Manufacturing process of corrosion-resistant blind plate with small wall thickness

Abstract

The invention discloses a manufacturing process of a small-wall-thickness corrosion-resistant blind plate, a carbon steel material with the diameter smaller than that of a finished product target and the thickness larger than that of the finished product target is adopted for surfacing, the surfacing thickness is larger than that required by the finished product target, then forging and pressing are carried out to reach the target size, and finally one-time machining is carried out to remove allowance to reach the finished product size. By means of the mode, according to the manufacturing process of the small-wall-thickness corrosion-resistant blind plate, the blank is subjected to two-face surfacing firstly and then subjected to one-time forging and machining, the production efficiency is greatly improved, the machining period is shortened, meanwhile, the use amount of corrosion-resistant surfacing materials can be reduced, the cost is saved, and therefore higher economical efficiency is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of blind plate production technology, in particular to a manufacturing process of a small-wall-thickness corrosion-resistant blind plate. Background Art

[0002] Blind plates are used to block pipeline ports to completely isolate the production medium and disconnect the pipeline, making it easier to inspect and repair the pipeline in sections. Since blind plates are in direct contact with the production medium, the blind plates used to block pipeline or equipment outlets in the petrochemical industry must be corrosion-resistant. Therefore, the blind plates used under these conditions need to be treated with corrosion resistance on the surface that contacts the medium. In order to achieve economic efficiency and reliability, surfacing is generally used to solve this problem.

[0003] However, cladding is a metallurgical composite process that requires high energy, so the blind plate will inevitably deform during this process, especially for small-walled blind plates. At present, there is still no particularly effective solution to avoid deformation during cladding. The deformation problem can only be solved by multiple shaping of the blind plate, multiple machining in different steps, and increasing the cladding thickness. This undoubtedly increases the difficulty and cost of production and reduces production efficiency. Summary of the invention

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: A manufacturing process for a small-wall-thickness corrosion-resistant blind plate is provided, the steps of which include: (1) Obtain the target diameter and target thickness of the finished blind plate, and select or cut out a blank with a diameter smaller than the target diameter of the finished blind plate and a thickness greater than the target thickness of the finished blind plate; wherein the thickness t of the blank is 1 / 3~1 / 2 of the target thickness t' added to the target thickness t', that is, t = t'+ (1 / 3~1 / 2) t'; the diameter d of the blank = target diameter d'*0.9; (2) Obtain the target cladding thickness on both sides of the finished blind plate, and perform cladding on both sides of the blank to form a corrosion-resistant cladding layer, the cladding thickness of which is greater than the target cladding thickness; wherein the cladding thickness D of each side is greater than the target cladding thickness D' by 3 mm or more, i.e., D - D' ≥ 3 mm; (3) Forging the workpiece after surfacing so that the thickness of the surfacing layer and the blank is reduced at the same time, until the diameter of the workpiece is 2-3 mm larger than the target diameter of the finished product, the total thickness is equal to the target thickness, and the thickness of the corrosion-resistant surfacing layer on each side of the workpiece is 1-1.5 mm larger than the target surfacing thickness on each side of the finished product. Only one forging is required to make both sides of the blind plate flat at the same time; (4) Machining: The outer circle and plane of the workpiece are machined according to the finished product size to form a finished product whose diameter, thickness and cladding thickness meet the target requirements.

[0005] In a preferred embodiment of the present invention, the blank is carbon steel.

[0006] In a preferred embodiment of the present invention, the target surfacing thickness on one side of the finished product is 3 mm, and the surfacing thickness on one side of the workpiece after forging is 4.275 mm, so that the excess of the corrosion-resistant surfacing layer on one side of the workpiece is 1.275 mm.

[0007] In a preferred embodiment of the present invention, the forging temperature is 800-1100 degrees.

[0008] The beneficial effects of the present invention are as follows: by first performing double-sided cladding on the blank and then performing forging and machining, the production efficiency is greatly improved and the processing cycle is reduced. At the same time, the amount of corrosion-resistant cladding material can be reduced, the cost can be saved, and higher economy can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which: Figure 1 It is a flow chart of a preferred embodiment of a manufacturing process of a small-wall-thickness corrosion-resistant blind plate of the present invention; Figure 2 It is a structural schematic diagram of a preferred embodiment of a manufacturing process of a small-wall-thickness corrosion-resistant blind plate of the present invention; Figure 3 It is a schematic diagram of the thickness of the substrate after forging in a preferred embodiment of a manufacturing process of a small-wall-thickness corrosion-resistant blind plate of the present invention; Figure 4 It is a schematic diagram of the thickness of the surfacing after forging in a preferred embodiment of a manufacturing process of a small-wall-thickness corrosion-resistant blind plate of the present invention. DETAILED DESCRIPTION

[0010] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0011] See also Figure 1-4 , the embodiment of the present invention includes: A manufacturing process for a small-wall-thickness corrosion-resistant blind plate solves the problem of deformation caused by multiple machining, shaping, and increasing the thickness of the surfacing welding process in the existing small-wall-thickness blind plate. The steps include: (1) Obtain the material, target diameter and target thickness of the finished blind plate, and select or cut out a carbon steel blank whose diameter is smaller than the target diameter of the finished blind plate and whose thickness is greater than the target thickness of the finished blind plate.

[0012] According to the regular data of forging deformation of carbon steel substrate, diameter change from small to large and thickness change, a suitable carbon steel blind plate with a smaller diameter than the finished product is selected for surfacing welding. This will increase the thickness and greatly reduce the deformation of the blank during surfacing welding.

[0013] Further preferably, before surfacing, the diameter of the blank is smaller than the target diameter, generally 0.9 of the target diameter, that is, the diameter d of the blank = target diameter d'*0.9; the thickness t of the blank is increased by 1 / 3~1 / 2 of the target thickness t' on the basis of the target thickness t', that is, t= t'+ (1 / 3~1 / 2) t'.

[0014] (2) Obtaining the target cladding thickness on both sides of the finished blind plate, and cladding the two sides of the blank to form a corrosion-resistant cladding layer, the cladding thickness being thicker than the target cladding thickness.

[0015] According to the regular data of forging deformation of the corrosion-resistant cladding layer, diameter change from small to large and thickness change, the thickness of the corrosion-resistant cladding layer is controlled to ensure that the thickness of the cladding layer meets the final requirements after forging to the required size.

[0016] Further preferably, before forging, the surfacing thickness of each side is about target thickness + 3 mm, that is, D-D'≥ 3 mm; after forging, the surfacing layer on each side will be thinned by 1-1.5 mm, and at this time, there is about 1.5 mm of margin left for final machining.

[0017] When both sides of the blank are welded, there will be a little deformation, but since forging is required later, the deformation can be solved simultaneously during the forging process.

[0018] (3) Forging the workpiece after surfacing welding so that the diameter of the workpiece reaches the target diameter size, and then machining the forged workpiece to remove the excess to the finished product size.

[0019] More preferably, the forging temperature is generally 800-1100 degrees.

[0020] The forging pressing method is used to increase the diameter of the workpiece after surfacing. In this process, the thickness of the surfacing layer and the carbon steel substrate (blank) is reduced at the same time, until the diameter of the workpiece (substrate) is 2~3mm larger than the target diameter of the finished product, the thickness T1 of the substrate after forging is equal to the target thickness, and the thickness D1 of the corrosion-resistant surfacing layer on each side of the workpiece (substrate) is 1-1.5mm larger than the target surfacing thickness on each side of the finished product (that is, the surfacing thickness margin). Only one forging is needed to make both sides of the blind plate flat at the same time, solving the deformation problem during the surfacing process.

[0021] Further preferably, the target surfacing thickness on one side of the finished product is 3 mm, and the surfacing thickness on one side of the workpiece after forging is 4.275 mm, so that the excess of the corrosion-resistant surfacing layer on one side of the workpiece is 1.275 mm.

[0022] (4) Machining (mainly turning): Final machining of the outer circle and plane according to the finished product size to form the finished product.

[0023] The beneficial effects of the manufacturing process of a small-wall-thickness corrosion-resistant blind plate of the present invention are: 1. The cladding on both sides is completed in one time, which reduces the need for two cladding operations. After cladding one side, the other side needs to be processed before welding, which reduces the processing cycle and saves costs. 2. It avoids the increase of cladding thickness to prevent deformation, saves the amount of corrosion-resistant cladding materials, and saves costs; 3. It avoids the need to increase the thickness of the base material by machining the surface twice to prevent deformation, reduces the processing cycle and saves costs.

[0024] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A manufacturing process for a small-wall-thickness corrosion-resistant blind plate, characterized in that the steps include: (1) Obtain the target diameter and target thickness of the finished blind plate, and select or cut out a blank with a diameter smaller than the target diameter of the finished blind plate and a thickness greater than the target thickness of the finished blind plate; wherein the thickness t of the blank is 1 / 3~1 / 2 of the target thickness t' added to the target thickness t', that is, t = t'+ (1 / 3~1 / 2) t'; the diameter d of the blank = target diameter d'*0.9; (2) Obtain the target cladding thickness on both sides of the finished blind plate, and perform cladding on both sides of the blank to form a corrosion-resistant cladding layer, the cladding thickness of which is greater than the target cladding thickness; wherein the cladding thickness D of each side is greater than the target cladding thickness D' by 3 mm or more, i.e., D - D' ≥ 3 mm; (3) Forging the workpiece after surfacing so that the thickness of the surfacing layer and the blank is reduced at the same time, until the diameter of the workpiece is 2-3 mm larger than the target diameter of the finished product, the total thickness is equal to the target thickness, and the thickness of the corrosion-resistant surfacing layer on each side of the workpiece is 1-1.5 mm larger than the target surfacing thickness on each side of the finished product. Only one forging is required to make both sides of the blind plate flat at the same time; (4) Machining: The outer circle and plane of the workpiece are machined according to the finished product size to form a finished product whose diameter, thickness and cladding thickness meet the target requirements.

2. The manufacturing process of a small-wall-thickness corrosion-resistant blind plate according to claim 1 is characterized in that: The blank is carbon steel.

3. The manufacturing process of a small-wall-thickness corrosion-resistant blind plate according to claim 1 is characterized in that: The target surfacing thickness on one side of the finished product is 3 mm, and the surfacing thickness on one side of the workpiece after forging is 4.275 mm, so that the excess of the corrosion-resistant surfacing layer on one side of the workpiece is 1.275 mm.

4. The manufacturing process of a small-wall-thickness corrosion-resistant blind plate according to claim 1 is characterized in that: The forging temperature is 800~1100 degrees.

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