A production process for the head of a large container

Abstract

The present invention relates to a production process for a large container head, comprising the following steps: S1. Hot pressing and forming: The plate body is subjected to hot pressing and forming treatment by hot pressing equipment to bend the plate body; S2. Butt welding: Multiple plate bodies are circumferentially butt welded together by butt welding equipment to form a spherical segment shape, obtaining a butt welded head; S3. Quenching: The butt welded head is heated from room temperature to 850°C - 900°C at a heating rate of ≤120°C / h, with a holding time of 50 - 100 minutes, and taken out of the furnace for air cooling when it reaches 300°C, obtaining a quenched head; S4. Tempering: The quenched head is heated from room temperature to 600°C - 620°C at a heating rate of ≤100°C / h, with a holding time of 80 - 120 minutes, and taken out of the furnace for air cooling when it reaches 300°C, obtaining the head. After the plate body is hot pressed and formed in the invention and then butt welded, compared with butt welding first and then hot pressing and forming, the stress on the welding part of two adjacent plate bodies can be reduced, the welding firmness can be improved, and the reliability of the head can be enhanced.

Description

Technical Field

[0001] The present invention relates to a production process for the head of a large container, belonging to the technical field of heads. Background Art

[0002] The head is the main pressure-bearing component of a pressure vessel. Heads with different plate thicknesses and different materials have different manufacturing processes. Generally, they are divided into cold forming and hot forming according to the forming temperature, and generally divided into spinning and die pressing according to the manufacturing process. The final acceptance criteria for the head include: dimensional accuracy, geometric tolerance, and the performance of the final head base material.

[0003] The invention patent with the application number CN202310162269.9 discloses a preparation method for the head of a large-sized pressure vessel, including the following steps: S1: Weld multiple Q690D steel plates together by welding wire to obtain a large-sized welded head. S2: Perform hot pressing forming treatment on the welded head to obtain a hot-pressed formed head. S3: Heat the hot-pressed formed head from room temperature to 900 - 920°C at a heating rate of ≤100°C / h, keep it warm for 1.5 - 2.5 min / mm, and obtain a quenched head after cooling. S4: Heat the quenched head from room temperature to 600 - 630°C at a heating rate of ≤100°C / h, keep it warm for 130 - 170 min, and obtain the head after air cooling. By optimizing the head preparation process, the present invention enables the base material of the large-sized head to maintain the Q690D quenched and tempered state, and at the same time, the tensile strength at the weld position also exceeds the tensile strength of the Q690D material, realizing the batch manufacturing of large-diameter high-strength heads. However, in the prior art, since six steel plates are first welded together and then hot-pressed formed, during the deformation process of the steel plates, the stress on the welding joint between two adjacent steel plates is too large, which easily leads to cracking, affecting the welding firmness and reducing the reliability of the head.

[0004] Therefore, a production process for the head of a large container is needed to improve the welding firmness of the steel plates and the reliability of the head. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to overcome the deficiencies of the prior art, and provide a production process for the head of a large container that can improve the welding firmness between two adjacent steel plates and enhance the reliability of the head.

[0006] The technical solution adopted by the present invention to solve the above problems is: a production process for the head of a large container, including the following steps;

[0007] S1, Hot Pressing Forming;

[0008] Perform hot pressing forming treatment on the plate body through hot pressing equipment to bend the plate body;

[0009] S2, Welding;

[0010] Use a welding equipment to circumferentially weld multiple plates together to form a spherical segment shape, obtaining a welded head;

[0011] S3. Quenching;

[0012] Heat the welded head from room temperature to 850°C - 900°C at a heating rate of ≤120°C / h, hold for 50 - 100 minutes, and air cool after taking it out of the furnace when it reaches 300°C, obtaining a quenched head;

[0013] S4. Tempering;

[0014] Heat the quenched head from room temperature to 600°C - 620°C at a heating rate of ≤100°C / h, hold for 80 - 120 minutes, and air cool after taking it out of the furnace when it reaches 300°C, obtaining the head.

[0015] Preferably, the step S2 specifically includes the following steps;

[0016] S2.1. Plate placement;

[0017] Circumferentially place multiple plates on the welding equipment, and there is a gap between adjacent two plates;

[0018] S2.2. Plate splicing;

[0019] The gap between adjacent two plates shrinks until they fit together;

[0020] S2.3. Position adjustment;

[0021] Adjust the positions between adjacent two plates to make the end of the head form a smooth surface, which is convenient for improving the welding accuracy;

[0022] S2.4. Welding;

[0023] Adjacent two plates are fixed by welding, so that multiple plates are circumferentially spliced into a spherical segment shape, obtaining a welded head;

[0024] S2.5. Removal;

[0025] Remove the welded head from the welding equipment.

[0026] Preferably, the welding equipment includes a welding seat, a notch is provided at the top of the welding seat, the notch matches the welded head, a first positioning mechanism and multiple second positioning mechanisms are provided on the welding seat, and the multiple second positioning mechanisms correspond to the multiple plates one by one.

[0027] Preferably, the first positioning mechanism includes a lifting disc, a lifting block is fixedly arranged on the top of the lifting disc, a plurality of grooves are arranged on the outer side wall of the lifting block, the plurality of grooves are circumferentially and evenly distributed around the vertical central line of the lifting block, the grooves extend to the top of the lifting block, the grooves are matched with the plate body, the vertical central line of the lifting block coincides with the vertical central line of the notch, the lifting disc is driven to lift by a hydraulic cylinder, an installation hole is arranged on the welding seat, the installation hole is matched with the lifting block, the hydraulic cylinder is located at the bottom of the lifting disc, the lifting block passes through the installation hole, and the top of the lifting block is matched with the welded head.

[0028] Preferably, the second positioning mechanism includes a support assembly and a second positioning assembly. The support assembly is used to support the plate body, and the second positioning assembly is used to reduce the distance between two adjacent plate bodies.

[0029] Preferably, the second positioning assembly includes a fixing plate, the fixing plate is fixedly connected with the welding seat, a lifting rod is vertically arranged on the fixing plate, the bottom end of the lifting rod is driven to lift by a lifting cylinder, and a pressing plate is rotatably connected to the lifting rod, and the pressing plate is arranged horizontally.

[0030] Preferably, two limiting rings are fixedly sleeved on the lifting rod, and the two limiting rings are respectively attached to the top and the bottom of the pressing plate.

[0031] Preferably, the support assembly includes a fixing seat fixedly arranged on the outer peripheral wall of the welding seat, and a support column is fixedly arranged on the fixing seat.

[0032] Preferably, a support roller is arranged on the top of the support column.

[0033] A large container head includes a plurality of plate bodies, the plurality of plate bodies are circumferentially spliced into a spherical segment shape, and two adjacent plate bodies are fixed by welding.

[0034] Compared with the prior art, the advantages of the present invention are as follows:

[0035] 1. After the plate body is hot-pressed and formed, it is welded. Compared with welding first and then hot-pressing and forming, the stress received at the welding place of two adjacent plate bodies can be reduced, the welding firmness can be improved, and the reliability of the head can be enhanced;

[0036] 2. Before the plate bodies are welded, through the cooperation between the plate body and the lifting block, the primary positioning of the plate body is realized, and the operation is simple and convenient;

[0037] 3. Through the cooperation between the plate body and the inner wall of the notch and the downward thrust applied by the pressing plate to the plate body, not only can the gap between two adjacent plate bodies be reduced, but also the relative position between two adjacent plate bodies can be adjusted, and the welding precision can be improved;

[0038] 4. After the plate bodies are welded together, the welded head is pushed upward by the lifting block to facilitate the removal of the welded head. Description of the Drawings

[0039] Figure 1 Is a perspective view of the welding equipment;

[0040] Figure 2 Is the front view of the welding equipment;

[0041] Figure 3 Is the left view of the welding equipment;

[0042] Figure 4 Is the top view of the welding equipment;

[0043] Figure 5 Is the schematic structural diagram of the welding equipment in the first state;

[0044] Figure 6 Is the schematic structural diagram of the connection between the plate body and the lifting block when the welding equipment is in the first state;

[0045] Figure 7 Is the schematic structural diagram of the welding equipment in the second state;

[0046] Figure 8 Is the schematic structural diagram of the welding equipment in the third state;

[0047] Figure 9 Is the schematic structural diagram of the welding seat;

[0048] Figure 10 Is the schematic structural diagram of the first positioning mechanism;

[0049] Figure 11 Is the schematic structural diagram of the support assembly;

[0050] Figure 12 Is the schematic structural diagram of the second positioning component;

[0051] Figure 13 Is the schematic structural diagram of the welded head;

[0052] Figure 14 Is the schematic structural diagram of the plate body.

[0053] Wherein:

[0054] Welded head 100;

[0055] Plate body 101;

[0056] Welding seat 1, notch 2, first positioning mechanism 3, second positioning mechanism 4, bottom plate 5;

[0057] Lifting disc 31, lifting block 32, groove 33, hydraulic cylinder 34, mounting hole 35;

[0058] A support component 41 and a second positioning component 42;

[0059] A fixed seat 41.1, a support column 41.2, and a support roller 41.3;

[0060] A fixing plate 42.1, a lifting rod 42.2, a lifting cylinder 42.3, a pressing plate 42.4, and a limiting ring 42.5. Specific implementation manners

[0061] As Figures 1-14 shown, a large container head in this embodiment includes six plate bodies 101. The six plate bodies 101 are circumferentially spliced into a spherical segment shape, and adjacent two plate bodies 101 are fixed by welding. The plate body 101 is a Q690D steel plate. Q690D belongs to high-strength welded structural steel, where Q represents the yield strength, 690 represents the yield strength value, and D represents the grade of the steel plate;

[0062] A production process of a large container head includes the following steps;

[0063] S1. Hot pressing and forming;

[0064] The plate body 101 is subjected to hot pressing and forming treatment by hot pressing equipment to bend the plate body 101;

[0065] S2. Welding;

[0066] The six plate bodies 101 are circumferentially welded together to form a spherical segment shape through welding equipment to obtain a welded head 100;

[0067] S2.1. Placement of the plate body 101;

[0068] The six plate bodies 101 are circumferentially placed on the welding equipment, and there is a gap between adjacent two plate bodies 101;

[0069] S2.2. Splicing of the plate body 101;

[0070] The gap between adjacent two plate bodies 101 shrinks until they are in contact;

[0071] S2.3. Position adjustment;

[0072] Adjust the positions between adjacent two plate bodies 101 to make the end of the head form a smooth surface, which is convenient for improving the welding accuracy;

[0073] S2.4. Welding;

[0074] Adjacent two plate bodies 101 are fixed by welding, so that the six plate bodies 101 are circumferentially spliced into a spherical segment shape to obtain a welded head 100;

[0075] S2.5. Removal;

[0076] Remove the welded head 100 from the welding equipment;

[0077] S3. Quenching;

[0078] Heat the welded head 100 from room temperature to 850°C - 900°C at a heating rate of ≤120°C / h, hold for 50 - 100 minutes, and air cool after taking it out of the furnace at 300°C to obtain a quenched head;

[0079] S4. Tempering;

[0080] Heat the quenched head from room temperature to 600°C - 620°C at a heating rate of ≤100°C / h, hold for 80 - 120 minutes, and air cool after taking it out of the furnace at 300°C to obtain the head;

[0081] The welding equipment includes a welding seat 1, a notch 2 is provided at the top of the welding seat 1, the notch 2 is matched with the welded head 100, a first positioning mechanism 3 and six second positioning mechanisms 4 are provided on the welding seat 1, and the six second positioning mechanisms 4 correspond to the six plate bodies 101 one by one;

[0082] The first positioning mechanism 3 includes a lifting disc 31, a lifting block 32 is fixedly provided at the top of the lifting disc 31, six grooves 33 are provided on the outer side wall of the lifting block 32, the six grooves 33 are circumferentially and uniformly distributed around the vertical center line of the lifting block 32, the grooves 33 extend to the top of the lifting block 32, the grooves 33 are matched with the plate body 101, the vertical center line of the lifting block 32 coincides with the vertical center line of the notch 2, the lifting disc 31 is driven to lift by a hydraulic cylinder 34, the hydraulic cylinder 34 is located at the bottom of the lifting disc 31, an installation hole 35 is provided on the welding seat 1, the installation hole 35 is matched with the lifting block 32, the lifting block 32 passes through the installation hole 35, and the top of the lifting block 32 is matched with the welded head 100;

[0083] The second positioning mechanism 4 includes a support assembly 41 and a second positioning assembly 42;

[0084] The support assembly 41 includes a fixed seat 41.1 fixedly provided on the outer peripheral wall of the welding seat 1, a support column 41.2 is fixedly provided on the fixed seat 41.1, the support column 41.2 is used to support the plate body 101, a support roller 41.3 is provided at the top of the support column 41.2, and the sliding friction between the support column 41.2 and the plate body 101 is converted into rolling friction through the support roller 41.3 to reduce the friction between the plate body 101 and the support column 41.2;

[0085] The second positioning component 42 includes a fixing plate 42.1 which is fixedly connected to the welding seat 1. A lifting rod 42.2 is vertically penetrated through the fixing plate 42.1. The bottom end of the lifting rod 42.2 is driven to lift by a lifting cylinder 42.3. A pressing plate 42.4 is rotatably connected to the lifting rod 42.2, and the pressing plate 42.4 is horizontally arranged;

[0086] Two limiting rings 42.5 are fixedly sleeved on the lifting rod 42.2, and the two limiting rings 42.5 are respectively in contact with the top and bottom of the pressing plate 42.4;

[0087] A bottom plate 5 is arranged below the welding seat 1. The welding seat 1 is fixedly connected to the bottom plate 5. The cylinder body of the hydraulic cylinder 34 is fixedly arranged on the top of the bottom plate 5;

[0088] The fixing seat 41.1 and the welding seat are of an integrally formed structure;

[0089] The welding equipment has the following several states during operation:

[0090] The first state;

[0091] The top of the lifting block 32 is located in the inner cavity of the notch 2. Six plate bodies 101 after hot pressing are respectively inserted into six grooves 33. The outer side walls of the plate bodies 101 are in contact with the inner wall of the notch 2, and the outer side walls of the plate bodies 101 are in contact with the rollers, realizing the support of the plate bodies 101, improving the stability of the plate bodies 101, achieving the primary positioning effect of the plate bodies 101, and at this time, the pressing plate 42.4 and the lifting rod 42.2 are both located on the side of the plate bodies 101 away from the vertical center line of the notch 2, and there is a gap between two adjacent plate bodies 101;

[0092] The second state;

[0093] Rotate the extrusion plate 42.4 to move the extrusion plate 42.4 downward so that it can abut against the top of the plate body 101. Drive the lifting plate 31 to descend through the hydraulic cylinder 34. The descent of the lifting plate 31 drives the lifting block 32 to descend until the top of the lifting block 32 is on the same smooth surface as the inner wall of the notch 2. As the lifting block 32 descends, the lifting block 32 is separated from the plate body 101. At this time, the plate body 101 slides downward on the inner wall of the notch 2 under the action of its own gravity, reducing the gap between two adjacent plate bodies 101 until they are in contact. In this way, six plate bodies 101 are combined to form an inverted head. Finally, drive the lifting rod 42.2 to descend through the lifting cylinder 42.3. The descent of the lifting rod 42.2 drives the extrusion plate 42.4 to descend through the limit ring 42.5, making the extrusion plate 42.4 abut against the top of the plate body 101 and applying a downward thrust to the plate body 101. In this way, the gap between two adjacent plate bodies 101 can be further reduced, improving the contact effect between two adjacent plate bodies 101. In addition, by applying a downward thrust to the plate body 101 through the extrusion plate 42.4, when there is an offset during the contact process of two adjacent plate bodies 101, the plate body 101 can be pushed to rotate within the notch 2, that is, adjust the relative position between two adjacent plate bodies 101, making the six plate bodies 101 evenly distributed circumferentially, realizing the secondary positioning of the plate body 101, facilitating the improvement of welding accuracy. Then, weld two adjacent plate bodies 101 firmly to obtain the welded head 100;

[0094] The third state;

[0095] The lifting cylinder 42.3 drives the lifting rod 42.2 to rise, that is, drives the extrusion plate 42.4 to rise and separate from the plate body 101. Subsequently, rotate the extrusion plate 42.4 in the reverse direction so that the turning plate is on the side of the plate body 101 away from the vertical center line of the notch 2. Then, drive the lifting plate 31 to rise through the hydraulic cylinder 34 to reset. The lifting and descending of the lifting plate 31 drive the lifting block 32 to rise. The rising of the lifting block 32 pushes the welded head 100 to rise, separating the welded head 100 from the inner wall of the notch 2, facilitating the removal of the welded head 100;

[0096] To sum up, during the production of the head, the plate body 101 is hot-pressed and then welded. Compared with welding first and then hot-pressing, the stress on the welding part of two adjacent plate bodies 101 can be reduced, the welding firmness can be improved, and the reliability of the head can be enhanced;

[0097] In addition, before welding the plate body 101, through the cooperation between the plate body 101 and the lifting block 32, the primary positioning of the plate body 101 is realized, and the operation is simple and convenient;

[0098] Moreover, through the cooperation between the plate body 101 and the inner wall of the notch 2 and the downward thrust applied to the plate body 101 by the pressing plate 42.4, not only can the gap between two adjacent plate bodies 101 be reduced, but also the relative position between two adjacent plate bodies 101 can be adjusted, improving the welding precision.

[0099] Secondly, after the plate bodies 101 are welded together, the lifting block 32 is used to push the welded head 100 upward, facilitating the removal of the welded head 100.

[0100] In addition to the above embodiments, the present invention also includes other implementation manners. Any technical solutions formed by equivalent transformation or equivalent substitution shall fall within the protection scope of the claims of the present invention.

Claims

1. A production process for the head of a large container, characterized in that: It includes the following steps; S1. Hot pressing and forming; The plate body (101) is subjected to hot pressing and forming treatment by a hot pressing device to bend the plate body (101); S2. Welding; Multiple plate bodies (101) are circumferentially welded together by a welding device to form a spherical segment shape, and a welded head (100) is obtained; Step S2 specifically includes the following steps; S2.

1. Placement of the plate body (101); Multiple plate bodies (101) are circumferentially placed on the welding device, and there is a gap between adjacent two plate bodies (101); S2.

2. Joining of the plate bodies (101); The gap between adjacent two plate bodies (101) shrinks until they fit together; S2.

3. Position adjustment; The positions between adjacent two plate bodies (101) are adjusted to make the end of the head form a smooth surface, which is convenient for improving the welding accuracy; S2.

4. Welding; Adjacent two plate bodies (101) are fixed by welding, so that multiple plate bodies (101) are circumferentially joined into a spherical segment shape, and a welded head (100) is obtained; S2.

5. Removal; The welded head (100) is removed from the welding device; S3. Quenching; The welded head (100) is heated from room temperature to 850°C - 900°C at a heating rate of ≤120°C / h, with a holding time of 50 - 100 minutes, and is taken out of the furnace and air-cooled when it reaches 300°C to obtain a quenched head; S4. Tempering; The quenched head is heated from room temperature to 600°C - 620°C at a heating rate of ≤100°C / h, with a holding time of 80 - 120 minutes, and is taken out of the furnace and air-cooled when it reaches 300°C to obtain a head; The welding device includes a welding seat (1), a notch (2) is arranged at the top of the welding seat (1), the notch (2) matches the welded head (100), a first positioning mechanism (3) and multiple second positioning mechanisms (4) are arranged on the welding seat (1), and the multiple second positioning mechanisms (4) correspond to the multiple plate bodies (101) one by one; The first positioning mechanism (3) includes a lifting disc (31), a lifting block (32) is fixedly arranged at the top of the lifting disc (31), multiple grooves (33) are arranged on the outer side wall of the lifting block (32), the multiple grooves (33) are circumferentially and uniformly distributed around the vertical center line of the lifting block (32), the grooves (33) extend to the top of the lifting block (32), the grooves (33) match the plate body (101), the vertical center line of the lifting block (32) coincides with the vertical center line of the notch (2), the lifting disc (31) is driven to lift by a hydraulic cylinder (34), an installation hole (35) is arranged on the welding seat (1), the installation hole (35) matches the lifting block (32), the hydraulic cylinder (34) is located at the bottom of the lifting disc (31), the lifting block (32) passes through the installation hole (35), and the top of the lifting block (32) matches the welded head (100).

2. The production process of a large container head according to claim 1, characterized in that: The second positioning mechanism (4) includes a support assembly (41) and a second positioning assembly (42), the support assembly (41) is used to support the plate body (101), and the second positioning assembly (42) is used to reduce the distance between adjacent two plate bodies (101).

3. The production process of a large container head according to claim 2, characterized in that: The second positioning component (42) includes a fixing plate (42.1), the fixing plate (42.1) is fixedly connected to the butt welding seat (1), a lifting rod (42.2) is vertically penetrated through the fixing plate (42.1), the bottom end of the lifting rod (42.2) is driven to lift by a lifting cylinder (42.3), and a pressing plate (42.4) is rotatably connected to the lifting rod (42.2), and the pressing plate (42.4) is horizontally arranged.

4. The production process of a large container head according to claim 3, characterized in that: Two limiting rings (42.5) are fixedly sleeved on the lifting rod (42.2), and the two limiting rings (42.5) are respectively attached to the top and bottom of the pressing plate (42.4).

5. The production process of a large container head according to claim 2, characterized in that: The support component (41) includes a fixed seat (41.1) fixedly arranged on the outer peripheral wall of the butt welding seat (1), and a support column (41.2) is fixedly arranged on the fixed seat (41.1).

6. The production process of a large container head according to claim 5, characterized in that: A support roller (41.3) is arranged at the top of the support column (41.2).

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