A forging method of a tube sheet with double-sided grooves

Abstract

The application discloses a forging method of a pipe plate with double-face grooves, and comprises the following steps: step 1, heating a blank to a forging temperature and performing pretreatment; step 2, upsetting and elongating the blank; step 3, secondarily upsetting the blank so that the diameter of the blank is equal to the height; step 4, performing n-pass spinning expansion on the blank after the secondary upsetting until the diameter of the blank reaches a target pipe plate diameter and a rolling deformation allowance is reserved; and step 5, vertically standing the blank after the spinning expansion, rolling processing is performed on the two end planes of the blank, under the rolling action, the edges of the two end planes of the blank gradually form protrusions, meanwhile, the two end planes of the blank generate corresponding grooves, and finally, a pipe plate forging with a size meeting the requirements is obtained. According to the application, the double-face grooves are directly formed through forging, so that the machining allowance and material consumption are reduced, the manufacturing cost is lowered, the integrity of metal fiber flow lines is maintained, and the mechanical properties and service life of the pipe plate are improved.

Description

Technical Field

[0001] This invention belongs to the field of metal pressure processing, and specifically relates to a forging method for a tube sheet with double-sided grooves. Background Technology

[0002] Tube sheets with double-sided grooves are core pressure-bearing components in heat exchangers, boilers, and pressure vessels. They are precision-machined from thick steel plates with numerous drilled holes to fix the heat exchange tube bundles and separate the two media, thereby achieving functions such as heat exchange, heating, or cooling.

[0003] Currently, the traditional forging process for tube sheets with double-sided grooves has the following main technical defects: (1) Traditional methods typically employ upsetting and spinning processes to forge billets into solid round discs, followed by large-scale machining to remove excess metal from the grooved areas. This machining method requires the removal of a large amount of billet, resulting in a significant increase in the original weight of the forging and substantial waste of raw materials. Especially for large tube sheet components, the roundness deviation during forging often necessitates additional machining allowances, further exacerbating material loss and leading to persistently high manufacturing costs.

[0004] (2) The use of mechanical cutting to process grooves will inevitably cut off the complete metal fiber flow lines formed by the forging process inside the forging. As a key factor in ensuring the mechanical properties of the forging, the disruption of the continuity of the fiber flow lines will directly weaken the strength, toughness and load-bearing capacity of the tube sheet, thereby significantly shortening its service life. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a forging method for a tube sheet with double-sided grooves. By forging, grooves are directly formed on both sides, which reduces machining allowances and material consumption, lowers manufacturing costs, maintains the integrity of the metal fiber flow lines, and improves the mechanical properties and service life of the tube sheet.

[0006] The main technical solution adopted in this invention is as follows: A forging method for a tube sheet with double-sided grooves includes the following steps: Step 1: Heat the billet to the forging temperature and perform pretreatment; Step 2: Upset and draw the pretreated billet to achieve the preset intermediate size; Step 3: Perform a second upsetting on the billet to make the diameter and height of the billet equal; Step 4: Perform n passes of spinning expansion on the billet after the second upsetting until the diameter of the billet reaches the target tube sheet diameter, and leave a rolling deformation allowance, and the height of the billet reaches the target tube sheet height; Step 5: Place the spun and expanded billet vertically and roll the two ends of the billet. Under the action of rolling, the edges of the two ends of the billet gradually form convexity, and at the same time, the two ends of the billet generate corresponding grooves, and finally obtain the tube sheet forging with the required dimensions.

[0007] Preferably, in step 1, the pretreatment includes chamfering and removing the sprue and riser.

[0008] Preferably, in step 1, the forging temperature is 1150–1250°C.

[0009] Preferably, in step 2, the pretreated billet is first upset to a height H0, and then the upset billet is drawn to a diameter d and a length L, satisfying L = (2~2.5)d.

[0010] Preferably, the specific steps of step 4 are as follows: The billet is spun and expanded to a diameter of D1 and a height of H1 in the first pass. The billet is spun and expanded in a second pass to a diameter of D2 and a height of H2. By analogy, the billet is spun and expanded n times until it reaches a diameter D. n +β, height H n , where D n H is the target tube sheet diameter. n β represents the target tube sheet height, and β represents the rolling deformation allowance.

[0011] Preferably, in step 4, the reserved rolling deformation allowance β is 100-400mm.

[0012] Preferably, in step 5, the blank is rolled 1 to 2 times on each of the two end faces to make the width of the protrusion formed on the end face of the blank ≥ L1 + 50 mm, and at the same time, the corresponding depth of the two end faces is H. m The groove, where L1 is the width of the protrusion of the target tube sheet, H m The groove depth of the target tube sheet.

[0013] Beneficial effects: This invention provides a forging method for a tube sheet with double-sided grooves, which has the following advantages: (1) The present invention directly forms the tube plate groove by forging, which reduces a large amount of blanks that need to be removed later, effectively reduces the weight of the forging, significantly improves the utilization rate of raw materials, and can reduce manufacturing costs.

[0014] (2) The groove of the present invention is formed directly by forging, and the metal fiber streamlines are naturally and continuously distributed along the groove contour without being cut off. The comprehensive mechanical properties such as strength and toughness of the tube sheet are effectively guaranteed, and the service life is significantly extended.

[0015] (3) Compared with complex machining methods, the present invention reduces a lot of cutting time, which not only helps to shorten the production cycle, but also allows the existing press equipment to complete the processing without investing in special groove tooling, further reducing tooling investment costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the blank in step 3 of Example 1; Figure 2 This is a schematic diagram of the third spinning expansion pass in step 4 of Example 1; Figure 3 This is a schematic diagram of the tube sheet blank being erected in step 5 of Example 1; Figure 4 This is a schematic diagram of the tube sheet blank rolling process in step 5 of Example 1. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application are clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application. Example 1

[0018] This embodiment uses a tube sheet with double-sided grooves as an example for detailed explanation. The target dimension of the tube sheet is: diameter D. n =4000mm, height H n =400mm, groove depth H m =30mm, the groove edge protrusion width L1=100mm. Based on the above dimensional requirements, this embodiment provides a forging method for a tube plate with double-sided grooves, specifically including the following steps: Step 1: Heat the billet to the forging temperature and perform pretreatment.

[0019] In this embodiment, a steel ingot of appropriate tonnage is selected and placed in a heating furnace. It is heated to a forging temperature of 1250°C and held at that temperature for a sufficient time to ensure uniform temperature throughout the ingot. The heated ingot is then removed from the furnace and chamfered to remove stress concentration points at the edges. Subsequently, the sprue and riser are removed, resulting in a pre-treated ingot ready for subsequent forging processes.

[0020] Step 2: Upset and draw the pretreated billet to achieve the preset intermediate size.

[0021] In this embodiment, the pretreated billet is placed on the press table for upsetting. During upsetting, the reduction is controlled to gradually decrease the billet height and gradually increase the diameter, ultimately upsetting to a height H0 = 1200 mm. The upset billet is then drawn to a diameter d = 1500 mm and a length L = 3140 mm. Calculations show that L / d ≈ 2.09, which meets the requirement of L = (2~2.5)d.

[0022] Step 3: Perform a second upsetting on the billet to make the diameter and height of the billet equal.

[0023] In this embodiment, the drawn billet is upset again. The deformation and billet shape are controlled during the upsetting process to gradually make the billet diameter and height more consistent. Finally, the billet is upset to a diameter D = 1860 mm and a height H = 1860 mm, at which point the billet is cylindrical. Figure 1 As shown.

[0024] Step 4: Perform 3 (n=3) passes of spinning expansion on the billet after the second upsetting until the diameter of the billet reaches the diameter of the target tube sheet, and reserve the rolling deformation allowance, and the height of the billet reaches the height of the target tube sheet.

[0025] In this embodiment, the specific steps for multi-pass spinning expansion of the billet after secondary upsetting are as follows: The billet undergoes its first spinning pass to expand its diameter: The billet is placed on a spinning machine and spun to expand its diameter. The spinning parameters are controlled to gradually increase the billet diameter and gradually decrease its height. After the first spinning pass, the billet diameter reaches D1=2800mm and the height decreases to H1=900mm.

[0026] The billet undergoes a second spinning expansion pass: Based on the first spinning expansion pass, the billet is further spun to expand its diameter. After the second spinning pass, the billet diameter reaches D2=3500mm, and the height decreases to H2=580mm.

[0027] The billet undergoes a third spinning expansion process: (e.g.) Figure 2 As shown, based on the second spinning pass, the billet is further spun to expand its diameter. After the third spinning pass, the billet diameter reaches D3=4200mm, including the rolling deformation allowance β200mm, and the height is reduced to H3=400mm.

[0028] During the three-pass spinning and diameter expansion process described above, the reduction and anvil feed rates for each pass are adjusted appropriately based on the current size of the billet and the equipment capacity to ensure uniform billet deformation and prevent cracking. The spinning dimensions for each pass are generally determined based on the actual dimensions achievable in each heat treatment.

[0029] Step 5: As Figure 3As shown, the spun tube sheet blank is placed vertically so that its axis is horizontal. The two ends of the blank are then rolled. Under the rolling action, the edges of the two ends of the blank gradually form convex shapes, while corresponding grooves are generated on the two ends of the blank, ultimately obtaining a tube sheet forging with the required dimensions.

[0030] During the rolling process, control the number of rolling revolutions to 1 to 2 revolutions and control the total reduction H. y The diameter is 100-400mm. In this embodiment, the number of rolling turns is 2, and the total reduction is H. y It is 150mm.

[0031] As the rolling process continues, the metal on both sides of the outer circle of the billet gradually bulges outward under pressure, forming protrusions at the edges of the two end faces of the tube sheet. Correspondingly, a depression is formed in the middle of the two end faces of the tube sheet, i.e., a double-sided groove structure, such as... Figure 4 As shown. In this embodiment, the protrusion width of the blank is controlled to be ≥L1+50 mm, and the corresponding depth of the two end planes is H. m A 30mm groove is created, where L1 is the 100mm width of the protrusion on the target tube sheet. This completes the forging process of the tube sheet with double-sided grooves.

[0032] It should be noted that the specific values ​​in the above embodiments are only a preferred embodiment of the present invention. In actual production, the values ​​can be adjusted according to the specific specifications of the tube sheet to be forged (e.g., D). n H n H m L1, H y Depending on the different parameters, the above process parameters should be adjusted accordingly, for example: The heating temperature of the steel ingot can be selected within the range of 1150 to 1250℃; In step 4, the number of spinning passes n can be determined based on the billet size and equipment capacity, and is not limited to 3 passes; In step 4, the allowance for rolling deformation β can be selected within the range of 100 to 200 mm; All of the above adjustments fall within the scope of the technical solution of this invention and can achieve the technical effect of directly forming double-sided grooves on the tube sheet through forging.

[0033] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A forging method for a tube sheet with double-sided grooves, characterized in that, Includes the following steps: Step 1: Heat the billet to the forging temperature and perform pretreatment; Step 2: Upset and draw the pretreated billet to achieve the preset intermediate size; Step 3: Perform a second upsetting on the billet to make the diameter and height of the billet equal; Step 4: Perform n passes of spinning expansion on the billet after the second upsetting until the diameter of the billet reaches the target tube sheet diameter, and reserve the rolling deformation allowance, and the height of the billet reaches the target tube sheet height; Step 5: Place the spun and expanded billet vertically and roll the two ends of the billet. Under the action of rolling, the edges of the two ends of the billet gradually form convexity, and at the same time, the two ends of the billet generate corresponding grooves, and finally obtain the tube sheet forging with the required dimensions.

2. The forging method for the tube sheet with double-sided grooves according to claim 1, characterized in that, In step 1, the pretreatment includes chamfering and removing the sprue and riser.

3. The forging method for a tube sheet with double-sided grooves according to claim 1, characterized in that, In step 1, the forging temperature is 1150–1250°C.

4. The forging method for a tube sheet with double-sided grooves according to claim 1, characterized in that, In step 2, the pretreated billet is first upset to a height H0, and then the upset billet is drawn to a diameter d and a length L, satisfying L = (2~2.5)d.

5. The forging method for a tube sheet with double-sided grooves according to claim 1, characterized in that, The specific steps of step 4 are as follows: The billet is spun and expanded to a diameter of D1 and a height of H1 in the first pass. The billet is spun and expanded in a second pass to a diameter of D2 and a height of H2. By analogy, the billet is spun and expanded n times until it reaches a diameter D. n +β, height H n , where D n H is the target tube sheet diameter. n β represents the target tube sheet height, and β represents the rolling deformation allowance.

6. The forging method for a tube sheet with double-sided grooves according to claim 5, characterized in that, In step 4, the reserved rolling deformation allowance β is 100-400mm.

7. The forging method for a tube sheet with double-sided grooves according to claim 1, characterized in that, In step 5, the blank is rolled 1 to 2 times on each of the two end faces to make the width of the protrusion formed on the end face of the blank ≥ L1 + 50 mm, and at the same time, the corresponding depth of the two end faces is H. m The groove, where L1 is the width of the protrusion of the target tube sheet, H m The groove depth of the target tube sheet.

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