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CN-121976136-A - Method for improving Haynes 214 high-temperature alloy as-cast grain boundary

CN121976136ACN 121976136 ACN121976136 ACN 121976136ACN-121976136-A

Abstract

The invention relates to the technical field of high-temperature alloy processing, in particular to a method for improving cast grain boundaries of a Haynes 214 high-temperature alloy, which is characterized in that a multidirectional forging process of upsetting before drawing is introduced in the processing process by reasonably designing the processing process of the Haynes 214 high-temperature alloy, and the synergistic effect of subsequent hot rolling deformation, solution treatment and cold rolling process is combined to promote the physical breaking and recrystallization reconstruction of primary cast grain boundaries in the alloy, so that loose, coarse and uneven alloy ingots are converted into compact, fine and uniform-structure high-quality forging stocks, and element segregation and brittle phase aggregation conditions at the grain boundaries are greatly improved. By adopting the method provided by the invention, a recrystallized equiaxed crystal structure with uniform structure and fine grains can be obtained, the risk of cracks generated by stress concentration in the thermal deformation process is reduced, and the Haynes 214 superalloy material with smooth surface and uniform internal structure is obtained.

Inventors

  • LING XINNAN
  • YU LIANXU
  • LI ZHIGANG
  • Miao Yingwei

Assignees

  • 江苏美特林科特殊合金股份有限公司

Dates

Publication Date
20260505
Application Date
20260121

Claims (8)

  1. 1. A method for improving Haynes 214 superalloy as-cast grain boundaries, comprising the steps of: s1, performing multidirectional free forging processing of upsetting deformation and drawing out on a Haynes 214 master alloy ingot, and destroying the continuity of a primary as-cast grain boundary to obtain a free forging plate blank with a recrystallization grain boundary; s2, carrying out hot rolling deformation on the free forging plate blank to form uniform recrystallized equiaxed crystal structures, and obtaining a strip blank; And S3, carrying out solution treatment, water cooling and cold rolling-annealing cycle processing on the strip blank to finally obtain the Haynes 214 superalloy material.
  2. 2. The method for improving the cast grain boundary of the Haynes 214 superalloy is characterized in that the process of upsetting, deforming and then drawing in the step S1 comprises the steps of vertically placing a Haynes 214 parent alloy ingot, upsetting the ingot to 60% -70% of the original height in the radial direction, keeping the temperature at not lower than 980 ℃, placing the upsetted blank in a lying manner, and axially reducing the thickness to enable the length of the blank to be increased to 1-2 times of the original length.
  3. 3. The method for improving the cast grain boundary of the Haynes 214 superalloy according to claim 1, wherein the thickness of the free forging blank obtained in the step S1 is 35-45 mm, and the total deformation of the free forging is 60-80%.
  4. 4. The method for improving the cast grain boundary of the Haynes 214 superalloy according to claim 1, wherein the hot rolling temperature in the step S2 is 1100-1200 ℃, the deformation is 92-98%, and the thickness of the obtained strip blank is 3-4 mm.
  5. 5. The method for improving the as-cast grain boundary of the Haynes 214 superalloy according to claim 1, wherein the solution treatment temperature in the step S3 is 1100-1200 ℃ for 50-70 min.
  6. 6. The method for improving the as-cast grain boundary of the Haynes 214 superalloy according to claim 1, wherein the number of times of cold rolling-annealing cycles in the step S3 is 5-7, the cold rolling intermediate annealing temperature is 1050-1150 ℃, the deformation is 30-60%, and the deformation of the last rolling Cheng Lengga is 20-25%.
  7. 7. The Haynes 214 superalloy material prepared by the method of any one of claims 1-6, wherein the interior structure of the Haynes 214 superalloy material is uniform equiaxed crystal and has no continuous as-cast grain boundary structure.
  8. 8. The application of the Haynes 214 superalloy material prepared by the method of any one of claims 1-6 in the field of metal material processing and manufacturing.

Description

Method for improving Haynes 214 high-temperature alloy as-cast grain boundary Technical Field The invention relates to the technical field of high-temperature alloy processing, in particular to a method for improving a Haynes 214 high-temperature alloy cast grain boundary. Background The Haynes 214 alloy is a Ni-Cr-Al based deformation superalloy, and has excellent high-temperature oxidation resistance because the alloy can form a compact and stable Al 2O3 protective film under the high-temperature condition. Meanwhile, the alloy has good corrosion resistance under the conditions of carburizing environment, nitriding environment, chlorine-containing atmosphere and the like, so that the alloy is widely applied to the manufacturing fields of honeycomb sealing members, flame covers, burners and other high-temperature parts. However, in the actual processing and application processes, the Haynes 214 alloy still faces the following main problems (1) because the alloy has higher Al content, the thermal processing temperature interval is relatively narrow, and the strengthening phase is easy to separate out in the thermal processing and heat treatment processes, so that the subsequent cold processing plasticity of the material is obviously reduced, the deformation resistance is increased, and the processing and preparation difficulty is increased. (2) In the solidification process of the cast ingot, the Haynes 214 alloy is easy to form coarse as-cast grains and obvious primary as-cast grain boundaries due to the slower cooling speed. The size of the as-cast crystal grain can reach 1-3 mm, the corresponding dendrite arm spacing is larger, the alloy element is obviously segregated in the grain boundary and the inter-dendrite area, and brittle phases (such as carbide, gamma' -thin film and the like) are promoted to be enriched at the grain boundary and are in a continuous distribution state. The primary cast grain boundary and the segregation structure thereof easily cause stress concentration in the subsequent thermal deformation process, become preferential positions for crack initiation and propagation, and obviously reduce the hot processing performance and the high-temperature service reliability of the material. Therefore, how to effectively improve the cast structure characteristics of the Haynes 214 alloy in the processing and preparing process and weaken the adverse effect of primary cast grain boundaries is a difficult problem to be solved for further expanding engineering application of the alloy. Disclosure of Invention The invention aims to solve the technical problems that the prior Haynes 214 superalloy is easy to form a primary as-cast grain boundary in the processing and preparation process, so that the microstructure is uneven, element segregation and brittle phases at the grain boundary are continuously gathered, and the stress concentration causes cracking during thermal deformation. According to the invention, through reasonably designing the processing technology of the Haynes 214 superalloy, a multidirectional forging technology of upsetting and then drawing is introduced in the processing process, and the synergistic effect of subsequent hot rolling deformation, solution treatment and cold rolling technology is combined, so that the primary cast grain boundary in the alloy is subjected to physical crushing and recrystallization reconstruction, loose, coarse and uneven alloy ingots are converted into compact, fine and uniform-structure high-quality forging billets, and element segregation and brittle phase aggregation conditions at the grain boundary are greatly improved. By adopting the method provided by the invention, a recrystallized equiaxed crystal structure with uniform structure and fine grains can be obtained, the risk of cracks generated by stress concentration in the thermal deformation process is reduced, and the Haynes 214 superalloy material with smooth surface and uniform internal structure is obtained. In order to achieve the above purpose, the present invention provides the following technical solutions: A method for improving Haynes 214 superalloy as-cast grain boundaries, comprising the steps of: s1, performing multidirectional free forging processing of upsetting deformation and drawing out on a Haynes 214 master alloy ingot, and destroying the continuity of a primary as-cast grain boundary to obtain a free forging plate blank with a recrystallization grain boundary; s2, carrying out hot rolling deformation on the free forging plate blank to form uniform recrystallized equiaxed crystal structures, and obtaining a strip blank; And S3, carrying out solution treatment, water cooling and cold rolling-annealing cycle processing on the strip blank to finally obtain the Haynes 214 superalloy material. Preferably, the process of upsetting, deforming and then drawing in the step S1 comprises the steps of vertically placing a Haynes 214 alloy ingot, radially upsetting to 60-70% of the