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CN-121988978-A - Upsetting technology for Inconel718 twelve-angle countersunk head bolt

CN121988978ACN 121988978 ACN121988978 ACN 121988978ACN-121988978-A

Abstract

A forging process for an Inconel718 twelve-angle countersunk head bolt is characterized by comprising the following steps of blanking by adopting a lathe according to the actual use length and diameter of the bolt, grinding the outer circle of a blank after blanking, lubricating, namely lubricating the blank after coreless grinding by adopting copper plating, and forging, namely heating the lubricated blank to a set temperature, then placing the blank into a forging die, forging by adopting a punch press, and forging the columnar blank once to form a bolt polished rod. The process can be used for one-time upsetting forming, avoids the defects caused by the traditional multiple upsetting forming, can ensure the consistency of the size of parts and the quality of products, can improve the production efficiency, reduces the cost, has strong practicability and is suitable for being widely popularized.

Inventors

  • SUN CHAO

Assignees

  • 深圳亚太航空技术股份有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (13)

  1. 1. The Inconel718 twelve-angle countersunk head bolt upsetting process is characterized by comprising the following steps of: Blanking, namely blanking by adopting a lathe according to the actual use length and diameter of the bolt; Centerless grinding, namely carrying out cylindrical grinding on the blank (30) after blanking; Lubrication, namely lubricating a blank (30) subjected to centerless grinding by adopting copper plating; And (3) upsetting, namely heating the lubricated blank (30), putting the blank into a upsetting die after reaching a set temperature, upsetting by adopting a punch, and forming the columnar blank (30) through one-time upsetting to obtain the bolt polished rod (40).
  2. 2. The Inconel718 twelve-angle countersunk head bolt upsetting process as in claim 1, wherein in the centerless grinding step, the diameter R of the ground blank is R1+0.2mm≤R≤R2, wherein R1 is the diameter of the shank of the finished bolt, and R2 is the diameter of the twelve-angle inscribed circle of the finished bolt.
  3. 3. The Inconel718 twelve-angle countersunk head bolt upsetting process according to claim 2, wherein in the upsetting step, when the lubricated blank (30) is heated, the blank is heated in a sectional manner, the blank is heated to 800-900 ℃ in the first stage, the blank is heated for 5-10 seconds in the second stage, the blank is heated to 1000-1050 ℃ in the second stage, and the blank is heated for 10-15 seconds in the first stage; When the heating is carried out in a sectional manner, the total heating time is 15-30S.
  4. 4. The Inconel718 twelve-angle countersunk bolt, upsetting process as recited in claim 3, wherein said die comprises an upper die (10) and a lower die (20) that are relatively movable, The lower die (20) includes: a lower die core (21) provided with a positioning hole (211) penetrating along a first direction Y; The upper die (10) includes: The upper die core (11) is provided with a die hole (111) penetrating along the first direction Y, the die hole (111) comprises a flange die hole part (1111) and a twelve-angle die hole part (1112), the flange die hole part (1111) is positioned at one end of the upper die core (11) facing the lower die core (21), the cross section of the twelve-angle die hole part (1112) is matched with the shape of a twelve-angle screwing part (41) of the bolt, and the flange die hole part (1111) is matched with the shape of a flange plate part (42) of the bolt; An upper ejector pin (12) arranged along a first direction Y and inserted into the die hole (111) for pressing the blank (30); The pushing block (13) is used for pushing the upper thimble (12) to move along the first direction Y.
  5. 5. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 4, wherein, In the upsetting step, after the preset temperature is reached, the upsetting method specifically comprises the following steps: Placing the blank (30) reaching the set temperature into the positioning hole (211), limiting the lower part of the blank (30) in the positioning hole (211), and exposing the upper part of the blank outside the lower die core (21); The upper die core (11) is sleeved on the upper part of the blank (30), and the top of the blank (30) is positioned in the die hole (111); The upper ejector pin (12) is pushed by the pushing block (13) to pressurize the blank (30), so that the blank (30) is deformed to pier a bolt polish rod (40) with a flange plate part (42) and a twelve-angle turning part (41).
  6. 6. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 5, wherein, The flange die hole part (1111) comprises a conical hole part (11111) and a cylindrical hole part (11112), wherein the conical hole part (11111) is connected between the dodecagonal die hole part (1112) and the cylindrical hole part (11112), and the dimension Q1 of the cylindrical hole part (11112) along the first direction Y is 1/2Q-Q1-Q, wherein Q is the thickness of the head part of the flange plate part (42) of the finished bolt; The radial dimension A1 of the cylindrical hole part (11112) is A1=A+0.5MM, wherein A is the outer circle diameter of the flange part (42) of the finished bolt.
  7. 7. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 5, wherein, The lower die (20) comprises a lower thimble (22), and the lower thimble (22) is arranged along a first direction Y and is inserted into the positioning hole (211); When the blank (30) is placed in the positioning hole (211), the lower ejector pin (22) pushes against the bottom of the blank (30) to limit the lower part of the blank (30) to be positioned in the positioning hole (211).
  8. 8. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 5, wherein, The upper die (10) further comprises an upper die sheath (14), the upper die sheath (14) is sleeved outside the upper die core (11), and the manufacturing material of the upper die sheath is different from that of the upper die core (11); The lower die (20) further comprises a lower die sheath (23), the lower die sheath (23) is sleeved outside the lower die core (21), and the manufacturing material of the lower die sheath is different from that of the lower die core (21).
  9. 9. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 8, wherein, The upper die core (11) comprises a first cylindrical part (112) and a second cylindrical part (113) which are coaxial and integrally formed, wherein the diameter of the first cylindrical part (112) is larger than that of the second cylindrical part (113) to form a stepped structure, and the axial direction of the upper die core (11) is parallel to the first direction Y; the upper die sheath (14) is provided with a first stepped hole (141) penetrating along a first direction Y, and the first stepped hole (141) comprises a first hole part (1411) and a second hole part (1412); The upper die core (11) is arranged in the first stepped hole (141), the first cylindrical part (112) is matched with the first hole part (1411), and the second cylindrical part (113) is matched with the second hole part (1412); the length of the second hole portion (1412) in the first direction Y is longer than the length of the second cylindrical portion (113) in the first direction Y.
  10. 10. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 9, wherein, The lower die core (21) comprises a third cylindrical part (212) and a fourth cylindrical part (213) which are coaxial and integrally formed, the diameter of the third cylindrical part (212) is smaller than that of the fourth cylindrical part (213) to form a stepped structure, and the axial direction of the lower die core (21) is parallel to the first direction Y; The lower die sheath (23) is provided with a second stepped hole (231), the second stepped hole (231) comprises a third hole part (2311) and a fourth hole part (2312), The lower die core (21) is arranged in the second stepped hole (231), the third cylindrical part (212) is matched with the third hole part (2311), and the fourth cylindrical part (213) is matched with the fourth hole part (2312); The length of the third cylindrical portion (212) along the first direction Y is greater than the length of the third hole portion (2311) along the first direction Y, so that the third cylindrical portion (212) is exposed out of the lower die core (21).
  11. 11. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 10, wherein, The difference in length between the second hole portion (1412) and the second cylindrical portion (113) is smaller than the difference in length between the third cylindrical portion (212) and the third hole portion (2311).
  12. 12. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 11, wherein, The lower die sheath (23) comprises an upper seat (232) and a lower seat (233) which are connected in a butt joint way, the upper seat (232) is provided with a second stepped hole (231), the second stepped hole (231) penetrates through the two ends of the upper seat (232) along a first direction Y, the lower seat (233) is provided with a jack coaxial with and penetrating through the positioning hole (211), and the lower thimble (22) is inserted into the positioning hole (211) through the jack of the lower seat (233).
  13. 13. The Inconel718 twelve-angle countersunk head bolt, as set forth in claim 12, wherein, The upper die (10) further comprises a push block sheath (16), the push block sheath (16) is connected to one end, far away from the lower die sheath (23), of the upper die sheath (14) in a involution mode, the push block sheath (16) is provided with a third stepped hole (161) penetrating along a first direction Y, the third stepped hole (161) comprises a fifth hole part (1611) and a sixth hole part (1612), and the diameter of the sixth hole part (1612) is smaller than the diameter of the first cylindrical part (112) and larger than the diameter of the upper thimble (12); The pushing block (13) comprises a pushing rod portion (131) and a pressing block portion (132), the pushing rod portion (131) is arranged in a fifth hole portion (1611) along a first direction Y, the pressing block portion (132) is arranged on the end portion of the pushing rod portion (131) and faces to the upper ejector pin (12), and the pressing block portion (132) is movably arranged in the sixth hole portion (1612).

Description

Upsetting technology for Inconel718 twelve-angle countersunk head bolt Technical Field The invention relates to the field of bolt processing, in particular to an Inconel718 twelve-angle countersunk head bolt upsetting process. Background Inconel718 is a nickel-iron-based wrought superalloy with very high strength, toughness, fatigue resistance and good comprehensive performance, especially below 650 ℃, and has very good stability in mechanical properties, and is widely applied to aeroengines at present. The technology and the application of the Inconel718 alloy are strictly kept secret abroad, so that the material characteristics and the manufacturing technology of the Inconel718 alloy need to be studied by oneself. The Inconel718 twelve-angle countersunk head bolt comprises a screw rod part 43, a flange plate part 42 and a twelve-angle turning part 41, and has the characteristics of complex head shape, large deformation, difficult forming and the like, the lower part of the twelve-angle turning part 41 is a flange surface, and metal tends to flow to the position with the minimum resistance during upsetting forming, so that the metal is not easy to accumulate in a die cavity during forming, but is accumulated at a flash outside the flange surface, and twelve edges are difficult to fill. Inconel718 alloy is a typical process-sensitive alloy, and has a narrow forging temperature range, and if the heating temperature is too low, the fluidity of metal is insufficient, twelve edges are not fully filled, and if the heating temperature is too high, the metal is easy to overheat and overburn, and the head of a bolt can generate hot cracks, so that the key is to solve the problems of die design and temperature control. At present, the forging of the Inconel718 alloy twelve-angle countersunk head bolt adopts a rough forging and final forging twice forging mode, the middle part needs to be heated twice, the forging process has the advantages of slow processing speed, low production efficiency and poor consistency of product quality. Disclosure of Invention The invention aims to solve the problems and provides an Inconel718 twelve-angle countersunk head bolt upsetting process. In order to solve the problems, the invention provides an Inconel718 twelve-angle countersunk head bolt upsetting process, which is characterized by comprising the following steps of: Blanking, namely blanking by adopting a lathe according to the actual use length and diameter of the bolt; centerless grinding, namely performing cylindrical grinding on the blank after blanking; lubrication, namely lubricating a blank subjected to centerless grinding by adopting copper plating; And (3) upsetting, namely heating the lubricated blank, putting the heated blank into a upsetting die after reaching a set temperature, upsetting by adopting a punch, and forming the columnar blank by one-time upsetting to obtain the bolt polished rod. In the centerless grinding step, the diameter R of the ground blank is R1+0.2mm≤R 2, wherein R1 is the rod diameter of the finished bolt product, and R2 is the twelve-angle inscribed circle diameter of the finished bolt product. Further, in the upsetting step, when the lubricated blank is heated, sectional heating is adopted, the first stage is heated to 800-900 ℃, the temperature is kept for 5-10 s, the second stage is rapidly heated to 1000-1050 ℃, the temperature is kept for 10-15 s, and the total heating time is 15-30 s when the sectional heating is carried out. Further, the die comprises an upper die and a lower die which can relatively move, The lower die includes: the lower die core is provided with a positioning hole which is communicated along a first direction Y; The upper die comprises: the upper die core is provided with a die hole penetrating along the first direction Y, the die hole comprises a flange die hole part and a twelve-angle die hole part, and the flange die hole part is positioned at one end of the upper die core facing the lower die core; the cross section of the twelve-angle die hole part is matched with the shape of a twelve-angle screwing part of the bolt, and the flange die hole part is matched with the shape of a flange plate part of the bolt; the upper ejector pin is arranged along the first direction Y, inserted into the die hole and used for pressing the blank; the pushing block is used for pushing the upper thimble to move along the first direction Y. Further, the method comprises the steps of, In the upsetting step, after the preset temperature is reached, the upsetting method specifically comprises the following steps: placing the blank reaching the set temperature into a positioning hole, limiting the lower part of the blank to be positioned in the positioning hole, and exposing the upper part of the blank outside the lower die core; The upper die core is sleeved on the upper part of a blank, and the top of the blank is positioned in the die hole; The upper ejector pin is pushed by the push