of the rupture disk. The manufacturing process comprises the following steps: processing a circular sheet, carrying out punch forming, milling a weakening groove and an air hole, overlapping and fixing the rupture disk, and carrying out vacuum diffusion welding forming. The split type assembly machining method is adopted, so that the cross-shaped weakening groove can be accurately machined when not in the same plane, the problem that local stress of the rupture disk is concentrated or is inconsistent with design due to behaviors such as tool abrasion and scratching in the machining process of the rupture disk is solved, and the real rupture pressure of the rupture disk is accurately matched with a calculated value.

Description

Technical Field

[0001] The invention relates to the technical field of bursting disc production and processing, and in particular to a vacuum diffusion welded positive arch bursting disc and a manufacturing process thereof. Background Art

[0002] Various pressure-bearing equipment used in industry often have the problem of increased internal pressure during service due to improper process operation and other means. If the internal pressure of the equipment exceeds the safe allowable value of the equipment, it may cause irreversible damage to the equipment itself. At the same time, the failure of the pressure-bearing equipment will cause unpredictable harm to the surrounding environment and personnel. At present, the most common method to avoid equipment overpressure is overpressure relief, using bursting discs or safety valves to release the overpressure medium in time. A bursting disc is an overpressure relief device controlled by a pressure difference. At the set bursting temperature, when the pressure difference on both sides of the bursting disc reaches a predetermined value, the bursting disc can be activated (ruptured or fallen off) and release the fluid medium.

[0003] As a safety accessory for pressure vessels, pipelines and equipment, bursting discs are crucial to ensure the safe operation of pressure vessels and pipelines under set pressure. However, for the positive arch bursting discs that are currently more commonly used, weakening grooves are usually processed on the bursting discs in order to directional blast and avoid the generation of fragments. However, during the processing of the weakening grooves on the positive arch bursting discs, the grooves are cut according to the curvature of the pre-arch surface, which requires extremely high tool accuracy, and the tool is not easy to repair after being damaged. Due to the wear of the tool during the weakening groove processing, the size of the weakening groove is inconsistent with the design size, or the tool scratches the weakening groove, causing stress concentration in the local position of the weakening groove, which can cause the actual blasting pressure of the bursting disc to be inconsistent with the design pressure. To solve this problem, Chinese patent with patent publication number CN114909502A records a positive arch ring groove type bursting disc and its production equipment, and designs the processing of the weakening groove to be on the same plane; Chinese patent with patent publication number CN115031045A discloses a cross four-arched grooved bursting disc pressure relief device and its manufacturing method, and designs the cross-shaped weakening groove to be on the same plane as the sealing surface, and adopts flat blade processing; Chinese patent with patent publication number CN206652871U invents a mold for accurately controlling the bursting pressure of cross-groove metal bursting discs. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art, to solve the problem that the bursting pressure is inconsistent with the calculated pressure and the bursting pressure fluctuates greatly during the bursting piece design process, and to provide a vacuum diffusion welded positive arch bursting piece and its manufacturing process.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A vacuum diffusion welded positive arch bursting disc comprises an upper bursting disc and a lower bursting disc, both of which are formed by stamping circular thin sheets and are superimposed and fixed to each other; a cross-shaped weakening groove is provided on the arc surface of the upper bursting disc, the weakening groove runs through the thickness direction of the upper bursting disc, and the end of the weakening groove has a smooth transition; four air holes are also provided on the upper bursting disc, respectively arranged in the four divided spaces of the cross-shaped weakening groove, and the diameter of each air hole is less than 0.1 times the diameter of the bursting disc.

[0007] Furthermore, the surface roughness of the circular slice is controlled to be less than 0.2 μm and is mirror-polished; the thickness of the circular slice is adjusted as required, and the pre-arch heights of the upper bursting disc and the lower bursting disc are the same.

[0008] Furthermore, the width of the cross-shaped weakening groove is 0.5-1 mm, and the transition radius of the end of the weakening groove is 0.5 times the width of the weakening groove.

[0009] Furthermore, a bursting disc fixing fixture is used in the processing of a vacuum diffusion welded positive arch bursting disc, and the bursting disc fixing fixture includes an upper fixing fixture and a corresponding lower fixing fixture. An inwardly recessed bursting disc cavity is provided at the center position of the bottom surface of the upper fixing fixture, and an outwardly protruding top block is provided on the top surface of the lower fixing fixture. When the upper fixing fixture and the lower fixing fixture are relatively buckled, the top block is embedded in the bursting disc cavity and surrounds a bursting disc placement space with it. The upper fixing fixture and the lower fixing fixture are relatively fixed on all sides by fastening bolts.

[0010] Furthermore, the upper fixing fixture and the lower fixing fixture are provided with corresponding ventilation holes, and the arrangement positions of the ventilation holes correspond to the ventilation holes on the bursting disc.

[0011] Furthermore, symmetrically arranged positioning grooves are respectively arranged on the top edge of the lower fixing fixture; and positioning blocks matched with the above positioning grooves are respectively arranged on the bottom edge of the upper fixing fixture.

[0012] The technical solution of the present invention also provides a manufacturing process for producing the above-mentioned vacuum diffusion welded positive arch bursting disc, which includes the following processing steps:

[0013] S1. Process circular thin sheets and stamp them at a slow rate; according to the diameter D1 of the bursting disc and the outer diameter D2 of the flat sealing surface, two circular thin sheets with a diameter of D2+2 to D2+3 are cut out by wire cutting. After cutting, the circular thin sheets are cleaned to remove surface oil and impurities; two circular thin sheets are stacked and covered with a layer of graphite powder in the middle; before stamping, the punching machine is cleaned and the stamping equipment is checked for sharp chamfers in the transition area between the pre-arch section and the flat sealing surface, and then covered with a layer of graphite powder; the punch of the punching machine is slowly moved, and the circular thin sheet is slowly fitted with the punch, and then kept for 10 minutes, unloaded, taken out, the surface graphite is cleaned, and whether there is mechanical scratch; the two stamped circular thin sheets are stacked again, and the bursting disc with a diameter of D2 is processed by wire cutting. After the processing is completed, the oil is cleaned; at the same time, tensile specimens of equal thickness are processed according to the tensile standard;

[0014] S2. Milling the blasting groove; only for the upper blasting piece, use a micro milling cutter to process the cross-shaped weakening groove; during the milling process, adjust the height of the milling cutter as the pre-arch height changes; at the same time, process four air holes on the upper blasting piece, and the diameter of the air holes is less than 0.1D1;

[0015] S3. The blasting discs are superimposed and fixed; the upper blasting discs and the lower blasting discs after cleaning are superimposed and assembled, fixed by a fixing fixture structure, and clamped vertically by bolts, and a layer of graphite powder is sprayed between the blasting disc and the fixing fixture;

[0016] S4. Vacuum diffusion welding molding; the entire fixing fixture structure holding the bursting disc in step S3 and the standard tensile test specimen in step S1 are placed in a vacuum diffusion welding furnace to complete the diffusion welding between the upper bursting disc and the lower bursting disc.

[0017] Furthermore, the cleaning method in step S3 is: first use a low concentration HNO3 aqueous solution to clean for 5 to 10 seconds, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100°C; after drying, use acetone to clean to remove surface grease, and then dry in a hot oven again.

[0018] Furthermore, the specific operation steps in step S4 include: first, extracting the air in the furnace body and ensuring the vacuum degree at about 0.001Pa; slowly heating up, with the heating rate controlled at less than 10°C / min, gradually heating up to about 900°C, and maintaining the temperature for 60 minutes to allow the material interface to fully diffuse; rapidly cooling, with the cooling rate controlled at 100°C / min, and after the temperature drops to 450°C, slowly cooling with the furnace until room temperature, and taking out.

[0019] Compared with the prior art, the present invention has the following beneficial effects: the present invention adopts a split assembly processing method to unify the processing depth of the weakening grooves on the bursting disc, ensures the processing accuracy, and enables precise processing even if the cross-shaped weakening grooves are not in the same plane, without considering the influence of tool wear, and avoids the problem of local stress concentration or inconsistency with the design caused by tool wear, scratches, etc. during the processing of the bursting disc, thereby improving the tolerance accuracy, so that the actual bursting pressure of the bursting disc is accurately consistent with the calculated value, and can be applied to gas cylinders, pressurized reactors, pressure-resistant pipelines and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 An exploded view of the bursting disc of the present invention;

[0021] Figure 2 It is a front view of the overall structure of the fixing fixture in the present invention;

[0022] Figure 3 An exploded view of the fixing fixture of the present invention;

[0023] In the figure: 1, upper bursting disc, 2, lower bursting disc, 3, fixing fixture, 11, cross-shaped weakening groove, 12, air vent, 31, upper fixing fixture, 32, lower fixing fixture, 33, fastening bolt, 34, nut, 35, top block, 36, air vent, 37, positioning groove, 38, positioning block, 39, bolt hole. DETAILED DESCRIPTION

[0024] It should be noted that, in the description of the present invention, terms such as "upper", "lower", "left", "right", "inside", "outside", "top surface", "bottom surface", "center" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various components in the present invention, and do not specifically mean that any component in the present invention must have a specific orientation, be constructed and operated in a specific orientation, and should not be understood as a limitation on the present invention.

[0025] In addition, unless otherwise clearly specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, they can be fixedly connected, detachably connected, or integrally connected; they can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] It should also be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0028] like Figure 1 As shown, a vacuum diffusion welded positive arch bursting disc is mainly used in a safety protection device for a pressure vessel, comprising an upper bursting disc 1 and a lower bursting disc 2, both of which are formed by stamping a circular sheet, the surface roughness of the circular sheet used is controlled to be less than 0.2 μm, mirror polished, and the thickness of the circular sheet is adjusted according to the specific needs of production and processing. The pre-arch heights of the upper bursting disc 1 and the lower bursting disc 2 after stamping are the same; the upper bursting disc 1 and the lower bursting disc 2 are stacked and fixed in sequence from top to bottom, and the upper A cross-shaped weakening groove 11 is provided on the arc surface of the bursting piece 1. The cross-shaped weakening groove 11 runs through the thickness direction of the upper bursting piece 1, and its setting width W is 0.5-1mm. At the same time, the end of the cross-shaped weakening groove 11 has a smooth transition, and its transition radius is 0.5W; four air holes 12 are also equidistantly provided on the upper bursting piece 1, and the four air holes 12 are respectively located in the four spaces divided by the cross-shaped weakening groove 11 on the arc surface of the upper bursting piece 1, and the diameter of each air hole 12 is less than 0.1 times the diameter of the bursting piece.

[0029] In the process of processing the vacuum diffusion welded positive arch bursting disc, a bursting disc fixing fixture 3 is also applied. Figure 2 and Figure 3As shown, the bursting disc fixing fixture 3 includes an upper fixing fixture 31 and a corresponding lower fixing fixture 32. An inwardly recessed bursting disc cavity is provided at the center position of the bottom surface of the upper fixing fixture 31, and an outwardly protruding top block 35 is provided at the center position of the top surface of the lower fixing fixture 32. The top block 35 is adapted to the bursting disc cavity. When the upper fixing fixture 31 and the lower fixing fixture 32 are relatively buckled, the top block 35 is just embedded in the bursting disc cavity and forms a bursting disc placement space therewith. The four corners of the upper fixing fixture 31 and the lower fixing fixture 32 are correspondingly provided with bolt holes 39 that penetrate the upper and lower thickness of the entire fixing fixture 3. When the upper fixing fixture 31 and the lower fixing fixture 32 are buckled, the clamping and fixing are completed by matching fastening bolts 33 and nuts 34. The bursting disc cavity of the upper fixing fixture 31 and the top block 35 of the lower fixing fixture 32 are both provided with four vent holes 36 that penetrate the upper and lower thicknesses and correspond to each other. The vent holes 36 are arranged at positions corresponding to the vent holes 12 on the upper bursting disc 1.

[0030] In order to facilitate the clamping fit between the upper fixing clamp 31 and the lower fixing clamp 32 and maintain the relative stillness between the two, symmetrically distributed positioning grooves 37 are respectively provided at the center positions of the four edges of the top surface of the above-mentioned lower fixing clamp 32; correspondingly, symmetrically distributed positioning blocks 38 are respectively provided at the center positions of the four edges of the bottom surface of the upper fixing clamp 31. When the two are relatively buckled, the positioning blocks 38 are inserted into the corresponding positioning grooves 37 to complete the limit engagement.

[0031] At the same time, in order to process and produce the above-mentioned vacuum diffusion welded positive arch rupture disc, the present invention also provides a manufacturing process for producing the above-mentioned vacuum diffusion welded positive arch rupture disc, which specifically includes the following processing steps:

[0032] S1. Process the circular thin slices and stamp them at a slow rate; according to the diameter D1 of the bursting disc and the outer diameter D2 of the flat sealing surface, two circular thin slices with diameters of D2+2 to D2+3 are cut out by wire cutting. After cutting, the circular thin slices are cleaned to remove surface oil and impurities; two circular thin slices are stacked and covered with a layer of graphite powder in the middle; before stamping, the stamping machine is cleaned and the stamping equipment is checked for sharp chamfers in the transition area between the pre-arch section and the flat sealing surface, and then covered with a layer of graphite powder; the stamping machine punch is slowly moved, and the circular thin slice and the punch are slowly fitted, and then kept for 10 min, unload, take out, clean the surface graphite, and check whether there is mechanical scratch; stack the two stamped circular sheets again, and process the rupture disc with a diameter of D2 by wire cutting, and clean the oil after processing; at the same time, process the tensile specimens of equal thickness according to the tensile standard to provide support for the subsequent theoretical calculation of the performance of vacuum diffusion welding materials after heat treatment; here, stamping the two circular sheets at the same time is beneficial to ensure the tolerance accuracy of the two circular sheets, and the beneficial effect of adding a thin layer of graphite powder is to reduce the friction between the interfaces and avoid mechanical damage;

[0033] S2. Milling blasting groove; only for the upper blasting piece 1, a micro milling cutter is used to process the cross-shaped weakening groove 11; during the milling process, the milling cutter height is adjusted as the pre-arch height changes; at the same time, four air holes 12 are processed on the upper blasting piece 1, and the diameter of the air hole 12 is less than 0.1D1;

[0034] S3. The blasting discs are stacked and fixed; the cleaned upper blasting disc 1 and the lower blasting disc 2 are stacked and assembled, fixed by a fixing fixture 3, and clamped and fixed in the vertical direction by bolts, and a layer of graphite powder is sprayed between the blasting disc and the fixing fixture 3; the cleaning method mentioned here is: first use a low-concentration HNO3 aqueous solution to clean for 5 to 10 seconds, then wash with hot water and then dry in a hot oven, and the drying temperature is controlled at <100°C; after drying, use acetone to clean and remove surface grease, and then dry in a hot oven again; the beneficial effect of the surface cleaning here is to ensure that the upper and lower layers of the blasting disc can be fully diffused, thereby improving the quality of diffusion welding;

[0035] S4. Vacuum diffusion welding molding; put the fixing fixture 3 holding the bursting disc in step S3 as a whole and the standard tensile test specimen in step S1 into a vacuum diffusion welding furnace to complete the diffusion welding between the upper bursting disc 1 and the lower bursting disc 2; the specific operation steps include: first, evacuate the air in the furnace body and ensure the vacuum degree to be around 0.001Pa; slowly heat up, control the heating rate to be less than 10℃ / min, gradually heat up to around 900℃, maintain the temperature for 60min, so that the material interface is fully diffused; quickly cool, control the cooling rate to 100℃ / min, and after the temperature drops to 450℃, slowly cool with the furnace until room temperature, and take out.

[0036] The upper bursting disc 1 is defined as BD1 (Bursting Disc), and the lower bursting disc 2 is defined as BD2.

[0037] Embodiment 1,

[0038] Taking a positive arch grooved bursting disc LC 60-4.0-20 on a chemical equipment as an example, a 0.2mm thick 316L stainless steel sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Wire cutting was used to process two circular sheets with a diameter of 110mm. The diameter D1 of the bursting disc was set to 60mm, and the diameter D2 of the flat sealing surface was set to 100mm. After the wire cutting was completed, the two circular sheets were placed in an acetone solution of an ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 316L stainless steel circular sheets were stacked and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform; before stamping, use an air gun to clean the stamping machine, and check whether there are sharp chamfers in the transition area between the pre-arch section and the flat sealing surface of the stamping equipment, and then apply a layer of graphite powder to reduce the friction at the chamfer during the stamping process. Slowly move the press punch downward at a constant rate of 2mm / min. After the circular sheet and the punch are slowly fitted, keep for 10 minutes, unload, take out, clean the surface graphite, and check whether there are mechanical scratches. Then stack the two stamped circular sheets, and process the 100mm diameter bursting disc circle through wire cutting. After processing, put it into the acetone solution of the ultrasonic cleaning equipment for oil cleaning. Then according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method", a standard tensile specimen of equal thickness is processed for material performance testing after vacuum diffusion welding.

[0039] In the second step, for the superimposed double-layer bursting discs, only the upper bursting disc BD1 is machined for weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, four air holes 12 are machined. Considering the locality and self-limitation of the pressure vessel stress, the diameter of each air hole 12 is 2 mm, evenly distributed on the upper bursting disc 1, and the distance between the air hole 12 and the sealing surface is 5 mm; then a cross-shaped weakening groove 11 is machined. The cross-shaped weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper bursting disc 1; the width W of the cross-shaped weakening groove 11 is 1 mm, and the projection length of the weakening groove on the horizontal plane is 24 mm, 3 mm from the center point, and 3 mm from the edge of the bursting disc; the end of the cross-shaped weakening groove 11 is smoothly transitioned, and the transition radius R is 0.5 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The cross-shaped weakening groove 11 includes four weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0040] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and the surface oil is removed before assembly to ensure that the impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and at the same time ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean to remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is limited and fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction with a hexagonal fastening bolt 33 and a nut 34, and a torque wrench is used during the bolt fixing process to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected with the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0041] The fourth step is to place the entire fixing fixture 3 after the superposition and clamping in the third step into a vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at less than 10℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0042] After processing, three vacuum diffusion welded bursting discs were selected and the processed composite cross groove bursting discs were tested. The bursting pressures were 3.90MPa, 4.06MPa and 4.14MPa, respectively. The deviations from the design errors were 3%, 2% and 4%, respectively, which were less than the standard design deviation of 5%. The bursting discs were qualified.

[0043] Embodiment 2,

[0044] Taking a positive arch grooved bursting disc LC 80-2.0-20 on a chemical equipment as an example, a 310s stainless steel 0.2mm thick sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Two circular sheets with a diameter of 110mm were processed by wire cutting. The diameter D1 of the bursting disc was set to 80mm and the diameter D2 of the plane sealing surface was set to 100mm. After the wire cutting was completed, it was placed in an acetone solution of an ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 310s stainless steel circular sheets were stacked and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform. Before stamping, the stamping machine was cleaned with an air gun to check whether there were sharp chamfers in the transition area between the pre-arch section and the plane sealing surface of the stamping equipment, and then a layer of graphite powder was applied to reduce the friction at the chamfer during the stamping process. Slowly move the punch of the press downward at a constant rate of 2mm / min. After the circular sheet is slowly attached to the punch, keep it for 10 minutes, unload, take it out, clean the surface graphite, and check whether there is any mechanical scratch. Stack the two stamped circular sheets, and process the 100mm diameter rupture disc by wire cutting. After processing, put it into the acetone solution of the ultrasonic cleaning equipment to clean the oil. Then, according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method", process the standard tensile specimen of equal thickness for material performance test after vacuum diffusion welding.

[0045] In the second step, for the superimposed double-layer blasting discs, only the upper blasting disc BD1 is machined with weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, four air holes 12 are machined. The diameter of each air hole 12 is 4 mm, which are evenly distributed on the upper blasting disc 1. The distance between the air holes 12 and the sealing surface is 10 mm. Then, a cross-shaped weakening groove 11 is machined. The cross-shaped weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper blasting disc 1. The width W of the cross-shaped weakening groove 11 is 2 mm, and the projection length of the weakening groove on the horizontal plane is 30 mm, 5 mm from the center point, and 5 mm from the edge of the blasting disc. The end of the cross-shaped weakening groove 11 is smoothly transitioned, and the transition radius R is 1 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The cross-shaped weakening groove 11 includes four weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0046] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and they are cleaned before assembly to remove surface oil stains, ensure that impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean and remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction by tightening the bolts 33 and nuts 34, and use a torque wrench during bolt fixing to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected to the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0047] The fourth step is to place the entire fixing fixture 3 after the superposition and clamping in the third step into a vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at less than 10℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0048] After processing, 3 pieces were selected and tested. The bursting pressures were 1.96MPa, 2.08MPa and 2.07MPa respectively. The deviations from the design error were 2%, 4% and 4% respectively, which were less than the standard design deviation of 5%. The bursting pieces were qualified.

[0049] Embodiment 3,

[0050] Taking a positive arch grooved bursting disc LC 60-4.0-20 on a chemical equipment as an example, a 0.2mm thick 316L stainless steel sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Wire cutting was used to process two circular sheets with a diameter of 110mm. The diameter D1 of the bursting disc was set to 60mm, and the diameter D2 of the flat sealing surface was set to 100mm. After the wire cutting was completed, the two circular sheets were placed in an acetone solution of an ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 316L stainless steel circular sheets were stacked and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform; before stamping, use an air gun to clean the stamping machine, and check whether there are sharp chamfers in the transition area between the pre-arch section and the flat sealing surface of the stamping equipment, and then apply a layer of graphite powder to reduce the friction at the chamfer during the stamping process. Slowly move the press punch downward at a constant rate of 2mm / min. After the circular sheet and the punch are slowly fitted, keep for 10 minutes, unload, take out, clean the surface graphite, and check whether there are mechanical scratches. Then stack the two stamped circular sheets, and process the 100mm diameter bursting disc circle through wire cutting. After processing, put it into the acetone solution of the ultrasonic cleaning equipment for oil cleaning. Then according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method", a standard tensile specimen of equal thickness is processed for material performance testing after vacuum diffusion welding.

[0051] In the second step, for the superimposed double-layer bursting discs, only the upper bursting disc BD1 is machined for weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, four air holes 12 are machined. Considering the locality and self-limitation of the pressure vessel stress, the diameter of each air hole 12 is 1 mm, evenly distributed on the upper bursting disc 1, and the distance between the air hole 12 and the sealing surface is 5 mm; then a cross-shaped weakening groove 11 is machined. The cross-shaped weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper bursting disc 1; the width W of the cross-shaped weakening groove 11 is 0.5 mm, and the projection length of the weakening groove on the horizontal plane is 24 mm, 3 mm from the center point, and 3 mm from the edge of the bursting disc; the end of the cross-shaped weakening groove 11 is smoothly transitioned, and the transition radius R is 0.25 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The cross-shaped weakening groove 11 includes four weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0052] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and the surface oil is removed before assembly to ensure that the impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and at the same time ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean to remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is limited and fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction with a hexagonal fastening bolt 33 and a nut 34, and a torque wrench is used during the bolt fixing process to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected with the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0053] The fourth step is to put the entire fixing fixture 3 after the superposition and clamping in the third step into the vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at 10℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0054] After processing, three vacuum diffusion welded bursting discs were selected and the processed composite cross groove bursting discs were tested. The bursting pressures were 3.88MPa, 4.1MPa and 4.15MPa, respectively. The deviations from the design errors were 3%, 2.5% and 3.75%, respectively, which were less than the standard design deviation of 5%. The bursting discs were qualified.

[0055] Embodiment 4,

[0056] Taking the six-slot positive arch grooved bursting disc LC 80-2.0-20 on a chemical equipment as an example, a 310s stainless steel 0.2mm thick sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Two circular sheets with a diameter of 110mm were processed by wire cutting. The diameter D1 of the bursting disc was set to 80mm, and the diameter D2 of the flat sealing surface was set to 100mm. After the wire cutting was completed, it was placed in the acetone solution of the ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 310s stainless steel circular sheets were superimposed, and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform. Before stamping, use an air gun to clean the stamping machine, check whether there are sharp chamfers in the transition area between the pre-arch section and the flat sealing surface of the stamping equipment, and then apply a layer of graphite powder to reduce the friction at the chamfer during the stamping process. Slowly move the press punch downward at a constant rate of 2mm / min. After the circular sheet and the punch are slowly fitted, keep it for 10 minutes, unload, take it out, clean the surface graphite, and check whether there are mechanical scratches. Superimpose two stamped circular sheets, and use wire cutting to process a 100mm diameter bursting disc circle. After processing, put it into an ultrasonic cleaning equipment in an acetone solution for oil cleaning. Then, according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method", process standard tensile specimens of equal thickness for material performance testing after vacuum diffusion welding.

[0057] In the second step, for the superimposed double-layer blasting discs, only the upper blasting disc BD1 is machined with weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, 6 air holes 12 are machined. The diameter of each air hole 12 is 2 mm, which are evenly distributed on the upper blasting disc 1. The distance between the air holes 12 and the sealing surface is 10 mm. Then, 6 evenly distributed weakening grooves 11 are machined. The weakening grooves 11 are of a penetrating type, which run through the entire thickness direction of the upper blasting disc 1. The width W of the weakening groove 11 is 1 mm, and the length of the weakening groove projection on the horizontal plane is 30 mm, 5 mm from the center point, and 5 mm from the edge of the blasting disc. The end of the weakening groove 11 is smoothly transitioned, and the transition radius R is 0.5 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The weakening grooves 11 include six weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0058] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and they are cleaned before assembly to remove surface oil stains, ensure that impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean and remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction by tightening the bolts 33 and nuts 34, and use a torque wrench during bolt fixing to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected to the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0059] The fourth step is to place the entire fixing fixture 3 after the superposition and clamping in the third step into a vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at less than 10℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0060] After processing, 3 pieces were selected for testing of the processed composite slotted bursting pieces. The bursting pressures were 1.97MPa, 1.91MPa and 2.05MPa, respectively. The deviations from the design errors were 1.5%, 4.5% and 2.5%, respectively, which were less than the standard design deviation of 5%. The bursting pieces were qualified.

[0061] Embodiment 5,

[0062] Taking the eight-slotted positive arch grooved bursting disc LC 80-2.0-20 on a chemical equipment as an example, a 310s stainless steel 0.2mm thick thin sheet was selected for processing. The surface roughness of the circular thin sheet was controlled at <0.2μm and mirror polished. Two circular thin sheets with a diameter of 110mm were processed by wire cutting. The diameter D1 of the bursting disc was set to 80mm, and the diameter D2 of the flat sealing surface was set to 100mm. After the wire cutting was completed, it was placed in the acetone solution of the ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 310s stainless steel circular thin sheets were superimposed, and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform. Before stamping, use an air gun to clean the stamping machine, check whether there are sharp chamfers in the transition area between the pre-arch section and the flat sealing surface of the stamping equipment, and then apply a layer of graphite powder to reduce the friction at the chamfer during the stamping process. Slowly move the press punch downward at a constant rate of 2mm / min. After the circular sheet and the punch are slowly fitted, keep it for 10 minutes, unload, take it out, clean the surface graphite, and check whether there are mechanical scratches. Superimpose two stamped circular sheets, and use wire cutting to process a 100mm diameter bursting disc circle. After processing, put it into an ultrasonic cleaning equipment in an acetone solution for oil cleaning. Then, according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method", process standard tensile specimens of equal thickness for material performance testing after vacuum diffusion welding.

[0063] In the second step, for the superimposed double-layer blasting discs, only the weakening groove is processed for the upper blasting disc BD1. A micro milling cutter with a diameter of 1mm is used to process the weakening groove 11. The weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper blasting disc 1; the width W of the weakening groove 11 is 1mm, and the length of the weakening groove projected on the horizontal plane is 30mm, 5mm from the center point, and 5mm from the edge of the blasting disc; the end of the weakening groove 11 is smoothly transitioned, and the transition radius R is 0.5mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The weakening groove 11 includes eight weakening grooves processed on the upper blasting disc BD1, and the weakening grooves 11 are evenly distributed at 45°.

[0064] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and they are cleaned before assembly to remove surface oil stains, ensure that impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean and remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction by tightening the bolts 33 and nuts 34, and use a torque wrench during bolt fixing to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected to the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0065] The fourth step is to put the entire fixing fixture 3 after the superposition and clamping in the third step into the vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at 9℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, avoid the martensite transformation of austenite and reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, slowly cool with the furnace until room temperature and take it out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0066] After processing, 3 pieces were selected and tested for the processed composite eight-slot bursting pieces. The bursting pressures were 2.07MPa, 2.06MPa, and 1.95MPa, respectively. The deviations from the design errors were 3.5%, 3%, and 2.5%, respectively, which were less than the standard design deviation of 5%. The bursting pieces were qualified.

[0067] Embodiment 6,

[0068] Taking the six-slot positive arched slotted bursting disc on a chemical equipment as an example, a 316L stainless steel 0.2mm thick sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Two circular sheets with a diameter of 110mm were processed by wire cutting. The diameter D1 of the bursting disc was set to 60mm and the diameter D2 of the plane sealing surface was set to 100mm. After the wire cutting was completed, the two circular sheets were placed in the acetone solution of the ultrasonic cleaning equipment to remove impurities such as surface oil and then dried with a hot air blower. Two 316L stainless steel circular sheets were stacked and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform; before stamping, the stamping machine is cleaned with an air gun, and the stamping equipment is checked for sharp chamfers in the transition area between the pre-arch section and the plane sealing surface, and then a layer of graphite powder is applied to reduce the friction at the chamfer during the stamping process. The punch of the press is slowly moved downward at a constant rate of 2mm / min. After the circular sheet is slowly fitted with the punch, it is kept for 10 minutes, unloaded, taken out, the surface graphite is cleaned, and mechanical scratches are checked. Then the two stamped circular sheets are stacked, and a 100mm diameter bursting disc is processed by wire cutting. After processing, it is placed in an ultrasonic cleaning device in an acetone solution for oil cleaning. Subsequently, a standard tensile specimen of equal thickness is processed according to GB / T 228.1 "Metallic Material Tensile Test Part 1: Instability Test Method" for material performance testing after vacuum diffusion welding.

[0069] In the second step, for the superimposed double-layer bursting discs, only the upper bursting disc BD1 is machined for weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, 6 air holes 12 are machined. Considering the locality and self-limitation of the pressure vessel stress, the diameter of each air hole 12 is 5 mm, evenly distributed on the upper bursting disc 1, and the distance between the air hole 12 and the sealing surface is 5 mm; then the weakening groove 11 is machined. The weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper bursting disc 1 and is evenly distributed in a 60° direction; the width W of the weakening groove 11 is 1 mm, and the length of the weakening groove projection on the horizontal plane is 24 mm, 3 mm from the center point, and 3 mm from the edge of the bursting disc; the end of the weakening groove 11 is smoothly transitioned, and the transition radius R is 0.5 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The weakening grooves 11 include six weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0070] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and the surface oil is removed before assembly to ensure that the impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and at the same time ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 5-10s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean to remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is limited and fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction with a hexagonal fastening bolt 33 and a nut 34, and a torque wrench is used during the bolt fixing process to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected with the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0071] The fourth step is to put the entire fixing fixture 3 after the superposition and clamping in the third step into the vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at 8℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0072] After processing, three vacuum diffusion welded bursting discs were selected and the processed composite six-slot bursting discs were tested. The bursting pressures were 3.94MPa, 3.84MPa, and 4.19MPa, respectively. The deviations from the design errors were 1.5%, 4%, and 4.8%, respectively, which were less than the standard design deviation of 5%. The bursting discs were qualified.

[0073] Embodiment 7,

[0074] Taking a positive arch grooved bursting disc on a chemical equipment as an example, a 310s stainless steel 0.2mm thick sheet was selected for processing. The surface roughness of the circular sheet was controlled at <0.2μm and mirror polished. Two circular sheets with a diameter of 110mm were processed by wire cutting. The diameter D1 of the bursting disc was set to 60mm and the diameter D2 of the plane sealing surface was set to 100mm. After the wire cutting was completed, it was placed in an acetone solution of an ultrasonic cleaning equipment to remove impurities such as surface oil and dirt, and then dried with a hot air blower. Two 310s stainless steel circular sheets were stacked and a thin layer of graphite powder was sprayed in the middle to reduce the mechanical friction damage caused by the mismatch of plastic deformation during the stamping process. The stamping process uses the corresponding elliptical punch and the corresponding concave platform. Before stamping, the stamping machine was cleaned with an air gun to check whether there were sharp chamfers in the transition area between the pre-arch section and the plane sealing surface of the stamping equipment, and then a layer of graphite powder was applied to reduce the friction at the chamfer during the stamping process. Slowly move the press punch downward at a constant rate of 2mm / min. After the circular sheet and the punch are slowly attached, keep it for 10 minutes, unload, take it out, clean the surface graphite, and check whether there are mechanical scratches. Stack the two stamped circular sheets, and process the 100mm diameter rupture disc circle by wire cutting. After processing, put it into the acetone solution of ultrasonic cleaning equipment for oil cleaning. Then process the standard tensile specimens of equal thickness according to GB / T228.1 "Metallic Material Tensile Test Part 1: Instability Test Method" for material performance testing after vacuum diffusion welding.

[0075] In the second step, for the superimposed double-layer blasting discs, only the upper blasting disc BD1 is machined with weakening grooves. A micro milling cutter with a diameter of 1 mm is used. First, four air holes 12 are machined. The diameter of each air hole 12 is 2 mm, evenly distributed on the upper blasting disc 1, and the distance between the air holes 12 and the sealing surface is 5 mm; then a cross-shaped weakening groove 11 is machined. The cross-shaped weakening groove 11 is a penetrating type, which runs through the entire thickness direction of the upper blasting disc 1; the width W of the cross-shaped weakening groove 11 is 1 mm, and the projection length of the weakening groove on the horizontal plane is 30 mm, 5 mm from the center point, and 5 mm from the edge of the blasting disc; the end of the cross-shaped weakening groove 11 is smoothly transitioned, and the transition radius R is 0.5 mm. During the milling process, the height of the milling cutter is adjusted as the pre-arch height changes to avoid excessive height between the lowest point of the milling cutter and the pre-arch surface, which will cause the milling cutter to shake and increase the processing error. The cross-shaped weakening groove 11 includes four weakening grooves processed on the upper bursting disc BD1, and the weakening grooves and the air holes 12 are evenly distributed.

[0076] The third step is to stack and fix the composite rupture discs using Figures 2 to 3 The fixing fixture 3 shown in is used for fixing. Before fixing, the upper bursting disc BD1 and the lower bursting disc BD2 are assembled, and they are cleaned before assembly to remove surface oil stains, ensure that impurities such as iron filings and iron wires generated during the weakening groove processing do not enter this link, and ensure that the two layers of bursting discs are free of scratches and deformation damage. The specific cleaning method is: first use a low-concentration HNO3 aqueous solution to clean for 8s, then use hot water to clean and then dry in a hot oven, and the drying temperature is controlled at <100℃; after drying, use acetone to clean and remove surface grease, and then dry in a hot oven again. Fix it with a fixing fixture 3, and spray a layer of graphite powder between the bursting disc and the fixing fixture 3; the fixing fixture 3 is fixed by the corresponding positioning block 38 and positioning groove 37 to avoid twisting during tightening; then fix it in the vertical direction by tightening the bolts 33 and nuts 34, and use a torque wrench during bolt fixing to ensure that the plane force points are evenly stressed. The stacking order from bottom to top is the lower fixing fixture 32, the lower bursting disc 2, the upper bursting disc 1, and the upper fixing fixture 31, which ensures a certain pre-tightening force in the entire diffusion welding process and improves the diffusion welding strength. The hexagonal fastening bolt 33 passes through the corresponding bolt hole 39 and is connected to the nut 34. After being fixed, it is placed in the vacuum diffusion welding furnace to avoid air oxidation.

[0077] The fourth step is to put the entire fixing fixture 3 after the superposition and clamping in the third step into the vacuum diffusion welding furnace to carry out vacuum diffusion welding connection. First, the air in the furnace body is evacuated to ensure that the vacuum degree is about 0.001Pa; slowly heat up, and the heating rate is controlled at 10℃ / min, gradually heat up to about 900℃, and keep the temperature for about 60min, so that the material interface can be fully diffused; quickly cool, and the cooling rate is controlled at 100℃ / min. According to the iron-carbon alloy phase diagram, the martensite transformation of austenite is avoided to reduce the toughness and corrosion resistance of stainless steel; after the temperature drops to 450℃, it is slowly cooled with the furnace until room temperature and taken out. Standard tensile specimens are used for material performance testing. Vacuum diffusion welding is equivalent to a heat treatment, and the material performance after heat treatment is used for design calculations.

[0078] After processing, 3 pieces were selected and tested for the processed composite cross groove bursting discs. The bursting pressures were 3.96MPa, 4.08MPa and 3.07MPa, respectively. The deviations from the design errors were 1%, 2.25% and 1.5%, respectively, which were less than the standard design deviation of 5%. The bursting discs were qualified.

[0079] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A vacuum diffusion welded positive dome rupture disc, characterized in that: It comprises an upper bursting piece and a lower bursting piece, both of which are formed by stamping circular sheets and are fixed to each other; a cross-shaped weakening groove is arranged on the arc surface of the upper bursting piece, the weakening groove runs through the thickness direction of the upper bursting piece, and the end of the weakening groove has a smooth transition; four air holes are also arranged on the upper bursting piece, respectively arranged in the four divided spaces of the cross-shaped weakening groove, and the diameter of each air hole is less than 0.1 times the diameter of the bursting piece.

2. A vacuum diffusion welded positive dome rupture disc according to claim 1, characterized in that: The surface roughness of the circular slice is controlled to be less than 0.2 μm and is mirror-polished; the thickness of the circular slice is adjusted as required, and the pre-arch heights of the upper bursting disc and the lower bursting disc are the same.

3. The vacuum diffusion welded positive dome rupture disc according to claim 1, characterized in that: The width of the cross-shaped weakening groove is 0.5-1 mm, and the transition radius of the end of the weakening groove is 0.5 times the width of the weakening groove.

4. The vacuum diffusion welded positive dome rupture disc according to claim 1, characterized in that: A bursting disc fixing fixture is applied in the processing process, which includes an upper fixing fixture and a corresponding lower fixing fixture. An inwardly recessed bursting disc cavity is provided at the center of the bottom surface of the upper fixing fixture, and an outwardly protruding top block is provided on the top surface of the lower fixing fixture. When the upper fixing fixture and the lower fixing fixture are relatively buckled, the top block is embedded in the bursting disc cavity and surrounds a bursting disc placement space. The upper fixing fixture and the lower fixing fixture are relatively fixed around by fastening bolts.

5. A vacuum diffusion welded positive dome rupture disc according to claim 4, characterized in that: The upper fixing fixture and the lower fixing fixture are provided with corresponding ventilation holes, and the arrangement positions of the ventilation holes correspond to the ventilation holes on the bursting disc.

6. A vacuum diffusion welded positive dome rupture disc according to claim 4, characterized in that: The top edge of the lower fixing fixture is provided with symmetrically arranged positioning grooves; the bottom edge of the upper fixing fixture is provided with positioning blocks matched with the positioning grooves.

7. A manufacturing process for producing the vacuum diffusion welded positive dome rupture disc as claimed in any one of claims 1 to 6, characterized in that: The processing steps include: S1. Process circular thin sheets and stamp them at a slow rate; according to the diameter D1 of the bursting disc and the outer diameter D2 of the flat sealing surface, two circular thin sheets with a diameter of D2+2 to D2+3 are cut out by wire cutting. After cutting, the circular thin sheets are cleaned to remove surface oil and impurities; two circular thin sheets are stacked and covered with a layer of graphite powder in the middle; before stamping, the punching machine is cleaned and the stamping equipment is checked for sharp chamfers in the transition area between the pre-arch section and the flat sealing surface, and then covered with a layer of graphite powder; the punch of the punching machine is slowly moved, and the circular thin sheet is slowly fitted with the punch, and then kept for 10 minutes, unloaded, taken out, the surface graphite is cleaned, and whether there is mechanical scratch; the two stamped circular thin sheets are stacked again, and the bursting disc with a diameter of D2 is processed by wire cutting. After the processing is completed, the oil is cleaned; at the same time, tensile specimens of equal thickness are processed according to the tensile standard; S2. Milling the blasting groove; only for the upper blasting piece, use a micro milling cutter to process the cross-shaped weakening groove; during the milling process, adjust the height of the milling cutter as the pre-arch height changes; at the same time, process four air holes on the upper blasting piece, and the diameter of the air holes is less than 0.1D1; S3. The blasting discs are superimposed and fixed; the upper blasting discs and the lower blasting discs after cleaning are superimposed and assembled, fixed by a fixing fixture structure, and clamped vertically by bolts, and a layer of graphite powder is sprayed between the blasting disc and the fixing fixture; S4. Vacuum diffusion welding molding; the entire fixing fixture structure holding the bursting disc in step S3 and the standard tensile test specimen in step S1 are placed in a vacuum diffusion welding furnace to complete the diffusion welding between the upper bursting disc and the lower bursting disc.

8. A manufacturing process for producing vacuum diffusion welded positive dome rupture discs according to claim 7, characterized in that: The cleaning method in step S3 is: first use a low-concentration HNO3 aqueous solution to clean for 5 to 10 seconds, then use hot water to clean and then dry in a hot oven, with the drying temperature controlled at <100°C; after drying, use acetone to clean to remove surface grease, and then dry in a hot oven again.

9. A manufacturing process for producing vacuum diffusion welded positive dome rupture discs according to claim 7, characterized in that: The specific operation steps in step S4 include: first, extracting the air in the furnace body and ensuring the vacuum degree at about 0.001Pa; slowly heating up, with the heating rate controlled at less than 10°C / min, gradually heating up to about 900°C, and maintaining the temperature for 60 minutes to allow the material interface to fully diffuse; quickly cooling, with the cooling rate controlled at 100°C / min, and after the temperature drops to 450°C, slowly cooling with the furnace until room temperature, and taking out.

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