TC4 wide titanium alloy sheet and short-process production and processing method thereof

Abstract

The invention relates to the technical field of material processing, in particular to a TC4 wide titanium alloy thin plate and a short-process production processing method thereof, and the TC4 wide titanium alloy thin plate is obtained according to the following method: first heating number rolling, intermediate semi-finished product hot coiled plate annealing and pickling, coating, finished product rolling, annealing, plate lifting, pre-cutting, creeping, surface treatment and finished product cutting to obtain the high-quality TC4 wide titanium alloy thin plate. Five heating numbers required by a traditional process are reduced to two heating numbers, a middle semi-finished product hot coil with the thickness of 3.0 mm to 5.5 mm is obtained after rolling, and then the high-quality TC4 wide titanium alloy thin plate with the width of 1500 mm to 2000 mm, the length of 3000 mm to 4000 mm and the thickness of 0.5 mm to 2.5 mm is obtained after rolling, so that the production efficiency is improved by 50%, the plate cost is reduced by 50%, the TC4 wide titanium alloy thin plate is more convenient to use in the application field, the welding requirement is lower, and the production cost is reduced. And the safety performance is higher.

Description

Technical Field

[0001] The present invention relates to the technical field of material processing, and is a high-quality TC4 wide-width titanium alloy thin plate and a short-process production and processing method therefor. Background Art

[0002] With the rapid development of China's aerospace, shipbuilding, high-end chemical industry and other fields, the market scale of titanium materials has grown rapidly. Titanium alloys have low density, high strength, high toughness, good fatigue resistance and excellent corrosion resistance, and can maintain the stability of their properties for a long time in harsh environments. The demand for titanium alloy thin plates is increasing, and the requirements for core properties, plate width and supply period are getting higher and higher.

[0003] The Chinese patent document with the authorization announcement number CN113560345B discloses a method for producing a TC4 titanium alloy ultra-wide plate by a direct rolling process. The production process flow is: EB ingot casting, primary heating, primary rolling, cooling, secondary heating, secondary rolling, and online annealing. However, the TC4 titanium alloy ultra-wide plate obtained by the above method is relatively thick.

[0004] The Chinese patent document with the publication number CN117583401A discloses a method for one-fire rolling of a TC4 titanium alloy wide and thick plate with a steel-titanium co-line TC4 titanium alloy slab. The method includes the following steps: Step 1, loading the TC4 titanium alloy slab (1) into a heating furnace (2) for heating; Step 2, after the TC4 titanium alloy slab (1) is heated, feeding it to a medium plate rolling mill (3) for pre-rolling preparation, and controlling the time interval from the TC4 titanium alloy slab (1) out of the furnace to the start of rolling; Step 3, adopting a large reduction ratio for the TC4 titanium alloy slab (1) and rolling the TC4 titanium alloy rolled piece (4) in the rolling temperature range; Step 4, controlling the finish rolling temperature and rolling to the target thickness TC4 titanium alloy wide and thick plate (5). However, the TC4 titanium alloy wide and thick plate obtained by the above method is relatively thick.

[0005] The Chinese patent document with the authorization announcement number CN113333469B discloses a hot rolling process for TC4 titanium alloy thin plates. The hot rolling process includes substrate preparation, roll wrapping preparation, first rolling, double rolling, annealing and post-treatment processes. By adopting a small deformation multi-fire rolling process to produce TC4 titanium alloy thin plates, two passes of vertical reverse rolling are carried out for each fire. Through reasonable control of rolling deformation, heating temperature, holding time and rolling speed design, the anisotropy of the plate is significantly reduced. At the same time, when preparing the roll wrapping, one end of the substrate is welded and fixed to prevent the substrate from slipping and misaligning during the rolling process. The produced TC4 titanium alloy thin plate has a low difference in the same plate. An air inlet is arranged at the edge of the roll wrapping. Argon is introduced from the air inlet during the first rolling, and argon is introduced into the heating furnace during the double rolling preheating, so that the substrate is always protected by argon in the high-temperature state, reducing the oxidation of the titanium alloy and eliminating the problems of too thick oxide layer affecting the plate thickness and the generation of drawing cracks caused by multi-fire rolling.

[0006] It can be seen that the current processes for producing titanium alloy sheets with a thickness of less than 2.5 mm mainly include two combined processes: multi-fire reversing rolling + cladding rolling and multi-fire reversing rolling + cold rolling. The titanium alloy sheets produced by these two methods have the problems of great production difficulty, long cycle and high cost.

[0007] At present, the industry produces 0.5mm to 2.5mm thick titanium alloy plates with a width of less than 1500mm, a production cycle of up to 3 months, a yield rate of about 50%, high cost and low efficiency. However, with the in-depth application of titanium alloy sheets in the "three aviation" fields of aerospace, aviation and navigation, in addition to cost and efficiency issues, there are many welding points when narrow-width titanium alloy sheets are used, because the weld is the source of cracks that cause material failure. Therefore, the high-efficiency, short-process and low-cost production of titanium alloy sheets with a width of more than 1500mm is an urgent problem to be solved in the titanium alloy industry, and it is also a demand for the development of the industry. Summary of the invention

[0008] The present invention provides a TC4 wide-width titanium alloy thin plate and a short-process production and processing method thereof, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problems of great production difficulty, long cycle and high cost in the existing production and processing of TC4 titanium alloy plates with a thickness of 0.5mm to 2.5mm and a width of less than 1500mm.

[0009] One of the technical solutions of the present invention is achieved by the following measures: A short-process production and processing method of high-quality TC4 wide-width titanium alloy thin plate is carried out according to the following method:

[0010] S1, first hot rolling: After cleaning and coating the titanium alloy slab, the slab is kept warm in a heating furnace and then sent to a hot rolling line for the first hot rolling to obtain an intermediate semi-finished hot rolled plate with a thickness of 3.0 mm to 5.5 mm;

[0011] S2, annealing and pickling of intermediate semi-finished hot-rolled plates: after annealing the intermediate semi-finished hot-rolled plates in a continuous annealing furnace, the surface of the annealed intermediate semi-finished hot-rolled plates is pickled in a pickling line to obtain pickled white coils;

[0012] S3, straightening and flattening: After pickling, the white coil is straightened on a tensioning and leveling machine and then flattened to obtain a semi-finished plate;

[0013] S4, encapsulation: use 20mm to 25mm thick steel plates to encapsulate and weld 3 to 4 plates to obtain a steel box;

[0014] S5, finished product rolling: the welded steel box is placed in a heating furnace for heat preservation, and then sent to a hot rolling mill for the second round of finished product rolling to obtain a finished plate;

[0015] S6, Annealing: Put the finished sheet into an annealing furnace for recrystallization annealing. The annealing temperature is 700°C to 800°C. After holding for 60 min to 90 min, take it out of the furnace and then air-cool to obtain the cooled steel plate;

[0016] S7, Sheet Lifting: Use a flame cutting machine to cut the cooled steel plate and lift out the wide-width titanium alloy thin sheet;

[0017] S8, Pre-Cutting: Pre-cut the lifted wide-width titanium alloy thin sheet to obtain the pre-cut sheet;

[0018] S9, Creeping: Use a vacuum creep furnace to perform creep straightening on the pre-cut sheet, hold the temperature, and then cool in the furnace to obtain the creep-straightened titanium plate;

[0019] S10, Surface Treatment: Use a sander to perform surface treatment on the creep-straightened titanium plate to obtain the sanded sheet;

[0020] S11, Cutting into Finished Products: Use a guillotine shear to cut the sanded sheet into finished products to obtain a high-quality wide-width TC4 titanium alloy thin sheet.

[0021] The following is a further optimization and / or improvement of one of the above-mentioned inventive technical solutions:

[0022] In the above step S1, the holding temperature in the heating furnace is 1000°C to 1110°C, the holding time is the thickness of the sheet in mm × 1.3 min / mm to 1.6 min / mm, the processing rate of the first rolling pass is 96.5% to 98.5%, and the first rolling pass adopts 5 rough rolling passes with a pass processing rate of 15% to 40%.

[0023] In the above step S1, the holding temperature in the heating furnace is 1080°C, the holding time is 240 min, and the pass processing rate is 15% to 30%.

[0024] In the above step S2, the annealing treatment temperature is 760°C to 880°C, the annealing treatment speed is 10 m / min to 60 m / min, and the acid solution used for surface pickling treatment is a mixed acid solution. Among them, the mixed acid solution is a mixed solution composed of a nitric acid solution with a volume concentration of 35% to 40% and a hydrofluoric acid solution with a pH value of 5 to 7.

[0025] In the above step S2, the annealing treatment temperature is 800°C and the annealing treatment speed is 12 m / min.

[0026] In the above-mentioned step S4, 4 plates are covered and welded with a 20-mm-thick steel plate; and / or, in step S5, the holding temperature of the heating furnace is 800°C to 900°C, the holding time is the plate thickness in mm × 0.8 min / mm to 1.2 min / mm, and the finish rolling in the second heating is 8 passes to 12 passes, and the pass reduction rate is 15% to 40%.

[0027] In the above-mentioned step S5, the holding temperature of the heating furnace is 880°C, the holding time is 60 min, and the pass reduction rate of the finish rolling in the second heating is 15% to 22%.

[0028] In the above-mentioned step S6, the annealing temperature is 760°C and the holding time is 60 min.

[0029] In the above-mentioned step S9, the creep straightening temperature is 550°C to 650°C, and the holding time is 2 hours to 5 hours.

[0030] In the above-mentioned step S9, the creep straightening temperature is 600°C and the holding time is 4 hours.

[0031] In the above-mentioned step S10, the abrasive belt grit used by the sander is 120#+180#+320#+600#, the grinding amount of the sander is 0.25 mm, and the surface roughness Ra ≤ 0.3 μm.

[0032] The second technical solution of the present invention is achieved by the following measures: a high-quality TC4 wide-width titanium alloy thin plate obtained by a short-process production and processing method for high-quality TC4 wide-width titanium alloy thin plates.

[0033] The present invention reduces the five heating processes required by the traditional process to two heating processes, and obtains an intermediate semi-finished hot coil with a thickness of 3.0 mm to 5.5 mm after rolling, and a high-quality TC4 wide-width titanium alloy thin plate with a width of 1500 mm to 2000 mm, a length of 3000 mm to 4000 mm, and a thickness of 0.5 mm to 2.5 mm after rolling. Its production efficiency is increased by 50%, the plate cost is reduced by 50%, it is more convenient to use in the application field, has less welding requirements, and has higher safety performance. Description of the Drawings

[0034] Attached Figure 1A is the transverse microstructural diagram of the TC4 wide-width titanium alloy thin plate obtained in Example 13 of the present invention.

[0035] Attached Figure 1B is the longitudinal microstructural diagram of the TC4 wide-width titanium alloy thin plate obtained in Example 13 of the present invention.

[0036] Attached Figure 2A is the transverse microstructural diagram of the TC4 wide-width titanium alloy thin plate obtained in Example 14 of the present invention.

[0037] Appendix Figure 2B This is the longitudinal micrograph of the TC4 wide-width titanium alloy thin sheet obtained in Example 14 of the present invention.

[0038] Appendix Figure 3A This is the transverse micrograph of the TC4 wide-width titanium alloy thin sheet obtained in Example 15 of the present invention.

[0039] Appendix Figure 3B This is the longitudinal micrograph of the TC4 wide-width titanium alloy thin sheet obtained in Example 15 of the present invention. Detailed implementation manners

[0040] The present invention is not limited by the following embodiments, and the specific implementation manners can be determined according to the technical solutions of the present invention and the actual situation. All chemical reagents and chemical supplies mentioned in the present invention are well-known and commonly used chemical reagents and chemical supplies in the prior art without special instructions; the percentages in the present invention are mass percentages without special instructions; the solutions in the present invention are aqueous solutions with water as the solvent without special instructions. For example, a hydrochloric acid solution is an aqueous solution of hydrochloric acid; normal temperature and room temperature in the present invention generally refer to a temperature range of 15°C to 25°C, and are generally defined as 25°C.

[0041] The present invention will be further described below in conjunction with embodiments:

[0042] Example 1: The short-process production and processing method of the TC4 wide-width titanium alloy thin sheet is carried out according to the following method:

[0043] S1, the first rolling pass: After cleaning and cladding the titanium alloy slab, it is heat-preserved in a heating furnace and then sent to a hot tandem mill for the first rolling pass to obtain an intermediate semi-finished hot-rolled coil sheet with a thickness of 3.0 mm to 5.5 mm.

[0044] S2, annealing and pickling of the intermediate semi-finished hot-rolled coil sheet: After annealing the intermediate semi-finished hot-rolled coil sheet using a continuous annealing furnace, the annealed intermediate semi-finished hot-rolled coil sheet is subjected to surface pickling treatment on a pickling line to obtain a pickled white coil.

[0045] S3, straightening and leveling: The pickled white coil is leveled on a tension leveling machine and then leveled to obtain a semi-finished sheet.

[0046] S4, cladding: Use a steel plate with a thickness of 20 mm to 25 mm to clad and weld 3 to 4 sheets to obtain a steel box.

[0047] S5, finished rolling: After the welded steel box is put into a heating furnace for heat preservation, it is sent to a hot rolling mill for the second rolling pass of finished rolling to obtain a finished sheet.

[0048] S6, Annealing: Put the finished sheet into an annealing furnace for recrystallization annealing. The annealing temperature is 700 °C to 800 °C. After holding for 60 min to 90 min, take it out of the furnace and then air-cool to obtain the cooled steel plate;

[0049] S7, Sheet Lifting: Use a flame cutting machine to cut the cooled steel plate and lift out the wide-width titanium alloy thin sheet;

[0050] S8, Pre-Cutting: Pre-cut the lifted wide-width titanium alloy thin sheet to obtain the pre-cut sheet;

[0051] S9, Creep: Use a vacuum creep furnace to perform creep straightening on the pre-cut sheet and hold it, then cool it in the furnace to obtain the creep-straightened titanium plate;

[0052] S10, Surface Treatment: Use a sander to perform surface treatment on the creep-straightened titanium plate to obtain the sanded sheet;

[0053] S11, Cutting into Finished Products: Use a guillotine shear to cut the sanded sheet into finished products to obtain the wide-width TC4 titanium alloy thin sheet.

[0054] On the premise of ensuring excellent mechanical properties of the titanium alloy thin sheet, the present invention produces a wide-width TC4 titanium alloy thin sheet with a thickness of 0.5 mm to 2.5 mm, a width of 1500 mm to 2000 mm, and a length of 3000 mm to 4000 mm with high efficiency, short process flow, and low cost. Its preparation efficiency is increased by 50% and the cost is reduced by 50%.

[0055] Example 2: As an optimization of the above example, in step S1, the holding temperature in the heating furnace is 1000 °C to 1110 °C, the holding time is the thickness of the sheet in mm × (1.3 min / mm to 1.6 min / mm), the processing rate of the first rolling pass is 96.5% to 98.5%, and the first rolling pass adopts 5 rough rolling passes with a pass processing rate of 15% to 40%.

[0056] Example 3: As an optimization of the above example, in step S1, the holding temperature in the heating furnace is 1080 °C, the holding time is 240 min, and the pass processing rate is 15% to 30%.

[0057] Example 4: As an optimization of the above example, in step S2, the annealing treatment temperature is 760 °C to 880 °C, the annealing treatment speed is 10 m / min to 60 m / min, and the acid solution used for surface pickling treatment is a mixed acid solution. Among them, the mixed acid solution is a mixed solution composed of a nitric acid solution (HNO3) with a volume concentration of 35% to 40% and a hydrofluoric acid solution (HF) with a pH value of 5 to 7.

[0058] Example 5: As an optimization of the above example, in step S2, the annealing temperature is 800 °C and the annealing speed is 12 m / min.

[0059] Example 6: As an optimization of the above example, in step S4, 4 plates are covered and welded with a 20 mm thick steel plate.

[0060] Example 7: As an optimization of the above example, in step S5, the temperature for heat preservation in the heating furnace is 800 °C to 900 °C, the heat preservation time is the plate thickness in mm × (0.8 min / mm to 1.2 min / mm), and the finish rolling in the second heat is 8 to 12 passes, with the pass processing rate being 15% to 40%.

[0061] Example 8: As an optimization of the above example, in step S5, the temperature for heat preservation in the heating furnace is 880 °C, the heat preservation time is 60 min, and the pass processing rate of the finish rolling in the second heat is 15% to 22%.

[0062] Example 9: As an optimization of the above example, in step S6, the annealing temperature is 760 °C and the heat preservation time is 60 min; or / and, in step S9, the creep straightening temperature is 550 °C to 650 °C and the heat preservation time is 2 to 5 hours.

[0063] Example 10: As an optimization of the above example, in step S9, the creep straightening temperature is 600 °C and the heat preservation time is 4 hours.

[0064] Example 11: As an optimization of the above example, in step S10, the abrasive belt grit used by the sander is 120#+180#+320#+600#, the grinding amount of the sander is 0.25 mm, and the surface roughness Ra ≤ 0.3 μm.

[0065] Example 12: The high-quality TC4 wide-width titanium alloy thin plate obtained by the short-process production and processing method of the high-quality TC4 wide-width titanium alloy thin plate.

[0066] Example 13: The high-quality TC4 wide-width titanium alloy thin plate is obtained by the following method:

[0067] S1, the first heat rolling: After surface cladding a titanium alloy slab with a size of 190 mm × 1108 mm × 6890 mm, it is placed in a heating furnace and kept at a temperature of 1080 °C for 270 min, and then sent to a rough rolling mill for 5 passes of rough rolling. The pass processing rate is controlled at 15% to 40%. The processing rate of this heat rolling is 97.79%. After rolling, an intermediate semi-finished hot-rolled sheet of 4.2 mm × 1120 mm × C mm is obtained (C mm is the length of the intermediate semi-finished hot-rolled sheet, unit: mm);

[0068] S2, Annealing and pickling of the intermediate semi-finished hot-rolled sheet: After annealing treatment using a continuous annealing furnace at 840 °C at a speed of 30 m / min, the surface of the sheet is treated with a mixed solution composed of nitric acid solution with a volume concentration of 35% to 40% and hydrofluoric acid solution with a pH value of 5 to 7 on the pickling line to obtain a pickled white coil;

[0069] S3, Straightening and leveling: The pickled white coil is leveled on a tension leveller and then leveled and trimmed to obtain a semi-finished sheet of 4.1 mm × 1080 mm × 2050 mm.

[0070] S4, Cladding: Four semi-finished sheets are clad with a 20 mm × 2150 mm × 1210 mm thick steel plate. First, spot welding is carried out using carbon dioxide gas shielded welding on a hydraulic press, and then it is transferred to an automatic welder for full welding to obtain a stacked-rolled package (i.e., a steel box);

[0071] S5, Finished product rolling: The welded steel box is placed in a heating furnace and kept at 880 °C for 60 min; after heat preservation, it is sent into a hot rolling mill for the second-pass finished product rolling for 10 passes, and the pass processing rate is 11% to 22% to obtain a finished sheet of 13.8 mm × 2150 mm × 4300 mm;

[0072] S6, Annealing: The finished sheet is placed in an annealing furnace for recrystallization annealing. The annealing temperature is 760 °C. After holding for 60 min, it is taken out of the furnace and then air-cooled to obtain a cooled steel plate;

[0073] S7, Sheet lifting: The cooled steel plate is cut using a flame cutting machine to lift out a wide-width titanium alloy thin sheet of 1.0 mm × 2050 mm × 4300 mm;

[0074] S8, Pre-cutting: The lifted wide-width titanium alloy thin sheet is pre-cut on a guillotine shear to obtain a pre-cut sheet of 1.0 mm × 2030 mm × 4050 mm.

[0075] S9, Creep: The pre-cut sheet is subjected to creep straightening using a vacuum creep furnace. The creep process is to hold at 600 °C for 4 hours and then furnace-cool to obtain a creep-straightened titanium plate, where the flatness of the titanium plate is less than 1 mm / m;

[0076] S10, Surface treatment: The wide-width titanium alloy thin sheet is surface-treated using a sander with 120#+180#+320#+600# sand belts to obtain a sanded sheet, where the surface roughness Ra of the sanded sheet is ≤ 0.3 μm;

[0077] S11, Cutting finished product: The sanded sheet is cut into finished products using a guillotine shear to obtain a high-quality TC4 wide-width titanium alloy thin sheet of 0.8 mm × 2000 mm × 4000 mm.

[0078] The room temperature mechanical properties of the high-quality TC4 wide-width titanium alloy sheet obtained in Example 13 are shown in Table 1, and the microstructural photos are as Figure 1A and Figure 1B shown.

[0079] As can be seen from Table 1, the product performance indexes of the high-quality TC4 wide-width titanium alloy sheet of the present invention can meet the requirements of GJB2505A.

[0080] Example 14: The high-quality TC4 wide-width titanium alloy sheet is obtained according to the following method:

[0081] S1, the first-pass rolling: After surface cladding the titanium alloy slab with the slab size of 192 mm×1020 mm×7200 mm, put it into a heating furnace and keep it warm at a temperature of 1110°C for 240 min, and then send it to a rough rolling mill for 7 passes of rough rolling. The processing rate of each rolling pass is controlled at 15% to 40%, and the processing rate of this pass of rolling is 98.40%. After rolling, an intermediate semi-finished hot-rolled coil sheet of 3.1 mm×1040 mm×C mm (C mm is the length of the intermediate semi-finished hot-rolled coil sheet, unit: mm) is obtained;

[0082] S2, annealing and pickling of the intermediate semi-finished hot-rolled coil sheet: After annealing treatment at a speed of 60 m / min under the condition of 880°C using a continuous annealing furnace, the surface of the sheet is treated with a mixed solution composed of nitric acid solution with a volume concentration of 35% to 40% and hydrofluoric acid solution with a pH value of 5 to 7 on a pickling line to obtain a pickled white coil;

[0083] S3, straightening and leveling: The pickled white coil is leveled on a tension leveling machine and then leveled and trimmed to obtain a semi-finished sheet of 3.0 mm×1000 mm×2050 mm.

[0084] S4, cladding: Use a 25 mm×2150 mm×1130 mm thick steel plate to clad 4 semi-finished sheets, first carry out spot welding on a hydraulic press using carbon dioxide gas shielded welding, and then transfer it to an automatic welding machine for full welding to obtain a stacked rolling package (i.e., a steel box);

[0085] S5, finished rolling: Put the welded steel box into a heating furnace and keep it warm at 900°C for 60 min; after keeping warm, send it into a hot rolling mill for 12 passes of finished rolling in the second pass, and the processing rate of each pass is 11% to 22% to obtain a finished sheet of 14.5 mm×2150 mm×4300 mm;

[0086] S6, annealing: Put the finished sheet into an annealing furnace for recrystallization annealing, the annealing temperature is 800°C, take it out of the furnace after keeping warm for 60 min, and then air-cool to obtain the cooled steel plate;

[0087] S7, Plate Lifting: Use a flame cutting machine to cut the cooled steel plate and lift out a wide titanium alloy thin plate with a size of 0.7 mm × 2050 mm × 4300 mm;

[0088] S8, Pre-Cutting: Pre-cut the lifted wide titanium alloy thin plate on a power shear to obtain a pre-cut plate with a size of 0.7 mm × 2030 mm × 4050 mm.

[0089] S9, Creeping: Use a vacuum creep furnace to perform creep straightening on the pre-cut plate. The creep process is to hold at 550 °C for 5 hours and then cool in the furnace to obtain a creep-straightened titanium plate, where the flatness of the titanium plate is less than 1 mm / m;

[0090] S10, Surface Treatment: Use a sander with 120#+180#+320#+600# sanding belts to perform surface treatment on the wide titanium alloy thin plate to obtain a sanded plate, where the surface roughness Ra of the sanded plate is ≤ 0.3 μm;

[0091] S11, Cutting into Finished Products: Use a power shear to cut the sanded plate into finished products to obtain a high-quality wide titanium alloy thin plate of TC4 with a size of 0.5 mm × 2000 mm × 4000 mm.

[0092] The room temperature mechanical properties of the high-quality wide titanium alloy thin plate of TC4 obtained in Example 14 are shown in Table 2, and the microstructural photos are as Figure 2A and Figure 2B shown.

[0093] As can be seen from Table 2, the product performance indicators of the high-quality wide titanium alloy thin plate of the present invention can all meet the requirements of GJB2505A.

[0094] Example 15: The high-quality wide titanium alloy thin plate of TC4 is obtained by the following method:

[0095] S1, First-Pass Rolling: After surface cladding a titanium alloy slab with a size of 182 mm × 1220 mm × 6900 mm, place it in a heating furnace and hold at a temperature of 1000 °C for 270 min, and then send it to a roughing mill for 7 passes of rough rolling. The processing rate of each rolling pass is controlled between 15% and 40%, and the processing rate of this pass of rolling is 96.97%. After rolling, an intermediate semi-finished hot-rolled coil plate with a size of 5.6 mm × 1250 mm × C mm (C mm is the length of the intermediate semi-finished hot-rolled coil plate, unit: mm) is obtained;

[0096] S2, Annealing and pickling of the intermediate semi-finished hot-rolled sheet: After annealing treatment using a continuous annealing furnace at 760 °C at a speed of 10 m / min, the surface of the sheet is treated with a mixed solution composed of nitric acid solution with a volume concentration of 35% to 40% and hydrofluoric acid solution with a pH value of 5 to 7 on the pickling line to obtain a pickled white coil;

[0097] S3, Straightening and leveling: The pickled white coil is leveled on a tension leveling machine and then leveled and trimmed to obtain a semi-finished sheet of 5.5 mm × 1200 mm × 1550 mm.

[0098] S4, Cladding: Three semi-finished sheets are clad with a 20 mm × 1670 mm × 1330 mm thick steel plate. First, spot welding is carried out using carbon dioxide gas shielded welding on a hydraulic press, and then it is transferred to an automatic welding machine for full welding to obtain a stacked rolling package (i.e., a steel box);

[0099] S5, Finished product rolling: The welded steel box is placed in a heating furnace and kept at 800 °C for 60 min; after heat preservation, it is sent into a hot rolling mill for 8 passes of the second heat treatment of finished product rolling, and the pass processing rate is 11% to 22% to obtain a finished sheet of 22.8 mm × 1670 mm × 3300 mm;

[0100] S6, Annealing: The finished sheet is placed in an annealing furnace for recrystallization annealing. The annealing temperature is 700 °C. After 60 min of heat preservation, it is taken out of the furnace and then air-cooled to obtain a cooled steel plate;

[0101] S7, Plate lifting: The cooled steel plate is cut using a flame cutting machine to lift out a wide titanium alloy thin plate of 2.0 mm × 1550 mm × 3300 mm;

[0102] S8, Pre-cutting: The lifted wide titanium alloy thin plate is pre-cut on a guillotine shear to obtain a pre-cut sheet of 2.0 mm × 1530 mm × 4050 mm.

[0103] S9, Creep: The pre-cut sheet is subjected to creep straightening using a vacuum creep furnace. The creep process is to keep at 650 °C for 2 hours and then furnace-cooled to obtain a creep-straightened titanium plate, where the flatness of the titanium plate is less than 1 mm / m;

[0104] S10, Surface treatment: The wide titanium alloy thin plate is surface-treated using a sander with 120#+180#+32#0+600# sand belts to obtain a sanded sheet, where the surface roughness Ra of the sanded sheet is ≤ 0.3 μm;

[0105] S11, Cutting finished products: The sanded sheet is cut into finished products using a guillotine shear to obtain a high-quality TC4 wide titanium alloy thin plate of 1.8 mm × 1500 mm × 3000 mm.

[0106] The room temperature mechanical properties of the high-quality TC4 wide-width titanium alloy thin sheet obtained in Example 15 are shown in Table 3, and the microstructural photos are as Figure 3A and Figure 3B shown.

[0107] As can be seen from Table 3, the product performance indexes of the high-quality TC4 wide-width titanium alloy thin sheet of the present invention can all meet the requirements of GJB2505A.

[0108] As can be seen from FIGS. 1 to 3, the high-quality TC4 wide-width titanium alloy thin sheet obtained by the present invention can fully reach the current industry level.

[0109] The yield rate of Example 13 of the present invention is 72%, the yield rate of Example 14 is 69%, and the yield rate of Example 15 is 69%. The production period from slab surface treatment to finished product is one and a half months, and the flatness is 0.95.

[0110] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0111] On the one hand, the production efficiency of the present invention is high. By using a tandem mill or a continuous rolling mill, the five heating passes required by the traditional process are reduced to two heating passes. The total processing rate of one heating pass is 96.5% to 98.5%. After rolling, an intermediate semi-finished hot coil with a thickness of 3.0 mm to 5.5 mm is obtained. The total processing rate of the finished product heating pass is 60% to 78%. After rolling, a high-quality TC4 wide-width titanium alloy thin sheet with a thickness of 0.5 mm to 2.5 mm is obtained.

[0112] On the other hand, the finished product plate of the present invention has a large width, with a thickness of 0.5 mm to 2.5 mm, a width of 1500 mm to 2000 mm, and a length of 3000 mm to 4000 mm. Moreover, this high-quality TC4 wide-width titanium alloy thin sheet is more convenient to use in the application field, has less welding requirements, and has high safety performance.

[0113] Therefore, compared with the titanium alloy thin sheet obtained by the traditional multi-pass hot rolling + clad rolling processing technology, the high-quality TC4 wide-width titanium alloy thin sheet obtained by the processing technology of the present invention has a wider plate width, a shorter process, and higher production efficiency;

[0114] Compared with the method of multi-pass hot rolling + sheet cold rolling, the high-quality TC4 wide-width titanium alloy thin sheet obtained by the processing technology of the present invention has a wider plate width, less anisotropy, and higher quality.

[0115] In summary, the present invention reduces the five heat treatments required by the traditional process to two heat treatments. After rolling, an intermediate semi-finished hot coil with a thickness of 3.0 mm to 5.5 mm is obtained. After rolling, a high-quality TC4 wide-width titanium alloy thin plate with a width of 1500 mm to 2000 mm, a length of 3000 mm to 4000 mm, and a thickness of 0.5 mm to 2.5 mm is obtained. Its production efficiency is increased by 50%, the cost of the plate is reduced by 50%, it is more convenient to use in the application field, has less welding requirements, and has higher safety performance.

[0116] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effects. Non-essential technical features can be added or subtracted according to actual needs to meet the requirements of different situations.

[0117] Table 1

[0118]

[0119] Table 2

[0120]

[0121] Table 3

[0122]

Claims

1. A short-process production and processing method for TC4 wide-width titanium alloy thin plates, characterized in that It is carried out according to the following method: S1, the first-pass rolling: After cleaning and cladding the titanium alloy slab, it is heat-preserved in a heating furnace and then fed into a hot tandem mill for the first-pass rolling to obtain an intermediate semi-finished hot-rolled sheet with a thickness of 3.0 mm to 5.5 mm. S2, annealing and pickling of the intermediate semi-finished hot-rolled sheet: After annealing the intermediate semi-finished hot-rolled sheet using a continuous annealing furnace, surface pickling treatment is carried out on the annealed intermediate semi-finished hot-rolled sheet on a pickling line to obtain a pickled white coil. S3, straightening and leveling: The pickled white coil is leveled on a tension leveling machine and then leveled to obtain a semi-finished sheet. S4, cladding: Use a steel plate with a thickness of 20 mm to 25 mm to clad and weld 3 to 4 sheets to obtain a steel box. S5, finished rolling: After heat-preserving the welded steel box in a heating furnace, it is fed into a hot rolling mill for the second-pass finished rolling to obtain a finished sheet. S6, annealing: The finished sheet is put into an annealing furnace for recrystallization annealing. The annealing temperature is 700 °C to 800 °C, and after heat-preserving for 60 min to 90 min, it is taken out of the furnace and then air-cooled to obtain a cooled steel plate. S7, plate lifting: Use a flame cutting machine to cut the cooled steel plate and lift out a wide-width titanium alloy thin plate. S8, pre-cutting: The lifted wide-width titanium alloy thin plate is pre-cut to obtain a pre-cut sheet. S9, creep: Use a vacuum creep furnace to carry out creep straightening and heat-preserving on the pre-cut sheet and then furnace-cool it to obtain a creep-straightened titanium plate. S10, surface treatment: Use a sander to carry out surface treatment on the creep-straightened titanium plate to obtain a sanded sheet. S11, cutting the finished product: Use a guillotine shear to cut the sanded sheet into finished products to obtain a wide-width TC4 titanium alloy thin plate.

2. The short-process production and processing method of the TC4 wide-width titanium alloy thin sheet according to claim 1, characterized in that In step S1, the heat-preserving temperature in the heating furnace is 1000 °C to 1110 °C, the heat-preserving time is the thickness of the sheet in mm × 1.3 min / mm to 1.6 min / mm, the processing rate of the first-pass rolling is 96.5% to 98.5%, and the first-pass rolling adopts 5 roughing passes with a pass processing rate of 15% to 40%.

3. The short-process production and processing method of the TC4 wide-width titanium alloy thin plate according to claim 2, characterized in that In step S1, the heat-preserving temperature in the heating furnace is 1080 °C, the heat-preserving time is 240 min, and the pass processing rate is 15% to 30%.

4. The short-process production and processing method of the TC4 wide titanium alloy thin plate according to claim 1 or 2, characterized in that In step S2, the annealing treatment temperature is 760 °C to 880 °C, the annealing treatment speed is 10 m / min to 60 m / min, and the acid solution used for surface pickling treatment is a mixed acid solution. Among them, the mixed acid solution is a mixed solution composed of a nitric acid solution with a volume concentration of 35% to 40% and a hydrofluoric acid solution with a pH value of 5 to 7.

5. The short-process production and processing method of the TC4 wide-width titanium alloy thin sheet according to claim 4, characterized in that In step S2, the annealing treatment temperature is 800 °C, and the annealing treatment speed is 12 m / min.

6. The short-process production and processing method of the TC4 wide-width titanium alloy thin plate according to any one of claims 1 to 5, characterized in that In step S4, use a 20-mm-thick steel plate to clad and weld 4 sheets; or / and, in step S5, the heat-preserving temperature in the heating furnace is 800 °C to 900 °C, the heat-preserving time is the thickness of the sheet in mm × 0.8 min / mm to 1.2 min / mm, and the second-pass finished rolling is 8 to 12 passes with a pass processing rate of 15% to 40%.

7. The short - process production and processing method of the TC4 wide - width titanium alloy thin sheet according to any one of claims 1 to 6, characterized in that In step S5, the holding temperature of the heating furnace is 880 °C, the holding time is 60 min, and the pass reduction rate of the finished rolling in the second heat is 15% to 22%.

8. The TC4 wide-width titanium alloy thin sheet and its short-process production and processing method according to any one of claims 1 to 7, characterized in that In step S6, the annealing temperature is 760 °C and the holding time is 60 min; and / or, in step S9, the creep straightening temperature is 550 °C to 650 °C and the holding time is 2 hours to 5 hours.

9. The short-process production and processing method of the TC4 wide-width titanium alloy thin sheet according to claim 8, characterized in that In step S9, the creep straightening temperature is 600 °C and the holding time is 4 hours; and / or, in step S10, the abrasive belt grit used by the sander is 120#+180#+320#+600#, the grinding amount of the sander is 0.25 mm, and the surface roughness Ra ≤ 0.3 μm.

10. A TC4 wide-width titanium alloy thin plate obtained by the short-process production and processing method according to any one of claims 1 to 9.

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