TC18 trapezoidal blank manufacturing method

Abstract

The invention discloses a TC18 trapezoidal blank making method, and relates to the technical field of blank making of blanks. The method comprises the following steps: preparing a blank; the method comprises the steps that S1, a heated blank is vertically placed on a preheated lower flat anvil, and local upsetting is conducted on the left side of the upper end face of the blank through a preheated upper flat anvil; s2, local upsetting is conducted on the right side of the upper end face of the blank according to the steps; s3, local upsetting is conducted on the middle part of the upper end face of the blank according to the steps, so that the upper end face is flush; s4, according to the steps and the blank shape requirement, the upper end face is locally upset alternately and repeatedly till the size of the upper end face meets the technological requirement; s5, the blank is flatly placed on a lower flat anvil, and the lower end of the blank is locally drawn out through an upper flat anvil till the size of the lower end face meets the technological requirement; s6, the blank is squared on a lower flat anvil, the trapezoidal section of the blank is parallel to the lower flat anvil, and the blank is forged, pressed and flattened through an upper flat anvil till the blank meets the process requirement; and S7, the blank is shaped through an upper flat anvil and a lower flat anvil, so that the shape and size of the blank meet the requirement of the rough blank. The method has the advantages of convenient working steps, few forging heating numbers, high production efficiency, energy saving, reduction of the production cost and great reduction of the production period.

Description

Technical Field

[0001] The invention belongs to the technical field of blank making, and in particular relates to a method for making a TC18 trapezoidal blank. Background Art

[0002] TC18 is a high-strength α+β dual-phase titanium alloy with excellent mechanical properties and corrosion resistance. It is widely used in aerospace, chemical, medical and other fields. The TC18 titanium alloy has roughly equal amounts of α phase and β phase in its annealed structure, which makes it have high strength in the annealed state. TC18 rough stock is mainly used to produce upper strut forgings, which are components of aircraft landing gear.

[0003] The rough shape is trapezoidal, with dimensions of 360 / 670×430×210 (mm). According to product requirements, the alloy needs to be heated to ɑ+β for forging and air-cooled. Since the forging temperature range of TC18 is very small and the deformation resistance is large, the entire deformation process is very difficult, and the rough shape needs to be returned to the furnace for preheating many times to complete the forging.

[0004] like Figure 1 As shown, the trapezoidal blank is conventionally forged by flat anvil and die, and the deformation process is: a. upsetting → b. flattening to square billet → c. oblique drawing to trapezoid → d. die forging → e. shaping; because the forgeable temperature range of the product material is very small, the billet needs to be returned to the furnace for preheating once after the upsetting and flattening to square billet steps are completed; the oblique drawing to trapezoidal step is difficult to deform, and the forging time is long, so the billet needs to be returned to the furnace for preheating once after forging; the die forging forming step has a long contact time with the die, so the billet needs to be returned to the furnace for preheating once after forging; the deformation process requires a total of 4 forgings;

[0005] The draft angle of the die f is designed considering the demolding of the blank. The thickness of the blank in different places during the die forging process is inconsistent, and there are local insufficiency defects. The forming effect is general and needs to be reshaped to meet the requirements. Moreover, the whole deformation process is complicated, with many forging times and low production efficiency, which not only causes energy waste and increased costs, but also prolongs the construction period. Summary of the invention

[0006] The purpose of the present invention is to provide a method for making TC18 trapezoidal blanks with fewer forging times and higher production efficiency, thereby solving the problems of the existing method for making TC18 trapezoidal blanks with complex working steps, many forging times and low production efficiency, which results in energy waste, increased costs and extended construction period.

[0007] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0008] The present invention discloses a method for making a TC18 trapezoidal blank, comprising the following steps:

[0009] S1: Place the heated blank upright on the preheated lower flat anvil, and use the preheated upper flat anvil to partially upset the left side of the upper end surface of the blank, with the upset surface less than 1 / 2 of the blank end surface and the upset height being 20 to 40 mm;

[0010] S2: According to the above steps, the right side of the upper end surface of the blank is partially upset, the upset surface is less than 1 / 2 of the end surface of the blank, and the upset height is 20 to 40 mm;

[0011] S3: According to the above steps, the middle part of the upper end surface of the blank is locally upset to make the upper end surface flush;

[0012] S4: According to the above steps and the shape requirements of the blank, the upper end surface is subjected to repeated local upsetting until the size of the upper end surface meets the process requirements;

[0013] S5: Place the blank flat on the lower flat anvil, and use the upper flat anvil to partially lengthen the lower end of the blank until the size of the lower end surface meets the process requirements;

[0014] S6: Place the blank on the lower flat anvil so that the trapezoidal cross section of the blank is parallel to the lower flat anvil, and use the upper flat anvil to forge and flatten the blank until it meets the process requirements;

[0015] S7: Use the upper flat anvil and the lower flat anvil to shape the blank so that the shape and size of the blank meet the requirements of the blank.

[0016] Furthermore, the temperature of the residual heat of the upper anvil and the lower anvil is 200-300°C.

[0017] Furthermore, the blank in step S1 should be kept at Tβ-40°C for 245 to 420 minutes before forging.

[0018] Furthermore, the blank in step S1 should be a forging rod made of TC18 before forging, and the size of the forging rod is φ350 mm×520 mm.

[0019] Furthermore, the width of the upper end surface in step S4 is 430 mm, the width of the lower end surface in step S5 is 300 mm, and the flattened thickness in step S6 is 210 mm.

[0020] The present invention has the following beneficial effects:

[0021] 1. The improved blank making process of the present invention is: a. local upsetting → b. local stretching → c. flattening → d. shaping, eliminating the tire die forging process step, and does not need to design a special mold, which greatly reduces the production cost, saves the time used for designing and processing the mold, and shortens the production cycle.

[0022] 2. The blank making method of the present invention improves production efficiency and reduces the number of preheating times of the blanks from 4 times to 1 time.

[0023] 3. The blank making method of the present invention can be used for forging various metal materials, simplifying the production process and improving the production rate.

[0024] 4. Compared with the existing technology, the present invention simplifies the forging steps. The shape and size of the blank before and after each forging step are clear, the forging requirements are clear, the deformation process is simple, the requirements for the operating level of the production workers are greatly reduced, the production difficulty is reduced, and the production controllability is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0026] Figure 1 The figure shows the shape of the blank in each process step of the existing trapezoidal blank making method;

[0027] Figure 2 It is a diagram showing the shape of the blank in each step of the method for making a trapezoidal blank of the present invention;

[0028] Figure 3 The forging is produced by the billet making method of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] See also Figure 2 and Figure 3 As shown, the present invention is a method for making TC18 trapezoidal blanks, comprising the following steps of making blanks;

[0031] Cutting: Select qualified forging rods, cut according to fixed specifications and weight, the material is TC18, the forging rod size is φ350mm×520mm, and the final blank is 360 / 670×430×210mm;

[0032] Heating: Place the blank at Tβ-40℃ for 245-420min. In titanium alloy, β transformation temperature is an important parameter. It refers to the temperature at which the titanium alloy cools from the β phase to the α phase under specific conditions. This temperature has an important influence on the performance and processing of titanium alloy. The β transformation temperature of titanium alloy can be determined by observing the metallographic structure of the sample after quenching at different temperatures at preset temperature intervals.

[0033] Step 1: Place the heated blank upright on the preheated lower anvil, and use the preheated upper anvil to partially upset the left side of the upper end surface of the blank. The upset surface is less than 1 / 2 of the blank end surface, the upset height is 20-40 mm, and the temperature of the residual heat of the upper and lower anvils is 200-300°C.

[0034] Step 2: According to the above steps, the right side of the upper end surface of the blank is partially upset, the upset surface is less than 1 / 2 of the end surface of the blank, and the upset height is 20-40mm;

[0035] Step 3: According to the above steps, the middle part of the upper end surface of the blank is partially upset to make the upper end surface flush;

[0036] Step 4: According to the above steps and the shape requirements of the blank, the upper end surface is repeatedly and alternately upset locally until the size of the upper end surface meets the process requirements and the width of the upper end surface is 430mm;

[0037] Step 5: Place the blank flat on the lower flat anvil, and use the upper flat anvil to partially lengthen the lower end of the blank until the size of the lower end surface meets the process requirements. The width of the lower end surface is 300mm;

[0038] Step 6: Place the blank squarely on the lower anvil, so that the trapezoidal cross section of the blank is parallel to the lower anvil, and use the upper anvil to forge and flatten the blank until it meets the process requirements. The flattened thickness is 210mm.

[0039] Step 7: Use the upper flat anvil and the lower flat anvil to shape the blank so that the shape and size of the blank meet the requirements of the blank.

[0040] In addition, it should be noted that Figure 1 and Figure 2 The unit of the dimensions is mm.

[0041] The above are only preferred embodiments of the present invention and do not limit the present invention. Any modification to the technical solutions recorded in the aforementioned embodiments, any equivalent replacement of some of the technical features therein, and any modification, equivalent replacement, and improvement made are all within the protection scope of the present invention.

Claims

1. A method for making TC18 trapezoidal blanks, characterized in that: The method comprises the following steps of making a blank: S1: Place the heated blank upright on the preheated lower flat anvil, and use the preheated upper flat anvil to partially upset the left side of the upper end surface of the blank, with the upset surface less than 1 / 2 of the blank end surface and the upset height being 20 to 40 mm; S2: According to the above steps, the right side of the upper end surface of the blank is partially upset, the upset surface is less than 1 / 2 of the end surface of the blank, and the upset height is 20 to 40 mm; S3: According to the above steps, the middle part of the upper end surface of the blank is locally upset to make the upper end surface flush; S4: According to the above steps and the shape requirements of the blank, the upper end surface is subjected to repeated local upsetting until the size of the upper end surface meets the process requirements; S5: Place the blank flat on the lower flat anvil, and use the upper flat anvil to partially lengthen the lower end of the blank until the size of the lower end surface meets the process requirements; S6: Place the blank on the lower flat anvil so that the trapezoidal cross section of the blank is parallel to the lower flat anvil, and use the upper flat anvil to forge and flatten the blank until it meets the process requirements; S7: Use the upper flat anvil and the lower flat anvil to shape the blank so that the shape and size of the blank meet the requirements of the blank.

2. A method for making TC18 trapezoidal blanks as claimed in claim 1, characterized in that: The temperature of the residual heat of the upper anvil and the lower anvil is 200-300°C.

3. A method for making TC18 trapezoidal blanks as claimed in claim 1 or 2, characterized in that: The blank in step S1 should be kept at Tβ-40°C for 245 to 420 minutes before forging.

4. A method for making TC18 trapezoidal blanks as claimed in claim 3, characterized in that: Before forging, the blank in step S1 should be a forging rod made of TC18, and the size of the forging rod is φ350mm×520mm.

5. A method for making TC18 trapezoidal blanks as claimed in claim 4, characterized in that: The width of the upper end surface in step S4 is 430 mm, the width of the lower end surface in step S5 is 300 mm, and the flattened thickness in step S6 is 210 mm.

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