CN117415236A - Processing method of large duplex stainless steel seal head - Google Patents
Processing method of large duplex stainless steel seal head Download PDFInfo
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- CN117415236A CN117415236A CN202311423576.4A CN202311423576A CN117415236A CN 117415236 A CN117415236 A CN 117415236A CN 202311423576 A CN202311423576 A CN 202311423576A CN 117415236 A CN117415236 A CN 117415236A
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- end socket
- heat treatment
- seal head
- stamping
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- 229910001039 duplex stainless steel Inorganic materials 0.000 title claims abstract description 21
- 238000003672 processing method Methods 0.000 title claims abstract description 10
- 238000003466 welding Methods 0.000 claims abstract description 49
- 238000010438 heat treatment Methods 0.000 claims abstract description 46
- 238000003825 pressing Methods 0.000 claims abstract description 34
- 238000009987 spinning Methods 0.000 claims abstract description 19
- 238000000465 moulding Methods 0.000 claims abstract description 9
- 238000004519 manufacturing process Methods 0.000 claims abstract description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 20
- 239000000463 material Substances 0.000 claims description 14
- 239000003345 natural gas Substances 0.000 claims description 10
- 238000007789 sealing Methods 0.000 claims description 9
- 238000000227 grinding Methods 0.000 claims description 8
- 238000005498 polishing Methods 0.000 claims description 8
- 238000002485 combustion reaction Methods 0.000 claims description 6
- 238000001514 detection method Methods 0.000 claims description 6
- 238000005554 pickling Methods 0.000 claims description 5
- 238000005520 cutting process Methods 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 3
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 230000004907 flux Effects 0.000 claims description 2
- 230000008901 benefit Effects 0.000 abstract description 4
- 238000005336 cracking Methods 0.000 abstract description 4
- 229910000885 Dual-phase steel Inorganic materials 0.000 description 6
- 238000004080 punching Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 206010070834 Sensitisation Diseases 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 230000008313 sensitization Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000002457 bidirectional effect Effects 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009837 dry grinding Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
Abstract
The invention discloses a processing method of a large duplex stainless steel seal head, which comprises the following steps: step S10: manufacturing a wafer; step S20: pre-stamping the wafer, namely cold stamping the wafer through a stamping machine and a stamping die to preliminarily form an end socket, wherein the stamping depth is 60% of the target depth; step S30: performing primary heat treatment, namely performing heat treatment on the preliminarily formed seal head; step S40: pressing the drum, namely placing the preliminarily molded end socket after heat treatment on a drum pressing machine for cold pressing drum operation, and processing the end socket to a target depth; step S50: secondary heat treatment, namely placing the seal head formed by the drum pressing in a heat treatment furnace for heat treatment; step S60: and (3) spinning, namely mounting the molding end socket on a spinning machine, and carrying out cold spinning on the end socket through the spinning machine to finally mold the end socket. The stress generated during cold stamping and cold pressing of the drum is eliminated through primary and secondary heat treatments, the risk of cracking of the welding seam is reduced, the rejection rate of products is reduced, and the economic benefit is increased.
Description
Technical Field
The invention relates to the technical field of end socket machining, in particular to a machining method of a large duplex stainless steel end socket.
Background
The 2507 stainless steel material is a super bidirectional steel material and consists of ferrite and austenite, and compared with the conventional dual-phase steel 2205, the chemical composition of the steel material contains more elements such as chromium, nickel and molybdenum, so that the 2507 steel material has better mechanical property and corrosion resistance, better resistance to chlorides and sulfides, better impact resistance and toughness and higher pressure and temperature resistance, and the container closure head materials adopted in the projects such as chemical industry, petroleum exploitation and ocean engineering are 2507 stainless steel.
For 2507 duplex stainless steel small-size end socket, the traditional processing mode is disc disposable punching, but for 2507 duplex stainless steel large-size (large diameter) end socket, a large punching machine for disposable punching forming is not yet appeared in China temporarily, and the forming can only be realized through a drum pressing mode. The method has extremely high requirements on the strength and toughness of the welding seam, the thickness of the wafer sheet material is gradually reduced along with the increasing depth of the sealing head, the toughness is reduced, ferrite is increased, the welding seam is easy to crack, the processing failure is caused, the rejection rate is high, and the production cost is increased.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: in order to overcome the defects in the prior art, the invention provides a processing method of a duplex stainless steel large-sized sealing head capable of reducing cracking at a welding line.
The technical scheme adopted for solving the technical problems is as follows: a processing method of a duplex stainless steel large-scale seal head comprises the following steps:
step S10: manufacturing a wafer;
step S20: pre-stamping the wafer, namely cold stamping the wafer through a stamping machine and a stamping die to preliminarily form an end socket, wherein the stamping depth is 60% of the target depth;
step S30: performing primary heat treatment, namely performing heat treatment on the preliminarily formed seal head;
step S40: pressing the drum, namely placing the preliminarily molded end socket after heat treatment on a drum pressing machine for cold pressing drum operation, and processing the end socket to a target depth;
step S50: secondary heat treatment, namely placing the seal head formed by the drum pressing in a heat treatment furnace for heat treatment;
step S60: and (3) spinning, namely mounting the molding end socket on a spinning machine, and carrying out cold spinning on the end socket through the spinning machine to finally mold the end socket.
Further, the step S10 includes the following steps,
step S101: selecting 2507 duplex stainless steel plates;
step S102: blanking, scribing the plate according to the design size requirement, and cutting the plate according to the scribing;
step S103: welding, namely welding all the cut part plates to form a whole circle;
step S104: polishing, namely polishing the welding seam to be level with the base material.
Further, in step S103, submerged arc welding is adopted, welding materials are selected from welding wires ER2594 phi 2.4 and matched with Flux805 to carry out welding, the welding current is 380-420A, the voltage is 28-30V, and the speed is 42-46cm/min.
Further, in step S30, the heat treatment is performed in a fully automatic computerized temperature-controlled natural gas furnace, where each burner of the natural gas furnace is provided with a solenoid valve in a gas pipeline, each control solenoid valve is controlled by an independent combustion controller, and the combustion controller can control the opening of the solenoid valve to regulate and control the temperature according to the measured temperature of a temperature-controlled thermocouple provided on the burner, so that the end enclosure is heated uniformly.
Further, the heating temperature of the natural gas furnace is 200+/-15 ℃, and the duration of the heating process is 20-30min.
Further, in step S50, the temperature in the heat treatment furnace is raised to 200 ℃, and the dimension is kept for 30min in the heating process.
Further, the processing method also comprises the following steps,
step S70: bevel and grinding, bevel treatment is carried out on the rotary-press-formed seal head, and bevel is ground so as to ensure the flatness of the bevel;
step S80: flaw detection, performing weld joint RT flaw detection by using an X-ray flaw detector;
step S90: and (3) pickling, namely uniformly smearing pickling solution on the surface of the end socket, and then washing the end socket with clear water to remove oxide layers, oil and rust matters on the surface of the end socket.
The beneficial effects of the invention are as follows: firstly, performing submerged-arc welding on 2507 dual-phase steel wafer plates, wherein the welding adopts low current and multi-layer multi-pass welding, so as to refine weld grains, then performing wafer pre-stamping to reduce the depth of a stamping part of the weld, subsequently performing heat treatment to reduce the surface hardness to enable the surface hardness to meet the condition of subsequent drum pressing, then performing drum pressing to enable the end socket to reach the target depth, performing primary molding of the end socket, and then performing secondary heat treatment to eliminate stress generated during drum pressing, and finally molding the end socket through a spinning process. Compared with the traditional direct drum pressing processing mode, the method solves the problem that the large-diameter 2507 dual-phase steel seal head is difficult to mold, reduces the risk of weld cracking, reduces the rejection rate of products, improves the production efficiency, and greatly increases the economic benefit.
Drawings
The invention is further described below with reference to the drawings and examples.
FIG. 1 is a flow chart of a method for processing a duplex stainless steel large-scale closure of the present invention;
fig. 2 is a flow chart of the process of making the wafer of fig. 1.
Detailed Description
The present invention will now be described in detail with reference to the accompanying drawings. The figure is a simplified schematic diagram illustrating the basic structure of the invention only by way of illustration, and therefore it shows only the constitution related to the invention.
Referring to fig. 1 and 2, the invention provides a processing method of a large duplex stainless steel seal head, which comprises the following steps:
step S10: and (5) manufacturing a wafer. The purpose of this step is to form a circular plate-like structure of uniform thickness.
The step S10 includes the steps of:
step S101: selecting materials. 2507 duplex stainless steel plates are selected, the thickness of the plates is consistent, and the ferrite content is between 35% and 55%.
Step S102: and (5) blanking. Scribing on the plate according to the design size requirement, and taking the scribing as the basis of blanking size, so that each part of scribing can form a whole circle after being spliced. Then, a dicing process is performed for each portion according to the scribe line. And deburring and polishing the edges of each cut part. Because 2507 dual-phase steel material has high strength, a notch is easy to appear in the cutting process, and therefore, when the depth of the notch is more than 2mm, repair welding treatment is needed.
Step S103: and (5) welding. And welding the cut part of plates to form a whole wafer. In the welding process, submerged arc welding is adopted, welding materials are welding by using ER2594 phi 2.4 welding wires and Flux805 welding Flux, the welding current is 380-420A, the voltage is 28-30V, and the speed is 42-46cm/min.
In addition, the welding adopts low-current welding, pressure welding and multi-layer multi-pass welding. The welding machine has the advantages that the small-current welding is adopted, so that the generation of the stress of the welding machine can be reduced, the welding seam crystal grains can be thinned in the small-current pressure channel welding, the increase of ferrite is controlled, the impact toughness of the welding seam is improved, the welding seam can bear larger pressure in the forming process, and the follow-up further processing of the welding seam is facilitated.
Step S104: polishing. And (3) polishing the welded wafer, wherein the weld is polished to be leveled with the base metal, the tolerance is +/-0.2 mm, and the surface of the weld is leveled and smooth like a mirror surface. The abrasive belt sander can be adopted for polishing during specific operation, so that no obvious abrasive marks are formed at the welding seam.
The steps S101-S104 are the whole process of manufacturing the wafer, and after the wafer is manufactured, the following operation steps are carried out:
step S20: and (5) pre-stamping the wafer. The wafer is subjected to cold stamping through a stamping machine and a stamping die, the stamping die comprises a movable die and a fixed die, the outer contour of the movable die is hemispherical according to the processing requirement of the final forming seal head, and the inner cavity of the fixed die is hemispherical. During punching, the movable die is arranged on the punching machine, the wafer is arranged on the fixed die, the punching machine is started, the movable die is punched in the fixed die, and the wafer is preliminarily a sealing head due to the extrusion action of the movable die and the fixed die. The depth of the pre-stamping is 60% of the target depth of the final formed seal head, and is specifically 600mm.
Step S30: and (5) performing primary heat treatment. And performing heat treatment on the preliminarily formed seal head. The heating process of heat treatment is carried out in a full-automatic computer temperature control natural gas furnace, an electromagnetic valve is arranged on a gas pipeline of each burner of the natural gas furnace, each control electromagnetic valve is controlled by an independent combustion controller, and the combustion controller can control the opening of the electromagnetic valve to regulate and control the temperature according to the measured temperature of a temperature control thermocouple arranged on the burner, so that the end enclosure is heated uniformly.
The heating temperature of the natural gas furnace is 200+/-15 ℃, and the duration of the heating process is 20-30min. In this example, 2507 dual phase steel has a larger sensitization temperature range, and the heating temperature in a natural gas furnace is 200 ℃ and the heat preservation time is 30 minutes in order to avoid the sensitization range. The processing stress of the seal head formed by stamping preliminarily is eliminated through heat treatment, and the surface hardness is reduced, so that the condition of subsequent drum pressing forming is met.
Step S40: and (5) pressing the drum. And carrying out cold pressing drum operation on the preliminarily molded seal head after heat treatment on a drum pressing machine. The drum pressing machine comprises a supporting die and a drum pressing die arranged above the supporting die, an inner cavity of the supporting die is hemispherical, the outer contour of the drum pressing die is hemispherical, when the drum is pressed, a preliminarily formed seal head is arranged on the supporting die, the drum pressing machine is started, the drum pressing die intermittently impacts the seal head, and the seal head is further formed by repeatedly adjusting the position of the drum pressing on the seal head, so that the seal head is finally processed to a target depth.
Step S50: and (5) secondary heat treatment. And placing the seal head formed by the pressing drum into a heat treatment furnace, heating to 200 ℃, and continuously preserving heat for 30min in the heating process.
Step S60: and (5) spinning. And installing the molding end socket after the drum pressing on a spinning machine, carrying out cold spinning on the end socket through the spinning machine, and forming the end socket by the disc under the rotary extrusion action of the pressure wheel and the molding wheel. After spinning is completed, checking the cross-sectional shape of the seal head through a sample plate.
Step S70: and (5) beveling and grinding. And (3) carrying out groove treatment on the spin-formed seal head, and carrying out grinding treatment on the groove so as to ensure the flatness of the groove. In order to obtain a groove with smooth surface and small thermal deformation, a numerical control cutting machine is matched in the groove processing mode to carry out plasma groove; in order to achieve the purpose of fine grinding, the grinding mode is mechanical grinding and dry grinding is adopted, and the granularity of the adopted micro powder grinding material is finer than W7.
Step S80: and (5) flaw detection. And performing weld RT flaw detection by using an X-ray flaw detector to remove unqualified products and improve the qualification rate of products.
Step S90: and (5) acid washing. And uniformly smearing the pickling solution on the surface of the end socket, and then washing the end socket with clear water to remove oxide layers, oil and rust matters on the surface of the end socket, so that the end socket is finally formed.
The processing method of the large duplex stainless steel sealing head comprises the steps of firstly carrying out submerged-arc welding on 2507 duplex steel wafer plates, adopting low current and multi-layer multi-pass welding, refining welding line crystal grains, then carrying out wafer pre-stamping, reducing the depth of a stamping part of the welding line, carrying out heat treatment subsequently, reducing the surface hardness to enable the surface hardness to meet the condition of subsequent drum pressing, carrying out drum pressing subsequently to enable the sealing head to reach the target depth, carrying out primary molding of the sealing head, carrying out secondary heat treatment, eliminating stress generated during drum pressing, and finally molding the sealing head through a spinning process. Compared with the traditional direct drum pressing processing mode, the method solves the problem that the large-diameter 2507 dual-phase steel seal head is difficult to mold, reduces the risk of weld cracking, reduces the rejection rate of products, improves the production efficiency, and greatly increases the economic benefit.
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. The technical scope of the present invention is not limited to the description, but must be determined according to the scope of claims.
Claims (7)
1. A processing method of a duplex stainless steel large-scale seal head comprises the following steps:
step S10: manufacturing a wafer;
step S20: pre-stamping the wafer, namely cold stamping the wafer through a stamping machine and a stamping die to preliminarily form an end socket, wherein the stamping depth is 60% of the target depth;
step S30: performing primary heat treatment, namely performing heat treatment on the preliminarily formed seal head;
step S40: pressing the drum, namely placing the preliminarily molded end socket after heat treatment on a drum pressing machine for cold pressing drum operation, and processing the end socket to a target depth;
step S50: secondary heat treatment, namely placing the seal head formed by the drum pressing in a heat treatment furnace for heat treatment;
step S60: and (3) spinning, namely mounting the molding end socket on a spinning machine, and carrying out cold spinning on the end socket through the spinning machine to finally mold the end socket.
2. The method for processing the duplex stainless steel large-scale seal head according to claim 1, wherein the method comprises the following steps: the step S10 includes the following steps,
step S101: selecting 2507 duplex stainless steel plates;
step S102: blanking, scribing the plate according to the design size requirement, and cutting the plate according to the scribing;
step S103: welding, namely welding all the cut part plates to form a whole circle;
step S104: polishing, namely polishing the welding seam to be level with the base material.
3. The method for processing the duplex stainless steel large-scale sealing head according to claim 2, which is characterized in that: in the step S103, submerged arc welding is adopted, welding materials are welded by using welding wires of ER2594 phi 2.4 and Flux805 Flux, the welding current is 380-420A, the voltage is 28-30V, and the speed is 42-46cm/min.
4. The method for processing the duplex stainless steel large-scale seal head according to claim 1, wherein the method comprises the following steps: in step S30, the heat treatment is performed in a fully automatic computerized temperature-controlled natural gas furnace, and each burner of the natural gas furnace is provided with a solenoid valve in a gas pipeline, each control solenoid valve is controlled by an independent combustion controller, and the combustion controller can control the temperature according to the measured temperature of a temperature-controlled thermocouple arranged on the burner, so that the opening of the solenoid valve is controlled to regulate and control the temperature, and the end enclosure is heated uniformly.
5. The method for processing the duplex stainless steel large-scale sealing head according to claim 4, which is characterized in that: the heating temperature of the natural gas furnace is 200+/-15 ℃, and the duration of the heating process is 20-30min.
6. The method for processing the duplex stainless steel large-scale seal head according to claim 1, wherein the method comprises the following steps: in the step S50, the temperature in the heat treatment furnace is raised to 200 ℃, and the size is kept for 30min in the heating process.
7. The method for processing the duplex stainless steel large-scale seal head according to claim 1, wherein the method comprises the following steps: the processing method further comprises the following steps of,
step S70: bevel and grinding, bevel treatment is carried out on the rotary-press-formed seal head, and bevel is ground so as to ensure the flatness of the bevel;
step S80: flaw detection, performing weld joint RT flaw detection by using an X-ray flaw detector;
step S90: and (3) pickling, namely uniformly smearing pickling solution on the surface of the end socket, and then washing the end socket with clear water to remove oxide layers, oil and rust matters on the surface of the end socket.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311423576.4A CN117415236A (en) | 2023-10-31 | 2023-10-31 | Processing method of large duplex stainless steel seal head |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311423576.4A CN117415236A (en) | 2023-10-31 | 2023-10-31 | Processing method of large duplex stainless steel seal head |
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| Publication Number | Publication Date |
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| CN117415236A true CN117415236A (en) | 2024-01-19 |
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| CN202311423576.4A Pending CN117415236A (en) | 2023-10-31 | 2023-10-31 | Processing method of large duplex stainless steel seal head |
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| Country | Link |
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| CN (1) | CN117415236A (en) |
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- 2023-10-31 CN CN202311423576.4A patent/CN117415236A/en active Pending
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