Preparation method of semi-automatic TC4 titanium alloy cold-rolled veneer

Abstract

The application provides a kind of preparation method of semi-automatic TC4 titanium alloy cold-rolled veneer, and relates to titanium alloy processing technical field, the method comprises: preparing TC4 titanium alloy blank, and the blank is pretreated;According to the preset cold-rolling system, the pretreated blank is cold-rolled, and the cold-rolling system includes multiple rolling processes, and each rolling process includes multiple passes;During the cold-rolling process, the rolling pass is manually operated by using the control console, after each pass and each pass is completed, the thickness data of multiple thickness measurement points are measured along the rolling direction, and the plate direction is manually adjusted according to the thickness data;The multiple thickness measurement points are uniformly distributed on both sides of the rolled piece along the rolling direction.The present application mainly aims at the thickness accuracy problem of cold-rolled sheet, adopts the mode of small deformation multi-pass process + semi-automatic manual adjustment, which can improve the plate shape and unevenness, ensure the product performance, and improve the size accuracy and finished product quality.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of titanium alloy processing, in particular to a preparation method of semi-automatic TC4 titanium alloy cold-rolled single plate. BACKGROUND

[0002] Titanium alloy has extremely excellent performance, such as high specific strength, excellent corrosion resistance, good cold workability and the like, and is widely applied in the fields of aviation, aerospace, chemical industry, construction and medical treatment and the like. In recent years, the use amount of titanium alloy plate material increases year by year, and the demand amount in various fields is greatly increased. In all titanium processing materials, the production amount of titanium plate band products is close to 50%, the current world titanium plate production amount reaches more than 20,000 tons, and there are nearly 30 kinds of plate materials. The most widely applied titanium alloy is Ti-6Al-4V (TC4) and Ti-5Al-2.55n (TA7), and the prospect is broad.

[0003] Meanwhile, as the titanium alloy thin plate is applied in some special fields, the precision and plate shape of the titanium alloy plate material are required to be higher and higher. In the preparation process of the titanium alloy cold-rolled single plate, the product thickness tolerance, surface quality and plate shape control are difficult, so that the quality of the titanium alloy single plate is not high for a long time, the material yield is low, the preparation cost is indirectly increased, and the wide application of the titanium alloy thin plate is hindered. SUMMARY

[0004] Therefore, the application provides a preparation method of semi-automatic TC4 titanium alloy cold-rolled single plate, which is suitable for preparing the TC4 titanium alloy cold-rolled single plate with a finished product thickness of 1.5-2.0 mm. The application mainly aims at the thickness precision problem, adopts a small deformation multi-pass process + semi-automatic manual adjustment combined mode, and can improve the plate shape and unevenness, thereby ensuring the product performance, improving the size precision and finished product quality.

[0005] Therefore, the application provides the following technical scheme.

[0006] The application provides a preparation method of semi-automatic TC4 titanium alloy cold-rolled single plate, and the method comprises the following steps:

[0007] TC4 titanium alloy blank is prepared, the chemical composition requirements are O≤0.11% and Fe≤0.15%, and the blank is pretreated;

[0008] The pretreated blank is cold-rolled according to a set cold-rolling system, the cold-rolling system comprises multiple rolling processes, each rolling process comprises multiple passes; in the cold-rolling process, the rolling pass is manually operated by a control console, after each pass and each pass is completed, the thickness data of multiple thickness measurement points are measured along the rolling direction, and the plate material direction is manually adjusted according to the thickness data; the multiple thickness measurement points are uniformly distributed on both sides of the rolled piece along the rolling direction.

[0009] Further, the prepared blank is a TC4 titanium alloy plate with a blank thickness of 3.0-3.3 mm and a width of 1000-1100 mm.

[0010] Further, the blank is pretreated, including: annealing, acid and alkali washing, surface grinding treatment, and peeling when necessary.

[0011] Further, the first rolling deformation is less than 30%, the pass control is 11-15, the deformation rate control of the first four passes is 8-12%, and the deformation rate control of the remaining passes is 5-8%; the second rolling deformation is less than 25%, the single pass deformation rate is less than or equal to 8%, and the pass control is 7-9.

[0012] Further, a, b, and c are three thickness measurement points uniformly distributed on one side of the rolled piece along the rolling direction, and d, e, and f are three thickness measurement points uniformly distributed on the other side of the rolled piece along the rolling direction.

[0013] The plate direction is manually adjusted according to the thickness data, including:

[0014] If the thickness of any pass on the a, b, and c sides is greater than that on the d, e, and f sides, the plate is rotated by 180° for turning over and then rolled in the next pass, and vice versa; if the plate appears C-curved plate shape due to excessive residual stress during the turning over process, the head direction is manually corrected to ensure normal biting in the next pass.

[0015] If the thickness of point a is greater than that of point d and the thickness of point c is less than that of point f in any two consecutive passes, the plate is rotated by 180° for head-to-tail adjustment and then rolled in the next pass, and vice versa.

[0016] If obvious C-curved plate shape appears in any two consecutive passes during rolling, the plate is rotated by 180° for head-to-tail adjustment and then rolled in the next pass.

[0017] Further, it also includes: intermediate blank treatment; the intermediate blank in the first rolling range is vacuum annealed, pickled, surface ground and polished to ensure that the intermediate blank has no surface microcracks and pit defects, and then the edges are cut for the next rolling range, and the heat treatment system is 820±10℃, the holding time is 0.5-2h, the furnace is cooled to 200℃, and then air cooling is performed.

[0018] The advantages and positive effects of the present application are: in the present application, TC4 titanium alloy single plates are prepared by adopting a semi-automatic rolling mode, which has the advantages that under the premise of reasonable rolling range and total deformation rate, the thickness precision of the single plate is adjusted and controlled in time by manual operation during the thin plate preparation process, the plate shape is better than that of automatic reversible rolling, the edge cutting is reduced, and the yield is improved. In view of the problem that the thickness precision is difficult to control in automatic reversible rolling, the small deformation multi-pass process + manual operation adjustment combined mode can improve the plate shape and unevenness, ensure the product performance, and improve the size precision. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The figure is a schematic diagram of the thickness measuring point in the embodiment of the present application.

[0021] Figure 2 The figure is a schematic diagram of the plate turning method in the embodiment of the present application.

[0022] Figure 3 The figure is a schematic diagram of the plate turning method in the embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the person skilled in the art better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0024] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] The present application provides a kind of semi-automatic TC4 titanium alloy cold-rolled veneer preparation method, it can be used to 3.0 ~ 3.3 mm thick hot semi-finished product TC4 titanium alloy cold working into 1.5 ~ 2.5 mm single sheet, specific steps are as follows:

[0026] S1, blank preparation: the chemical composition of the alloy should meet the requirements of GB / T3620.1 related grade, the chemical composition requirements O≤0.11%, Fe≤0.15%. The TC4 titanium alloy plate with a thickness of 3.0-3.3mm and a width of 1000-1100mm needs to be annealed, acid and alkali washed, surface ground (pushed and ground) treated to ensure that the incoming material thickness is uniform, and the surface is free of microcracks, holes, indentations, foreign matter indentation and other defects.

[0027] S2, cold rolling system: the target thickness of the rolled product is 1.5-2.0mm of TC4 titanium alloy, which is divided into double rolling process. The first rolling process deformation is less than 30%, the pass control is 11-15, the deformation rate of the first 4 passes is controlled to be 8-12%, and the deformation rate of the remaining passes is controlled to be 5-8%. The second rolling process deformation is less than 25%, the single pass deformation rate is less than or equal to 8%, and the pass control is 7-9.

[0028] S3, process control: during the cold rolling process, the rolling pass is manually operated by the control console (non-programmed automatic reversible rolling), after each pass is completed, the thickness data of points a-f along the rolling direction is measured, as shown in Figure 1 , a, b, c are three thickness measurement points uniformly distributed on one side of the rolled piece, d, e, f are three thickness measurement points uniformly distributed on the other side of the rolled piece. According to the following situations, the plate direction is manually adjusted.

[0029] Case 1: if the thickness of any pass on the a, b, c side is greater than d, e, f, as shown in Figure 2 , then the plate is rotated 180° to flip and then rolled in the next pass, and vice versa. During this flipping process, if the plate appears "C-warp" due to excessive residual stress, the head direction needs to be manually corrected to ensure normal bite in the next pass.

[0030] Case 2: if the thickness of a point is greater than d point and the thickness of c point is less than f point in any two consecutive passes, as shown in Figure 3 , then the plate is rotated 180° with the head and tail reversed and then rolled in the next pass, and vice versa.

[0031] Case 3: if there is obvious C-warp in any two consecutive passes during rolling, as shown in Figure 3 , then the plate is rotated 180° with the head and tail reversed and then rolled in the next pass.

[0032] S4, intermediate blank treatment: the intermediate blank in the first rolling process is vacuum annealed, pickled, surface ground and polished to ensure that the intermediate blank is free of surface microcracks, pits and other defects before edge cutting for the next rolling process. The heat treatment system is 820±10℃, the holding time is 0.5-2h, the furnace cooling is carried out to 200℃, and then the air cooling is carried out.

[0033] In the above embodiments, a semi-automatic rolling method is used to prepare TC4 titanium alloy single plates. Its advantage lies in ensuring that, under the premise of a reasonably designed rolling stroke and total deformation rate, manual operation can be used to adjust and control the thickness accuracy of the single plate during the thin plate preparation process. The plate shape is superior compared to automatic reversible rolling, reducing edge trimming and increasing the yield. To address the difficulty in controlling thickness accuracy in automatic reversible rolling, a combination of small deformation multi-pass process and manual adjustment is used. This improves the plate shape and flatness, ensuring product performance while enhancing dimensional accuracy.

[0034] Example 1:

[0035] The 3*1000*1000mm TC4 titanium alloy hot-rolled intermediate billet is annealed, acid-alkali washed, and surface ground before being prepared for rolling. After each pass, manual measurement is performed. Figure 1 The thickness data at the six points shown is used to adjust the plate orientation. The first rolling pass achieves the target thickness of 2.2mm in 14 passes, with a pass deformation rate of <9%. The third pass of this rolling pass matches the description in Case 1; the billet is flipped before the fourth pass. After the first rolling pass, the intermediate billet undergoes vacuum annealing at 820℃ and is then cooled in the furnace to 200℃ before air cooling. After exiting the furnace, it undergoes acid and alkali washing, surface grinding, and polishing for material preparation. The second rolling pass achieves the target thickness of 2mm in 7 passes, with a pass deformation rate of <5%. After vacuum annealing, it undergoes acid washing, surface polishing, and finally edge trimming for length determination.

[0036] Example 2:

[0037] This embodiment is compared with Embodiment 1. The billet size and processing method are the same. The difference is that the first rolling pass follows the same rolling procedure as in Embodiment 1. The control panel program is set to perform automatic reversible rolling without any manual operation. The second rolling pass consists of 5 passes. Other steps and operations remain unchanged.

[0038] Example 3:

[0039] The 3.3*1000*1000mm TC4 titanium alloy hot-rolled intermediate billet was annealed, acid-base washed, and surface ground before being prepared for rolling. After each pass, the thickness data at 6 points was manually measured, and the plate orientation was adjusted according to the data. The first rolling pass was rolled to the target thickness of 2.0mm in 15 passes, with a pass deformation rate of <8%. The 3rd and 4th passes of this rolling pass were consistent with the description in Case 2. After the billet was turned over, the 5th rolling pass was performed. After the first rolling pass was completed, the intermediate billet was annealed at 820℃ and then cooled in the furnace to 200℃. After exiting the furnace, it was acid-base washed, surface ground, and polished before being prepared for rolling. The second rolling pass was rolled to the target thickness of 1.5mm in 8 passes, with a pass deformation rate of <4%. After vacuum annealing, it was acid-washed, surface polished, and finally trimmed to length.

[0040] The plate material of different embodiments is sampled and detected, and the room temperature transverse mechanical properties of the TC4 titanium alloy cold-rolled single plate are shown in Table 1.

[0041] Table 1

[0042]

[0043] As can be seen from the room temperature mechanical properties (transverse) and size results shown in Table 1, embodiments 1, 2 and 3 can all meet the requirements of GJB2505A on room temperature mechanical properties. However, there are differences in thickness tolerance and size difference between the plates. The TC4 cold-rolled sheet prepared by automatic rolling in embodiment 2 exceeds the national standard thickness tolerance in some positions, has a larger size difference between the plates compared with embodiments 1 and 3, and the thickness control in a pass in the automatic rolling process deviates from the preset, and cannot be adjusted in time. Therefore, the advantage of semi-automatic control is that it can be adjusted in time to obtain better thickness precision control.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A semi-automatic method for preparing TC4 titanium alloy cold-rolled veneer, characterized in that, The method includes: Prepare TC4 titanium alloy billets with a chemical composition requirement of O ≤0.13% and Fe ≤0.16%, and pretreat the billets. The pretreated billet is cold rolled according to the set cold rolling regime, which includes multiple rolling passes, each of which includes multiple passes. During the cold rolling process, the rolling passes are manually operated using a control console. After each rolling pass is completed, the thickness data of multiple thickness measurement points along the rolling direction is measured. The plate orientation is manually adjusted according to the thickness data. The multiple thickness measurement points are evenly distributed on both sides of the rolled piece along the rolling direction. Wherein, a, b, and c are three thickness measurement points evenly distributed along the rolling direction on one side of the workpiece, and d, e, and f are three thickness measurement points evenly distributed along the rolling direction on the other side of the workpiece. The orientation of the sheet material is manually adjusted based on the thickness data, including: If the thickness of any pass a, b, c side is greater than d, e, f, then the plate is rotated 180° to flip it over before the next pass rolling, and vice versa. During this flipping process, if the plate develops a C-shaped warp due to excessive residual stress, the warp direction is manually corrected to ensure that the next pass can bite in normally. If, in any two consecutive passes, the thickness at point a is greater than the thickness at point d, and the thickness at point c is less than the thickness at point f, then the ends of the sheet should be swapped and rotated 180° before proceeding to the next rolling pass; the reverse is also true. If significant C-curve occurs in any two consecutive passes during rolling, the ends of the sheet should be swapped and rotated 180° before proceeding to the next rolling pass.

2. The method for preparing a semi-automatic TC4 titanium alloy cold-rolled veneer according to claim 1, characterized in that, Prepare TC4 titanium alloy plates with a thickness of 3.0~3.3mm and a width of 1000~1100mm for hot semi-finished products.

3. The method for preparing a semi-automatic TC4 titanium alloy cold-rolled veneer according to claim 1, characterized in that, The pretreatment of the billet includes: annealing, acid and alkali washing, surface grinding and peeling.

4. The method for preparing a semi-automatic TC4 titanium alloy cold-rolled veneer according to claim 1, characterized in that, For the first rolling pass, the deformation amount is less than 30%, and the number of passes is controlled at 11 to 15. The deformation rate of the first 4 passes is controlled at 8 to 12%, and the deformation rate of the remaining passes is controlled at 5 to 8%. For the second rolling pass, the deformation amount is less than 25%, and the deformation rate of a single pass is ≤ 8%. The number of passes is controlled at 7 to 9.

5. The method for preparing a semi-automatic TC4 titanium alloy cold-rolled veneer according to claim 1, characterized in that, Also includes: Intermediate billet processing; The intermediate billet in the first rolling pass undergoes vacuum annealing, acid and alkali washing, surface grinding and polishing to ensure that there are no surface micro-cracks or pits. After the intermediate billet is free of defects, the edges are trimmed before proceeding to the next rolling pass. The heat treatment regime is 820±10℃, held for 0.5~2h, and then cooled in the furnace to ≤200℃ before air cooling.

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