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CN-122012904-A - Wind power main shaft and manufacturing method for improving fatigue resistance of wind power main shaft

CN122012904ACN 122012904 ACN122012904 ACN 122012904ACN-122012904-A

Abstract

The invention discloses a wind power main shaft and a manufacturing method for improving fatigue resistance of the wind power main shaft, and belongs to the technical field of manufacturing key components of wind power generation equipment. The method comprises the following steps of performing multidirectional upsetting forging on a medium-carbon alloy steel ingot to obtain a forging stock, performing cryogenic pretreatment on the forging stock, then heating to room temperature, and then sequentially performing composite tempering heat treatment, surface composite strengthening treatment and low-temperature aging treatment. The method is easy to operate, the fatigue life of the wind power main shaft can be effectively prolonged by 50% -100% compared with that of the wind power main shaft manufactured by the traditional process, and the damage tolerance and the safety reliability of the wind power main shaft under severe working conditions can be greatly improved.

Inventors

  • GAN CHUNLEI
  • LI XIAOHUI
  • CHEN LIJIE
  • ZHOU NAN
  • LIU LIANHAO
  • CHEN FENG

Assignees

  • 广东省科学院新材料研究所
  • 佛山大学
  • 中集海洋工程有限公司

Dates

Publication Date
20260512
Application Date
20260214

Claims (10)

  1. 1. A manufacturing method for improving fatigue resistance of a wind power main shaft is characterized by comprising the following steps of performing multidirectional upsetting forging on a medium-carbon alloy steel ingot to obtain a forging stock, performing cryogenic pretreatment on the forging stock, then heating to room temperature, and then sequentially performing composite tempering heat treatment, surface composite strengthening treatment and low-temperature aging treatment.
  2. 2. The method of manufacturing according to claim 1, wherein the medium carbon alloy ingot comprises at least one of a 42CrMo4 ingot and a 34CrNiMo6 ingot.
  3. 3. The method according to claim 1, wherein the temperature of the multidirectional upsetting forging is 1200 ℃ to 1250 ℃, the forging ratio is not less than 6, and the deformation path is formed by alternately upsetting and drawing.
  4. 4. The method according to claim 1, wherein the cryogenic pretreatment is performed at a liquid nitrogen temperature of-80 ℃ to-196 ℃ for a heat preservation time of 1h/100mm cross-sectional thickness to 2h/100mm cross-sectional thickness.
  5. 5. The production method according to claim 1, wherein the composite tempering heat treatment includes a high-temperature austenitizing treatment, a step quenching treatment, and a double tempering treatment which are sequentially performed.
  6. 6. The method according to claim 5, wherein the high-temperature austenitizing treatment is performed under a protective atmosphere, heated to 860 ℃ to 890 ℃ and kept at a temperature of 1.2min/mm cross-sectional thickness to 1.5min/mm cross-sectional thickness; And/or the step quenching treatment comprises quenching and cooling to 300-350 ℃ in 80-120 ℃ hot oil, and then rapidly transferring to 180-220 ℃ low-temperature salt bath for 2-4 h, wherein the transfer is preferably completed within 30s; And/or the twice tempering treatment comprises the steps of preserving heat for 5-7 hours at 580-620 ℃ to perform primary tempering, preserving heat for 5-7 hours at 30-50 ℃ lower than the primary tempering temperature after air cooling to perform secondary tempering, and then air cooling.
  7. 7. The method according to claim 1, wherein the surface composite strengthening treatment comprises a supersonic particle peening treatment and a laser shock peening treatment performed sequentially.
  8. 8. The method according to claim 7, wherein the shot diameter for shot blasting of the supersonic particles is 0.3mm to 0.5mm, the shot velocity is 70m/s to 100m/s, and the treatment time is 3min to 5min; And/or the conditions of laser shock peening treatment comprise 28-32J pulse energy and 15-25 ns pulse width, and forming a residual compressive stress layer of 0.8-1.2 mm; preferably, after the ultrasonic particles are sprayed, forming a plastic deformation layer with the depth of 0.3 mm-0.5 mm; preferably, a residual compressive stress layer with the depth of 0.8 mm-1.2 mm is formed after laser shock peening.
  9. 9. The method according to claim 1, wherein the low-temperature aging treatment is performed at 120 ℃ to 150 ℃ for 48 hours to 72 hours; preferably, the low-temperature aging treatment is further followed by fine grinding treatment; Preferably, in the fine grinding process, the unilateral removal amount is less than or equal to 0.05mm.
  10. 10. A wind power main shaft, characterized in that it is obtained by the manufacturing method according to any one of claims 1 to 9; Preferably, in a rotational bending fatigue test of R= -1, the fatigue limit of the wind power main shaft is more than or equal to 1000MPa.

Description

Wind power main shaft and manufacturing method for improving fatigue resistance of wind power main shaft Technical Field The invention relates to the technical field of manufacturing of key components of wind power generation equipment, in particular to a wind power main shaft and a manufacturing method for improving fatigue resistance of the wind power main shaft. Background The wind power main shaft is a core bearing component for connecting a wind wheel and a gear box (or directly driving a generator) in a wind generating set, and bears huge alternating bending, torsion and impact loads for a long time, and the fatigue performance directly determines the service life and operation safety of the set. At present, the large-scale wind power main shaft is generally formed by forging medium carbon alloy steel such as 42CrMo4, 34CrNiMo6 and the like, and the manufacturing process generally comprises forging forming, rough machining, heat treatment and finish machining. However, the fatigue resistance of the wind power main shaft prepared by the traditional process is still insufficient, and especially for the wind power main shaft with the megawatt level or more, the requirement of the ultra-long design life with the megawatt level or more is difficult to meet. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a wind power main shaft and a manufacturing method for improving fatigue resistance of the wind power main shaft so as to solve or improve the technical problems. The invention can be realized as follows: the invention provides a manufacturing method for improving fatigue resistance of a wind power main shaft, which comprises the following steps of performing multidirectional upsetting forging on a medium-carbon alloy steel ingot to obtain a forging stock, performing cryogenic pretreatment on the forging stock, then heating to room temperature, and then sequentially performing composite tempering heat treatment, surface composite strengthening treatment and low-temperature aging treatment. In an alternative embodiment, the medium carbon alloy steel ingot comprises at least one of a 42CrMo4 steel ingot and a 34CrNiMo6 steel ingot. In an alternative embodiment, the temperature of the multidirectional upsetting forging is 1200-1250 ℃, the forging ratio is more than or equal to 6, and the deformation path is formed by alternately upsetting and drawing. In an alternative embodiment, the cryogenic pretreatment is carried out under the condition that the liquid nitrogen temperature is between 80 ℃ below zero and 196 ℃ below zero, and the heat preservation time is 1h/100mm section thickness to 2h/100mm section thickness. In an alternative embodiment, the composite temper heat treatment includes a high temperature austenitizing treatment, a staged quenching treatment, and a double tempering treatment performed sequentially. In an alternative embodiment, the high-temperature austenitizing treatment is carried out under a protective atmosphere, heated to 860-890 ℃, and kept at the temperature of 1.2-1.5 min/mm in section thickness; And/or the step quenching treatment comprises quenching and cooling to 300-350 ℃ in 80-120 ℃ hot oil, and then rapidly transferring to 180-220 ℃ low-temperature salt bath for 2-4 h, wherein the transfer is preferably completed within 30s; And/or the twice tempering treatment comprises the steps of preserving heat for 5-7 hours at 580-620 ℃ to perform primary tempering, preserving heat for 5-7 hours at 30-50 ℃ lower than the primary tempering temperature after air cooling to perform secondary tempering, and then air cooling. In an alternative embodiment, the surface composite strengthening treatment comprises a supersonic particle peening treatment and a laser shock peening treatment performed sequentially. In an alternative embodiment, the shot diameter used for the shot blasting treatment of the supersonic particles is 0.3 mm-0.5 mm, the speed of the shot is 70 m/s-100 m/s, and the treatment time is 3 min-5 min; and/or the conditions of laser shock peening treatment comprise 28-32J pulse energy and 15-25 ns pulse width, and a residual compressive stress layer of 0.8-1.2 mm is formed. In an alternative embodiment, the supersonic particles are sprayed to form a plastic deformation layer with a depth of 0.3 mm-0.5 mm. In an alternative embodiment, a residual compressive stress layer with a depth of 0.8 mm-1.2 mm is formed after laser shock peening. In an alternative embodiment, the low temperature ageing treatment is performed at 120-150 ℃ for 48-72 hours. In an alternative embodiment, the low temperature ageing treatment is followed by a refining treatment; in an alternative embodiment, the single edge removal is less than or equal to 0.05mm during the refining process. In a second aspect, the present invention provides a wind power main shaft obtained by the method according to any one of the above embodiments. In an alternative e