A die and process for producing titanium alloy cylinder forgings

Abstract

A die for producing titanium alloy cylinder forgings comprises an upper die, a lower die and a heat-resistant bearing base, wherein the upper die is arranged above the lower die, the lower die is fixedly arranged on the heat-resistant bearing base, the cross section of the upper die is T-shaped, a first through groove is arranged in the lower die, a stop is arranged at the lower end of the first through groove, the upper end surface of the stop is a conical surface, a second through groove is arranged in the heat-resistant bearing base, and the upper die is coaxially arranged with the first through groove and the second through groove. The present invention can utilize the latter forging blank to extrude the former forging, and then after the forging is formed, the forging can be directly taken out from the second through groove of the heat-resistant base, thereby eliminating the ejection device, reducing the friction between the forging and the working surface of the lower die, increasing the surface quality of the forging, reducing the wear of the working surface of the lower die, and realizing the continuous and stable production of the isothermal forging of the cylinder, thereby improving the production efficiency.

Description

Technical Field

[0001] The invention relates to the field of metallurgy, in particular to the field of isothermal forging, and in particular to a die and a process method for producing titanium alloy cylinder forgings. Background Art

[0002] At present, the main methods for producing titanium alloy thin-walled hollow cylinders on the market are wire threading cold processing, hot extrusion or hot rolling. CN101244507A discloses a method for producing a thin-walled pressure-resistant cylinder by subjecting a TC4 titanium alloy ingot to blanking, two-phase zone forging, recrystallization annealing, external surface processing, nondestructive testing, wire threading hole processing, and electrospark cutting of the inner circle; CN101733641A discloses a method for producing a large-diameter seamless titanium alloy cylinder by vacuum melting and casting a large-diameter titanium alloy cylinder blank, hot isostatic pressing, machining, multi-pass strong spinning, and subsequent processing. Isothermal forging is commonly used for titanium alloy forgings. At present, the isothermal forging method is used to produce titanium alloy cylinder forgings, and an ejector device needs to be designed to eject the forgings from the lower die after forging is completed. However, in this way, the forgings need to undergo two sliding frictions with the working surface of the lower die, resulting in low surface quality of the forgings and severe wear of the working surface of the die, which is not conducive to stable production. Moreover, after the forgings are produced, cone-shaped flash is easily generated, resulting in a reduced yield rate. Summary of the invention

[0003] The purpose of the present invention is to provide a mold and a process method for producing titanium alloy cylinder forgings. The mold and process method for producing titanium alloy cylinder forgings are intended to solve the technical problems of low surface quality of forgings produced by isothermal forging dies in the prior art and severe wear of the die working surface.

[0004] The present invention discloses a mold for producing titanium alloy cylinder forgings, comprising an upper mold, a lower mold and a heat-resistant load-bearing base, wherein the upper mold is arranged above the lower mold, and the lower mold is fixedly arranged on the heat-resistant load-bearing base, the cross-section of the upper mold is T-shaped, a first through groove is arranged in the lower mold, a stop is arranged at the lower end of the first through groove, and the upper end surface of the stop is a conical surface, a second through groove is arranged in the heat-resistant load-bearing base, and the upper mold and the first through groove and the second through groove are all coaxially arranged.

[0005] Furthermore, the diameter of the second through groove is greater than or equal to the inner diameter of the stop.

[0006] A process for producing a titanium alloy cylinder forging using the mold of the present invention comprises the following steps:

[0007] Step 10: Installation: Install the mold on the hydraulic press, the upper mold is fixedly connected to the upper slider of the hydraulic press, the heat-resistant bearing base is fixedly connected to the lower base of the hydraulic press, the lower mold is fixed on the heat-resistant bearing base, and the upper mold and the lower mold are placed in the mold heating furnace;

[0008] Step 20: Raw material preparation: preparing annular preforms, including a first preform and a second preform;

[0009] Step 30: Heating: Apply lubricant to the surfaces of the first preform and the second preform, and place them in a heating furnace for heating and heat preservation after drying. The heat preservation time T1 (minutes) = (0.4-1) × D1 (mm), where D1 is the outer diameter of the preform;

[0010] Step 40: Forging: preheat the mold through the mold heating furnace, transfer the first preform into the mold, start the hydraulic press, and the upper slider of the hydraulic press drives the upper mold to forge the first preform. When the working surface of the upper mold is pressed to the upper end of the cone surface of the lower mold, the upper mold is depressurized and returns; graphite powder is evenly sprinkled on the upper surface of the first preform, and the second preform is transferred into the mold and placed on the graphite powder. The forging process of the first preform is repeated. The upper mold and the lower mold are coaxial with the first preform and the second preform. The upper slider of the hydraulic press drives the upper mold to extrude the first preform and the second preform. The first preform is extruded by the pressure of the upper mold, so that the first preform is formed at the stop of the lower mold and flows into the heat-resistant bearing base and stays in the heat-resistant bearing base. The forged product is a thin-walled hollow cylindrical forging, and the above forging process is repeated later;

[0011] Step 50: Removal: After the first preform is forged into a cylindrical forging, the upper die is retracted, the first cylindrical forging is naturally separated from the second preform, and then the first cylindrical forging is pushed out from the second through groove of the heat-resistant bearing base to achieve the removal of the forging, and the forging removal process is repeated subsequently.

[0012] Furthermore, the annular preform is obtained by forging and finishing a cylindrical blank.

[0013] Furthermore, the specifications of the cylindrical blank are that the diameter is greater than Φ20mm and the height is greater than 20mm, and the specifications of the annular preform are that the outer diameter is greater than Φ30mm, the inner diameter is less than Φ10mm, and the height is greater than 20mm.

[0014] Furthermore, after the titanium alloy preform is heated to the forging temperature and kept warm, it is placed in a mold kept at the same forging temperature and subjected to continuous superplastic isothermal forging.

[0015] Compared with the prior art, the present invention has positive and obvious effects, which are mainly reflected in:

[0016] 1. The superplastic isothermal forging method is used to continuously produce titanium alloy cylinder forgings, which has the advantages of fewer processes, light weight, high strength, good performance and low manufacturing cost.

[0017] 2. The forgings produced are stable in shape and easy to separate.

[0018] 3. The second preform is both an auxiliary material for the forming of the previous cylinder forging and a blank for the forming of the next cylinder forging (the second preform). Therefore, the blank of the next forging can be used to extrude the previous forging. After the forging is formed, the forging can be directly taken out from the second through groove of the heat-resistant base, thereby eliminating the ejector device, reducing the friction between the forging and the working surface of the lower die, increasing the quality of the forging surface, reducing the wear of the working surface of the lower die, and realizing continuous and stable production of isothermal forging of the cylinder, thereby improving production efficiency.

[0019] 4. After the production of the cylindrical forging, there is no cone-shaped flash, which improves the yield rate and material utilization rate.

[0020] 5. It has high quality performance, uniform structure, complex shape and no residual stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic diagram of the assembly structure of a die and a process method for producing a titanium alloy cylinder forging.

[0022] Figure 2 The first production process schematic diagram of a mold and process method for producing titanium alloy cylinder forgings of the present invention.

[0023] Figure 3 It is a schematic diagram of the second production process of a mold and process method for producing titanium alloy cylinder forgings of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the embodiments, and all similar structures and similar variations of the present invention should be included in the protection scope of the present invention. The use of directions such as up, down, front, back, left, and right in the present invention is only for the convenience of description and is not a limitation on the technical solution of the present invention. Example

[0025] like Figure 1 As shown, a mold for producing titanium alloy cylinder forgings of the present invention comprises an upper mold 1, a lower mold 2 and a heat-resistant bearing base 3, the upper mold 1 is arranged above the lower mold 2, the lower mold 2 is fixedly arranged on the heat-resistant bearing base 3, the cross-section of the upper mold 1 is T-shaped, a first through groove 4 is arranged in the lower mold 2, a stop 5 is arranged at the lower end of the first through groove 4, the upper end surface of the stop 5 is a conical surface 6, a second through groove 7 is arranged in the heat-resistant bearing base 3, and the upper mold 1 and the first through groove 4 and the second through groove 7 are all coaxially arranged.

[0026] Furthermore, the diameter of the second through groove 7 is greater than or equal to the inner diameter of the stop 5 .

[0027] Furthermore, the angle formed by the conical surface 6 and the horizontal plane is 25°~75°.

[0028] like Figure 1 , Figure 2 and Figure 3 As shown, a process for producing a titanium alloy cylinder forging using the mold of the present invention comprises the following steps:

[0029] Step 10: Installation: The mold is installed on the hydraulic press, the upper mold 1 is fixedly connected to the upper slider of the hydraulic press, the heat-resistant bearing base 3 is fixedly connected to the lower base of the hydraulic press, the lower mold 2 is fixed on the heat-resistant bearing base 3, and the upper mold 1 and the lower mold 2 are placed in the mold heating furnace 12;

[0030] Step 20: Raw material preparation: preparing annular preforms, including a first preform 8 and a second preform 9;

[0031] Step 30: Heating: Apply lubricant to the surface of the first preform 8 and the second preform 9, and place them in a heating furnace for heating and heat preservation after drying. The heat preservation time T1 (minutes) = (0.4-1) × D1 (mm), where D1 is the outer diameter of the preform;

[0032] Step 40: Forging: The mold is preheated by the mold heating furnace 12, and the first preform 8 is transferred into the mold. The hydraulic press starts to work, and the upper slide of the hydraulic press drives the upper mold 1 to forge the first preform 8. When the working surface of the upper mold 1 is pressed to the upper end of the conical surface of the lower mold 2, the state is achieved as shown in FIG. Figure 2 After reaching the position shown in the figure, the upper mold 1 is depressurized and returns; Figure 2 As shown, a small amount of graphite powder 10 is evenly sprinkled on the upper surface of the first preform 8, the second preform 9 is transferred into the mold and placed above the graphite powder 10, and the forging process of the first preform 8 is repeated. The upper mold 1 and the lower mold 2 are coaxial with the first preform 8 and the second preform 9, and the temperature of the preform and the mold are close. The upper slider of the hydraulic press drives the upper mold 1 to extrude the first preform 8 and the second preform 9. The first preform 8 is extruded by the pressure of the upper mold 1, so that the first preform 8 is formed at the stop 5 of the lower mold 2 and flows into the heat-resistant bearing base 3 and stays in the heat-resistant bearing base 3. The forged product is a thin-walled hollow cylindrical forging 11, and the above forging process is repeated later;

[0033] Step 50: Removal: After the first preform 8 is forged into the cylindrical forging 11, the upper die 1 is retracted, the first cylindrical forging 11 is naturally separated from the second preform 9, and then the first cylindrical forging 11 is pushed out from the second through groove 7 of the heat-resistant load-bearing base 3 to achieve the removal of the forging, and the forging removal process is repeated subsequently.

[0034] Furthermore, the annular preform is obtained by forging and finishing a cylindrical blank.

[0035] Furthermore, the specifications of the cylindrical blank are that the diameter is greater than Φ20mm and the height is greater than 20mm, and the specifications of the annular preform are that the outer diameter is greater than Φ30mm, the inner diameter is less than Φ10mm, and the height is greater than 20mm.

[0036] Furthermore, after the titanium alloy preform is heated to the forging temperature and kept warm, it is placed in a mold kept at the same forging temperature and subjected to continuous superplastic isothermal forging.

[0037] Specifically, the mold heating furnace 12, lubricant, graphite powder 10, hydraulic press, etc. in this embodiment all adopt well-known solutions in the prior art, which are well known to those skilled in the art and will not be described in detail here.

[0038] Compared with the existing process methods and molds, the present invention has significant improvements, mainly reflected in:

[0039] 1. The superplastic isothermal forging method is used to continuously produce titanium alloy cylinder forgings, which has the advantages of fewer processes, light weight, high strength, good performance and low manufacturing cost.

[0040] 2. The forgings produced are stable in shape and easy to separate.

[0041] 3. The second preform 9 is both an auxiliary material for forming the previous cylinder forging and a blank for forming the next cylinder forging (the second preform 9). Therefore, the blank of the next forging can be used to extrude the previous forging. Then, after the forging is formed, the forging can be directly taken out from the second through groove 7 of the heat-resistant bearing base 3, thereby eliminating the ejection device, reducing the friction between the forging and the working surface of the lower die 2, increasing the quality of the forging surface, reducing the wear of the working surface of the lower die 2, and realizing continuous and stable production of isothermal forging of the cylinder, thereby improving production efficiency.

[0042] 4. After the production of the cylindrical forging, there is no cone-shaped flash, which improves the yield rate and material utilization rate.

[0043] 5. It has high quality performance, uniform structure, complex shape and no residual stress.

Claims

1. A process for producing titanium alloy cylinder forgings, It is characterized in that The following steps are involved: Step 10: Installation: Install the mold on the hydraulic press, the upper mold is fixedly connected to the upper slider of the hydraulic press, the heat-resistant bearing base is fixedly connected to the lower base of the hydraulic press, the lower mold is fixed on the heat-resistant bearing base, and the upper mold and the lower mold are placed in the mold heating furnace; Step 20: Raw material preparation: preparing annular preforms, including a first preform and a second preform; Step 30: Heating: Apply lubricant to the surfaces of the first preform and the second preform, place them in a heating furnace for heating and heat preservation after drying, and the heat preservation time is T1 = (0.4-1) × D1, T1 is in minutes, and D1 is the outer diameter of the preform in mm; Step 40: Forging: preheat the mold through the mold heating furnace, transfer the first preform into the mold, start the hydraulic press, and the upper slider of the hydraulic press drives the upper mold to forge the first preform. When the working surface of the upper mold is pressed to the upper end of the cone surface of the lower mold, the upper mold is depressurized and returns; graphite powder is evenly sprinkled on the upper surface of the first preform, and the second preform is transferred into the mold and placed on the graphite powder. The forging process of the first preform is repeated. The upper mold and the lower mold are coaxial with the first preform and the second preform. The upper slider of the hydraulic press drives the upper mold to extrude the first preform and the second preform. The first preform is squeezed by the pressure of the upper mold, so that the first preform is formed at the stop of the lower mold and flows into the heat-resistant bearing base and stays in the heat-resistant bearing base. The forged product is a thin-walled hollow cylindrical forging, and the above forging process is repeated later; Step 50: Removal: After the first preform is forged into a cylindrical forging, the upper die is retracted, the first cylindrical forging is naturally separated from the second preform, and then the first cylindrical forging is pushed out from the second through groove of the heat-resistant bearing base to achieve the removal of the forging, and the forging removal process is repeated subsequently.

2. A process for producing a titanium alloy cylinder forging according to claim 1, It is characterized in that The annular preform described in step 20 is obtained by forging and finishing a cylindrical blank.

3. A process for producing a titanium alloy cylinder forging according to claim 2, It is characterized in that The specifications of the cylindrical blank are that the diameter is greater than Φ20mm and the height is greater than 20mm, and the specifications of the annular preform are that the outer diameter is greater than Φ30mm, the inner diameter is less than Φ10mm, and the height is greater than 20mm.

4. A process for producing a titanium alloy cylinder forging according to claim 1, It is characterized in that In step 40, the titanium alloy preform is heated to the forging temperature and kept warm, and then placed in a mold kept warm at the same forging temperature for continuous superplastic isothermal forging.

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