Die-pressing cold-drawing forming method for titanium alloy thin-wall profile

Abstract

The invention discloses a die-pressing cold-drawing forming method for a titanium alloy thin-wall profile. The method comprises the following steps: selecting an 0A-grade titanium alloy cast ingot, and carrying out solution annealing to obtain a fine-grain plastic titanium alloy forged ingot; annealing and forging the titanium alloy forging ingot to obtain a forged bar blank; a rough profile blank is obtained through one-time mold pressing; carrying out secondary precise mold pressing to obtain a profile; preserving heat and shaping; and the thin-wall profile is obtained through cold drawing and shaping. The product obtained by the invention can meet dozens of national standards and military standards; for thin-wall products with the thickness smaller than 2 mm, the trial-manufacturing yield of the thin-wall products is lower than 50% in domestic tip titanium alloy research institutes and manufacturers, and the yield of the thin-wall products is 95% or above through the technology; the thickness of the high-precision and high-quality titanium alloy profile product obtained through the researched and developed technology reaches 2 mm or below, related size requirements are met, the mechanical strength can reach 1000-1200 MPa, and the high-precision and high-quality titanium alloy profile product is suitable for the fields of aerospace ships, nuclear power engineering and the like.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy profile processing technology, and in particular to a method for cold drawing and molding thin-walled titanium alloy profiles. Background Technology

[0002] Chinese Patent 201810833924.8 provides a method for extruding thin-walled titanium alloy profiles. The corrosion-resistant titanium alloy comprises: melting a TC4 titanium alloy ingot with a diameter of Φ710mm; forging the ingot into a Φ220XLmm bar; preheating the extrusion cylinder, extrusion die, and extrusion pad at a temperature of 300-500℃; lubricating the extrusion tools with a lubricant; rapidly transferring the bar into the extrusion cylinder in a time of less than 1 minute; and extruding at a speed of 120-300mm / s to obtain the titanium alloy profile. The extrusion method for thin-walled titanium alloy profiles provided in this invention not only enables the extrusion of thin-walled, small-section profiles on a high-tonnage extrusion press, but also significantly reduces mold costs, personnel costs, and equipment operating costs. Compared with traditional processes, this method requires no additional steps or special treatments, is highly operable, and can achieve the extrusion of titanium alloy profiles with all currently available cross-sectional shapes. The process is difficult during extrusion, and thin-walled profiles are prone to breakage and twisting. If titanium alloy thin-walled profiles with a wall thickness of less than 2mm are processed, the yield is less than 20%.

[0003] Chinese Patent 202011540231.3 discloses a method for preparing titanium or titanium alloy extruded and rolled thin-walled profiles. The method includes: 1. preparing titanium or titanium alloy ingots by melting in a vacuum consumable arc furnace; 2. forging a forged billet by 2-4 passes at 900°C to 1200°C; 3. obtaining an extruded ingot by sawing and machining; 4. lubricating the extruded ingot and then heating and extruding it to obtain an extruded die; 5. surface-treating the extruded die and then heating it below the phase transformation point of titanium or titanium alloy for hot rolling to obtain a rolled profile; 6. annealing the rolled profile after surface treatment to obtain a titanium or titanium alloy profile. This invention combines heated extrusion with hot rolling and annealing below the phase transformation point, ensuring the surface quality and dimensional accuracy of the extruded die. The prepared titanium or titanium alloy profiles have good surface quality, uniform microstructure, and stable mechanical properties. Different shapes and specifications of titanium or titanium alloy extruded and rolled thin-walled profiles can be flexibly produced according to actual needs, with low manufacturing costs. The thin-walled profiles produced by this process lack sufficient strength and surface uniformity, failing to meet the high standards required by aerospace.

[0004] Other technologies disclosed in patents such as CN108907619A - A composite processing method for thin-walled precision titanium alloy profiles, CN110293143A - A hot drawing and forming device and method for titanium alloy profiles, CN110340172A - A method for near-net-shape forming of thin-walled titanium alloy profiles by extrusion and rolling, and CN116213494A - A preparation method for L-shaped thin-walled titanium alloy profiles, cannot meet the product requirements of a wall thickness of less than 2mm and a strength of more than 1000 MPa. Summary of the Invention

[0005] The purpose of this invention is to provide a method for cold drawing and molding thin-walled titanium alloy profiles to solve the problems existing in the prior art.

[0006] The technical solution of the present invention:

[0007] A method for cold drawing and molding thin-walled titanium alloy profiles, comprising the following steps:

[0008] Step 1: Select 0A grade titanium alloy ingots, and use a vacuum arc furnace to perform 2 to 4 solution annealing processes, and test the transformation point to be 960℃~1050℃ to prepare fine-grained plastic titanium alloy forging ingots.

[0009] Step 2: The titanium alloy forging ingot obtained in Step 1 is annealed and forged 2 to 4 times at 890℃~1090℃ to obtain a forging billet.

[0010] Step 3: Obtain the profile blank by pressing the forged bar billet obtained in Step 2 through a single die pressing process;

[0011] Step 4: Apply abrasive to the rough profile blank obtained in Step 3, and then perform a second precision molding to obtain the profile;

[0012] Step 5: Heat the profile obtained in Step 4 to 570-680℃ and hold it at that temperature for 3-6 hours to set the shape;

[0013] Step 6: Apply abrasive to the shaped profile obtained in Step 5, and then cold draw it to obtain a thin-walled profile.

[0014] The specific process of the first molding described in step three is as follows: the forged billet is heated to 780-830℃, and then annealed and molded for 2-4 hours.

[0015] The specific process of the first molding described in step three is as follows: the forged billet is heated to 790-810℃, and then annealed and molded for 2-4 hours.

[0016] The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 620-690℃, and then annealed and molded for 2-4 hours.

[0017] The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 640-670℃, and then annealed and molded for 2-4 hours.

[0018] The titanium alloy thin-walled profile is H-shaped, T-shaped, L-shaped, U-shaped, Z-shaped or cross-shaped, and the profile wall thickness is less than or equal to 2mm.

[0019] It also includes step seven, which involves surface treatment of the thin-walled profile obtained in step six using a sandblasting process.

[0020] In step three, free forging with a capacity of over 5,000 tons is used to forge the rough billet.

[0021] The beneficial effects of this invention compared with existing technologies are as follows: The products obtained by this invention can meet more than a dozen national and military standards; for thin-walled products with a thickness of less than 2mm, the trial production rate of leading domestic titanium alloy research institutes and manufacturers is less than 50%, while our technology has a production rate of over 95%; the titanium alloy thin-walled profiles obtained by our research and development technology not only achieve a thickness of less than 2mm, meeting relevant dimensional requirements, but also have a mechanical strength of 1000-1200 MPa, making them suitable for aerospace, shipbuilding, nuclear power engineering and other fields. Attached Figure Description

[0022] Figure 1 This is the first test report for the product obtained by the present invention;

[0023] Figure 2 This is the second test report for the product obtained by the present invention;

[0024] Figure 3 This is a structural diagram of the Z-shaped profile processed according to the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1.

[0027] A method for cold drawing and molding thin-walled titanium alloy profiles, comprising the following steps:

[0028] Step 1: Select 0A grade titanium alloy ingots, and use a vacuum arc furnace to perform 2 to 4 solution annealing processes, and test the transformation point to be 960℃~1050℃ to prepare fine-grained plastic titanium alloy forging ingots.

[0029] Step 2: The titanium alloy forging ingot obtained in Step 1 is annealed and forged 2 to 4 times at 890℃~1090℃ to obtain a forging billet.

[0030] Step 3: Obtain the profile blank by pressing the forged bar billet obtained in Step 2 through a single die pressing process;

[0031] Step 4: Apply abrasive to the rough profile blank obtained in Step 3, and then perform a second precision molding to obtain the profile;

[0032] Step 5: Heat the profile obtained in Step 4 to 570-680℃ and hold it at that temperature for 3-6 hours to set the shape;

[0033] Step 6: Apply abrasive to the shaped profile obtained in Step 5, and then cold draw it to obtain a thin-walled profile.

[0034] The specific process of the first molding described in step three is as follows: the forged billet is heated to 780-830℃, and then annealed and molded for 2-4 hours.

[0035] The specific process of the first molding described in step three is as follows: the forged billet is heated to 790-810℃, and then annealed and molded for 2-4 hours.

[0036] The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 620-690℃, and then annealed and molded for 2-4 hours.

[0037] The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 640-670℃, and then annealed and molded for 2-4 hours.

[0038] The titanium alloy thin-walled profile is H-shaped, T-shaped, L-shaped, U-shaped, Z-shaped or cross-shaped, and the profile wall thickness is less than or equal to 2mm.

[0039] It also includes step seven, which involves surface treatment of the thin-walled profile obtained in step six using a sandblasting process.

[0040] In step three, free forging with a capacity of over 5,000 tons is used to forge the rough billet.

[0041] Example 2.

[0042] A method for cold drawing and molding thin-walled titanium alloy profiles, comprising the following steps:

[0043] Step 1: Select 0A grade titanium alloy ingots, use a vacuum arc remelting furnace to perform three solution annealing processes, and test the transformation point to be 990℃ to prepare titanium alloy forging ingots.

[0044] Step 2: The titanium alloy forging ingot obtained in Step 1 is annealed and forged three times at 950℃ to obtain a forging billet.

[0045] Step 3: Heat the forged billet obtained in Step 2 to 800℃, then anneal and press for 3 hours to obtain the profile blank in one pressing.

[0046] Step 4: Heat the profile blank obtained in Step 3 to 650℃, apply abrasive, then anneal and press for 3 hours, and then perform a second precision molding to obtain the profile.

[0047] Step 5: Heat the profile obtained in Step 4 to 620℃ and hold it at that temperature for 4 hours to set the shape;

[0048] Step 6: Apply abrasive to the shaped profile obtained in Step 5, and then cold draw it to obtain a thin-walled profile.

[0049] Step 7: The thin-walled profile obtained in Step 6 is surface-treated by sandblasting.

[0050] Example 3.

[0051] This process manufactures various thin-walled titanium alloy profiles, such as H-shaped, T-shaped, L-shaped, U-shaped, Z-shaped, or cross-shaped profiles, with a wall thickness of less than or equal to 2mm. Figure 1 and 2 As shown, the tensile strength can reach 1046 MPa, the specified plastic elongation strength can reach 938 MPa, and the product dimensions are qualified.

[0052] Example 4.

[0053] A method for cold drawing and molding Z-shaped titanium alloy thin-walled profiles, the method comprising the following steps:

[0054] Step 1: Select 0A grade titanium alloy ingots, use a vacuum arc remelting furnace to perform three solution annealing processes, and test the transformation point to be 1010℃ to prepare titanium alloy forging ingots.

[0055] Step 2: The titanium alloy forging ingot obtained in Step 1 is annealed and forged three times at 990℃ to obtain a forging billet.

[0056] Step 3: Heat the forged billet obtained in Step 2 to 805℃, then anneal and press for 2.5 hours to obtain the profile blank in one pressing.

[0057] Step 4: Heat the profile blank obtained in Step 3 to 660℃, apply abrasive, then anneal and press for 2.5 hours, followed by a second precision pressing to obtain the profile;

[0058] Step 5: Heat the profile obtained in Step 4 to 640℃ and hold it at that temperature for 5 hours to set the shape;

[0059] Step Six: Apply abrasive to the shaped profile obtained in Step Five, and then cold-draw it to obtain a thin-walled profile, shaped as shown in the image. Figure 3 As shown.

[0060] Step 7: The thin-walled profile obtained in Step 6 is surface-treated by sandblasting.

[0061] In addition to the preferred embodiments described above, the present invention has other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection claimed by the present invention.

Claims

1. A method for cold drawing and molding thin-walled titanium alloy profiles, characterized in that, The method includes the following steps: Step 1: Select 0A grade titanium alloy ingots, and use a vacuum arc furnace to perform 2 to 4 solution annealing processes, and test the transformation point to be 960℃~1050℃ to prepare fine-grained plastic titanium alloy forging ingots. Step 2: The titanium alloy forging ingot obtained in Step 1 is annealed and forged 2 to 4 times at 890℃~1090℃ to obtain a forging billet. Step 3: Obtain the profile blank by pressing the forged bar billet obtained in Step 2 through a single die pressing process; Step 4: Apply abrasive to the rough profile blank obtained in Step 3, and then perform a second precision molding to obtain the profile; Step 5: Heat the profile obtained in Step 4 to 570-680℃ and hold it at that temperature for 3-6 hours to set the shape; Step 6: Apply abrasive to the shaped profile obtained in Step 5, and then cold draw it to obtain a thin-walled profile.

2. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 1, characterized in that, The specific process of the first molding described in step three is as follows: the forged billet is heated to 780-830℃, and then annealed and molded for 2-4 hours.

3. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 2, characterized in that, The specific process of the first molding described in step three is as follows: the forged billet is heated to 790-810℃, and then annealed and molded for 2-4 hours.

4. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 1, characterized in that, The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 620-690℃, and then annealed and molded for 2-4 hours.

5. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 4, characterized in that, The specific process of the secondary precision molding described in step four is as follows: the profile is heated to 640-670℃, and then annealed and molded for 2-4 hours.

6. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 1, characterized in that, The titanium alloy thin-walled profile is H-shaped, T-shaped, L-shaped, U-shaped, Z-shaped or cross-shaped, and the profile wall thickness is less than or equal to 2mm.

7. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 1, characterized in that, It also includes step seven, which involves surface treatment of the thin-walled profile obtained in step six using a sandblasting process.

8. The method for cold drawing and molding thin-walled titanium alloy profiles according to claim 1, characterized in that, In step three, free forging with a capacity of over 5,000 tons is used to forge the rough billet.

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