Manufacturing method of titanium alloy forge piece with steps on one side

Abstract

The invention relates to a manufacturing method of a single-side stepped titanium alloy forge piece, belongs to the technical field of metal forging processing, and solves the problem that the cost increase caused by excessive dressing and overlarge corner collapse cannot be effectively reduced by the existing manufacturing method of the single-side stepped titanium alloy forge piece. The method comprises the steps that the blanking specification is determined according to the weight of a forge piece and the maximum sectional area, blanking is conducted according to the blanking specification, and a bar blank is obtained; an upsetting tool is used for conducting variable cross-section upsetting on the rectangular blank in the length direction, and a big-end-down trapezoidal blank is obtained; the trapezoidal blank is placed on a lower flat anvil, and the bottom face of the trapezoidal blank is attached to the lower flat anvil; according to the step size, an impressing and distributing tool is used for pressing a distributing mark on the top face of the trapezoidal blank, and the distributing mark divides the trapezoidal blank into a main body area and a target area; forging equipment is used for driving the upper flat anvil to forge the target area, the target area is pressed downwards to form a step, and an intermediate billet is obtained; and drawing out the main body area by using a drawing-out tool to obtain a freely-forged forge piece.

Description

Technical Field

[0001] The invention belongs to the technical field of metal forging processing, and in particular relates to a method for manufacturing a single-side step titanium alloy forging. Background Art

[0002] Titanium alloys have unique performance characteristics such as high strength, low density and good corrosion resistance, and are widely used in the aerospace field. In order to quickly obtain titanium alloy products to test the rationality of product design and the reliability of performance, titanium alloy parts are often processed by free forging.

[0003] The design of traditional free forgings is generally based on the envelope of the maximum outer contour of the part, and the outer dimensions are simple cuboids. This method has a low material utilization rate for forgings. In order to improve the material utilization rate of forgings, a single-side step is often designed for the forgings according to the part structure. At present, during the forging process of single-side step forgings, such as Figure 1 As shown, the square forging blank 1 is usually placed on the lower anvil 2 first, and then the upper anvil 3 is used to forge the local edge position of the square forging blank 1 (that is, the part corresponding to the step). In this process, because the bottom surface of the square forging blank 1 is fully fitted with the lower anvil 2, and the upper anvil 3 can only act on a partial area of ​​the upper surface of the square forging blank 1, the speed of the metal in the area forged by the upper anvil 3 flowing toward the periphery is greater than that of the bottom metal, so the edge of the step will protrude outward from the bottom edge of the square forging blank 1, and the protruding distance is defined as ΔS. However, the shortest size is usually used to determine whether a part can be processed, so the square forging blank 1 after the step is processed is determined by its bottom edge as a reference, so the part of the step edge protruding from the bottom edge will be regarded as a dressing 4. Although it can be eliminated by cutting in the subsequent processing, it will cause material waste and increase the cost of forgings.

[0004] In addition, in the prior art, an upper flat anvil 3 is usually used to directly forge a local edge position of the square forging blank 1. Although a step can be forged, due to the rigid and adhesive effects of the metal, a larger collapsed angle 5 will be formed at the position where the upper surface of the square forging blank 1 meets the step when the upper flat anvil 3 is forged, and the collapsed angle 5 increases with the increase of the step height. Of course, the collapsed angle 5 can be compensated by the forging process. However, the larger the collapsed angle 5, the more corresponding materials are required to compensate, which will also increase the cost of the forging.

[0005] The current method for manufacturing single-sided step titanium alloy forgings cannot effectively reduce the forging costs caused by the above two reasons. Based on this, a more reasonable and low-cost method for manufacturing single-sided step titanium alloy forgings is urgently needed. Summary of the invention

[0006] The present invention provides a method for manufacturing a single-side step titanium alloy forging, which is used to solve the technical problem that the current method for manufacturing a single-side step titanium alloy forging cannot effectively reduce the increased forging cost caused by excessive dressing and excessive collapse angle.

[0007] The present invention is achieved through the following technical solution: A method for manufacturing a single-side step titanium alloy forging, comprising:

[0008] Step 1: Determine the blanking specifications according to the weight and maximum cross-sectional area of ​​the forging, and blank the forging according to the blanking specifications to obtain a bar blank;

[0009] Step 2: Using a drawing tool to draw the rod blank to obtain a rectangular blank;

[0010] Step 3: using an upsetting tool to perform variable-section upsetting on the rectangular blank along its length direction to obtain a trapezoidal blank with a small top and a large bottom;

[0011] Step 4: placing the trapezoidal blank on a lower flat anvil so that the bottom surface of the trapezoidal blank is in contact with the lower flat anvil;

[0012] Step 5: according to the step size, using a stamping material dividing tool to press out a material dividing mark on the top surface of the trapezoidal blank, wherein the material dividing mark divides the trapezoidal blank into a main body area and a target area;

[0013] Step 6: Using a forging device to drive an upper flat anvil to forge the target area, so that the target area is pressed down to form a step, thereby obtaining an intermediate billet;

[0014] Step 7: Utilize a drawing tool to draw the main body region to obtain a free forged forging.

[0015] Further, in order to better implement the present invention, in the step 1, the weight of the rod blank is M, and the diameter of the rod blank is D;

[0016] 1.05m≤M≤1.3m, where m is the weight of the forging;

[0017] 1.1s≤S≤1.5s, where s is the maximum cross-sectional area of ​​the forging, and S=ΠD2 / 4.

[0018] Further, in order to better implement the present invention, in the step 3, the bottom angle of the trapezoidal blank is α, 3°≤α≤10°;

[0019] The height of the trapezoidal blank is H, h+20mm≤H≤h+40mm, wherein h is the total height of the forging;

[0020] The horizontal distance between the upper base and the lower base of the trapezoidal blank on one side is L, where L=ΔS.

[0021] Furthermore, in order to better implement the present invention, there is a positive correlation between the bottom angle α of the trapezoidal blank and the height H of the trapezoidal blank.

[0022] Furthermore, in order to better implement the present invention, in step 5, the depth of the material dividing mark is t, 20mm≤t≤40mm.

[0023] Furthermore, in order to better implement the present invention, there is a positive correlation between the depth t of the material dividing mark and the height H of the trapezoidal blank.

[0024] Furthermore, in order to better realize the present invention, the stamping material dividing tool is a conical structure with a larger top and a smaller bottom, and the corners between the bottom end surface and the side surface of the stamping material dividing tool are provided with rounded corners;

[0025] The radius of the fillet is r, 8mm≤r≤15mm;

[0026] The width of the stamping material dividing tool is W, 30mm≤W≤60mm;

[0027] The inclination angle of the side surface of the stamping material dividing tool is β, 2°≤β≤3°.

[0028] Furthermore, in order to better realize the present invention, in the process of obtaining the intermediate billet in step 6, if the step depth is greater than the depth of the dividing mark, the target area is forged multiple times using the upper flat anvil, and before each forging, the stamping dividing tool is used to press out an mark at the location where the step meets the main part.

[0029] Furthermore, in order to better realize the present invention, the rod material is heated to 30-70° below the phase change point by an electric furnace before being drawn, the rectangular blank is heated before being upsetting, the trapezoidal blank is heated before being embossed with powder, and the intermediate blank is heated before being drawn, and the heating time is calculated as 0.3-1.1 min / mm.

[0030] Furthermore, in order to better realize the present invention, the drawing tool, the upsetting tool, the upper flat anvil, the lower flat anvil and the pressing and dividing tool are all preheated by a natural gas furnace before use, and the preheating time is not less than 10 hours, so that the temperature of the drawing tool, the upsetting tool, the upper flat anvil, the lower flat anvil and the pressing and dividing tool is not lower than 200°C when in use.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The manufacturing method of a single-side step titanium alloy forging provided by the present invention comprises the following steps: determining the blanking specifications according to the weight and the maximum cross-sectional area of ​​the forging, and blanking according to the blanking specifications to obtain a rod blank; using an upsetting tool to perform variable-section upsetting on a rectangular blank along its length direction to obtain a trapezoidal blank with a small upper portion and a large lower portion; placing the trapezoidal blank on a lower flat anvil so that the bottom surface of the trapezoidal blank is in contact with the lower flat anvil; according to the step size, using a stamping dividing tool to press a dividing mark on the top surface of the trapezoidal blank, the dividing mark dividing the trapezoidal blank into a main body area and a target area; using a forging device to drive the upper flat anvil to forge the target area so that the target area is pressed downward to form a step to obtain an intermediate blank; using a drawing tool to draw the main body area to obtain a free forged forging.

[0033] In the above method, the rectangular billet forged into a single-side step forging is subjected to variable-section upsetting to form a trapezoidal billet with a small upper part and a large lower part. In this way, when the target area is forged using the upper flat anvil, the metal in the target area continuously flows toward the side edge, so that the upper edge of the step continuously extends outward, thereby making the upper edge of the step continuously approach the lower edge of the step in the horizontal direction. By reasonably setting the size of the trapezoidal billet, when the step is formed, its upper edge coincides with the lower edge. In this way, the bulge formed on the side is smaller, thereby reducing unnecessary dressings and reducing costs to a great extent. Furthermore, in this method, Before forging the target area on the flat anvil, a dividing mark is pressed on the top surface of the trapezoidal blank by a stamping dividing tool. The dividing mark divides the trapezoidal blank into a main area and a target area. Since the contact area between the stamping dividing tool and the top surface of the trapezoidal blank is smaller, it can quickly sink into the top surface of the trapezoidal blank and cut the top surface of the trapezoidal blank apart. Although a certain collapse angle will still be formed at the separated part due to the rigid adhesion of the metal, the collapse angle is smaller than that formed by direct forging. In this way, less material is used to make up for the collapse angle in subsequent processing, thereby saving more material for forgings and further reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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 described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a schematic diagram of the structure when a conventional square forging blank in the background art is processed into a single-side step;

[0036] Figure 2 It is a schematic structural diagram of a forging produced by the method for manufacturing a single-side step titanium alloy forging provided by an embodiment of the present invention;

[0037] Figure 3 is a schematic structural diagram of a trapezoidal billet described in an embodiment of the present invention;

[0038] Figure 4 It is a structural schematic diagram of the stamping material separation tooling described in an embodiment of the present invention;

[0039] Figure 5 Schematic diagram of the structure of the stamping and material separation process described in the embodiment of the present invention;

[0040] Figure 6 is a schematic structural diagram of the upper flat anvil forging target area described in an embodiment of the present invention;

[0041] Figure 7 It is a flow chart of a method for manufacturing a single-side step titanium alloy forging provided in an embodiment of the present invention.

[0042] In the figure:

[0043] 1-square forging blank, 2-lower flat anvil, 3-upper flat anvil, 4-dressing, 5-sag angle;

[0044] 100-forgings, 200-trapezoidal billets, 300-stamping dividing tooling. DETAILED DESCRIPTION

[0045] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0046] Example:

[0047] The manufacturing method of the single-side step titanium alloy forging provided in this embodiment is as follows Figure 7 As shown, it includes:

[0048] Step 1: According to the forging 100 (such as Figure 2 The weight of the forging 100 and the maximum cross-sectional area are determined according to the blanking specifications, and blanking is performed according to the blanking specifications to obtain a bar blank. In this step, the weight of the forging 100 is defined as m, the maximum cross-sectional area of ​​the forging 100 is defined as s, the diameter of the bar is defined as D, the cross-sectional area of ​​the bar is defined as S=ΠD2 / 4, the weight of the bar is defined as M, and considering the control error of the forming process of the free forging 100 and the bulging dressing 4, etc., as well as the deformation during the forming process, 1.05m≤M≤1.3m, 1.1s≤S≤1.5s.

[0049] Step 2: Use the drawing tool to draw the rod blank to obtain a rectangular blank. Before this process, the drawing tool needs to be preheated. The preheating method is to heat it with a natural gas furnace for no less than 10 hours, and ensure that the temperature of the drawing tool is not less than 200°C when in use. Before the bar is drawn, use an electric furnace to heat it to 30-70° below the phase change point, and the heating time is calculated according to 0.3-1.1min / mm.

[0050] Step 3: Use an upsetting tool to perform variable-section upsetting on the rectangular blank along its length direction to obtain a trapezoidal blank 200 (such as Figure 3 As shown). Before this process, the upsetting tool needs to be preheated. The preheating method is to use a natural gas furnace to heat it for no less than 10 hours, and ensure that the temperature of the upsetting tool is not less than 200°C when in use. Before upsetting, the rectangular billet is heated in an electric furnace to 30-70° below the phase change point, and the heating time is calculated according to 0.3-1.1min / mm.

[0051] The bottom angle of the trapezoidal blank 200 obtained by this step is defined as α, 3°≤α≤10°, and optionally, the value of α can be 3°, 4°, 5°, 6°, 7°, 8°, 9°, 10°, etc.

[0052] The height of the trapezoidal blank 200 is defined as H, h+20 mm≤H≤h+40 mm, wherein h is the total height of the forging 100, and optionally, the value of H may be h+20 mm, h+25 mm, h+30 mm, h+35 mm, h+40 mm, etc.;

[0053] The horizontal distance between the upper and lower bottoms of the trapezoidal blank 200 on one side is defined as L, where L=ΔS, wherein ΔS is the protruding distance of the step edge portion protruding outward from the bottom edge of the square forging blank 1 during forging by the prior art method in the background art. In this way, when the step forging is completed, the top edge of the step is flush with the bottom edge.

[0054] More preferably, the bottom angle α of the trapezoidal blank 200 in this embodiment is positively correlated with the height H of the trapezoidal blank 200. The larger the height H of the trapezoidal blank 200, that is, the thicker the trapezoidal blank 200, the larger the bottom angle α of the trapezoidal blank 200. On the contrary, the smaller the height of the trapezoidal blank 200, the smaller the bottom angle α.

[0055] Step 4: Place the trapezoidal blank 200 on the lower flat anvil 2 so that the bottom surface of the trapezoidal blank 200 is in contact with the lower flat anvil 2. Of course, the lower flat anvil 2 can also be preheated in advance by heating it in a natural gas furnace for not less than 10 hours, and ensuring that the temperature of the drawing tool is not less than 200°C when in use.

[0056] Step 5: According to the step size, use the stamping material dividing tool 300 (such as Figure 4 As shown in FIG. 1 , a material dividing mark is pressed on the top surface of the trapezoidal blank 200, and the material dividing mark separates the trapezoidal blank 200 into a main body area and a target area. Figure 5 Before the process is carried out, the stamping and dividing tool 300 needs to be preheated by heating it in a natural gas furnace for not less than 10 hours, and the temperature of the stamping and dividing tool 300 is ensured to be not less than 200°C during use. In addition, the trapezoidal blank 200 is heated to 30-70° below the phase change point by an electric furnace before stamping and dividing the material, and the heating time is calculated as 0.3-1.1min / mm.

[0057] Optionally, the stamping material distributor 300 has a tapered structure with a larger top and a smaller bottom, and the corners between the bottom end face and the side face of the stamping material distributor 300 are provided with rounded corners, so that the stamping material distributor 300 can easily cut into the top surface of the trapezoidal blank 200. When in use, the stamping material distributor 300 is driven downward by a press or forging equipment to press out an impression on the top surface of the trapezoidal blank 200, and the depth of the impression is defined as t, 20mm≤t≤40mm, and specifically, the value of t can be 20mm, 25mm, 30mm, 35mm, 40mm, etc. Moreover, the depth t of the impression is positively correlated with the height H of the trapezoidal blank 200, that is, the depth of the impression increases with the increase of the thickness of the trapezoidal blank 200, or the depth of the impression decreases with the decrease of the thickness of the trapezoidal blank 200.

[0058] The radius of the fillet is defined as r, 8mm≤r≤15mm. Specifically, the value of r can be 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc.

[0059] The width of the stamping material dividing tool 300 is defined as W, 30 mm ≤ W ≤ 60 mm. Specifically, the value of W can be 30 mm, 40 mm, 50 mm, 60 mm, etc.

[0060] The inclination angle of the side surface of the stamping material dividing tool 300 is defined as β, 2°≤β≤3°. Specifically, the value of β can be 2°, 2.5°, 3°, etc.

[0061] Step 6: Use the forging equipment to drive the upper anvil 3 to forge the target area, as follows: Figure 6As shown, the target area is pressed down to form a step to obtain an intermediate billet. Before this step, the upper flat anvil 3 needs to be preheated by heating it in a natural gas furnace for not less than 10 hours, and the temperature of the upper flat anvil 3 is not less than 200°C when in use. Before forging the step, the trapezoidal billet 200 is heated in an electric furnace to 30-70° below the phase change point, and the heating time is calculated according to 0.3-1.1min / mm.

[0062] Because the stamping and dividing tool 300 has been used to press the dividing mark on the top surface of the trapezoidal blank 200 beforehand, when the upper flat anvil 3 forges the step, the collapse angle 5 of the main part near the step is smaller. If the depth of the step is greater than the depth of the dividing mark, the upper flat anvil 3 is used to forge the target area multiple times, and before each forging, the stamping and dividing tool 300 is used to press the mark at the junction of the step and the main part.

[0063] In addition, if steps need to be processed on both sides of the forging 100, corresponding steps are also processed on the other side of the trapezoidal blank 200 according to the above steps 5 and 6.

[0064] Step 7: Use the drawing tool to draw the main body area to obtain the free forged forging 100. Before this process, the drawing tool needs to be preheated by heating it in a natural gas furnace for not less than 10 hours, and the temperature of the drawing tool is not less than 200°C when in use, and the intermediate skin is heated to 30-70° below the phase change point by an electric furnace before drawing, and the heating time is calculated according to 0.3-1.1min / mm.

[0065] The height of the main part of the intermediate blank is the same as that of the trapezoidal blank 200, which is still H. The intermediate blank is stretched and thickened using a stretching tool so that the height of the main part of the intermediate blank is reduced to h. During the stretching process, the edge collapse angle 5 of the main part can also be repaired.

[0066] If necessary, the bulging dressing 4 at the edge of the forging 100 can be cut off.

[0067] In the above method, the rectangular blank forged into a single-side step forging 100 is subjected to variable-section upsetting to be formed into a trapezoidal blank 200 with a small upper part and a large lower part. In this way, when the upper flat anvil 3 is used to forge the target area, the metal in the target area continuously flows toward the side edge, so that the upper edge of the step continuously extends outward, so that the upper edge of the step continuously approaches the lower edge of the step in the horizontal direction. By reasonably setting the size of the trapezoidal blank 200, when the step is formed, its upper edge and the lower edge coincide with each other, so that the bulge formed on the side is smaller, thereby greatly reducing unnecessary dressings 4 and reducing costs; furthermore, in this method, before the upper flat anvil 3 is used to forge the target area, the stamping material dividing tool 300 is used to stamp the trapezoidal blank 2 00 is pressed out with a dividing mark on the top surface, and the dividing mark divides the trapezoidal blank 200 into a main area and a target area. Since the contact area between the stamping dividing tool 300 and the top surface of the trapezoidal blank 200 is smaller, it can quickly sink into the top surface of the trapezoidal blank 200 to cut the top surface of the trapezoidal blank 200 apart. Although a certain collapse angle 5 will still be formed at the separated part due to the rigid adhesion of the metal, the collapse angle 5 is smaller than the collapse angle 5 directly forged in the background technology. In this way, less material is used to make up for the collapse angle 5 in subsequent processing, thereby saving more material for the forging 100 and further reducing costs. The overall deformation of the forging 100 is uniform, which improves material utilization and ensures the quality of the forging 100.

[0068] In addition, it should be noted that in order to prevent too small a deformation from causing the forging 100 to not be forged through, and too large a deformation from causing the end to crack, the forging ratio of each fire should be between 1.1-1.6, and during each forging process, the single deformation should be controlled between 10%-70%.

[0069] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for manufacturing a single-side stepped titanium alloy forging, characterized in that: include: Step 1: Determine the blanking specifications according to the weight and maximum cross-sectional area of ​​the forging, and blank the forging according to the blanking specifications to obtain a bar blank; Step 2: Using a drawing tool to draw the rod blank to obtain a rectangular blank; Step 3: using an upsetting tool to perform variable-section upsetting on the rectangular blank along its length direction to obtain a trapezoidal blank with a small top and a large bottom; Step 4: placing the trapezoidal blank on a lower flat anvil so that the bottom surface of the trapezoidal blank is in contact with the lower flat anvil; Step 5: according to the step size, using a stamping material dividing tool to press out a material dividing mark on the top surface of the trapezoidal blank, wherein the material dividing mark divides the trapezoidal blank into a main body area and a target area; Step 6: Using a forging device to drive an upper flat anvil to forge the target area, so that the target area is pressed down to form a step, and an intermediate billet is obtained; Step 7: Utilize a drawing tool to draw the main body region to obtain a free forged forging.

2. The method for manufacturing a single-side stepped titanium alloy forging according to claim 1, characterized in that: In step 1, the weight of the rod blank is M, and the diameter of the rod blank is D; 1.05m≤M≤1.3m, where m is the weight of the forging; 1.1s≤S≤1.5s, where s is the maximum cross-sectional area of ​​the forging, and S=ΠD2 / 4.

3. The method for manufacturing a single-side stepped titanium alloy forging according to claim 1, characterized in that: In step 3, the bottom angle of the trapezoidal blank is α, 3°≤α≤10°; The height of the trapezoidal blank is H, h+20mm≤H≤h+40mm, wherein h is the total height of the forging; The horizontal distance between the upper base and the lower base of the trapezoidal blank on one side is L, where L=ΔS.

4. The method for manufacturing a single-side stepped titanium alloy forging according to claim 3, characterized in that: There is a positive correlation between the bottom angle α of the trapezoidal blank and the height H of the trapezoidal blank.

5. The method for manufacturing a single-side stepped titanium alloy forging according to claim 1, characterized in that: In step 5, the depth of the material dividing mark is t, 20mm≤t≤40mm.

6. The method for manufacturing a single-side stepped titanium alloy forging according to claim 5, characterized in that: There is a positive correlation between the depth t of the material dividing mark and the height H of the trapezoidal blank.

7. The method for manufacturing a single-side stepped titanium alloy forging according to claim 5, characterized in that: The stamping material dividing tool is a conical structure with a larger top and a smaller bottom, and the corners between the bottom end surface and the side surface of the stamping material dividing tool are provided with rounded corners; The radius of the fillet is r, 8mm≤r≤15mm; The width of the stamping material dividing tool is W, 30mm≤W≤60mm; The inclination angle of the side surface of the stamping material dividing tool is β, 2°≤β≤3°.

8. The method for manufacturing a single-side stepped titanium alloy forging according to claim 5, characterized in that: In the process of obtaining the intermediate blank in step 6, if the step depth is greater than the depth of the dividing mark, the target area is forged multiple times using the upper flat anvil, and before each forging, the stamping dividing tool is used to press out an mark at the junction of the step and the main part.

9. The method for manufacturing a single-side stepped titanium alloy forging according to claim 1, characterized in that: The bar material is heated to 30-70° below the phase change point by an electric furnace before being drawn, the rectangular blank is heated to 0.3-1.1 min / mm before being upset, the trapezoidal blank is heated to 0.5-1.0° before being pressed into powder, and the intermediate blank is heated to 0.5-1.0° before being drawn.

10. The method for manufacturing a single-side stepped titanium alloy forging according to claim 9, characterized in that: The drawing tool, the upsetting tool, the upper flat anvil, the lower flat anvil and the pressing and dividing tool are all preheated using a natural gas furnace before use, and the preheating time is not less than 10 hours, so that the temperature of the drawing tool, the upsetting tool, the upper flat anvil, the lower flat anvil and the pressing and dividing tool is not lower than 200°C when in use.

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