A processing method for high-quality TC11 titanium alloy wire

Abstract

This application introduces a TC11 titanium alloy high-quality wire processing method, which relates to the field of wire drawing technology. The specific steps are: S1: blank forging; S2: repeated upsetting; S3: first fire rough rolling; S4: cutting to size; S5: second fire rough rolling; S6: coil heat treatment; S7: roller die cold drawing + continuous annealing; S8: surface treatment. The process means of the present invention enables the TC11 titanium alloy microstructure to be fully refined and homogenized, which is conducive to the smooth implementation of the subsequent drawing process; in the subsequent direct roller die cold drawing process, the roller die cold drawing pass deformation, cold drawing rate, etc. are strictly controlled to avoid the occurrence of cracks, defects and even wire breakage that may occur during the drawing process. At the same time, it solves the bottleneck of large single weight drawing of titanium alloy that cannot be achieved due to hot drawing in the traditional drawing process, greatly improving production efficiency and yield rate.

Description

Technical Field

[0001] The invention relates to the technical field of wire drawing technology, and in particular to a processing method for high-quality TC11 titanium alloy wire. Background Art

[0002] TC11 titanium alloy is a martensitic α+β heat-resistant titanium alloy with good comprehensive properties. Its nominal composition is Ti-6.5Al-3.5Mo-1.5Zr-0.3Si. This alloy not only has the advantages of general titanium alloys, high room temperature strength, excellent heat resistance and good hot processing performance, but also can work for a long time above 500℃ and maintain good mechanical properties. It can replace high-temperature alloys, stainless steel and Ti-6Al-4V alloy in the compressor part of the engine, and can work for a long time at 350℃. In the high-temperature parts of the aircraft, such as the rear fuselage, it can replace aluminum alloys whose high-temperature performance cannot meet the requirements. Therefore, TC11 titanium alloy has been widely used in the manufacture of aircraft engine compressor disks, blades and drums, etc., and is an important aviation and aerospace material. In addition, TC11 titanium alloy also has good processing properties and can be hot-processed, welded and various forms of machining.

[0003] In the traditional manufacturing process of titanium alloys, the development of large and complex structural parts requires the use of forging + machining manufacturing methods, which have high equipment costs, long production cycles, heavy pollution, cumbersome processes and low material utilization rates, generally less than 5-10%, which seriously restricts the widespread application of large titanium alloy structural parts in advanced industries and equipment; therefore, with the development of advanced forming technology for metal materials, additive manufacturing technology, namely AM, has become the best new technology for responding to technical challenges in the field of aircraft and aero engines because it can achieve mold-free, rapid, fully dense and near-net forming of high-performance complex structural metal parts; at the same time, the free solid forming characteristics of additive manufacturing technology have also created important conditions for realizing the lightweight, compact and multifunctional design of advanced aircraft structures and improving the efficiency of aircraft design and R&D.

[0004] The raw materials for titanium alloy metal additive manufacturing mainly include powder and wire. Among them, wire has many advantages such as low processing cost, high material utilization rate and excellent mechanical properties of formed components. Therefore, the arc / electron beam fuse additive manufacturing technology using titanium alloy wire as raw material provides an efficient, fast and low-cost manufacturing technical approach for the development of large and complex integral titanium alloy components.

[0005] At present, the existing titanium alloy wires in China are mainly used in the fields of welding wires and fasteners. The traditional wire drawing preparation process is: fixed die hot drawing, heat treatment, pickling, and polishing. This preparation process is mostly delivered with wire rods and machined surfaces. The main problems are: (1) The fixed die drawing speed is slow, the single-pass diameter reduction is small, the processing steps are long, the production efficiency is low, and the unit weight is small; (2) Hot drawing can easily cause the wire to absorb harmful elements such as nitrogen, hydrogen, and oxygen in the air under heating, reducing the consistency of material performance; (3) When the wire is drawn, there is a very large sliding friction between the die and the wire, which can easily lead to an increase in the dimensional tolerance of the wire and scratches on the wire surface, forming a continuous quality defect; (4) After the wire is drawn, electrolytic polishing or pickling must be used to remove the graphite or phosphated lubricant on the wire surface, resulting in high energy consumption and high pollution in the preparation of the wire. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a TC11 titanium alloy high-quality wire processing process method, which realizes the processing of high-quality TC11 titanium alloy wire through a combination of blanking forging, repeated upsetting, rolling, vacuum dehydrogenation, roller die drawing, continuous annealing and surface treatment. The operation is simple, the yield rate is high, and the process is stable and controllable.

[0007] The technical solution adopted by the present invention is:

[0008] A TC11 titanium alloy high-quality wire processing method, the specific steps are:

[0009] S1: blank forging; heating the qualified TC11 titanium alloy ingot to between 1100-1200°C, and performing one-time forging, wherein the number of forging and drawing in this fire is no more than two piers and two draws, the single piercing deformation is 35%-50%, the pressing amount of each hammer is 20mm-50mm, the pressing rate is 20mm / s-40mm / s, the final forging temperature is not less than 800°C, and the surface is ground after air cooling to obtain the blank forging;

[0010] S2: Repeated upsetting and drawing: The forging billet obtained in S1 is heated to between 1050°C and 1200°C, and a fire forging is performed, wherein the number of upsetting and drawing in this fire is not more than two upsetting and two drawing, and the ingot is drawn to a square billet with a cross-sectional side length of 180-200 mm, and then the surface is ground after water cooling to obtain a square billet after opening;

[0011] S3: First rough rolling: the square billet obtained in S2 is heated to 950-1050℃ and rolled once to obtain a round bar with a diameter of Φ90-110mm and a length greater than 9m. The ovality of the round bar is required to be no greater than ±5cm. After air cooling, the round bar is peeled and manually ground.

[0012] S4: Cut to size: Cut the round bar after grinding into sections, with each section of the round bar being 4-6m long;

[0013] S5: second rough rolling; the round bar obtained in S4 is heated to 900-1000°C and rolled once to obtain a coil with a diameter of Φ8-10mm. The ovality of the coil is required to be no more than ±0.5cm. After air cooling, the coil is coiled and the coil diameter is controlled to be 0.8-1.1m.

[0014] S6: heat treatment of the coil; the coil obtained in S5 is peeled, and the removal amount is controlled to be 0.2-0.5mm. After peeling, it is annealed in a vacuum furnace at a heating temperature of 750-850℃, and kept at this temperature for 20-40min. After the furnace is cooled to no higher than 100℃, it is taken out of the furnace and air-cooled;

[0015] S7: roller die cold drawing + continuous annealing: the wire obtained in S6 is repeatedly cold drawn and annealed on a roller die wire drawing machine to obtain a titanium alloy wire of target diameter;

[0016] S8: surface treatment; ultrasonically clean and polish the wire of target diameter obtained in S7 to obtain a finished titanium alloy wire with dimensions meeting the precision requirements.

[0017] Specifically, the titanium alloy ingot in S1 is a polished ingot with a diameter of 550-650 mm and a unit weight of 2-5 tons, and has no surface defects or damage.

[0018] Specifically, the pull-out deformation of S2 is 35-55%, and the deformation rate is controlled at 20-50 mm / s.

[0019] Specifically, the rolling rate in S3 is controlled at 0.2-0.5 m / s.

[0020] Specifically, in the S5, the rolling rate is controlled at 0.5-1.0 m / s.

[0021] Specifically, in the above-mentioned S7, the cold drawing and annealing treatments are repeated, and according to the gradual thinning of the wire diameter, the cold drawing is performed 1-3 times between each annealing.

[0022] More specifically, in the cold drawing in S7, the drawing speed is 5-20 m / min, the deformation per drawing pass is less than 35%, and the surface of the wire needs to be coated with an emulsion as a drawing lubricant.

[0023] Specifically, the annealing furnace for the annealing treatment in S7 is an online continuous annealing treatment with continuous argon filling, the purity of the argon gas filled in the furnace is ≥99.999%, and a slight positive pressure is maintained so that inert gas overflows.

[0024] More specifically, the continuous annealing temperature in S7 is 700-900° C., and the holding time is 5-20 min.

[0025] Due to the adoption of the above-mentioned technical solution, the present invention has the following advantages:

[0026] The present invention effectively combines the means of open forging, repeated upsetting, rolling, vacuum dehydrogenation, roller die cold drawing + continuous annealing and surface treatment, strictly controls the open forging process, hot rolling temperature, etc., so that the microstructure of TC11 titanium alloy is fully refined and uniform, which is conducive to the smooth implementation of the subsequent drawing process; in the subsequent direct roller die cold drawing process, the roller die cold drawing pass deformation, cold drawing rate, etc. are strictly controlled to avoid the occurrence of cracks, defects and even wire breakage that may occur in the drawing process, and at the same time realizes the titanium alloy that cannot be achieved due to hot drawing in the traditional drawing process. The bottleneck of Jinda's single-weight drawing has been solved, which has greatly improved the production efficiency and yield rate, and avoided many problems such as hydrogen permeation and oxygen permeation during the drawing process; during the drawing process, the continuous annealing process in the cold drawing process is reasonably arranged, which effectively removes the residual stress caused by local uneven deformation of the titanium alloy wire during the drawing process, realizes static recrystallization annealing, and further refines the grain structure. At the same time, since the entire annealing process is completely carried out in an argon-filled environment, it effectively avoids the subsequent use of electrolytic polishing or pickling to remove graphite or phosphated lubricants on the wire surface, thereby achieving energy saving and environmental protection. DETAILED DESCRIPTION

[0027] The present invention will be further explained below in conjunction with the embodiments, which are not intended to limit the protection scope of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. Example 1

[0028] The specific steps of preparing TC11 titanium alloy wire with a diameter of 1.2 mm and a single weight of 80 kg by the method of the present invention are as follows:

[0029] S1: Open forging: The qualified TC11 titanium alloy ingot with a diameter of 600mm and a weight of 3 tons is heated to 1200℃ and forged once. Two piers and two pulls are completed in this piercing. The deformation of each piercing is 40%, the reduction of each hammer is 20mm, and the reduction rate is 30mm / s. The final forging temperature is not less than 800℃, and the surface is ground after air cooling to obtain the open forging billet.

[0030] S2: Repeated upsetting and drawing; the forging billet obtained by S2 is heated to 1200°C and subjected to one forging. The forging upsetting and drawing times of this forging upsetting and drawing are two upsetting and two drawing. The upsetting and drawing deformation is 55% and the deformation rate is 30 mm / s. After water cooling, the surface is ground to obtain a square billet with a cross section of 180×190 mm.

[0031] S3: First fire rough rolling; the square billet obtained in S2 is heated to 1030°C and rolled once, with the rolling rate controlled at 0.5 m / s; a total of 8 round bars with a diameter of Φ110 mm and a length of 10 m are obtained, and the ovality of the round bars is 5 cm. After air cooling, the round bars are peeled and manually ground.

[0032] S4: Cut to size: Cut the round bar after grinding into sections, each section of the round bar is 5m long.

[0033] S5: second rough rolling; the round bar obtained in S4 is heated to 950°C and rolled once at a rolling rate of 1.0 m / s to obtain a coil with a diameter of Φ8.5 mm and an ovality of 0.5 cm. After air cooling, the coil is coiled and the coil diameter is 1.1 m.

[0034] S6: heat treatment of the coil; the coil obtained in S5 is peeled, and the removal amount is controlled at 0.4mm. After peeling, it is annealed at a heating temperature of 850°C, kept warm for 25 minutes, cooled in the furnace to 80°C, and then air-cooled to obtain a Φ8.1mm wire.

[0035] S7: roller die cold drawing + continuous annealing; the wire obtained in S6 is repeatedly cold drawn and annealed on a roller die wire drawing machine. The wire diameters after each roller die cold drawing are Ф7.0mm, Ф6.2mm, Ф5.4mm, Ф4.8mm, Ф4.2mm, Ф3.5mm, Ф3.0mm, Ф2.6mm, Ф2.2mm, Ф1.8mm, Ф1.5mm, Ф1.3mm, and Ф1.2mm, respectively. After annealing, the wire diameters are set to Ф5.4mm, Ф4.2mm, Ф2.6mm, Ф1.8mm, Ф1.3mm, and Ф1.2mm, respectively. The drawing speed is controlled at 20m / min, the annealing temperature is 900℃, and the holding time is 12min to obtain a titanium alloy wire with a diameter of Ф1.2mm.

[0036] S8: Surface treatment: The wire obtained in S7 is ultrasonically cleaned and polished to finally obtain a finished TC11 titanium alloy wire with a diameter tolerance of -0.01-0.02mm, a straightness of 3‰, an ellipticity of 0.01mm, and an overall yield rate of 73% from ingot to wire, with a single weight of 80kg and no weld points of Ф1.2mm. Example 2

[0037] The specific steps of preparing TC11 titanium alloy wire with a diameter of 1.6 mm and a single weight of 60 kg by the method of the present invention are as follows:

[0038] S1: Open forging: The qualified TC11 titanium alloy ingot with a diameter of 580 mm and a weight of 3 tons is heated to 1100℃ and forged once. Two piers and two pulls are completed in this piercing. The deformation of each piercing is 35%, the reduction of each hammer is 50 mm, and the reduction rate is 40 mm / s. The final forging temperature is not less than 800℃, and the surface is ground after air cooling to obtain the open forging billet.

[0039] S2: Repeated upsetting and drawing; the forging billet obtained in S1 is heated to 1150°C and subjected to one forging. The forging upsetting and drawing times in this forging upsetting and drawing are two upsetting and two drawing. The upsetting and drawing deformation is 45% and the deformation rate is 50 mm / s. After water cooling, the surface is ground to obtain a square billet with a cross section of 190 mm×200 mm.

[0040] S3: First fire rough rolling; the square billet obtained in S2 is heated to 1050°C and rolled once, with the rolling rate controlled at 0.20m / s; a total of 8 round bars with a diameter of Φ90mm and a length of 10m are obtained, and the ovality of the round bars is 5cm. After air cooling, the round bars are peeled and manually ground.

[0041] S4: Cut to size: Cut the round bar after grinding into sections, each section of the round bar is 5m long.

[0042] S5: second rough rolling; the round bar obtained in S4 is heated to 900°C and rolled once at a rolling rate of 0.5 m / s to obtain a coil with a diameter of Φ8.0 mm and an ovality of 0.2 cm. After air cooling, the coil is coiled and the coil diameter is 1.1 m.

[0043] S6: heat treatment of the coil; the coil obtained in S5 is peeled, and the removal amount is controlled to 0.2mm. After peeling, it is annealed at a heating temperature of 750°C and kept warm for 40 minutes. After cooling to 60°C in the furnace, it is taken out of the furnace and air-cooled to obtain a wire with a diameter of Φ7.8mm.

[0044] S7: roller die cold drawing + continuous annealing; the wire obtained in S6 is repeatedly cold drawn and annealed on a roller die wire drawing machine. The wire diameters after each roller die cold drawing are Ф7.0mm, Ф6.2mm, Ф5.4mm, Ф4.6mm, Ф3.9mm, Ф3.2mm, Ф2.7mm, Ф2.3mm, Ф1.9mm, and Ф1.6mm, respectively. After annealing, the wire diameters are set to Ф6.3mm, Ф3.9mm, Ф2.3mm, and Ф1.6mm, respectively. The drawing speed is controlled at 15m / min, the annealing temperature is 700°C, and the holding time is 20min to obtain a Ф1.6mm titanium alloy wire.

[0045] S8: surface treatment; the titanium alloy wire obtained in S7 is ultrasonically cleaned and polished, and finally a finished product of TC11 titanium alloy wire with a single weight of 60kg and a diameter of 1.6mm without weld spots is obtained, with a diameter tolerance of -0.01-0.01mm, a straightness of 2.8‰, an ellipticity of 0.02mm, and an overall yield rate of 76% from ingot to wire. Example 3

[0046] The specific steps of preparing TC11 titanium alloy wire with a diameter of 1.0 mm and a single weight of 120 kg by the method of the present invention are as follows:

[0047] S1: Open forging: The qualified TC11 titanium alloy ingot with a diameter of 620 mm and a weight of 3.5 tons is heated to 1150°C and forged once. Two piers and two pulls are completed in this piercing. The deformation of each piercing is 50%, the reduction of each hammer is 35 mm, and the reduction rate is 20 mm / s. The final forging temperature is not less than 800°C, and the surface is ground after air cooling to obtain the open forging billet.

[0048] S2: Repeated upsetting and drawing: The forging billet obtained in S1 is heated to 1050°C and subjected to one forging. The forging upsetting and drawing times in this forging upsetting and drawing are two upsetting and two drawing. The upsetting and drawing deformation is 35% and the deformation rate is 20 mm / s. After water cooling, the surface is ground to obtain a square billet with a cross section of 180×200 mm.

[0049] S3: First fire rough rolling; the square billet obtained in S2 is heated to 950°C and rolled once, with the rolling rate controlled at 0.40 m / s; a total of 8 round bars with a diameter of Φ105 mm and a length of 11 m are obtained, and the ovality of the round bars is 2 cm. After air cooling, the round bars are peeled and manually ground.

[0050] S4: Cut to size: Cut the round bar after grinding into sections, and the length of each section of the round bar is about 5.5m.

[0051] S5: second rough rolling; the round bar obtained in S4 is heated to 1000°C and rolled once at a rolling rate of 0.7m / s to obtain a coil with a diameter of Φ8.6mm and an ovality of 0.3cm. After air cooling, the coil is coiled and the coil diameter is 1.0m.

[0052] S6: heat treatment of the coil; the coil obtained in S5 is peeled, and the removal amount is controlled to be 0.5 mm. After peeling, it is annealed at a heating temperature of 820°C, kept warm for 20 minutes, cooled in the furnace to 90°C, and then air-cooled to obtain a wire with a diameter of Φ8.1 mm.

[0053] S7: roller die cold drawing + continuous annealing; the TC11 titanium alloy wire obtained in S6 is repeatedly cold drawn and annealed on a roller die wire drawing machine. The wire diameters after each roller die cold drawing are Ф6.9mm, Ф6.0mm, Ф5.2mm, Ф4.3mm, Ф3.5mm, Ф2.9mm, Ф2.4mm, Ф2.0mm, Ф1.7mm, Ф1.4mm, Ф1.2mm and Ф1.0mm, respectively. After annealing, the wire diameters are set to Ф6.0mm, Ф3.5mm, Ф2.4mm, Ф1.4mm and Ф1.0mm, respectively. The drawing speed is controlled at 5m / min, the annealing temperature is 820℃, and the holding time is 5min to obtain a titanium alloy wire with a diameter of Ф1.0mm.

[0054] S8: surface treatment; ultrasonically clean and polish the TC11 titanium alloy wire obtained in S7, and finally obtain a finished TC11 titanium alloy wire with a diameter tolerance of -0.01-0.01mm, a straightness of 2.6‰, an ellipticity of 0.01mm, and an overall yield rate of 72% from ingot to wire, with a single weight of 120kg and no weld points of Ф1.0mm.

[0055] In summary, a comparison table of product data of TC11 titanium alloy wires processed by the three embodiments of the present invention and the hot drawing process of the prior art is as follows. It can be seen that the process method adopted by the present invention significantly reduces the processing time, greatly increases the unit weight of the product, and the yield rate of the wire is significantly improved.

[0056]

[0057] Parts of the present invention not described in detail are prior art.

[0058] The embodiments selected herein for the purpose of disclosing the invention are currently considered to be suitable, but it should be understood that the invention is intended to include all changes and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A TC11 titanium alloy high-quality wire processing method, characterized by: The specific steps are: S1: forging; the titanium alloy ingot is a polished ingot with a diameter of 550-650mm and a single weight of 2-5 tons, and there is no surface defect or damage. The qualified TC11 titanium alloy ingot is heated to between 1100-1200℃ and forged once. The number of forging and drawing in this fire is no more than two piers and two draws. The single piercing deformation is 35%~50%, the pressing amount of each hammer is 20mm~50mm, and the pressing rate is 20mm / s~40mm / s; the final forging temperature is not less than 800℃, and the surface is ground after air cooling to obtain the forged billet after forging; S2: Repeated upsetting and drawing: heating the forging billet obtained in S1 to between 1050-1200°C, and performing one-time forging, wherein the forging upsetting and drawing times of the forging upsetting and drawing are no more than two upsetting and two-drawing, the upsetting and drawing deformation is 35-55%, and the deformation rate is controlled at 20-50mm / s; the ingot is drawn to a square billet with a cross-sectional side length of 180-200mm, and the surface is ground after water cooling to obtain a square billet after opening; S3: First rough rolling: The billet obtained in S2 is heated to 950-1050°C and rolled once, with the rolling rate controlled at 0.2-0.5m / s to obtain a round bar with a diameter of Φ 90-110mm and a length greater than 9m. The ovality of the round bar is required to be no greater than ±5cm. After air cooling, the round bar is peeled and manually ground. S4: Cut to size: Cut the round bar after grinding into sections, with each section of the round bar being 4-6m long; S5: second rough rolling; the round bar obtained in S4 is heated to 900-1000°C and rolled once, the rolling rate is controlled at 0.5-1.0m / s, and a coil with a diameter of Φ8-10mm is obtained. The ovality of the coil is required to be no more than ±0.5cm. After air cooling, the coil is coiled, and the coil diameter is controlled at 0.8-1.1m; S6: heat treatment of the coil; the coil obtained in S5 is peeled, and the removal amount is controlled to be 0.2-0.5mm. After peeling, it is annealed in a vacuum furnace at a heating temperature of 750-850℃, and kept at this temperature for 20-40min. After the furnace is cooled to no higher than 100℃, it is taken out of the furnace and air-cooled; S7: roller die cold drawing + continuous annealing; the wire obtained in S6 is repeatedly cold drawn and annealed on a roller die wire drawing machine. According to the gradual thinning of the wire diameter, 1-3 cold drawing times are determined between each annealing. The cold drawing speed is 5-20m / min, and the deformation of each drawing pass is less than 35%. The surface of the wire needs to be coated with an emulsion as a drawing lubricant to obtain a titanium alloy wire of the target diameter; S8: surface treatment; ultrasonically clean and polish the wire of target diameter obtained in S7 to obtain a finished titanium alloy wire with dimensions meeting the precision requirements.

2. The TC11 titanium alloy high-quality wire processing method according to claim 1 is characterized in that: The annealing furnace for the annealing treatment in S7 is an online continuous annealing treatment with continuous argon filling, the purity of the argon filled in the furnace is ≥99.999%, and a slight positive pressure is maintained to ensure inert gas overflow.

3. The TC11 titanium alloy high-quality wire processing method according to claim 2 is characterized in that: The continuous annealing temperature in S7 is 700-900° C., and the holding time is 5-20 min.

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