Forming method of TC4 curved cone forgings for underwater equipment

Abstract

The present application relates to a forming method of TC4 curved cone forging for underwater equipment, comprising the following steps: blanking; chamfering; forging heating; upsetting and rounding; forging heating; spinning upsetting and punching; forging heating; mandrel hole expanding; forging heating; shaping according to part machining profile; annealing; rough machining; ultrasonic flaw detection. In the first forging, the diameter of the blank obtained by the first forging step is controlled, in the second forging, the height size and the large end diameter of the blank are controlled, and in the mandrel hole expanding of each fire, the height size, the large end size and the small end size of the forging are controlled to prevent the blank from excessively reducing the height due to the increase of the cross-section bevel angle in the mandrel hole expanding, so as to ensure that the forged forging meets the required size, and the free forging cone ring with a taper exceeding 35° is suitable for production. Compared with the traditional free forging method without size control, more than 30% of materials are saved.

Description

Technical Field

[0001] This invention relates to the field of cone forging technology, and more particularly to a forming method for TC4 cone forgings for underwater equipment. Background Technology

[0002] Unmanned underwater vehicles (UUVs) are underwater navigation devices that operate without human pilots, relying on remote or automatic control. They primarily replace divers or manned small submarines in high-risk underwater operations such as deep-sea exploration, rescue, and mine clearance. As the applications of UUVs continue to expand, higher demands are being placed on the overall strength of the equipment. The traditional method of rolling and welding plates is gradually being replaced by integral forging, thus improving the overall strength of the equipment. Significant design changes are also occurring in the dimensions of different parts, necessitating the use of large-angle conical integral forgings.

[0003] However, this type of conical shell forging has a large taper and a large size span between the large and small ends, making it difficult to achieve whether by die forging or ring rolling. Furthermore, the investment in large molds is too costly for small-batch production.

[0004] Existing technologies mainly employ a free forging + frame reaming forming method, where frame reaming is the primary means of achieving conical deformation of the billet. However, frame reaming primarily controls the wall thickness and conical angle of the forging, but cannot directly control the height of the forging. This results in significant dimensional errors in the height of forgings when producing free-forged conical rings with a taper exceeding 35°. It is difficult to simultaneously meet the set requirements for the height dimension and the dimensions of the large and small ends. Production can only be achieved by increasing the allowance and reducing the conical angle, leading to low material utilization and low yield.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention discloses a method for forming TC4 cone forgings for underwater equipment.

[0007] The technical solution adopted in this invention is as follows:

[0008] The forming method of TC4 cone forgings for underwater equipment includes the following steps:

[0009] Material feeding;

[0010] Chamfer;

[0011] The first forging step includes:

[0012] Forging heating: Load the furnace to the set temperature of 950-970℃, and calculate the holding time based on the effective thickness of 0.7 min / mm;

[0013] Determine the diameter of the billet obtained in the first forging step;

[0014] Rough and rounded;

[0015] The second forging step includes:

[0016] Forging heating: Load the furnace to the set temperature of 950-970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0017] Spinning upsetting and punching, controlling the height and large end diameter of the billet during spinning;

[0018] The third forging step includes:

[0019] Forging heating: Load the furnace to the set temperature of 950-970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0020] Frame reaming: Perform multiple reaming operations on the frame until the inclination angle of the inclined side of the forging section increases from the first angle to the second angle. After each reaming operation, control the height, large end, and small end dimensions of the forging.

[0021] The fourth forging step includes:

[0022] Forging heating: Load the furnace to the set temperature of 950-970℃, hold the cold material for 80 minutes, and hold the hot material for 60 minutes.

[0023] Shape the part according to its machining contour;

[0024] annealing;

[0025] roughing;

[0026] Ultrasonic flaw detection.

[0027] Furthermore, in the first forging step, the diameter D2 of the resulting billet satisfies the following formula:

[0028] D2 2 -d 2 =D4' 2 -d2' 2 ;

[0029] Where d is the punch size during punching, D4' is the small end outer diameter set for the forging, and d2' is the small end inner diameter set for the forging. This formula means that the small end area of ​​the billet obtained in the first forging step is equal to the small end area set for the forging.

[0030] Furthermore, in the second forging step, the large end diameter of the obtained billet satisfies the following formula:

[0031] D3 2 -d 2 =D5' 2 -d3' 2 ;

[0032] Where D5' is the outer diameter of the large end of the forging set, and d3' is the inner diameter of the large end of the forging set; this formula means that the area of ​​the large end of the billet obtained in the second forging step is equal to the area of ​​the large end set by the forging.

[0033] The height H3 of the obtained billet is calculated based on the billet volume using digital modeling software. Furthermore, in the reaming step, the steps for controlling the height, large end, and small end dimensions of the forging after each reaming operation include:

[0034] After each forging process, the following measurements are taken: forging height H4, large end inner diameter d3, large end outer diameter D5, small end inner diameter d2, small end outer diameter D4, and section hypotenuse length h4.

[0035] If h4 is less than the length of the hypotenuse of the forging section h4', or H4 is less than the height of the forging H4', then the mandrel is used to lengthen the small end of the forging to increase h4, so that h4≥h4';

[0036] If both the inner diameter d3 and the outer diameter D5 of the large end are larger than the inner diameter d3' and the outer diameter D5' of the large end set for the forging, then the large end of the forging is rounded and shaped to reduce the diameter of the large end of the forging until the inclination angle of the inclined side of the forging section is consistent with the second angle, and then the forming continues.

[0037] If the inner diameter d2 and outer diameter D4 of the small end are both greater than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then the small end of the forging is lengthened by mandrel until the inner diameter d2 and outer diameter D4 of the small end are equal to the inner diameter d2' and outer diameter D4' of the small end set in the forging, and then the small end of the forging is flattened.

[0038] If both the large end inner diameter d3 and the large end outer diameter D5 are smaller than the large end inner diameter d3' and large end outer diameter D5' set by the forging, or if both the small end inner diameter d2 and small end outer diameter D4 are smaller than the small end inner diameter d2' and small end outer diameter D4' set by the forging, or if both the large end inner diameter d3 and large end outer diameter D5 are smaller than the large end inner diameter d3' and large end outer diameter D5' set by the forging and both the small end inner diameter d2 and small end outer diameter D4 are smaller than the small end inner diameter d2' and small end outer diameter D4' set by the forging, then continue to the next firing cycle of the frame reaming.

[0039] By controlling the large end face area, large end size, small end face area, small end size, and height during forging, the height of the billet is prevented from decreasing excessively due to the increased angle of the cross-section during the reaming process, thus ensuring that the forged parts meet the required dimensions.

[0040] Furthermore, the annealing step includes:

[0041] Hold at 780-800℃ for 120-150 minutes, then air cool.

[0042] Furthermore, the ultrasonic flaw detection step includes:

[0043] According to GB / T5193-2007, Class A acceptance shall be conducted, and the diameter of a single discontinuous hole shall be <2.0 mm.

[0044] Furthermore, the first angle is 7°, and the second angle is not less than 35°.

[0045] Furthermore, the forging process involves 10-12 forging passes using a reamer, ensuring the forging temperature remains within the forging temperature range during each pass. Each reaming pass increases the inclination angle of the forging's cross-section by 2.2° to 4.0°. Because the material has high resistance to forging deformation and the forging temperature range is only 140°C, the amount of forging deformation must be strictly controlled during the forging process to prevent excessive deformation from causing the forging core to burn and resulting in scrap.

[0046] Furthermore, the weight percentage of each chemical element in the forging is as follows: Al: 5.5%-6.75%; V: 3.5%-4.5%; Fe≤0.3%; C≤0.08%; N≤0.05%; H≤0.015%; O≤0.20%; other elements alone ≤0.10%; total of other elements ≤0.40%; balance is Ti.

[0047] The beneficial effects of the embodiments of the present invention are as follows:

[0048] (I) The forming method of the TC4 conical forging for underwater equipment of the present invention includes the following steps: blanking; chamfering; forging heating; upsetting and rounding; forging heating; spinning upsetting and punching; forging heating; frame hole expansion; forging heating; shaping according to the machining contour of the part; annealing; rough machining; ultrasonic flaw detection.

[0049] In this process, the diameter of the billet obtained in the first forging step is controlled during the first forging. The height and large end diameter of the billet are controlled during the second forging. The height, large end, and small end dimensions of the forging are controlled during each forging pass. This prevents the billet from excessively reducing its height due to the increased angle of the cross-section during forging, ensuring that the forged parts meet the required dimensions. This method is suitable for producing free forging cone rings with a taper exceeding 35°, has a high yield, and saves more than 30% of material compared to traditional free forging methods without dimensional control.

[0050] (ii) Furthermore, a multi-stage forging frame is used to expand the hole, with each stage tilted at a certain angle until the tilt angle of the forging cross-section increases from the first angle to the second angle, to prevent the forging core from burning due to excessive deformation and to ensure the performance of the forging. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the billet cutting process in the forming method of the TC4 cone forging for underwater equipment of the present invention.

[0052] Figure 2 This is a schematic diagram of the structure of the billet after upsetting and rounding in the forming method of the TC4 conical forging for underwater equipment of the present invention.

[0053] Figure 3 This is a schematic diagram of the structure of the billet after spinning, upsetting, and punching in the forming method of the TC4 cone forging for underwater equipment of the present invention.

[0054] Figure 4 This is a schematic diagram of the structure of the forging frame after hole enlargement in the forming method of the TC4 conical forging for underwater equipment of the present invention.

[0055] Figure 5 This is a schematic diagram of the forging profile in the forming method of the TC4 conical forging for underwater equipment of the present invention.

[0056] Figure 6 This is a schematic diagram of the machining profile for producing a cone forging by increasing the allowance in the first comparative example of the present invention. Detailed Implementation

[0057] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the device proposed by this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0059] First embodiment:

[0060] like Figures 1-5 As shown, the forming method of TC4 cone forgings for underwater equipment includes the following steps:

[0061] Step S1: Unload the material.

[0062] like Figure 1 As shown, specifically, select bars with a diameter conforming to GB / T 2965-2007 "Titanium and Titanium Alloy Bars". The above-mentioned round bars, after being re-inspected according to standards, are put into production only after passing the inspection. For example, D1 is 460mm and H1 is 1400mm. The weight percentage of each chemical element in the bars is as follows: Al: 5.5%–6.75%; V: 3.5%–4.5%; Fe≤0.3%; C≤0.08%; N≤0.05%; H≤0.015%; O≤0.20%; other elements alone ≤0.10%; total of other elements ≤0.40%; balance is Ti.

[0063] Step S2, chamfering.

[0064] Specifically, the radius R of the corners on both ends of the blank is 25mm.

[0065] Step S3, the first forging step, includes:

[0066] Step S31, forging heating: Load the furnace to the set temperature of 950℃, and calculate the holding time based on the effective thickness of 0.7 min / mm.

[0067] Step S32: Determine the diameter of the billet obtained in the first forging step.

[0068] Specifically, the diameter D2 of the billet obtained in the first forging step satisfies the following formula:

[0069] D2 2 -d 2 =D4' 2 -d2' 2 ;

[0070] Where d is the punch size during punching, D4' is the small end outer diameter set for the forging, and d2' is the small end inner diameter set for the forging.

[0071] Step S33: Upsetting and rounding.

[0072] like Figure 2 As shown, specifically, the upsetting and rounding are carried out to the dimensions of diameter D2 and height H2, with diameter D2 being 572mm and height H2 being 830mm.

[0073] Step S4, the second forging step, includes:

[0074] Step S41, forging heating: Load the furnace to the set temperature of 950℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0075] Step S42: Spin upsetting and punching. During spinning, control the height and large end diameter of the billet.

[0076] like Figure 3 As shown, specifically, the large end diameter D3 of the billet obtained in the second forging step satisfies the following formula:

[0077] D3 2 -d 2 =D5' 2 -d3' 2 ;

[0078] Where d is the punch size during punching, D5' is the outer diameter of the large end of the forging, and d3' is the inner diameter of the large end of the forging.

[0079] The height H3 of the obtained billet is calculated using digital modeling software based on the billet volume. Since the billet volume is the same as the forging volume, the forging volume can be calculated first using the digital modeling software. Then, this volume, along with the large end diameter D3, punch size d, and small end diameter D2, can be input to calculate the height H3. The diameter D3 is 752 mm, and the height H3 is 700 mm.

[0080] Step S5, the third forging step, includes:

[0081] Step S51, forging heating: Load the material into the furnace at the set temperature of 950℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0082] Step S52, reaming: Perform multiple reaming operations until the inclination angle of the inclined side of the forging section increases from the first angle to the second angle. After each reaming operation, control the height, large end, and small end dimensions of the forging.

[0083] like Figure 4 and Figure 5 As shown, specifically, the small end outer diameter D4' of the forging is set to 936±10mm, the small end inner diameter d2' is set to 710±10mm, the large end outer diameter D5' is set to 1756±10mm, the large end inner diameter d3' is set to 1530±10mm, and the forging height H4' is set to 470±8mm. The first angle is 7°, and the second angle is 41°. Ten passes of forging are performed using a reaming machine, ensuring the forging temperature remains within the forging temperature range during each pass. Each reaming pass increases the inclination angle of the forging cross-section by 2.2° to 4.0°.

[0084] In the reaming process, the steps for controlling the height, large end, and small end dimensions of the forging after each reaming operation include:

[0085] Step S521: After each forging process, measure the forging height H4, large end inner diameter d3, large end outer diameter D5, small end inner diameter d2, small end outer diameter D4, and cross-sectional hypotenuse length h4. These parameters can be measured directly with a steel tape measure or using an infrared distance sensor.

[0086] In step S522, if h4 is less than the length of the inclined side of the forging section h4', or H4 is less than the height of the forging H4', then the small end of the forging is lengthened by mandrel to increase h4 so that h4≥h4'.

[0087] Step S523: If the inner diameter d3 and outer diameter D5 of the large end are both greater than the inner diameter d3' and outer diameter D5' of the large end set for the forging, then the large end of the forging is rounded and shaped to reduce the diameter of the large end of the forging until the inclination angle of the inclined side of the forging section is consistent with the second angle, and then the forming continues.

[0088] Step S524: If the inner diameter d2 and outer diameter D4 of the small end are both greater than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then the small end of the forging is lengthened by mandrel until the inner diameter d2 and outer diameter D4 of the small end are equal to the inner diameter d2' and outer diameter D4' of the small end set in the forging, and then the small end of the forging is flattened.

[0089] Step S525: If the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging, or the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, or the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging and the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then continue to perform the next firing cycle of the frame reaming.

[0090] Step S6, the fourth forging step, includes:

[0091] Step S61, forging heating: charge the furnace to the set temperature of 950℃, hold the cold material for 80 minutes, and hold the hot material for 60 minutes.

[0092] Step S62: Correct the diameter and height of the large and small ends according to the machining contour of the part.

[0093] Specifically, the outline of the part is as follows Figure 5 As shown.

[0094] Step S7, annealing.

[0095] Specifically, it is kept at 780℃ for 120 minutes and then air-cooled.

[0096] Step S8, rough machining.

[0097] Specifically, polish until the surface is shiny.

[0098] Step S9, ultrasonic flaw detection.

[0099] Specifically, Class A acceptance shall be conducted in accordance with GB / T5193-2007, with the diameter of a single discontinuous hole being <2.0mm.

[0100] Second embodiment:

[0101] like Figures 1-5 As shown, the forming method of TC4 cone forgings for underwater equipment includes the following steps:

[0102] Step S1: Unload the material.

[0103] like Figure 1 As shown, specifically, select bars with a diameter conforming to GB / T 2965-2007 "Titanium and Titanium Alloy Bars". Round bars are produced and re-inspected according to standards. Production begins only after the bars pass inspection. The weight percentage of each chemical element in the bars is as follows: Al: 5.5%–6.75%; V: 3.5%–4.5%; Fe ≤ 0.3%; C ≤ 0.08%; N ≤ 0.05%; H ≤ 0.015%; O ≤ 0.20%; other elements alone ≤ 0.10%; total other elements ≤ 0.40%; balance is Ti.

[0104] Step S2, chamfering.

[0105] Specifically, the radius R of the corners on both ends of the blank is 27mm.

[0106] Step S3, the first forging step, includes:

[0107] Step S31, forging heating: Load the furnace to the set temperature of 960℃, and calculate the holding time based on the effective thickness of 0.7 min / mm.

[0108] Step S32: Determine the diameter of the billet obtained in the first forging step.

[0109] Specifically, the diameter D2 of the billet obtained in the first forging step satisfies the following formula:

[0110] D2 2 -d 2 =D4' 2 -d2' 2 ;

[0111] Where d is the punch size during punching, D4' is the small end outer diameter set for the forging, and d2' is the small end inner diameter set for the forging.

[0112] Step S33: Upsetting and rounding.

[0113] like Figure 2 As shown, specifically, the upsetting and rounding are carried out to the dimensions of diameter D2 and height H2, with diameter D2 being 572mm and height H2 being 830mm.

[0114] Step S4, the second forging step, includes:

[0115] Step S41, forging heating: charge the furnace to the set temperature of 960℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0116] Step S42: Spin upsetting and punching. During spinning, control the height and large end diameter of the billet.

[0117] like Figure 3 As shown, specifically, the large end diameter D3 of the billet obtained in the second forging step satisfies the following formula:

[0118] D3 2 -d 2 =D5' 2 -d3' 2 ;

[0119] Where d is the punch size during punching, D5' is the outer diameter of the large end of the forging, and d3' is the inner diameter of the large end of the forging.

[0120] The height H3 of the obtained billet is calculated using digital modeling software based on the billet volume. Since the billet volume is the same as the forging volume, the forging volume can be calculated first using the digital modeling software. Then, this volume, along with the large end diameter D3, punch size d, and small end diameter D2, can be input to calculate the height H3. The diameter D3 is 752 mm, and the height H3 is 700 mm.

[0121] Step S5, the third forging step, includes:

[0122] Step S51, forging heating: charge the furnace to the set temperature of 960℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0123] Step S52, reaming: Perform multiple reaming operations until the inclination angle of the inclined side of the forging section increases from the first angle to the second angle. After each reaming operation, control the height, large end, and small end dimensions of the forging.

[0124] like Figure 4 and Figure 5 As shown, specifically, the small end outer diameter D4' of the forging is set to 936±10mm, the small end inner diameter d2' is set to 710±10mm, the large end outer diameter D5' is set to 1756±10mm, the large end inner diameter d3' is set to 1530±10mm, and the forging height H4' is set to 470±8mm. The first angle is 7°, and the second angle is 41°. Eleven passes of forging are performed using a reaming machine, ensuring the forging temperature remains within the forging temperature range during each pass. Each reaming pass increases the inclination angle of the forging cross-section by 2.2° to 4.0°.

[0125] In the reaming process, the steps for controlling the height, large end, and small end dimensions of the forging after each reaming operation include:

[0126] Step S521: After each forging process, measure the forging height H4, large end inner diameter d3, large end outer diameter D5, small end inner diameter d2, small end outer diameter D4, and cross-sectional hypotenuse length h4. These parameters can be measured directly with a steel tape measure or using an infrared distance sensor.

[0127] In step S522, if h4 is less than the length of the inclined side of the forging section h4', or H4 is less than the height of the forging H4', then the small end of the forging is lengthened by mandrel to increase h4 so that h4≥h4'.

[0128] Step S523: If the inner diameter d3 and outer diameter D5 of the large end are both greater than the inner diameter d3' and outer diameter D5' of the large end set for the forging, then the large end of the forging is rounded and shaped to reduce the diameter of the large end of the forging before continuing the forming process.

[0129] Step S524: If the inner diameter d2 and outer diameter D4 of the small end are both greater than the inner diameter d2' and outer diameter D4' of the small end set for the forging, then the small end of the forging is lengthened by mandrel and the small end of the forging is flattened.

[0130] Step S525: If the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging, or the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, or the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging and the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then continue to perform the next firing cycle of the frame reaming.

[0131] Step S6, the fourth forging step, includes:

[0132] Step S61, forging heating: charge the furnace to the set temperature of 960℃, hold the cold material for 80 minutes, and hold the hot material for 60 minutes.

[0133] Step S62: Correct the diameter and height of the large and small ends according to the machining contour of the part.

[0134] Specifically, the outline of the part is as follows Figure 5 As shown.

[0135] Step S7, annealing.

[0136] Specifically, it is kept at 790℃ for 135 minutes and then air-cooled.

[0137] Step S8, rough machining.

[0138] Specifically, polish until the surface is shiny.

[0139] Step S9, ultrasonic flaw detection.

[0140] Specifically, Class A acceptance shall be conducted in accordance with GB / T5193-2007, with the diameter of a single discontinuous hole being <2.0mm.

[0141] Third embodiment:

[0142] like Figures 1-5 As shown, the forming method of TC4 cone forgings for underwater equipment includes the following steps:

[0143] Step S1: Unload the material.

[0144] like Figure 1 As shown, specifically, select bars with a diameter conforming to GB / T 2965-2007 "Titanium and Titanium Alloy Bars". Round bars are produced and re-inspected according to standards. Production begins only after the bars pass inspection. The weight percentage of each chemical element in the bars is as follows: Al: 5.5%–6.75%; V: 3.5%–4.5%; Fe ≤ 0.3%; C ≤ 0.08%; N ≤ 0.05%; H ≤ 0.015%; O ≤ 0.20%; other elements alone ≤ 0.10%; total other elements ≤ 0.40%; balance is Ti.

[0145] Step S2, chamfering.

[0146] Specifically, the radius R of the corners on both ends of the blank is 30mm.

[0147] Step S3, the first forging step, includes:

[0148] Step S31, forging heating: Load the furnace to the set temperature of 970℃, and calculate the holding time based on the effective thickness of 0.7 min / mm.

[0149] Step S32: Determine the diameter of the billet obtained in the first forging step.

[0150] Specifically, the diameter D2 of the billet obtained in the first forging step satisfies the following formula:

[0151] D2 2 -d 2 =D4' 2 -d2' 2 ;

[0152] Where d is the punch size during punching, D4' is the small end outer diameter set for the forging, and d2' is the small end inner diameter set for the forging.

[0153] Step S33: Upsetting and rounding.

[0154] like Figure 2 As shown, specifically, the upsetting and rounding are carried out to the dimensions of diameter D2 and height H2, with diameter D2 being 572mm and height H2 being 830mm.

[0155] Step S4, the second forging step, includes:

[0156] Step S41, forging heating: Load the furnace to the set temperature of 970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0157] Step S42: Spin upsetting and punching. During spinning, control the height and large end diameter of the billet.

[0158] like Figure 3 As shown, specifically, the large end diameter D3 of the billet obtained in the second forging step satisfies the following formula:

[0159] D3 2 -d 2 =D5' 2 -d3' 2 ;

[0160] Where d is the punch size during punching, D5' is the outer diameter of the large end of the forging, and d3' is the inner diameter of the large end of the forging.

[0161] The height H3 of the obtained billet is calculated using digital modeling software based on the billet volume. Since the billet volume is the same as the forging volume, the forging volume can be calculated first using the digital modeling software. Then, this volume, along with the large end diameter D3, punch size d, and small end diameter D2, can be input to calculate the height H3. The diameter D3 is 752 mm, and the height H3 is 700 mm.

[0162] Step S5, the third forging step, includes:

[0163] Step S51, forging heating: Load the furnace to the set temperature of 970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm.

[0164] Step S52, reaming: Perform multiple reaming operations until the inclination angle of the inclined side of the forging section increases from the first angle to the second angle. After each reaming operation, control the height, large end, and small end dimensions of the forging.

[0165] like Figure 4 and Figure 5 As shown, specifically, the small end outer diameter D4' of the forging is set to 936±10mm, the small end inner diameter d2' is set to 710±10mm, the large end outer diameter D5' is set to 1756±10mm, the large end inner diameter d3' is set to 1530±10mm, and the forging height H4' is set to 470±8mm. The first angle is 7°, and the second angle is 41°. Twelve passes of forging with a reamer are performed, ensuring the forging temperature remains within the forging temperature range during each pass. Each reaming operation increases the inclination angle of the forging cross-section by 2.2° to 4.0°.

[0166] In the reaming process, the steps for controlling the height, large end, and small end dimensions of the forging after each reaming operation include:

[0167] Step S521: After each forging process, measure the forging height H4, large end inner diameter d3, large end outer diameter D5, small end inner diameter d2, small end outer diameter D4, and cross-sectional hypotenuse length h4. These parameters can be measured directly with a steel tape measure or using an infrared distance sensor.

[0168] In step S522, if h4 is less than the length of the inclined side of the forging section h4', or H4 is less than the height of the forging H4', then the small end of the forging is lengthened by mandrel to increase h4 so that h4≥h4'.

[0169] Step S523: If the inner diameter d3 and outer diameter D5 of the large end are both greater than the inner diameter d3' and outer diameter D5' of the large end set for the forging, then the large end of the forging is rounded and shaped to reduce the diameter of the large end of the forging before continuing the forming process.

[0170] Step S524: If the inner diameter d2 and outer diameter D4 of the small end are both greater than the inner diameter d2' and outer diameter D4' of the small end set for the forging, then the small end of the forging is lengthened by mandrel and the small end of the forging is flattened.

[0171] Step S525: If the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging, or the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, or the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging and the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then continue to perform the next firing cycle of the frame reaming.

[0172] Step S6, the fourth forging step, includes:

[0173] Step S61, forging heating: charge the furnace to the set temperature of 970℃, hold the cold material for 80 minutes, and hold the hot material for 60 minutes.

[0174] Step S62: Correct the diameter and height of the large and small ends according to the machining contour of the part.

[0175] Specifically, the outline of the part is as follows Figure 5 As shown.

[0176] Step S7, annealing.

[0177] Specifically, it is kept at 800℃ for 150 minutes and then air-cooled.

[0178] Step S8, rough machining.

[0179] Specifically, polish until the surface is shiny.

[0180] Step S9, ultrasonic flaw detection.

[0181] Specifically, Class A acceptance shall be conducted in accordance with GB / T5193-2007, with the diameter of a single discontinuous hole being <2.0mm.

[0182] First comparison example:

[0183] The first comparative example is largely the same as the first embodiment, except that the control of the forging height, large end, and small end dimensions after each forging pass in step S52 of the first embodiment is omitted, and a forging allowance is increased. The dimensions in the first comparative example are recalculated based on the dimensions after the increase in allowance. Figure 6 As shown, the dashed lines represent the outlines of the parts, the first comparative forging has a thick solid line outline, and the forging of the first embodiment has a thin solid line outline.

[0184] Conical forgings of the same size were produced using the methods of the first embodiment and the first comparative example, respectively. The dimensions of the conical forgings produced by the first embodiment and the first comparative example are shown in Table 1.

[0185] Table 1 Dimensions of Conical Forgings

[0186]

[0187] from Figure 6 It can be seen that, when producing conical forgings of the same size, the first embodiment has less allowance and higher material utilization compared to the first comparative embodiment.

[0188] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0189] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A forming method for TC4 cone forgings for underwater equipment, characterized in that, Includes the following steps: Material feeding; Chamfer; The first forging step includes: Forging heating: Load the furnace to the set temperature of 950~970℃, and calculate the holding time based on the effective thickness of 0.7min / mm; Determine the diameter of the billet obtained in the first forging step; Rough and rounded; The second forging step includes: Forging heating: Load the furnace to the set temperature of 950~970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm. Spinning upsetting and punching, controlling the height and large end diameter of the billet during spinning; The third forging step includes: Forging heating: Load the furnace to the set temperature of 950~970℃. The holding time for cold material is calculated based on an effective thickness of 0.7 min / mm, and the holding time for hot material is calculated based on an effective thickness of 0.4 min / mm. Forging reaming: Perform multiple reaming operations using a forging frame until the inclination angle of the inclined side of the forging section increases from a first angle to a second angle. After each reaming operation, control the forging height, large end dimension, and small end dimension. The steps for controlling the forging height, large end dimension, and small end dimension after each reaming operation include: After each forging process, the following measurements are taken: forging height H4, large end inner diameter d3, large end outer diameter D5, small end inner diameter d2, small end outer diameter D4, and section hypotenuse length h4. If h4 is less than the length of the hypotenuse of the forging section h4', or H4 is less than the height of the forging H4', then the mandrel is used to lengthen the small end of the forging to increase h4, so that h4≥h4'; If both the inner diameter d3 and the outer diameter D5 of the large end are larger than the inner diameter d3' and the outer diameter D5' of the large end set for the forging, then the large end of the forging is rounded and shaped to reduce the diameter of the large end of the forging until the inclination angle of the inclined side of the forging section is consistent with the second angle, and then the forming continues. If the inner diameter d2 and outer diameter D4 of the small end are both greater than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then the small end of the forging is lengthened by mandrel until the inner diameter d2 and outer diameter D4 of the small end are equal to the inner diameter d2' and outer diameter D4' of the small end set in the forging, and then the small end of the forging is flattened. If the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging, or the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, or the inner diameter d3 and outer diameter D5 of the large end are both smaller than the inner diameter d3' and outer diameter D5' of the large end set in the forging and the inner diameter d2 and outer diameter D4 of the small end are both smaller than the inner diameter d2' and outer diameter D4' of the small end set in the forging, then continue to perform the next firing cycle of the frame reaming. The fourth forging step includes: Forging heating: Load the furnace to the set temperature of 950~970℃, hold the cold material for 80 minutes, and hold the hot material for 60 minutes; Shape the part according to its machining contour; annealing; roughing; Ultrasonic flaw detection.

2. The forming method of the TC4 cone forging for underwater equipment according to claim 1, characterized in that: In the first forging step, the diameter D2 of the obtained billet satisfies the following formula: D2 2 -d 2 = D4' 2 - d2' 2 ; Where d is the punch size during punching, D4' is the small end outer diameter set for the forging, and d2' is the small end inner diameter set for the forging.

3. The forming method of the TC4 cone forging for underwater equipment according to claim 2, characterized in that: In the second forging step, the large end diameter of the obtained billet satisfies the following formula: D3 2 -d 2 = D5' 2 - d3' 2 4 Where D5' is the outer diameter of the large end of the forging, and d3' is the inner diameter of the large end of the forging; The height H3 of the obtained billet is calculated based on the billet volume using digital modeling software.

4. The forming method of the TC4 cone forging for underwater equipment according to claim 1, characterized in that, The annealing step includes: Hold at 780~800℃ for 120~150 minutes, then air cool.

5. The forming method of the TC4 cone forging for underwater equipment according to claim 1, characterized in that, The ultrasonic flaw detection step includes: According to GB / T5193-2007, Class A acceptance shall be conducted, and the diameter of a single discontinuous hole shall be <2.0 mm.

6. The forming method of the TC4 cone forging for underwater equipment according to claim 1, characterized in that, The first angle is 7°, and the second angle is not less than 35°.

7. The forming method of the TC4 cone forging for underwater equipment according to claim 6, characterized in that, Perform 10 to 12 rounds of reaming with a frame, each round of reaming increasing the inclination angle of the inclined side of the forging section by 2.2° to 4.0°.

8. The forming method of the TC4 cone forging for underwater equipment according to claim 1, characterized in that, The weight percentage of each chemical element in the forging is as follows: Al: 5.5%-6.75%; V: 3.5%-4.5%; Fe≤0.3%; C≤0.08%; N≤0.05%; H≤0.015%; O≤0.20%; other elements alone ≤0.10%; total of other elements ≤0.40%; balance is Ti.

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