Ring rolling forming method and device for continuous multi-step titanium alloy inner rib barrel

Abstract

The invention provides a ring rolling forming method and device for a continuous multi-step titanium alloy inner rib barrel, and the method comprises the following steps: step 1, machining a titanium alloy rod according to a design size to obtain a ring blank; 2, the surface of the ring blank is evenly coated with an anti-oxidation coating and aired, a resistance furnace is adopted for heating the ring blank, the heating temperature is controlled to be 30-50 DEG C below the phase transformation point of the titanium alloy, and heat preservation is conducted for 2-4 h; 3, a ring rolling mill is used for sequentially conducting pre-rolling forming, final rolling forming and final shaping on the ring blank; 4, after the surface of the ring blank is coated with an anti-oxidation coating, the ring blank is put into a non-vacuum heat treatment furnace, the heating temperature is set to be 600-650 DEG C, heat preservation is conducted for 60-120 min after the set temperature is reached, and the ring blank is discharged out of the furnace and subjected to air cooling; and 5, according to the design size of the titanium alloy barrel, the ring blank obtained after heat treatment is machined, a surface oxidation layer is removed, and the finished titanium alloy barrel is obtained. The material utilization rate is high, the production efficiency is high, the cost is low, and the overall mechanical property is good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic processing forming of metal materials, in particular to a continuous multi-step titanium alloy inner rib cylinder ring rolling forming method and device. BACKGROUND

[0002] The equipment manufacturing industry for ocean engineering has entered a rapid development stage, and there is an urgent demand for titanium alloy equipment for ocean engineering; titanium alloy material has low density, high specific strength, strong corrosion resistance, and also has excellent resistance to seawater scouring, non-magnetic, no cold brittleness, high acoustic transmission coefficient and excellent neutron irradiation attenuation performance, is an excellent lightweight structural material, known as "ocean metal" and "the third metal". The titanium alloy continuous multi-step inner rib cylinder is a key main load-bearing ring component of new type of ocean engineering equipment, has the characteristics of thin wall, high rib, complex and sudden change of cross section, and has the characteristics of integration, lightweight and high precision, and has become the research focus and hotspot in the field of ocean engineering.

[0003] For the above-mentioned structure, the current traditional process mainly adopts two technical means for preparation, one is the machining method of titanium alloy thick-walled forgings or hot extruded thick-walled pipes, due to a large amount of machining, the material utilization rate of the cylinder is extremely low (less than 10%), causing great waste of materials, and machining will damage the overall flow line of the material, causing the uniformity of the mechanical properties of the structure to decrease, the fatigue life to decrease, and the service period to be affected. The other form is to adopt the cylinder coiling forming + local reinforcing rib welding method, which will affect the product precision and safety due to the existence of multiple welds, and further affect the service life.

[0004] Chinese patent CN103111557A, entitled "Rolling Forming Method for Complex Irregular Cross-Section Ring Parts of TC25 Titanium Alloy", proposes a rolling forming technology for irregular cross-section ring parts in the aerospace field. Through a multi-stage process of "preparation of rectangular pre-rolled billet → pre-rolling irregular cross-section rolling → final rolling irregular cross-section rolling", it achieves precision forming of irregular cross-section ring parts and solves the defects such as incomplete cross-section contour and folded outer surface that are easy to occur in irregular cross-section ring parts in traditional processes. However, this technology still has the following shortcomings: First, the product targets are irregularly shaped cross-section ring parts in the aerospace field, and it does not involve the "continuous multi-step internal ribbed cylinder" structure required for marine engineering, so it cannot solve the problem of accurate filling of continuous step-type internal ribs inside the cylinder; Second, the forming device only includes pre-rolling inner / outer shape modules and final rolling inner / outer shape modules, and lacks a shaping module for correcting the dimensional accuracy of the internal ribs, making it difficult to meet the high precision requirements of multi-step internal ribs; Third, the process parameter design does not consider the correlation control of titanium alloy phase transformation points and mold preheating, and cannot adapt to the requirements of "slowing down the temperature drop and ensuring sufficient metal flow time" in the forming process of continuous multi-step internal ribs; Fourth, the application scenarios focus on the strength and lightweight requirements of the aerospace field, and the technology has not been adapted for the characteristics of marine engineering such as seawater corrosion resistance, non-magnetism, and long service life.

[0005] In summary, existing technologies suffer from problems such as low efficiency, high cost, serious material waste, and poor overall performance of parts. There is an urgent need for an integrated manufacturing method and device that can achieve near-net-shape forming, high efficiency, and high performance for such complex cylindrical structures. Summary of the Invention

[0006] In view of this, the present invention aims to propose a ring rolling forming method and apparatus for continuous multi-step titanium alloy internal ribbed cylinders to solve the problems of low efficiency, high cost, serious material waste and poor overall performance of parts in the prior art.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A method for ring rolling forming of a continuous multi-step titanium alloy internally ribbed cylinder includes the following steps:

[0009] Step 1: Based on the design dimensions of the titanium alloy cylinder, a solid cylindrical titanium alloy rod is used to obtain a ring blank through punching, mandrel drawing, and frame reaming.

[0010] Step 2: Apply an anti-oxidation coating evenly to the surface of the ring blank and let it dry. Heat the ring blank in a resistance furnace and control the heating temperature at 30-50°C below the phase transformation point of the titanium alloy for 2-4 hours.

[0011] Step 3: Use a ring mill to pre-roll, final roll, and finally shape the ring billet in sequence;

[0012] Step 4: After applying an anti-oxidation coating to the surface of the ring billet, place it in a non-vacuum heat treatment furnace, set the heating temperature to 600-650℃, hold it at the set temperature for 60-120 minutes, and then remove it from the furnace and air cool it.

[0013] Step 5: According to the design dimensions of the titanium alloy cylinder, the heat-treated ring blank is machined to remove the surface oxide layer and obtain the finished titanium alloy cylinder.

[0014] Furthermore, in step 3, the deformation of the ring billet in the pre-rolling, final rolling and final shaping processes is 20% to 40%.

[0015] A ring rolling forming apparatus for the aforementioned continuous multi-step titanium alloy inner ribbed cylinder ring rolling forming method includes a main roll and an intermediate mandrel, wherein a forming module is sleeved on the intermediate mandrel, and the main roll cooperates with the intermediate mandrel for rolling the ring billet;

[0016] The forming module includes a pre-roll forming module, a final rolling forming module, and a shaping module. The pre-roll forming module is used to pre-roll the ring billet, the final rolling forming module is used to final roll the ring billet, and the shaping module is used to finally shape the ring billet.

[0017] Furthermore, the pre-rolling forming module includes a first core roll, and the main roll and the first core roll cooperate to pre-roll the ring billet.

[0018] The first core roller includes a first upper core roller and a first lower core roller arranged sequentially from top to bottom, with the first upper core roller abutting against the first lower core roller;

[0019] The lower end of the first lower core roller is provided with a core roller pad ring, which abuts against the boss on the intermediate core shaft. The core roller pad ring is used to support and limit the first lower core roller.

[0020] The upper end of the first core roller is provided with a first core roller cover plate, the first core roller cover plate is provided with a first central hole, the first core roller cover plate is sleeved on the intermediate mandrel through the first central hole, and the first core roller cover plate is used to seal the first core roller.

[0021] A nut is provided at the upper end of the first core roller cover plate, and the nut is screwed to the intermediate mandrel to limit and fix the first core roller cover plate.

[0022] Furthermore, the final rolling forming module includes a second core roll, and the main roll and the second core roll cooperate to perform final rolling forming on the ring billet;

[0023] The second core roller includes a second upper core roller and a second lower core roller arranged sequentially from top to bottom, with the second upper core roller abutting against the second lower core roller;

[0024] The lower end of the second lower core roller is provided with a core roller pad ring, which abuts against the boss on the intermediate core shaft. The core roller pad ring is used to support and limit the second lower core roller.

[0025] The upper end of the second upper core roller is provided with a second core roller cover plate, and the second core roller cover plate is provided with a second central hole. The second core roller cover plate is sleeved on the intermediate core shaft through the second central hole. The second core roller cover plate is used to seal the second upper core roller.

[0026] A nut is provided at the upper end of the second core roller cover plate, and the nut is screwed to the intermediate mandrel to limit and fix the second core roller cover plate.

[0027] Furthermore, the forming module includes a third core roller, which cooperates with the main roller to perform final forming on the ring blank;

[0028] The third core roller includes a third upper core roller and a third lower core roller arranged sequentially from top to bottom, and the third upper core roller abuts against the third lower core roller;

[0029] The lower end of the third lower core roller is provided with a core roller pad ring, which abuts against the boss on the intermediate core shaft. The core roller pad ring is used to support and limit the third lower core roller.

[0030] The upper end of the third upper core roller is provided with a third core roller cover plate, the third core roller cover plate is provided with a third center hole, the third core roller cover plate is sleeved on the intermediate core shaft through the third center hole, and the third core roller cover plate is used to seal the third upper core roller.

[0031] A nut is provided at the upper end of the third core roller cover plate, and the nut is screwed to the intermediate mandrel to limit and fix the third core roller cover plate.

[0032] Furthermore, before rolling, the pre-rolling forming module, the final rolling forming module, and the finishing forming module are assembled onto the ring rolling mill in sequence, and the core roll is preheated to 200-300°C.

[0033] Furthermore, the outer diameter D1 of the first core roller cover plate is φ560mm, and the inner diameter of the first central hole is... The first core roller has four equally spaced first ribs along the axial direction of the first central axis, and the first ribs are located on the side wall of the first core roller away from the first central axis. The radius of the first ribs is... The spacing between adjacent first ribs .

[0034] Furthermore, the outer diameter of the second core roller cover plate The inner diameter of the second central hole The second core roller has three equally spaced second ribs along the axial direction of the second central axis, and the second ribs are located on the side wall of the second core roller away from the second central axis. The radius of the second ribs is... The spacing between adjacent second ribs .

[0035] Furthermore, the outer diameter of the third core roller cover plate The inner diameter of the third central hole The third core roller has seven equally spaced third ribs along the axial direction of the third central axis, and the third ribs are located on the side wall of the third core roller away from the third central axis. The radius of the third ribs is... The spacing between adjacent third ribs .

[0036] Compared with the prior art, the ring rolling forming method and apparatus for continuous multi-step titanium alloy internal ribbed cylinders of the present invention have the following advantages:

[0037] 1) Material utilization has been greatly improved, significantly reducing waste of titanium alloy materials;

[0038] 2) It significantly reduced machining workload and working hours, improved production efficiency, and thus reduced costs;

[0039] 3) The molding process is a warm plastic molding process, which preserves the complete metal flow lines, refines the grains, and improves the strength, fatigue life and overall mechanical properties of the ribbed components. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the axial cross-sectional structure of the continuous multi-step titanium alloy internal ribbed cylinder according to an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of the axial cross-sectional structure of the ring blank according to an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of the axial cross-sectional structure of the pre-rolling forming module according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the axial cross-sectional structure of the final rolling forming module according to an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of the axial cross-sectional structure of the final shaping module according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of the axial cross-sectional structure of the pre-rolling forming die according to an embodiment of the present invention;

[0046] Figure 7This is a schematic diagram of the axial cross-sectional structure of the final rolling forming die according to an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of the axial cross-sectional structure of the forming mold described in an embodiment of the present invention.

[0048] Explanation of reference numerals in the attached figures:

[0049] 1. Main roller; 2. Intermediate mandrel; 3. First mandrel; 31. First upper mandrel; 311. First mandrel cover plate; 3110. First center hole; 32. First lower mandrel; 33. First central shaft; 34. First rib; 4. Mandrel washer ring; 5. Nut; 6. Second mandrel; 61. Second upper mandrel; 611. Second mandrel cover plate; 6110. Second center hole; 62. Second lower mandrel; 63. Second central shaft; 64. Second rib; 7. Third mandrel; 71. Third upper mandrel; 711. Third mandrel cover plate; 7110. Third center hole; 72. Third lower mandrel; 73. Third central shaft; 74. Third rib; 100. Ring blank. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the described embodiments are only some, not all, of the embodiments of this invention. The specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0051] like Figures 1-8 As shown, this embodiment provides a method for ring rolling a continuous multi-step titanium alloy inner ribbed cylinder, including the following steps:

[0052] Step 1: Based on the design dimensions of the titanium alloy cylinder, a solid cylindrical titanium alloy rod is used to obtain a ring blank of 100 through punching, mandrel elongation, and frame reaming.

[0053] Step 2: Apply an anti-oxidation coating evenly to the surface of the ring blank 100 and let it dry. Heat the ring blank 100 in a resistance furnace and control the heating temperature at 30-50°C below the phase transformation point of the titanium alloy for 2-4 hours.

[0054] Step 3: Use a ring mill to pre-roll, final roll, and finally shape the ring billet 100 in sequence;

[0055] Step 4: After applying an anti-oxidation coating to the surface of the ring billet 100, place it in a non-vacuum heat treatment furnace, set the heating temperature to 600-650℃, hold it at the set temperature for 60-120 minutes, and then remove it from the furnace and air cool it.

[0056] Step 5: According to the design dimensions of the titanium alloy cylinder, the heat-treated titanium alloy ring blank 100 is machined to remove the surface oxide layer and obtain the finished titanium alloy cylinder.

[0057] Specifically, the ring rolling forming method for continuous multi-step titanium alloy internal ribbed cylinders described in this application significantly improves material utilization and reduces waste of titanium alloy materials; it greatly reduces machining workload and time, improves production efficiency, and thus reduces costs; the forming process is a warm plastic forming process, which preserves complete metal flow lines, refines grains, and improves the strength, fatigue life, and overall mechanical properties of ribbed components.

[0058] Preferably, in step 2, the surface of the ring blank 100 is uniformly coated with 2 to 3 coats of anti-oxidation coating and then dried.

[0059] As a preferred example of this application, in step 3, the deformation of the ring billet 100 in the pre-rolling, final rolling and final shaping is 20% to 40%.

[0060] Specifically, this deformation can drive the ring billet metal to precisely fill the grooves and cavities of the forming module along the axial direction, solving the problem of "not being able to fill" the inner ribs of continuous multi-step structures and ensuring the integrity of the inner rib structure. At the same time, it will not cause insufficient metal flow and loose structure due to too small deformation, nor will it cause defects such as cracks and folds due to too large deformation, thus taking into account the forming stability.

[0061] This application also provides a ring rolling forming apparatus for the aforementioned ring rolling forming method of continuous multi-step titanium alloy inner ribbed cylinder, including a main roll 1 and an intermediate mandrel 2, wherein a forming module is sleeved on the intermediate mandrel 2, and the main roll 1 cooperates with the intermediate mandrel 2 to roll the ring billet 100.

[0062] The forming module includes a pre-roll forming module, a final rolling forming module, and a shaping module. The pre-roll forming module is used to pre-roll the ring billet 100, the final rolling forming module is used to final roll the ring billet 100, and the shaping module is used to finally shape the ring billet 100.

[0063] Specifically, this dedicated forming module can specifically correct the deviation of the inner rib size. With the preheating of the core roller, it can meet the high precision requirements of multi-step inner ribs. In addition, the main roller 1 and the intermediate core shaft 2 cooperate internally and externally. With the constraint of the closed forming module, the metal is forced to accurately fill the rib groove and cavity, which can avoid defects such as folding and loosening, and form a dense forging.

[0064] Preferably, during rolling, the intermediate mandrel 2 is located inside the annular billet 100, and the main roll 1 is located outside the annular billet 100.

[0065] As a preferred example of this application, the pre-rolling forming module includes a first core roll 3, and the main roll 1 and the first core roll 3 cooperate to pre-roll the ring billet 100.

[0066] The first core roller 3 includes a first upper core roller 31 and a first lower core roller 32 arranged sequentially from top to bottom, with the first upper core roller 31 abutting against the first lower core roller 32;

[0067] The lower end of the first lower core roller 32 is provided with a core roller pad ring 4, which abuts against the boss on the intermediate core shaft 2. The core roller pad ring 4 is used to support and limit the first lower core roller 32.

[0068] The upper end of the first upper core roller 31 is provided with a first core roller cover plate 311. The first core roller cover plate 311 is provided with a first central hole 3110. The first core roller cover plate 311 is sleeved on the intermediate core shaft 2 through the first central hole 3110. The first core roller cover plate 311 is used to seal the first upper core roller 31.

[0069] A nut 5 is provided at the upper end of the first core roller cover plate 311. The nut 5 is screwed to the intermediate core shaft 2 and is used to limit and fix the first core roller cover plate 311.

[0070] Specifically, the first core roller 3 is divided into upper and lower parts. With the modular design of the core roller pad ring 4, cover plate and nut, it is easy to install and disassemble. It can also adapt to the pre-rolling requirements of different sizes of ring billets 100 and reduce maintenance costs.

[0071] In detail, the first core roller cover plate 311 and the first core roller 3 form a pre-rolling forming mold.

[0072] Preferably, the nut 5, the first core roller cover plate 311, the first upper core roller 31, the first lower core roller 32 and the core roller washer 4 are sequentially sleeved on the intermediate core shaft 2 from top to bottom.

[0073] As a preferred example of this application, the final rolling forming module includes a second core roll 6, and the main roll 1 and the second core roll 6 cooperate to perform final rolling forming on the ring billet 100.

[0074] The second core roller 6 includes a second upper core roller 61 and a second lower core roller 62 arranged sequentially from top to bottom, with the second upper core roller 61 abutting against the second lower core roller 62;

[0075] The lower end of the second lower core roller 62 is provided with a core roller pad ring 4, which abuts against the boss on the intermediate core shaft 2. The core roller pad ring 4 is used to support and limit the second lower core roller 62.

[0076] The upper end of the second upper core roller 61 is provided with a second core roller cover plate 611. The second core roller cover plate 611 is provided with a second central hole 6110. The second core roller cover plate 611 is sleeved on the intermediate core shaft 2 through the second central hole 6110. The second core roller cover plate 611 is used to seal the second upper core roller 61.

[0077] A nut 5 is provided at the upper end of the second core roller cover plate 611. The nut 5 is screwed to the intermediate core shaft 2 and is used to limit and fix the second core roller cover plate 611.

[0078] Specifically, the second core roll 6 is divided into upper and lower parts, and is combined with the core roll pad ring 4, cover plate and nut to facilitate installation, disassembly and later maintenance. It can also be adapted to the final rolling requirements of different specifications of ring billet 100, and has strong versatility.

[0079] In detail, the second core roller cover plate 611 and the second core roller 6 form the final rolling forming mold.

[0080] Preferably, the nut 5, the second core roller cover plate 611, the second upper core roller 61, the second lower core roller 62, and the core roller washer 4 are sequentially sleeved on the intermediate core shaft 2 from top to bottom.

[0081] As a preferred example of this application, the forming module includes a third core roller 7, and the main roller 1 and the third core roller 7 cooperate to perform final forming of the ring blank 100;

[0082] The third core roller 7 includes a third upper core roller 71 and a third lower core roller 72 arranged sequentially from top to bottom, with the third upper core roller 71 and the third lower core roller 72 abutting against each other.

[0083] The lower end of the third lower core roller 72 is provided with a core roller pad ring 4, which abuts against the boss on the intermediate core shaft 2. The core roller pad ring 4 is used to support and limit the third lower core roller 72.

[0084] The upper end of the third upper core roller 71 is provided with a third core roller cover plate 711. The third core roller cover plate 711 is provided with a third center hole 7110. The third core roller cover plate 711 is sleeved on the intermediate core shaft 2 through the third center hole 7110. The third core roller cover plate 711 is used to seal the third upper core roller 71.

[0085] A nut 5 is provided at the upper end of the third core roller cover plate 711. The nut 5 is screwed to the intermediate core shaft 2 and is used to limit and fix the third core roller cover plate 711.

[0086] Specifically, the third core roller 7 is divided into upper and lower parts, and is combined with the core roller pad ring 4, cover plate and nut to facilitate installation, disassembly and later maintenance. It can also be adapted to the final shaping requirements of different specifications of ring blank 100, and has strong versatility.

[0087] In detail, the third core roller cover plate 711 and the third core roller 7 form an integral forming mold.

[0088] Preferably, the nut 5, the third core roller cover plate 711, the third upper core roller 71, the third lower core roller 72, and the core roller washer 4 are sequentially sleeved on the intermediate core shaft 2 from top to bottom.

[0089] As a preferred example of this application, before rolling, the pre-rolling forming module, the final rolling forming module and the shaping forming module are sequentially and in order assembled on the ring rolling mill, and the core roll is preheated to 200-300°C.

[0090] Specifically, the preheated core roller can reduce the temperature difference between the ring blank and the mold, prevent the titanium alloy from cooling down too quickly during the forming process, ensure that the metal has sufficient flow time, reserve more operating time for the forming process, and solve the problem of the multi-step inner ribs not being fully filled.

[0091] During rolling, the main roll 1 rotates as the driving roll, and the core roll applies pressure to the ring billet 100 as the driven roll. Under the action of radial rolling force, the billet wall thickness is reduced, and the metal material is forced to flow axially. Due to the strong constraint of the closed forming module, the flowing metal cannot freely expand outward, but is precisely squeezed and filled into the ribs and cavities of the forming module. This process is carried out continuously at high temperature until the billet completely fills the cavity of the entire forming module, forming a dense, streamlined cylindrical forging.

[0092] As a preferred example of this application, the outer diameter of the first core roller cover 311 is... The inner diameter of the first central hole 3110 The first core roller 3 is provided with four equally spaced first ribs 34 along the axial direction of the first central axis 33, and the first ribs 34 are located on the side wall of the first core roller 3 away from the first central axis 33, and the radius of the first ribs 34 is... The spacing between adjacent first protruding ribs 34 .

[0093] Specifically, this setting provides room for optimization in the final rolling precision shaping and correction, and can avoid defects caused by excessive pressure in one forming.

[0094] As a preferred example of this application, the outer diameter of the second core roller cover 611 The inner diameter of the second central hole 6110 The second core roller 6 is provided with three equally spaced second ribs 64 along the axial direction of the second central axis 63, and the second ribs 64 are located on the side wall of the second core roller 6 away from the second central axis 63, and the radius of the second ribs 64 is... The spacing between adjacent second ribs 64 .

[0095] Specifically, three equally spaced second ribs with a spacing of 232mm support the pre-rolled metal profile. The ribs with a radius of 22mm further compress and fill the rib grooves, refine the inner rib structure profile, and push the metal towards the "finished product approach state". This can avoid the loosening of the inner ribs caused by excessive pressure during one-time forming.

[0096] As a preferred example of this application, the outer diameter of the third core roller cover 711 The inner diameter of the third central hole 7110 The third core roller 7 is provided with seven equally spaced third ribs 74 along the axial direction of the third central axis 73, and the third ribs 74 are located on the side wall of the third core roller 7 away from the third central axis 73. The radius of the third ribs 74 is... The spacing between adjacent third ribs 74 .

[0097] Specifically, the convex rib radius of 24mm is slightly larger than the finished rib height (20mm). It can fill the micro-cavity defects remaining after final rolling through slight extrusion, ensuring that the inner rib is densely filled and has a clear outline, meeting the high precision requirements of marine engineering for multi-step inner ribs.

[0098] Example 1

[0099] As a preferred example of this application, the ring blank 100 is made of TC4 alloy, and the outer diameter of the ring blank 100 is... , inner diameter ,high .

[0100] As a preferred example of this application, the outer diameter of the titanium alloy cylinder is... ,high Wall thickness The titanium alloy cylinder is internally provided with 6 annular reinforcing ribs, the height of which is... rib width The distance between adjacent annular reinforcing ribs .

[0101] Preferably, before rolling, a resistance furnace is used to process the material to a size of [missing information]. The TC4 alloy ring billet 100 is continuously and uniformly heated. The heating temperature for pre-rolling is 960±10℃ and the holding time is 120min; the heating temperature for final rolling is 950±10℃ and the holding time is 120min; the heating temperature for shaping is 940±10℃ and the holding time is 120min. Then, the pre-rolling module, the final rolling module and the shaping die module are assembled onto the ring rolling mill in sequence, and the first core roll 3, the second core roll 6 and the third core roll 7 are preheated to 250℃ respectively.

[0102] Preferably, the specifications of the ring mill are φ3500mm.

[0103] Preferably, in step 3, the deformation of the ring billet 100 in the pre-rolling, final rolling and final shaping is 30%.

[0104] Preferably, in step 4, the heating temperature is set to 620℃, and the temperature is maintained for 100 minutes after reaching the set temperature. This setting ensures uniform heating of the cylinder.

[0105] Compared with the prior art, the ring rolling forming method and apparatus for continuous multi-step titanium alloy internal ribbed cylinders described in this application have the following advantages: 1) It realizes the overall forming of complex internal ribbed structures, and the material utilization rate is increased from less than 10% to more than 60%, which significantly improves the material utilization rate and significantly reduces the waste of titanium alloy materials; 2) It greatly reduces the amount of machining and working time, improves production efficiency, and thus reduces costs; 3) The forming process is a warm plastic forming process, which preserves the complete metal flow lines, refines the grains, and improves the strength, fatigue life and overall mechanical properties of the ribbed components.

[0106] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for ring rolling forming of a continuous multi-step titanium alloy internally ribbed cylinder, characterized in that, Including the following steps: Step 1: Based on the design dimensions of the titanium alloy cylinder, a solid cylindrical titanium alloy rod is used to obtain a ring blank (100) through punching, mandrel elongation, and frame reaming. Step 2: Apply an anti-oxidation coating evenly to the surface of the ring blank (100) and let it dry. Heat the ring blank (100) in a resistance furnace and control the heating temperature at 30-50°C below the phase transformation point of the titanium alloy for 2-4 hours. Step 3: Use a ring mill to pre-roll, final roll and finally shape the ring billet (100); Step 4: After applying an anti-oxidation coating to the surface of the ring billet (100), place it in a non-vacuum heat treatment furnace, set the heating temperature to 600-650℃, hold it at the set temperature for 60-120 minutes, and then air cool it after removing it from the furnace. Step 5: According to the design dimensions of the titanium alloy cylinder, the heat-treated ring blank (100) is machined to remove the surface oxide layer and obtain the finished titanium alloy cylinder.

2. The ring rolling forming method for a continuous multi-step titanium alloy internal ribbed cylinder according to claim 1, characterized in that, In step 3, the deformation of the ring billet (100) in the pre-rolling, final rolling and final shaping is 20% to 40%.

3. A ring rolling forming apparatus for the ring rolling forming method of the continuous multi-step titanium alloy internal ribbed cylinder according to any one of claims 1 to 2, characterized in that, It includes a main roller (1) and an intermediate mandrel (2), on which a forming module is sleeved. The main roller (1) cooperates with the intermediate mandrel (2) to roll the ring blank (100). The forming module includes a pre-roll forming module, a final rolling forming module and a shaping module. The pre-roll forming module is used to pre-roll the ring billet (100), the final rolling forming module is used to final roll the ring billet (100), and the shaping module is used to finally shape the ring billet (100).

4. The ring rolling forming apparatus according to claim 3, characterized in that, The pre-rolling forming module includes a first core roll (3), and the main roll (1) and the first core roll (3) cooperate to pre-roll the ring billet (100); The first core roller (3) includes a first upper core roller (31) and a first lower core roller (32) arranged sequentially from top to bottom, with the first upper core roller (31) abutting against the first lower core roller (32); The lower end of the first lower core roller (32) is provided with a core roller pad ring (4), which abuts against the boss on the intermediate core shaft (2). The core roller pad ring (4) is used to support and limit the first lower core roller (32). The upper end of the first upper core roller (31) is provided with a first core roller cover plate (311), and the first core roller cover plate (311) is provided with a first center hole (3110). The first core roller cover plate (311) is sleeved on the intermediate core shaft (2) through the first center hole (3110). The first core roller cover plate (311) is used to seal the first upper core roller (31). A nut (5) is provided at the upper end of the first core roller cover plate (311). The nut (5) is screwed to the intermediate spindle (2) to limit and fix the first core roller cover plate (311).

5. The ring rolling forming apparatus according to claim 3, characterized in that, The final rolling forming module includes a second core roll (6), and the main roll (1) and the second core roll (6) cooperate to perform final rolling forming on the ring billet (100); The second core roller (6) includes a second upper core roller (61) and a second lower core roller (62) arranged sequentially from top to bottom, with the second upper core roller (61) and the second lower core roller (62) abutting each other; The lower end of the second lower core roller (62) is provided with a core roller pad ring (4), which abuts against the boss on the intermediate core shaft (2). The core roller pad ring (4) is used to support and limit the second lower core roller (62). The upper end of the second upper core roller (61) is provided with a second core roller cover plate (611), and the second core roller cover plate (611) is provided with a second center hole (6110). The second core roller cover plate (611) is sleeved on the intermediate core shaft (2) through the second center hole (6110). The second core roller cover plate (611) is used to seal the second upper core roller (61). The upper end of the second core roller cover plate (611) is provided with a nut (5), which is screwed to the intermediate core shaft (2) for limiting and fixing the second core roller cover plate (611).

6. The ring rolling forming apparatus according to claim 3, characterized in that, The forming module includes a third core roller (7), and the main roller (1) and the third core roller (7) cooperate to perform final forming on the ring blank (100); The third core roller (7) includes a third upper core roller (71) and a third lower core roller (72) arranged sequentially from top to bottom, with the third upper core roller (71) and the third lower core roller (72) abutting each other; The lower end of the third lower core roller (72) is provided with a core roller pad ring (4), which abuts against the boss on the intermediate core shaft (2). The core roller pad ring (4) is used to support and limit the third lower core roller (72). The upper end of the third upper core roller (71) is provided with a third core roller cover plate (711), the third core roller cover plate (711) is provided with a third center hole (7110), the third core roller cover plate (711) is sleeved on the intermediate mandrel (2) through the third center hole (7110), and the third core roller cover plate (711) is used to seal the third upper core roller (71); The upper end of the third core roller cover (711) is provided with a nut (5), which is screwed to the intermediate core shaft (2) for limiting and fixing the third core roller cover (711).

7. The ring rolling forming apparatus according to claim 3, characterized in that, Before rolling, the pre-rolling forming module, the final rolling forming module and the shaping forming module are assembled on the ring rolling mill in sequence, and the core roll is preheated to 200-300°C.

8. The ring rolling forming apparatus according to claim 4, characterized in that, The outer diameter of the first core roller cover plate (311) The inner diameter of the first central hole (3110) The first core roller (3) is provided with four equally spaced first ribs (34) along the axial direction of the first central axis (33), and the first ribs (34) are located on the side wall of the first core roller (3) away from the first central axis (33), and the radius of the first ribs (34) is... The spacing between adjacent first ribs (34) .

9. The ring rolling forming apparatus according to claim 5, characterized in that, The outer diameter of the second core roller cover plate (611) The inner diameter of the second central hole (6110) The second core roller (6) is provided with three equally spaced second ribs (64) along the axial direction of the second central axis (63), and the second ribs (64) are located on the side wall of the second core roller (6) away from the second central axis (63), and the radius of the second ribs (64) is... The spacing between adjacent second ribs (64) .

10. The ring rolling forming apparatus according to claim 6, characterized in that, The outer diameter of the third core roller cover (711) The inner diameter of the third central hole (7110) The third core roller (7) is provided with seven equally spaced third ribs (74) along the axial direction of the third central axis (73), and the third ribs (74) are located on the side wall of the third core roller (7) away from the third central axis (73), and the radius of the third ribs (74) is... The spacing between adjacent third ribs (74) .

Images