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CN-122012994-A - GH4141 high-temperature alloy forging bar free of notch sensitivity and preparation method thereof

CN122012994ACN 122012994 ACN122012994 ACN 122012994ACN-122012994-A

Abstract

The invention relates to the technical field of high-temperature alloy, in particular to a GH4141 high-temperature alloy forging bar without notch sensitivity and a preparation method thereof. In the microstructure of the GH4141 high-temperature alloy forging rod, M 6 C carbide is distributed in a circular particle shape on a grain boundary, the durable breaking time of a high-temperature notch of the forging rod under the temperature condition of 732 ℃ and the stress condition of 603MPa is more than or equal to 40h, and the breaking positions are all positioned on a smooth section.

Inventors

  • XIAO DONGPING
  • FENG XU
  • LAI YU
  • XIA CHANGLIN

Assignees

  • 成都先进金属材料产业技术研究院股份有限公司

Dates

Publication Date
20260512
Application Date
20260414

Claims (10)

  1. 1. A non-notch sensitive GH4141 superalloy forging rod is characterized by comprising, by mass, ：C：0.06～0.12％,Cr：18.0～20.0％,Co：10.0～12.0％,Mo：9.50～10.50％,Al：1.4～1.8％,Ti：3.0～3.5％,B：0.003～0.010％,Si≤0.5％,Mn≤0.5％,Cu≤0.5％,P≤0.015％,S≤0.015％,Fe≤5.0％,Zr≤0.07％, parts of Ni and unavoidable impurities as the balance, wherein M 6 C carbides are distributed in a circular particle shape on a grain boundary in a microstructure of the forging rod, the durable fracture time of a high-temperature notch of the forging rod under the temperature condition of 732 ℃ and the stress condition of 603MPa is more than or equal to 40 hours, and fracture positions are all located in a smooth section.
  2. 2. A method for preparing a non-notch sensitive GH4141 superalloy wrought bar, characterized in that it is used for preparing a non-notch sensitive GH4141 superalloy wrought bar according to claim 1, comprising the steps of: Sequentially carrying out primary homogenization heat treatment, pre-forging, secondary homogenization heat treatment, secondary forging and subsequent forging on the GH4141 superalloy ingot to obtain a forged rod; The temperature of the first homogenization heat treatment is 1160-1200 ℃ and the heat preservation time is 36-48h; The temperature of the second homogenization heat treatment is 1170-1190 ℃ and the heat preservation time is 10-15h.
  3. 3. The preparation method according to claim 2, wherein the ingot furnace is cooled to 950-1050 ℃ after the first homogenization heat treatment and before pre-forging, and then is directly transferred to a rapid forging machine heating furnace for heating and heat preservation before forging, or is cooled to room temperature after discharging for subsequent use.
  4. 4. The method according to claim 2, wherein the pre-forging comprises heating the ingot subjected to the first homogenizing heat treatment to 1130-1160 ℃ and maintaining the temperature for 2-3 hours, and then performing upsetting forging for at least three fires to obtain a first intermediate billet, wherein the upsetting deformation is 15% -35% and the drawing deformation is 20% -40%.
  5. 5. The method according to claim 2, wherein the secondary forging comprises furnace-cooling the intermediate billet after the second homogenizing heat treatment to 1130-1160 ℃, maintaining the temperature for 2-3 hours, and then performing upsetting forging for at least four fires to obtain a second intermediate billet, wherein the upsetting deformation is 15% -35% and the drawing deformation is 20% -40%.
  6. 6. The method according to claim 2, wherein the subsequent forging comprises final hot rapid forging, wherein the second intermediate billet obtained through the secondary forging is heated to 1100-1120 ℃, the temperature is kept for 2-3 hours, and one hot drawing forging is performed, wherein the deformation is 45% -60%, and the rapid forging billet is obtained.
  7. 7. The method according to claim 6, wherein the subsequent forging further comprises radial forging performed after the final hot rapid forging, wherein the rapid forging stock is heated to 1100 ℃ to 1120 ℃ and is kept at the temperature for 2 to 3 hours, and radial forging is performed for one hot time, wherein the deformation amount is 30 to 45%, and the forged bar is obtained.
  8. 8. The method according to claim 2, further comprising the step of subjecting the forged bar to a performance heat treatment comprising sequentially subjecting the forged bar to a solution treatment at 1070-1100 ℃ and a water cooling after heat preservation, and subjecting the forged bar to an aging treatment at 750-770 ℃ and an air cooling after heat preservation.
  9. 9. The method according to claim 2, wherein the blank is sheathed with insulating cotton during the elongation forging of the pre-forging, the secondary forging, and the subsequent forging.
  10. 10. The method of claim 2, wherein the GH4141 superalloy ingot is produced by a vacuum induction melting and vacuum consumable remelting duplex process.

Description

GH4141 high-temperature alloy forging bar free of notch sensitivity and preparation method thereof Technical Field The invention relates to the technical field of high-temperature alloy, in particular to a GH4141 high-temperature alloy forging bar without notch sensitivity and a preparation method thereof. Background GH4141 superalloy is a precipitation-hardenable nickel-base wrought alloy with a main strengthening phase of gamma prime and M 6 C carbide. The alloy has excellent high-temperature strength (applicable to below 870 ℃) and good oxidation resistance (applicable to below 980 ℃), and is widely used for manufacturing key hot end bearing parts of aviation and aerospace engines. However, the GH4141 alloy has a high degree of alloying, and is extremely prone to severe element segregation during solidification, accompanied by precipitation of large amounts of coarse carbides between dendrites. The cast carbides mainly comprise MC, M 6 C, M 23C6 and other types, are generally distributed in a strip shape, a block shape or a Chinese character shape, and have larger size. If conventional homogenization heat treatment is used, it is difficult to completely dissolve or eliminate the solution. Research shows that the distribution, quantity and size of the carbide have decisive influence on the hot working plasticity and final mechanical property of the alloy, that the large-size MC and M 6 C carbide in an as-cast structure can obviously reduce the hot working plasticity of the alloy and increase the cogging difficulty, and that the precipitation behavior of M 6 C and M 23C6 carbide at the grain boundary of a forging bar directly relates to the high-temperature durability of the material. Currently, the existing research is mainly focused on improving the hot working plasticity of GH4141 alloy, the uniformity of carbide distribution and the control of grain size. For example, the invention patent with publication number of CN114472770B discloses a forging process of GH141 alloy large round bar, which adopts a mode of combining quick forging and finish forging, and successfully obtains a forged bar with uniform grain size by strictly controlling a heating process and deformation. However, this patent does not address the carbide distribution characteristics of the forged bar and its impact on durability performance. For another example, patent application publication No. CN116809829a discloses a forging method for improving the stripe distribution of GH4141 alloy carbide, which effectively improves the stripe distribution of carbide by introducing a multiple firing upsetting process during the cogging forging process. However, the patent likewise does not intensively study the influence of the specific type, size and precipitation position of carbides on the alloy durability properties, in particular on the notch sensitivity. With the continuous improvement of the performance parameters of the aero-engine, more stringent requirements are put forward on the high-temperature durability of the material. At present, for GH4141 alloy, not only the high-temperature notch durable breaking time of the alloy at 732 ℃ per 603MPa is more than or equal to 23 hours, but also the breaking position of the alloy is required to be positioned in a smooth section, namely the notch sensitivity is completely eliminated. However, no report is currently available on how to systematically eliminate the notch sensitivity of GH4141 alloys by process control. Therefore, there is a need to provide a GH4141 superalloy wrought bar and method of making same that eliminates notch sensitivity to meet the stringent demands of high-end equipment for material reliability and consistency. Disclosure of Invention In view of the above, the present invention aims to provide a GH4141 superalloy forged bar without notch sensitivity and a preparation method thereof, which at least can solve the problems of lower high temperature durability and notch sensitivity of the existing GH4141 alloy. The invention provides a non-notch sensitive GH4141 high-temperature alloy forging rod, which comprises the following chemical components in percentage by mass, wherein the balance of ：C：0.06～0.12％,Cr：18.0～20.0％,Co：10.0～12.0％,Mo：9.50～10.50％,Al：1.4～1.8％,Ti：3.0～3.5％,B：0.003～0.010％,Si≤0.5％,Mn≤0.5％,Cu≤0.5％,P≤0.015％,S≤0.015％,Fe≤5.0％,Zr≤0.07％, is Ni and unavoidable impurities, M 6 C carbide is distributed in a circular particle shape in a grain boundary in a microstructure of the forging rod, the durable breaking time of a high-temperature notch of the forging rod under the temperature condition of 732 ℃ and the stress condition of 603MPa is more than or equal to 40 hours, and the breaking positions are all positioned in a smooth section. The invention provides a preparation method of a non-notch sensitive GH4141 superalloy forged rod, which is used for preparing the non-notch sensitive GH4141 superalloy forged rod and comprises the following steps of sequentially carrying