Preparation method of TA2 alloy thin-wall profile

Abstract

The invention discloses a preparation method of a TA2 alloy thin-wall profile. The preparation method comprises an extrusion blank preparation step, a pretreatment step, a blank heating step, a blank extrusion step and a profile straightening step. According to the preparation method of the TA2 alloy thin-wall sectional material, the TA2 alloy thin-wall sectional material with excellent structure performance and surface quality is obtained by improving the extrusion preparation technology, the prepared TA2 alloy thin-wall sectional material is good in straightness and excellent in mechanical performance, defects such as longitudinal grooves and pits are not found on the surface, the dimensional tolerance is within a reasonable range, and the TA2 alloy thin-wall sectional material has the advantages of being good in mechanical property, good in mechanical property and good in mechanical property. And the use requirements of users can be met.

Description

Technical Field

[0001] The invention relates to the technical field of titanium alloy preparation, in particular to a method for preparing a TA2 alloy thin-wall profile. Background Art

[0002] Titanium alloys have high specific strength, deep hardenability and good corrosion resistance, and are widely used in aerospace and marine engineering. As a structural material, titanium alloy thin-walled profiles have a wide range of application markets.

[0003] Due to the inherent characteristics of titanium alloys, their forming process is greatly limited. The preparation of some titanium alloy profiles is quite difficult, especially titanium alloy thin-walled profiles. The use of extrusion to prepare titanium alloy thin-walled profiles can effectively improve the mechanical properties of titanium alloy profiles through large deformation.

[0004] Therefore, developing a method for preparing TA2 alloy thin-walled profiles and obtaining TA2 alloy thin-walled profiles with excellent organizational properties and surface quality through an extrusion preparation method is of great significance to the development of the titanium alloy field. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a TA2 alloy thin-walled profile. By improving the extrusion preparation process, a TA2 alloy thin-walled profile with excellent organizational properties and surface quality is obtained. The prepared TA2 alloy thin-walled profile has good flatness and excellent mechanical properties. No defects such as longitudinal grooves and pits are found on the surface. The dimensional tolerance is within a reasonable range, which can meet the user's usage requirements.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a method for preparing a TA2 alloy thin-walled profile, comprising the following steps: Extrusion blank preparation steps: machining the forged TA2 bar blank to obtain the extrusion blank; Pretreatment step: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying glass paint on the surface of the extruded blank to obtain a pretreated blank; Blank heating step: placing the pre-treated blank in an electric heating furnace for heating, and then subjecting the pre-treated blank to rapid induction heating after being taken out of the furnace to obtain a heat-treated blank; Billet extrusion steps: the billet is extruded on a horizontal extruder, lubricating oil is first applied to the pre-treated glass mat and the inner wall of the extrusion barrel, and then the glass mat is preheated and placed in the extrusion barrel, the heat-treated billet is rolled on the roller coating powder for 1 to 3 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile; wherein, the extrusion ratio is 8 to 40, and the extrusion rate is 50 to 250 mm / s; Profile straightening steps: Use a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightening machine; after the TA2 alloy thin-walled profile is electrically heated, the first straightening is carried out, the heating rate is 30~100℃ / min, the straightening temperature is 450℃~850℃, and the straightening stretching amount is 2~8%; when the profile is cooled to 50~250℃ on the straightening machine, the second straightening is carried out, and the stretching amount of the second straightening is 1~5%.

[0007] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the pretreatment step, the pressing force of the glass pad is 5~10MPa, and the thickness is 10~30mm; the extruded billet is heated to 50~350℃ before spraying the glass coating, and the spraying thickness is 0.1~1.8mm.

[0008] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the billet extrusion step, lubricating oil is applied to the pre-treated glass mat and the inner wall of the extrusion cylinder with a coating thickness of 0.5-3 mm.

[0009] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the billet heating step, the charging temperature of the pretreated billet is 600~850°C, the heating temperature of the electric heating furnace is 750~1050°C, and the insulation time is 2~6h; the induction heating temperature is 800°C~1100°C.

[0010] According to the method for preparing a TA2 alloy thin-walled profile of the present invention, preferably, in the blank heating step, the induction heating temperature is 50-100° C. higher than the heating temperature of the heating furnace.

[0011] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the billet extrusion step, the extrusion mold and the glass pad are preheated, and the preheating temperature is 150~400℃.

[0012] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the billet extrusion step, the horizontal extruder is a 45MN horizontal extruder.

[0013] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the extrusion billet preparation step, the end face of the extrusion billet is chamfered, and the chamfer has an angle of R10~R50mm.

[0014] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, in the extrusion billet preparation step, the extrusion billet processing size is φ185×200~600mm or φ215×200~600mm.

[0015] According to the method for preparing a TA2 alloy thin-walled profile described in the present invention, preferably, the main components of the glass pad, glass coating and roller coating powder include SiO2, B2O3, Al2O3, MgO, TiO2, CaO, Na2CO3, PbO, Na2O and K2O.

[0016] The beneficial effects of the present invention are: The present invention provides a method for preparing a TA2 alloy thin-walled profile. By improving the extrusion preparation process, a TA2 alloy thin-walled profile with excellent organizational properties and surface quality is obtained. The prepared TA2 alloy thin-walled profile has good flatness and excellent mechanical properties. No defects such as longitudinal grooves and pits are found on the surface. The dimensional tolerance is within a reasonable range, which can meet the user's usage requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a cross-sectional view of a spherical flat profile prepared by a method for preparing a TA2 alloy thin-walled profile of the present invention.

[0019] Figure 2 This is a cross-sectional view of a U-profile prepared by a method for preparing a TA2 alloy thin-walled profile of the present invention.

[0020] Figure 3 This is a cross-sectional view of an L-profile prepared by a method for preparing a TA2 alloy thin-walled profile of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0022] The invention discloses a method for preparing a TA2 alloy thin-walled profile, comprising the following steps: an extrusion blank preparation step, a pretreatment step, a blank heating step, a blank extrusion step and a profile straightening step.

[0023] The extrusion blank preparation step of the present invention is: machining the forged TA2 bar blank to obtain the extrusion blank. Preferably, the end face of the extrusion blank is chamfered, and the chamfer is R10~R50mm. More preferably, in the extrusion blank preparation step, the extrusion blank processing size is φ185×200~600mm or φ215×200~600mm.

[0024] The pretreatment step of the present invention is: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying the surface of the extruded blank with glass coating to obtain a pretreated blank. Preferably, the pressing force of the glass mat is 5-10 MPa, and the thickness is 10-30 mm; more preferably, the extruded blank is heated to 50-350° C. before spraying the glass coating, and the spraying thickness is 0.1-1.8 mm.

[0025] As a specific embodiment of the present invention, the main components of the glass mat and glass coating include SiO2, B2O3, Al2O3, MgO, TiO2, CaO, Na2CO3, PbO, Na2O and K2O. The glass mat and glass coating used in the present invention have different composition ratios and preparation processes. During the preparation of the glass mat, the glass mat is kept as soft as possible, which is conducive to the orderly melting of the glass mat and improves the lubrication effect. In the technical solution of the present invention, the glass coating needs to be sprayed evenly without bubbles.

[0026] The blank heating step of the present invention is as follows: the pre-treated blank is placed in an electric heating furnace for heating, and then subjected to rapid induction heating after being taken out of the furnace to obtain a heat-treated blank. Preferably, the charging temperature of the pre-treated blank is 600-850°C, the heating temperature of the electric heating furnace is 750-1050°C, and the holding time is 2-6 hours; more preferably, the induction heating temperature is 800°C-1100°C.

[0027] As a specific embodiment of the present invention, the induction heating temperature is 50-100° C. higher than the heating temperature of the heating furnace. The heating method of the present invention is beneficial to improving the surface quality of the profile during the extrusion process.

[0028] The billet extrusion step of the present invention is as follows: the billet is extruded on a horizontal extruder, lubricating oil is first applied to the pretreated glass mat and the inner wall of the extrusion barrel, and then the glass mat is preheated and placed in the extrusion barrel, the heat-treated billet is rolled on the roller coating powder for 1 to 3 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile. Preferably, the extrusion ratio is 8 to 40, and the extrusion rate is 50 to 250 mm / s. More preferably, lubricating oil is applied to the pretreated glass mat and the inner wall of the extrusion barrel, and the coating thickness is 0.5 to 3 mm.

[0029] In the present invention, the main components of the roller coating powder include SiO2, B2O3, Al2O3, MgO, TiO2, CaO, Na2CO3, PbO, Na2O and K2O. According to the inventor's multiple studies, the roller coating powder should have a uniform and fine particle size for better effect. Therefore, the roller coating powder used in the present invention can be sieved using a 100-mesh screen, which is conducive to uniform adhesion and softening of the roller coating powder during the roller coating process.

[0030] In the present invention, 185 series and 220 series group spacing are used for extrusion, and the extrusion die determines the optimal core position, die hole number, inlet chamfer and working belt length through digital simulation.

[0031] As a specific embodiment of the present invention, the extrusion cylinder, the extrusion mold and the glass mat are preheated at a temperature of 150-400° C. The specific embodiment of the present invention is used to increase the softening speed of the glass mat and reduce the temperature drop rate of the blank, which is conducive to the smooth extrusion process.

[0032] As another specific embodiment of the present invention, the horizontal extruder is a 45MN horizontal extruder.

[0033] The profile straightening step of the present invention is: using a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightener; after electrically heating the TA2 alloy thin-walled profile, the first straightening and the second straightening operations are performed. Preferably, the heating rate is 30-100°C / min; more preferably, the straightening temperature of the first straightening is 450-850°C, and the straightening stretching amount is 2-8%; further preferably, when the profile is cooled to 50-250°C on the straightener, the second straightening is performed, and the stretching amount of the second straightening is 1-5%.

[0034] In the straightening process of the present invention, the total straightening stretching amount should be adjusted according to the degree of distortion of the profile before straightening. When the distortion of the profile is serious, a larger straightening stretching amount is required.

[0035] Example 1 Example 1 Preparation Figure 1 The preparation method used for the bulb-flat profile shown comprises the following steps: Extrusion billet preparation steps: machining the forged TA2 bar billet, turning the billet into an extrusion billet of φ180×550mm, and then chamfering the end face of the extrusion billet with a chamfer R40mm; Pretreatment step: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying the glass coating on the surface of the extruded blank to obtain a pretreated blank; wherein the pressing force of the hydraulic press is 8MPa and the thickness is 30mm; heating the extruded blank to 150°C before spraying the glass coating, and then spraying, the spraying thickness is 0.5mm; Billet heating step: placing the pretreated billet into an electric heating furnace for heating, the charging temperature of the pretreated billet is 900° C., the heating temperature is 1000° C., the holding time is 4 hours, and then the pretreated billet is rapidly induction heated to 1050° C. after being taken out of the furnace; obtaining a heat-treated billet; Billet extrusion steps: billet extrusion is performed on a 45MN horizontal extruder, lubricating oil is first applied to the pre-treated glass mat, the mold and the inner wall of the extrusion barrel with a thickness of 0.5 mm, and then the glass mat is preheated and placed in the extrusion barrel, the heat-treated billet is rolled on the roller coating powder for 2 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile; wherein, the extrusion ratio is 25 and the extrusion rate is 50 mm / s; Profile straightening steps: Use a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightener; after the TA2 alloy thin-walled profile is electrically heated, the first straightening is carried out at a heating rate of 150℃ / min, a straightening temperature of 700℃, and a straightening stretching amount of 6%; when the profile is cooled to 250℃ on the straightener, the second straightening is carried out, and the stretching amount of the second straightening is 2%.

[0036] No obvious defects were found on the surface of the TA2 alloy spherical flat profile prepared in Example 1, and the flatness was good.

[0037] Example 2 Example 2 Preparation Figure 2 The preparation method used for the U-shaped material shown comprises the following steps: Extrusion billet preparation steps: machining the forged TA2 bar billet, turning the billet into an extrusion billet of φ215×250mm, and then chamfering the end face of the extrusion billet with a chamfer R20mm; Pretreatment step: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying the glass coating on the surface of the extruded blank to obtain a pretreated blank; wherein the pressing force of the hydraulic press is 9 MPa and the thickness is 20 mm; heating the extruded blank to 80° C. before spraying the glass coating, and then spraying, the spraying thickness is 0.3 mm; Billet heating step: placing the pretreated billet into an electric heating furnace for heating, the charging temperature of the pretreated billet is 800° C., the heating temperature is 900° C., the holding time is 3 hours, and then the pretreated billet is rapidly induction heated to 1000° C. after being taken out of the furnace; obtaining a heat-treated billet; Billet extrusion steps: billet extrusion is performed on a 45MN horizontal extruder, lubricating oil is first applied to the pre-treated glass mat, the mold and the inner wall of the extrusion barrel with a thickness of 0.5 mm, and then the glass mat is preheated and placed in the extrusion barrel, and the heat-treated billet is rolled on the roller coating powder for 2 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile; wherein, the extrusion ratio is 30 and the extrusion rate is 100 mm / s; Profile straightening steps: Use a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightener; after the TA2 alloy thin-walled profile is electrically heated, the first straightening is carried out with a heating rate of 80℃ / min, a straightening temperature of 750℃, and a straightening stretching amount of 5%; when the profile is cooled to 50℃ on the straightener, the second straightening is carried out with a stretching amount of 1%.

[0038] No obvious defects were found on the surface of the TA2 alloy U-profile prepared in Example 2, and the straightness was good.

[0039] Example 3 Example 3 Preparation Figure 3 The preparation method used for the L-shaped material shown comprises the following steps: Extrusion billet preparation steps: machining the forged TA2 bar billet, turning the billet into an extrusion billet of φ180×250mm, and then chamfering the end face of the extrusion billet with a chamfer R30mm; Pretreatment step: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying the glass coating on the surface of the extruded blank to obtain a pretreated blank; wherein the pressing force of the hydraulic press is 8MPa and the thickness is 25mm; heating the extruded blank to 200°C before spraying the glass coating, and then spraying, the spraying thickness is 0.5mm; Billet heating step: placing the pretreated billet into an electric heating furnace for heating, the charging temperature of the pretreated billet is 600° C., the heating temperature is 800° C., the holding time is 5 hours, and then the pretreated billet is rapidly induction heated to 850° C. after being taken out of the furnace; obtaining a heat-treated billet; Billet extrusion steps: billet extrusion is performed on a 45MN horizontal extruder, lubricating oil is first applied to the pre-treated glass mat, the mold and the inner wall of the extrusion barrel to a thickness of 0.8 mm, and then the glass mat is preheated and placed in the extrusion barrel, the heat-treated billet is rolled on the roller coating powder for 2 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile; wherein, the extrusion ratio is 36, and the extrusion rate is 100 mm / s; Profile straightening steps: Use a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightener; after the TA2 alloy thin-walled profile is electrically heated, the first straightening is carried out at a heating rate of 150℃ / min, a straightening temperature of 550℃, and a straightening stretching amount of 2%; when the profile is cooled to 50℃ on the straightener, the second straightening is carried out, and the stretching amount of the second straightening is 2%.

[0040] No obvious defects were found on the surface of the TA2 alloy L-profile prepared in Example 3, and the straightness was good.

[0041] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for preparing a TA2 alloy thin-walled profile, characterized in that: The following steps are included: Extrusion blank preparation steps: machining the forged TA2 bar blank to obtain the extrusion blank; Pretreatment step: pressing the glass mat with a hydraulic press to obtain a pretreated glass mat, spraying glass paint on the surface of the extruded blank to obtain a pretreated blank; Blank heating step: placing the pre-treated blank in an electric heating furnace for heating, and then subjecting the pre-treated blank to rapid induction heating after being taken out of the furnace to obtain a heat-treated blank; Billet extrusion steps: the billet is extruded on a horizontal extruder, lubricating oil is first applied to the pre-treated glass mat and the inner wall of the extrusion barrel, and then the glass mat is preheated and placed in the extrusion barrel, the heat-treated billet is rolled on the roller coating powder for 1 to 3 circles and then placed in the extrusion barrel for extrusion, and the extruded profile is air-cooled or rapidly water-cooled to obtain a TA2 alloy thin-walled profile; wherein, the extrusion ratio is 8 to 40, and the extrusion rate is 50 to 250 mm / s; Profile straightening steps: Use a clamp to fix the two ends of the TA2 alloy thin-walled profile on the clamping end of the straightening machine; after the TA2 alloy thin-walled profile is electrically heated, the first straightening is carried out, the heating rate is 30~100℃ / min, the straightening temperature is 450℃~850℃, and the straightening stretching amount is 2~8%; when the profile is cooled to 50~250℃ on the straightening machine, the second straightening is carried out, and the stretching amount of the second straightening is 1~5%.

2. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the pretreatment step, the pressing force of the glass mat is 5-10 MPa and the thickness is 10-30 mm; the extruded blank is heated to 50-350° C. before spraying the glass coating, and the spraying thickness is 0.1-1.8 mm.

3. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the billet extrusion step, lubricating oil is applied to the pre-treated glass mat and the inner wall of the extrusion cylinder with a thickness of 0.5 to 3 mm.

4. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the billet heating step, the charging temperature of the pre-treated billet is 600~850℃, the heating temperature of the electric heating furnace is 750~1050℃, and the insulation time is 2~6h; the induction heating temperature is 800℃~1100℃.

5. The method for preparing a TA2 alloy thin-walled profile according to claim 4, characterized in that: In the billet heating step, the induction heating temperature is 50-100°C higher than the heating furnace heating temperature.

6. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the billet extrusion step, the extrusion mold and the glass pad are preheated at a temperature of 150-400°C.

7. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the billet extrusion step, the horizontal extruder is a 45MN horizontal extruder.

8. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the extrusion billet preparation step, the end surface of the extrusion billet is chamfered, and the chamfer is R10~R50mm.

9. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: In the extrusion billet preparation step, the extrusion billet processing size is φ185×200~600mm or φ215×200~600mm.

10. The method for preparing a TA2 alloy thin-walled profile according to claim 1, characterized in that: The main components of glass mats, glass coatings and roller coating powders include SiO2, B2O3, Al2O3, MgO, TiO2, CaO, Na2CO3, PbO, Na2O and K2O.

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