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CN-122012874-A - Aviation gear steel based on surface fine grain treatment and preparation method and application thereof

CN122012874ACN 122012874 ACN122012874 ACN 122012874ACN-122012874-A

Abstract

The invention discloses an aviation gear steel based on surface fine grain treatment and a preparation method and application thereof. The preparation method of the aerogear steel based on the surface fine grain treatment comprises the following steps of carrying out quenching and tempering on the aerogear steel to obtain a tempered sorbite matrix, carrying out ultrasonic shot blasting treatment on the surface of the tempered sorbite matrix to obtain a surface modified sample, and carrying out gas nitriding treatment on the surface modified sample to obtain the aerogear steel based on the surface fine grain treatment. The invention provides a method for improving the precipitation of steel ball-shaped nitrides of an aviation gear by surface fine grain pretreatment, which can efficiently promote the generation of nanoscale spherical nitrides in the gas nitriding process, avoid the damage of brittleness of the nitrides and improve the surface toughness and service life of the nitrides.

Inventors

  • YIN FEI
  • WANG TAO

Assignees

  • 武汉市纳威超晶科技发展有限公司

Dates

Publication Date
20260512
Application Date
20260323

Claims (10)

  1. 1. The preparation method of the aviation gear steel based on surface fine grain treatment is characterized by comprising the following steps of: s1, performing quenching and tempering on aviation gear steel to obtain a tempered sorbite matrix; S2, performing ultrasonic peening treatment on the surface of the tempered sorbite matrix in the S1 to obtain a surface modified sample, wherein the working parameters of the ultrasonic peening treatment comprise ultrasonic frequency of 15-20 kHz, amplitude of 30-50 mu m, machining distance of 8.5-10 mm, feeding speed of 15-20 m/S and peening time of 2-10 min; And S3, carrying out gas nitriding treatment on the surface-modified sample obtained in the step S2, and obtaining the aviation gear steel based on surface fine grain treatment.
  2. 2. The method for preparing the aviation gear steel based on the surface fine grain treatment according to claim 1, wherein the specific step of performing the quenching and tempering treatment on the aviation gear steel in the step S1 is characterized in that a sample is heated to 850-870 ℃ and is subjected to oil cooling quenching after being kept at the temperature of 150-180 min, then is heated to 505-525 ℃ and is subjected to high-temperature tempering after being subjected to air cooling after being kept at the temperature of 180-210 min, and a uniform tempered sorbite matrix is obtained, and/or The aviation gear steel in the step S1 is 18Cr2Ni4W alloy steel.
  3. 3. The method for preparing the aviation gear steel based on the surface fine grain treatment according to claim 2 is characterized in that the specific step of performing thermal refining on the aviation gear steel in the step S1 is that a sample is heated to 860-870 ℃ and is subjected to oil cooling quenching after being kept at the temperature for 150-180 min, and then is heated to 515-525 ℃ and is subjected to high-temperature tempering for 180-210 min and then is subjected to air cooling, so that a uniform tempered sorbite matrix is obtained.
  4. 4. The method for preparing the aviation gear steel based on the surface fine grain treatment according to claim 1, wherein the working parameters of the ultrasonic peening treatment in the step S2 further comprise the step of adopting cemented carbide balls with diameters of 3-4 mm as peening media.
  5. 5. The method for producing an aircraft gear steel based on surface fine grain treatment according to claim 4, wherein YG6 cemented carbide balls having a diameter of 4mm are used as shot blasting media, and/or The shot blasting time is 8-10 min.
  6. 6. The method for preparing the aviation gear steel based on the surface fine grain treatment according to claim 1, wherein the specific step of performing gas nitriding treatment on the surface-modified sample in the step S3 is that the sample is placed into a nitriding furnace, and is subjected to gas nitriding at the temperature of 480-540 ℃ for 15-70 hours, and the ammonia decomposition rate is controlled to be 20-50%.
  7. 7. The method for preparing the aviation gear steel based on the surface fine grain treatment according to claim 6, wherein in the gas nitriding treatment, the gas nitriding is performed at the temperature of 480-490 ℃ for 40-70 hours.
  8. 8. The method for producing an aircraft gear steel based on surface fine grain treatment according to claim 6, wherein in the gas nitriding treatment, the ammonia decomposition rate is controlled to be 35 to 50%.
  9. 9. An aircraft gear steel based on surface fine grain treatment, which is characterized by being prepared by the method for preparing the aircraft gear steel based on surface fine grain treatment according to any one of claims 1-8.
  10. 10. The use of the surface fine grain treatment-based aircraft gear steel according to claim 9 for preparing aircraft engine gears and transmission shafts.

Description

Aviation gear steel based on surface fine grain treatment and preparation method and application thereof Technical Field The invention belongs to the technical field of severe plastic deformation of a metal material surface and chemical heat treatment composite modification, and particularly relates to an aviation gear steel based on surface fine grain treatment and a preparation method and application thereof. Background Gas nitriding is a main mode of chemical infiltration and diffusion of the surface of a metal material, and is widely applied to surface strengthening of 18Cr2Ni4W high-strength alloy steel parts of aero-engine gears, transmission shafts and the like. In the nitriding process, active nitrogen atoms permeate into the surface of steel and diffuse into the steel, and are combined with alloy elements such as chromium in a matrix to form nitride, so that obvious dispersion strengthening and solid solution strengthening effects are generated. Compared with the traditional carburizing or induction quenching process, the gas nitriding has the advantages of low treatment temperature, small deformation, extremely high surface hardness, excellent wear resistance and fatigue resistance and the like. Gas nitriding has been shown to significantly alter the surface microstructure of metals such as 18Cr2Ni4W steel, forming a dispersion alloy nitride that modifies the metal surface by second phase particle strengthening and solid solution strengthening, resulting in significant increases in surface strength and hardness. However, the strength and the hardness are improved, and meanwhile, the 18Cr2Ni4W steel tempered sorbite matrix contains more strong nitride forming elements such as chromium, nitrogen atoms are easy to gather and grow along ferrite grain boundaries, coarse pulse-shaped or net-shaped nitrides are formed, so that the brittleness of the permeable layer nitride is generated, the toughness of the metal surface is obviously reduced, and the long-service life of the aviation gear and the transmission shaft under the high-speed heavy-load environment is not facilitated. The introduction of severe plastic deformation (such as ultrasonic shot blasting) on the surface can realize the remarkable refinement and nanocrystallization of the surface texture, and the surface fine crystal structure has a key regulation and control effect on the subsequent chemical heat treatment. The thinned nanometer/submicron crystal grains introduce massive crystal boundaries, and the high-density crystal boundaries not only provide a rapid diffusion channel for nitrogen atoms, but also provide nucleation sites in dispersion distribution, so that the precipitation of nitrides is greatly dispersed, and the enrichment of the nitrides at the coarse original ferrite crystal boundaries is avoided. At the same time, the volume-constrained effect of the fine-grain structure limits the long-range directional growth of the nitride, forcing it to tend to spherically precipitate in order to reduce the surface energy. However, in practical engineering application, how to convert the theoretical fine grain advantage into the practical nano-scale spherical nitride structure through specific process parameter matching, so that the problem of nitride brittleness is thoroughly solved while high hardness is obtained, and the technical problem to be solved in the field of surface strengthening of the prior aviation gears and transmission shafts is urgently needed. Disclosure of Invention Aiming at the defects of the prior art, the primary aim of the invention is to provide a preparation method of aviation gear steel based on surface fine grain treatment. Another object of the present invention is to provide an aircraft gear steel based on surface fine grain treatment, which is prepared by the above method for preparing an aircraft gear steel based on surface fine grain treatment. It is still another object of the present invention to provide an application of the above-mentioned aero-gear steel based on surface fine grain treatment in preparation of aero-engine gears and transmission shafts. The aim of the invention is achieved by the following technical scheme: A preparation method of aviation gear steel based on surface fine grain treatment comprises the following steps: s1, performing quenching and tempering on aviation gear steel to obtain a tempered sorbite matrix; S2, performing ultrasonic peening treatment on the surface of the tempered sorbite matrix in the S1 to obtain a surface modified sample, wherein the working parameters of the ultrasonic peening treatment comprise ultrasonic frequency of 15-20 kHz, amplitude of 30-50 mu m, machining distance of 8.5-10 mm, feeding speed of 15-20 m/S and peening time of 2-10 min; And S3, carrying out gas nitriding treatment on the surface-modified sample obtained in the step S2, and obtaining the aviation gear steel based on surface fine grain treatment. Preferably, the specific step of perfor