CN115069801A - Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube - Google Patents
Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube Download PDFInfo
- Publication number
- CN115069801A CN115069801A CN202210669397.8A CN202210669397A CN115069801A CN 115069801 A CN115069801 A CN 115069801A CN 202210669397 A CN202210669397 A CN 202210669397A CN 115069801 A CN115069801 A CN 115069801A
- Authority
- CN
- China
- Prior art keywords
- special
- shaped
- straight
- tube
- cladding tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 55
- 230000008569 process Effects 0.000 title claims abstract description 54
- 238000005253 cladding Methods 0.000 title claims abstract description 47
- 238000011049 filling Methods 0.000 claims abstract description 34
- 238000000137 annealing Methods 0.000 claims abstract description 4
- 238000004513 sizing Methods 0.000 claims description 35
- 230000007704 transition Effects 0.000 claims description 13
- 230000009467 reduction Effects 0.000 claims description 9
- 230000009471 action Effects 0.000 claims description 6
- 230000007547 defect Effects 0.000 abstract description 22
- 229910052751 metal Inorganic materials 0.000 abstract description 4
- 239000002184 metal Substances 0.000 abstract description 4
- 239000004033 plastic Substances 0.000 abstract description 4
- 238000005429 filling process Methods 0.000 abstract description 3
- 238000005482 strain hardening Methods 0.000 abstract description 3
- 239000000047 product Substances 0.000 description 20
- 239000003758 nuclear fuel Substances 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000002826 coolant Substances 0.000 description 2
- 230000001627 detrimental effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000010687 lubricating oil Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910001093 Zr alloy Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 229910001256 stainless steel alloy Inorganic materials 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
- B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes
- B21C1/22—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes specially adapted for making tubular articles
- B21C1/24—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes specially adapted for making tubular articles by means of mandrels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C3/00—Profiling tools for metal drawing; Combinations of dies and mandrels
- B21C3/02—Dies; Selection of material therefor; Cleaning thereof
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Metal Extraction Processes (AREA)
Abstract
The invention relates to the technical field of metal plastic forming process and equipment, and provides a multi-pass drawing forming process of a cladding tube with a straight rib. Bright annealing is used between different forming stages to eliminate residual stress, improve work hardening and further restore its plasticity. The invention reduces the problems of limited filling height of the rib in single-pass drawing forming and defects caused by the inner surface depression of the corresponding position of the rib in the rib groove filling process, the section of the tube is gradually transited among the passes after the process is adopted for forming, the ribbed tube with the wall thickness larger than that of the finished tube can be formed, and the formed tube has high section precision, small error and higher strength and rigidity.
Description
Technical Field
The invention relates to the technical field of metal plastic forming processes and equipment, in particular to a multi-pass drawing forming process of a cladding tube with straight ribs and the cladding tube.
Background
The cladding tube is an important structural component of the core and mainly functions to protect the fuel pellets from corrosion by the coolant and to prevent the escape of fissionable materials in the cladding. The ribbed tube has ribs protruding from the tube on the outer surface, so that the heat transfer performance of the coolant can be enhanced, the fluid mixing is promoted, and the ribbed tube is a novel nuclear fuel cladding tube applied at present. Because the size of the outer surface rib is smaller, the traditional production process of the ribbed pipe is to wind an iron wire on the outer surface of the thin-walled pipe and fix the thin-walled pipe by electric welding. However, the method cannot realize integral forming, has low production efficiency and poor surface size, and causes the phenomenon of cladding tube isolation failure easily caused by rib separation in the subsequent high-temperature and high-pressure service process. In order to improve the situation and improve the safety service performance of the cladding tube, the integral forming of the ribbed tube is urgently needed. Meanwhile, because the height of the ribs on the outer surface of the ribbed pipe is greater than or equal to the wall thickness of the finished pipe, the problems of insufficient rib filling height, rib and groove defects on the inner surface of the corresponding position due to rib filling on the outer surface of the pipe and the like can be caused in the forming process, and therefore, how to simultaneously ensure the height of the ribs on the outer surface of the pipe and eliminate the rib and groove defects on the inner surface in the integrated forming process is a technical problem.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a multi-pass drawing forming process of a cladding tube with straight ribs and the cladding tube, the process reduces the defects that the section error of the finished tube is large, the defects are easy to generate and the requirements cannot be met in single-pass drawing forming, the tube formed by the process has high section precision and small error, has higher strength and rigidity, and ensures the requirement of the safety service of the cladding tube for nuclear fuel.
The invention adopts the following technical scheme:
on one hand, the invention provides a multi-pass drawing forming process of a cladding tube with straight ribs, which comprises the following steps: taking a circular section pipe as an initial pipe blank, and sequentially performing a pre-forming stage corresponding to a first special-shaped die, a transition forming stage corresponding to a second special-shaped die and a finished product forming stage corresponding to a third special-shaped die on the initial pipe blank under the combined action of the die and a core rod to finally form a finished pipe with a straight-rib cladding pipe with a certain characteristic section; the mandrel is used for controlling the inner diameter of the special-shaped section pipe formed in the corresponding pass, and the first special-shaped die, the second special-shaped die and the third special-shaped die are respectively used for controlling the outer diameter and the straight rib of the special-shaped section pipe formed in the corresponding pass.
In any of the above possible implementation manners, there is further provided an implementation manner, in which bright annealing is adopted among the forming stages of the pre-forming stage, the transition forming stage and the finished product forming stage to eliminate residual stress, improve work hardening and further recover plasticity thereof.
In any of the above possible implementation manners, there is further provided an implementation manner, where the number of the first special-shaped mold and the number of the third special-shaped mold are both one, and the number of the second special-shaped mold is one or several;
the first special-shaped die, the second special-shaped die and the third special-shaped die respectively comprise a conical inlet section and a cylindrical sizing section which are connected in sequence;
the conicity of the inlet section is alpha, and one or a plurality of chutes with the conicity of beta are arranged on the inlet section; alpha is 5-15 degrees, beta is 2-10 degrees; too little or too much of α, β can lead to poor rib filling and to tube breakage during drawing;
one or a plurality of special-shaped grooves with certain width, height and filling angle are arranged on the inner wall of the sizing section, the bottoms of the special-shaped grooves are rounded, and the radius of the rounded angle is R;
in any of the possible implementations described above, there is further provided an implementation that, in the preforming stage, the sizing section of the first profile mold has the profile groove with the width W1, the height H1, the fillet radius R1 and the filling angle ω 1, and the process parameters are selected in the range of: w1 ═ W3 (1 to 1.5), H1 ═ H3 (0.2 to 0.5), R1 ═ R3 (1 to 20), and ω 1 ═ 90 to 150 °; w3, H3, R3, ω 3 are the mold parameters of the third profile mold (final product forming stage), respectively: the width, the height, the fillet radius and the filling angle of the irregular groove of the sizing section are determined by the finished pipe and are the same as the finished pipe in size.
In any of the above possible implementations, there is further provided an implementation manner that, in the transition forming stage, the sizing section of the second profile mold has a profiled groove with a width W2, a height H2, a fillet radius R2 and a filling angle ω 2, and the process parameters are selected from the following ranges: w2 ═ W3 (1.5-2), H2 ═ H3 (0.7-0.8), R2 ═ R3 (1-5), and ω 2 ═ 90-130 °; w3, H3, R3, ω 3 are the mold parameters of the third profile mold (final product forming stage), respectively: the sizing section is provided with the width, the height, the fillet radius and the filling angle of the special-shaped groove.
In any of the above possible implementation manners, there is further provided an implementation manner, where a process parameter selection range between adjacent passes of drawing is: the diameter reduction rate is 10-35%, and the wall thickness reduction rate is 10-25%. A reduction rate below the minimum value of the selected range does not meet the rib filling requirement, while above the maximum value of the selected range results in an excessive amount of deformation and snapping.
Any of the possible implementations described above further provides an implementation in which the height of the straight ribs of the finished tubing is greater than or equal to the wall thickness of the finished tubing.
In any of the above possible implementations, there is further provided an implementation manner that, when the plurality of second special-shaped molds are adopted, the deformation amounts of the pipe diameter, the pipe wall thickness, the width of the straight rib, the height of the straight rib, and the filling angle of the straight rib in the transition forming stage are jointly realized by the plurality of second special-shaped molds.
In any of the possible implementations described above, there is further provided an implementation in which the core rod at different forming stages consists of a conical inlet section with a taper γ and an outer diameter Φ 2 Length L of 2 Is formed by the cylindrical sizing section. The selection range of the process parameters is as follows: l is 2 0.1-1 mm, and 10-30 degrees; the lengths L of the sizing sections of the first special-shaped mould, the second special-shaped mould and the third special-shaped mould 1 The range of (A) is as follows: l is 1 ＝0.5～5mm，L 1 Too small will cause the pipe to rebound and cause the pipe to deform and then the outer diameter of the pipe is larger than the target value, L 1 If the pulling force is too large, the tube is broken due to too large pulling force; l is a radical of an alcohol 2 Too small to ensure the dimensional accuracy of the inner surface of the deformed pipe, L 2 Too much will result in too much drawing force and tube breakage.
In any of the above possible implementation manners, there is further provided an implementation manner that the different forming stages are the special-shaped mold and the core rod, and the sizing section L of the special-shaped mold is used when the special-shaped mold and the core rod are used together 1 Greater than or equal to the core rod sizing section L 2 The sizing section of the die should include a core rod sizing section.
In any of the above possible implementations, there is further provided an implementation in which the straight-ribbed cladding tube is made of a stainless steel or zirconium alloy tube for nuclear fuel.
Any one of the above possible implementation manners further provides an implementation manner, and the specific step of drawing in each pass is:
firstly, fixing a special-shaped mold on a frame; adjusting the positions of the core rod sizing section and the special-shaped die sizing section by adjusting the nut at the end part of the core rod, so that the die sizing section comprises the sizing section of the core rod; reducing one end of the pipe by a reducing machine to enable the outer diameter of the pipe blank to be smaller than the size of the inner hole of the special-shaped die; evenly coating drawing lubricating oil on the inner surface and the outer surface of the pipe; fifthly, enabling the pipe at the warp shrinking end to pass through a die; plugging the adjusted core rod from the other end of the pipe; seventhly, drawing force is applied to the pipe penetrating through the die, the core rod inserted into the pipe moves towards the direction of the applied force, and the position of the nut at the end of the core rod is fixed by a baffle plate, so that the core rod cannot be changed after moving to the previously adjusted position; the tube blank generates plastic deformation under the combined action of the special-shaped mould and the core rod.
When the combination is carried out between different passes, in order to increase the rib filling degree and prevent the inner surface of the position corresponding to the rib from flowing into the die cavity due to metal transition, and further, the groove defect is generated on the inner surface, so that the deformation degree of different passes is different in process design. Values below the minimum of the selected range are detrimental to the next rib fill, while values above the maximum of the selected range are detrimental to rib and groove defects and all affect the dimensional accuracy of the finished tube.
On the other hand, the invention also provides a cladding tube with the straight ribs, which is prepared by the multi-pass drawing forming process of the cladding tube with the straight ribs, wherein the rib height of the cladding tube with the straight ribs is greater than or equal to the wall thickness of the cladding tube with the straight ribs.
The invention has the beneficial effects that:
the invention reduces the problems of limited filling height of the rib in single-pass drawing forming and defects caused by the inner surface depression of the corresponding position of the rib in the rib groove filling process, the section of the tube is gradually transited among the passes after the process is adopted for forming, the ribbed tube with the wall thickness larger than that of the finished tube can be formed, and the formed tube has high section precision, small error and higher strength and rigidity.
Drawings
FIG. 1 is a schematic drawing of a straight-ribbed jacketed pipe drawing process according to an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of a cladding tube with straight ribs in the embodiment.
FIG. 3 is a cross-sectional view of the tube after different passes of forming in the multi-pass drawing process of the clad tube with straight ribs in the embodiment.
FIG. 4 is an enlarged partial cross-sectional view of the tubing after different passes of the straight ribbed clad tube have been formed during the multiple pass drawing process of the exemplary embodiment.
Fig. 5 is a schematic structural view of the special-shaped die in the drawing forming process of the cladding tube with the straight ribs in the embodiment.
FIG. 6 is a schematic diagram showing the structure of a mandrel in the drawing forming process of the cladding tube with straight ribs in the embodiment.
Detailed Description
Specific embodiments of the present invention will be described in detail below with reference to the specific drawings. It should be noted that technical features or combinations of technical features described in the following embodiments should not be considered as being isolated, and they may be combined with each other to achieve better technical effects. In the drawings of the embodiments described below, the same reference numerals appearing in the respective drawings denote the same features or components, and may be applied to different embodiments.
The embodiment of the invention provides a multi-pass drawing forming process of a cladding tube with straight ribs, which comprises the following steps: taking a circular section pipe as an initial pipe blank, and sequentially performing a pre-forming stage corresponding to a first special-shaped die, a transition forming stage corresponding to a second special-shaped die and a finished product forming stage corresponding to a third special-shaped die on the initial pipe blank under the combined action of the die and a core rod to finally form a finished pipe with a straight-rib cladding pipe with a certain characteristic section; the mandrel is used for controlling the inner diameter of the special-shaped section pipe formed in the corresponding pass, and the first special-shaped die, the second special-shaped die and the third special-shaped die are respectively used for controlling the outer diameter and the straight rib of the special-shaped section pipe formed in the corresponding pass.
In a specific embodiment, bright annealing is adopted among the forming stages of the pre-forming stage, the transition forming stage and the finished product forming stage to eliminate residual stress, improve work hardening and further recover plasticity.
In a specific embodiment, the number of the first special-shaped mold and the number of the third special-shaped mold are both one, and the number of the second special-shaped mold is one or a plurality of. When a plurality of second special-shaped molds are adopted, the deformation of the diameter of the pipe, the wall thickness of the pipe, the width of the straight rib, the height of the straight rib and the filling angle of the straight rib in the transition forming stage is realized by the plurality of second special-shaped molds together.
As shown in fig. 1, the drawing step of any pass is as follows: firstly, fixing a mould on a frame; adjusting a nut at the end of the core rod to enable the sizing section of the core rod to coincide with the sizing section of the die; reducing one end of the pipe by a head reducing machine to enable the outer diameter of the pipe blank to be smaller than the size of the inner hole of the die; evenly coating drawing lubricating oil on the inner surface and the outer surface of the pipe to form the pipe; fifthly, enabling the pipe at the warp shrinking end to pass through a die; plugging the mandrel with the adjusted position from the other end of the pipe; seventhly, drawing force is applied to the pipe penetrating through the die, the core rod inserted into the pipe moves towards the direction of the applied force, and the position of the nut at the end of the core rod is fixed by a baffle plate, so that the core rod cannot be changed after moving to the previously adjusted position; and the pipe blank generates plastic deformation under the combined action of the mold and the core rod.
As shown in figure 2, the cladding tube with the straight ribs prepared by the invention has one or more ribs protruding out of the outer surface, wherein the ribs are straight, the height of the ribs is greater than or equal to the wall thickness of the tube, and the tube is a typical special-wall special-shaped tube difficult to integrally form.
As shown in fig. 3, in a specific embodiment, a sectional view of a tube after being formed by different passes in a multi-pass drawing process of a cladding tube with straight ribs is obtained by taking a tube with a circular section as an initial blank, sequentially passing through a first special-shaped die, a second special-shaped die and a third special-shaped die, and drawing a tube blank with a circular section into a special-shaped tube with a certain characteristic section under the combined action of a mandrel and the special-shaped dies, wherein corresponding forming stages are respectively called a first-stage pre-forming stage, a second-stage transitional forming stage and a third-stage finished product forming stage. The drawing process of each pass is a forming process for reducing the diameter and the wall thickness of the pipe, except that the outer diameter and the wall thickness of a final finished product are determined by target dimensions, the selection ranges of the process parameters among the other passes are as follows: the diameter reduction rate is 10-35%, and the wall thickness reduction rate is 10-25%. A reduction rate below the minimum value of the selected range does not meet the rib filling requirement, while above the maximum value of the selected range results in an excessive amount of deformation and snapping.
In one embodiment, as shown in fig. 4, the tube has a partially enlarged cross-sectional view after being formed in different passes of the multi-pass drawing process of the cladding tube with the straight ribs. Wherein the preformed sizing section is provided with a profiled groove with the width of W1, the height of H1, the fillet radius of R1 and the filling angle omega 1. The selection range of the process parameters is as follows: w1 is (1-1.5) W3, H1 is (0.2-0.5) H3, R1 is (1-20) R3, and omega 1 is 90-150 degrees. The transition forming sizing section is provided with a profiled groove with the width of W2, the height of H2, the fillet radius of R2 and the filling angle omega 2. The selection range of the process parameters is as follows: w2 is (1.5-2) W3, H2 is (0.7-0.8) H3, R2 is (1-5) R3, and omega 2 is 90-130 degrees. Third differential mold parameter (inner bore diameter Φ) in the final drawing stage (product forming stage) 1 Width W3, height H3, fillet radius R3 and fill angle ω 3) and mandrel parameters (outside diameter Φ 2 ) The size of the finished pipe is determined, and the finished pipe is the same as the size of a target product. When the combination is carried out between different passes, in order to increase the rib filling degree and prevent the inner surface of the position corresponding to the rib from flowing into the die cavity due to metal transition, and further, the groove defect is generated on the inner surface, so that the deformation degrees of the rest different passes are different in process design. Values of the parameters below the minimum of the selected range are disadvantageousThe next rib filling, above the maximum value of the selected range, will result in rib and groove defects, all of which will affect the dimensional accuracy of the finished tube.
In one embodiment, as shown in fig. 5, the profile mold is schematically constructed. The special-shaped dies in different forming stages are used for controlling the outer diameter size and rib size of the formed special-shaped section pipe and consist of a conical inlet section and a cylindrical sizing section. Wherein the conicity of the inlet section is alpha, and a plurality of chutes with the conicity of beta are arranged on the inlet section. The process parameter selection range is as follows: alpha is 5-15 degrees, beta is 2-10 degrees, and both alpha and beta are too small or too large, which can result in poor rib filling effect and pipe breakage in the drawing process. The inlet section is provided with a plurality of special-shaped cross section chutes which are respectively the width W, the height H, the fillet radius R and the filling angle omega. The length of the sizing section is L 1 The selection range of (A) is as follows: l is 1 ＝0.5～5mm。L 1 Too small will cause the pipe to rebound and cause the pipe to deform and then the outer diameter of the pipe is larger than the target value, L 1 Too much will result in too much drawing force and tube breakage.
In one embodiment, as shown in FIG. 6, the mandrel is shown schematically. The core rods in different forming stages are used for controlling the inner diameter of the shaped cross-section pipe after forming and consist of a conical inlet section with the taper of gamma and a conical inlet section with the outer diameter of phi 2 Length L 2 Is formed by the cylindrical sizing section. The selection range of the process parameters is as follows: l is 2 ＝0.1～1mm，γ＝10～30°。L 2 Too small to ensure the dimensional accuracy of the inner surface of the deformed pipe, L 2 If the lambda is too large, the drawing force is too large to cause the tube to be broken, the lubricating effect of the lambda in the parameter range is better, and the drawing force can be reduced. The different forming stages are matched by the special-shaped die and the core rod, and the sizing section L of the special-shaped die is used 1 Greater than or equal to the core rod sizing section L 2 The sizing section of the die should include a core rod sizing section.
The material of the tube in the comparative example is 316L stainless steel.
Comparative example 1
When the diameter of a target product pipe is 6mm and the wall thickness is 0.5mm, the size and the performance of the product obtained by single pass and multiple passes (3 passes) are compared. The maximum rib height obtained in a single pass is 0.284mm, which is only 56.8% filled compared to the wall thickness. The maximum rib height achieved after multiple passes of drawing as proposed herein is 0.496mm, up to 99.2% filling compared to wall thickness. Therefore, compared with the product obtained by the single-pass scheme, the multi-pass drawing scheme provided by the invention has the advantages that the rib height is improved by 42.4%, and the rib filling effect is obviously improved. In addition, the increase of the height of the outer surface rib can improve the tensile strength of the ribbed pipe by 6-12%.
Comparative example 2
The target product pipe diameter 6mm and wall thickness 0.5mm, product size and performance were compared to those obtained with the conventional and multi-pass protocol proposed herein (both 3 passes). By adopting a common multi-pass drawing scheme, namely setting the rib groove width W and the rib groove height H of each pass to be the same (W1-W2-W3 and H1-H2-H3), the maximum value of the rib height is 0.418mm, the defect that the inner surface of the pipe corresponding to the rib is filled with 83.6 percent of the wall thickness, the defect that the depth of the inner surface of the pipe corresponding to the rib is 0.298mm appears, and the defect accounts for more than half of the wall thickness compared with 59.6 percent of the wall thickness. When the multi-pass drawing scheme proposed herein is used, i.e. different rib groove widths W and rib groove heights H are set (W1-1.5W 3, W2-1.3W 3, H1-0.4H 3, H2-0.8H 3), a maximum rib height of 0.496mm is obtained, up to 99.2% filling compared to wall thickness, and a defect depth of 0.076mm, accounting for 15.2% compared to wall thickness. In conclusion, compared with the product obtained by the conventional scheme, the multi-pass drawing scheme provided by the invention has the advantages that the rib height is improved by 15.6%, the defect depth is reduced by 44.4%, the rib filling effect is obviously improved, and the rib groove defect is further eliminated. In addition, the increase of the height of the outer surface rib enables the tensile strength of the ribbed tube to be improved by 6-8%, the reduction of the inner surface rib groove enables the stability and the strength of the combination of the rib and the tube to be greatly improved, and the service life of the cladding tube in the extreme environment of nuclear fuel is prolonged.
Comparative example 3
When the diameter of a target product pipe is 6mm and the wall thickness is 0.5mm, the size and the performance of the product are compared with those of a product obtained by a common multi-pass scheme (4 passes, and two second special-shaped dies are correspondingly adopted in the invention) and a multi-pass scheme (provided by the invention). The common multi-pass drawing scheme is adopted, namely, the rib groove width W and the rib groove height H of each pass are the same (W1-W21-W3, H1-H21-H22-H3). The maximum rib height obtained in this case was 0.478mm, which was 95.6% greater than the wall thickness, and the inner surface of the tube at the position corresponding to the rib had a defect of 0.364mm depth, which was 72.8% greater than the wall thickness, which was half the wall thickness. When the multi-pass drawing scheme proposed herein is adopted, i.e. different rib and groove widths W and heights H are set (W1-1.6W 3, W21-1.4W 3, W22-1.2W 3, H1-0.35H 3, H21-0.7H 3, and H22-0.85H 3), where W21 and W22 are the widths of the two second profile die sizing section profile grooves, and H21 and H22 are the heights of the two second profile die sizing section profile grooves, respectively, the maximum value of rib height is 0.734mm, 146.8% compared to wall thickness filling, and the depth of defect is 0.136mm, 27.2% compared to wall thickness. In conclusion, compared with the product obtained by the conventional scheme, the product obtained by the multi-pass drawing scheme provided by the invention has the advantages that the rib height is improved by 51.2%, the defect depth is reduced by 45.6%, the pipe with the rib filling height larger than the wall thickness is obtained, and the rib groove defect is further eliminated. The increase of the height of the outer surface ribs enables the tensile strength of the ribbed pipe to be improved by 7-9%, and the height of the outer surface ribs of the ribbed pipe is greatly increased. Furthermore, a tube with a rib height greater than the wall thickness may further increase the positioning distance of the ribbed cladding tubes relative to each other in nuclear fuel applications. By extending the solution herein to different passes, a variety of ribbed tubes of different rib heights can be manufactured, enabling a versatile selection of products of different rib heights in the nuclear fuel cladding.
It should be noted that the pre-formed shape, the transitional formed shape, and the final formed shape, even the number of drawing passes, selected in the above examples are only one of many options, and those skilled in the art can expand the scope of the present invention to other types of multi-pass forming processes for cladding tubes.
The invention reduces the problems of limited filling height of the rib in single-pass drawing forming and defects caused by the inner surface depression of the corresponding position of the rib in the rib groove filling process, the section of the tube is gradually transited among the passes after the process is adopted for forming, the ribbed tube with the wall thickness larger than that of the finished tube can be formed, and the formed tube has high section precision, small error and higher strength and rigidity.
While several embodiments of the present invention have been presented herein, it will be appreciated by those skilled in the art that changes may be made to the embodiments herein without departing from the spirit of the invention. The above examples are merely illustrative and should not be taken as limiting the scope of the invention.
Claims (10)
1. The multi-pass drawing forming process of the cladding tube with the straight ribs is characterized by comprising the following steps of: taking a prepared pipe with a circular section as an initial pipe blank, and sequentially performing a pre-forming stage corresponding to a first special-shaped die, a transition forming stage corresponding to a second special-shaped die and a finished product forming stage corresponding to a third special-shaped die on the initial pipe blank under the combined action of the dies and a core rod to finally form a finished pipe with a straight-ribbed clad pipe with a certain characteristic section; the mandrel is used for controlling the inner diameter of the special-shaped section pipe formed in the corresponding pass, and the first special-shaped die, the second special-shaped die and the third special-shaped die are respectively used for controlling the outer diameter and the straight rib of the special-shaped section pipe formed in the corresponding pass.
2. The multi-pass drawing forming process of the cladding tube with the straight rib of claim 1, wherein bright annealing is adopted among the forming stages of the pre-forming stage, the transition forming stage and the finished product forming stage to eliminate residual stress and restore plasticity.
3. The multi-pass drawing forming process of the cladding tube with the straight ribs according to claim 1, wherein the number of the first special-shaped dies and the number of the third special-shaped dies are one, and the number of the second special-shaped dies is one or more;
the first special-shaped die, the second special-shaped die and the third special-shaped die respectively comprise a conical inlet section and a cylindrical sizing section which are connected in sequence;
the conicity of the inlet section is alpha, and one or a plurality of chutes with the conicity of beta are arranged on the inlet section; alpha is 5-15 degrees, beta is 2-10 degrees;
the inner wall of the sizing section is provided with one or a plurality of special-shaped grooves with certain width, height and filling angle, the bottoms of the special-shaped grooves are rounded, and the radius of the round angle is R.
4. The multiple-pass drawing forming process for the cladding tube with the straight rib of claim 3, wherein in the pre-forming stage, the sizing section of the first special-shaped die is provided with the special-shaped grooves with the width W1, the height H1, the fillet radius R1 and the filling angle omega 1, and the process parameters are selected from the following ranges: w1 (1-1.5) W3, H1 (0.2-0.5) H3, R1 (1-20) R3, and omega 1 (90-150 degrees); w3, H3, R3 and ω 3 are the width, height, fillet radius and filling angle of the profiled groove of the fixed-diameter section of the third differential die, respectively.
5. The multi-pass drawing forming process for the cladding tube with the straight rib of claim 3, wherein in the transitional forming stage, the sizing section of the second special-shaped die is provided with a special-shaped groove with the width W2, the height H2, the fillet radius R2 and the filling angle omega 2, and the process parameters are selected from the following ranges: w2 (1.5-2) W3, H2 (0.7-0.8) H3, R2 (1-5) R3, and omega 2 (90-130 degrees); w3, H3, R3 and ω 3 are the width, height, fillet radius and filling angle of the profiled groove of the fixed-diameter section of the third differential die, respectively.
6. The multi-pass drawing forming process for the cladding tube with the straight ribs according to any one of claims 1 to 5, wherein the process parameters between adjacent passes are selected in the range of: the diameter reduction rate is 10-35%, and the wall thickness reduction rate is 10-25%.
7. The multi-pass draw forming process of the cladding tube with straight ribs according to claim 1, wherein the height of the straight ribs of the finished tube is greater than or equal to the wall thickness of the finished tube.
8. The multiple-pass drawing forming process of the cladding tube with the straight ribs according to claim 3, wherein when a plurality of second special-shaped dies are adopted, the deformation of the diameter of the tube, the wall thickness of the tube, the width of the straight ribs, the height of the straight ribs and the filling angle of the straight ribs in the transition forming stage is realized by the plurality of second special-shaped dies together.
9. The multi-pass draw forming process of the cladding tube with straight ribs according to claim 1, wherein the core rod consists of a conical inlet section with a taper gamma and an outer diameter phi 2 Length L of 2 Is formed by the cylindrical sizing section. The selection range of the process parameters is as follows: l is 2 0.1-1 mm, and 10-30 degrees; the lengths L of the sizing sections of the first special-shaped mould, the second special-shaped mould and the third special-shaped mould 1 The range of (A) is as follows: l is 1 ＝0.5～5mm。
10. A straight-ribbed cladding tube produced by the multi-pass draw forming process of the straight-ribbed cladding tube according to any one of claims 1 to 9, wherein the height of the straight-ribbed cladding tube is greater than or equal to the wall thickness of the straight-ribbed cladding tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210669397.8A CN115069801B (en) | 2022-06-14 | 2022-06-14 | Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210669397.8A CN115069801B (en) | 2022-06-14 | 2022-06-14 | Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115069801A true CN115069801A (en) | 2022-09-20 |
| CN115069801B CN115069801B (en) | 2023-10-24 |
Family
ID=83250667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210669397.8A Active CN115069801B (en) | 2022-06-14 | 2022-06-14 | Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115069801B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001162319A (en) * | 1999-12-03 | 2001-06-19 | Hitachi Ltd | Branch pipe having annular rib, and its manufacturing method |
| CN101537435A (en) * | 2009-05-06 | 2009-09-23 | 北京科技大学 | Dieless drawing forming process for conical metal pipe |
| CN102632094A (en) * | 2012-04-24 | 2012-08-15 | 西北有色金属研究院 | Method for improving surface quality of titanium and titanium alloy pipes and drawing die |
| CN103357696A (en) * | 2013-07-18 | 2013-10-23 | 中铝洛阳铜业有限公司 | Production manufacturing process of large-diameter copper-nickel alloy seamless pipe |
| JP2015024434A (en) * | 2013-07-29 | 2015-02-05 | 株式会社新富士空調 | Spiral tube, spiral tube manufacturing device, manufacturing method |
| CN109675946A (en) * | 2018-12-28 | 2019-04-26 | 张家港华程特种材料股份有限公司 | Octagon drawing die |
| CN111842517A (en) * | 2020-07-24 | 2020-10-30 | 浙江久立特材科技股份有限公司 | Cold drawing die for ribbed cladding tube, production process and finished tube thereof |
| CN113458166A (en) * | 2021-06-30 | 2021-10-01 | 北京科技大学 | Cold-drawing forming device and forming method for cladding tube with spiral ribs |
| CN114082803A (en) * | 2021-11-22 | 2022-02-25 | 韩维新 | Production process and cold-drawing die for ribbed thin-wall cladding tube |
| CN114082798A (en) * | 2021-11-22 | 2022-02-25 | 韩维新 | Production process and production device for outer wall spiral rib cladding tube |
-
2022
- 2022-06-14 CN CN202210669397.8A patent/CN115069801B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001162319A (en) * | 1999-12-03 | 2001-06-19 | Hitachi Ltd | Branch pipe having annular rib, and its manufacturing method |
| CN101537435A (en) * | 2009-05-06 | 2009-09-23 | 北京科技大学 | Dieless drawing forming process for conical metal pipe |
| CN102632094A (en) * | 2012-04-24 | 2012-08-15 | 西北有色金属研究院 | Method for improving surface quality of titanium and titanium alloy pipes and drawing die |
| CN103357696A (en) * | 2013-07-18 | 2013-10-23 | 中铝洛阳铜业有限公司 | Production manufacturing process of large-diameter copper-nickel alloy seamless pipe |
| JP2015024434A (en) * | 2013-07-29 | 2015-02-05 | 株式会社新富士空調 | Spiral tube, spiral tube manufacturing device, manufacturing method |
| CN109675946A (en) * | 2018-12-28 | 2019-04-26 | 张家港华程特种材料股份有限公司 | Octagon drawing die |
| CN111842517A (en) * | 2020-07-24 | 2020-10-30 | 浙江久立特材科技股份有限公司 | Cold drawing die for ribbed cladding tube, production process and finished tube thereof |
| CN113458166A (en) * | 2021-06-30 | 2021-10-01 | 北京科技大学 | Cold-drawing forming device and forming method for cladding tube with spiral ribs |
| CN114082803A (en) * | 2021-11-22 | 2022-02-25 | 韩维新 | Production process and cold-drawing die for ribbed thin-wall cladding tube |
| CN114082798A (en) * | 2021-11-22 | 2022-02-25 | 韩维新 | Production process and production device for outer wall spiral rib cladding tube |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115069801B (en) | 2023-10-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5507535B2 (en) | Guide tube | |
| CA2580420C (en) | Plug, method of expanding inside diameter of metal pipe or tube using such plug, method of manufacturing metal pipe or tube, and metal pipe or tube | |
| US4161112A (en) | Tube drawing technique | |
| EP3583302B1 (en) | Method for the production of hollow chamber valves | |
| CN100506423C (en) | Method for manufacturing over-length upset end drilling rod | |
| CN111822634B (en) | Shape control method for improving homogeneity of die steel | |
| JP2007505789A (en) | Compound steering rack | |
| CN1555298A (en) | Manufacture of metal tubes | |
| CN113649427B (en) | 6061 aluminum alloy thin-wall pipe forming process | |
| CN111842517A (en) | Cold drawing die for ribbed cladding tube, production process and finished tube thereof | |
| BR102018004502B1 (en) | METHOD FOR PRODUCING A BRUCT OF LONG CARTRIDGE CASE AND PUNCTURES AND DIE KIT | |
| US4692978A (en) | Method for making heat exchange tubes | |
| CN115069801A (en) | Multi-pass drawing forming process for cladding tube with straight ribs and cladding tube | |
| CN114472731A (en) | Pipe end machining method of heater pipe | |
| CN110961560B (en) | Forging method for one-time upsetting forming of large-height-diameter-ratio bar | |
| CN115213248A (en) | Multi-pass drawing forming process for cladding tube with spiral ribs and cladding tube | |
| US4915166A (en) | Titanium heat exchange tubes | |
| EP0133801A2 (en) | Finned heat exchanger tubes and method and apparatus for making same | |
| JPH09103819A (en) | Production for tube excellent in shape precision by using drawing and drawing tool | |
| DE102020132822B4 (en) | Process for manufacturing an internal stop in a tubular component | |
| CN110314951B (en) | Method for manufacturing large-caliber high-strength thick-wall cold drawn pipe | |
| DE102007034895A1 (en) | Method of producing hot-finished seamless tubes with optimized fatigue properties in the welded state | |
| CN114082803A (en) | Production process and cold-drawing die for ribbed thin-wall cladding tube | |
| EP1447158A2 (en) | Method for producing rack bar | |
| US5036693A (en) | Integral finned tubes and a method of manufacturing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |