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CN-121976002-A - High-strength high-toughness steel, stud and heat treatment method

CN121976002ACN 121976002 ACN121976002 ACN 121976002ACN-121976002-A

Abstract

The invention belongs to the technical field of metal heat treatment processes, and particularly relates to a high-strength high-toughness steel, a stud and a heat treatment method, which comprises the following steps that 1) a workpiece is placed in a mesh belt furnace quenching furnace, the mesh belt furnace quenching furnace drives the workpiece to operate, the temperature of each region of the mesh belt furnace quenching furnace is controlled, the total quenching heating and heat preservation time of the workpiece is not less than 240min, 2) the workpiece enters a quenching tank for quenching and cooling, and the cooling speed, the quenching tank temperature and the quenching time are controlled; 3) tempering the workpiece, controlling the temperature of each region, wherein the total tempering time of the workpiece is not less than 460min, and 4) cooling to obtain the processed high-strength high-toughness steel.

Inventors

  • REN YOUPING
  • YAN QIN
  • TANG BIN
  • TONG BO
  • Gao Qianling

Assignees

  • 湖南飞沃新能源科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260208

Claims (10)

  1. 1. A heat treatment method of high-strength high-toughness steel is characterized by comprising the following steps: 1) Placing a workpiece in a mesh belt furnace quenching furnace, wherein the workpiece is high-strength high-toughness steel to be treated, the mesh belt furnace quenching furnace drives the workpiece to operate, the quenching heating and heat preservation temperature of a mesh belt furnace quenching furnace 1 area is controlled to be not lower than 710 ℃, the quenching heating and heat preservation temperature of a 2-4 area is controlled to be not lower than 850 ℃, the quenching heating and heat preservation temperature of a 5-6 area is controlled to be not lower than 840 ℃, and the total quenching heating and heat preservation time of the workpiece is controlled to be not lower than 240min; 2) The workpiece enters a quenching tank for quenching and cooling, the cooling speed is controlled to be not lower than 50 ℃ per second, the maximum cooling speed is controlled to be not lower than 153 ℃ per second, the temperature of the quenching tank is not higher than 45 ℃, and the quenching and cooling time is controlled to be not lower than 28min; 3) Tempering the workpiece, wherein the tempering heating and heat preservation temperature of the 1 area is controlled to be 430-615 ℃, the tempering heating and heat preservation temperature of the 2-10 area is controlled to be 535-615 ℃, and the total tempering time of the workpiece is not less than 460min; 4) And cooling to obtain the processed high-strength high-toughness steel.
  2. 2. The heat treatment method according to claim 1, wherein in step 1), the quenching heating and holding temperature of the zone 1 of the quenching furnace of the mesh belt furnace is controlled to 780-800 ℃, the quenching heating and holding temperature of the zone 2-4 is controlled to 850-860 ℃, and the quenching heating and holding temperature of the zone 5-6 is controlled to 840-850 ℃.
  3. 3. The heat treatment method according to claim 2, wherein in the step 1), the quenching heating and holding temperature of the zone 1 of the quenching furnace of the mesh belt furnace is controlled to 790 ℃.
  4. 4. The heat treatment method according to claim 1, wherein in the step 2), the cooling rate is controlled to be 50-61 ℃ per second at 300 ℃, the maximum cooling rate is 153-160 ℃ per second, and the temperature of the quenching tank is 37-45 ℃.
  5. 5. The heat treatment method according to claim 1, wherein in the step 1), the quenching heating and heat preservation temperature of the zone 1 of the quenching furnace of the mesh belt furnace is controlled to 790 ℃, the quenching heating and heat preservation temperature of the zone 2-4 is controlled to 860 ℃, the quenching heating and heat preservation temperature of the zone 5-6 is controlled to 850 ℃, the total quenching heating and heat preservation time of the workpiece is 240min, and in the step 2), the cooling rate of 300 ℃ is controlled to 61 ℃ per second, the maximum cooling rate is 160 ℃ per second, the quenching bath temperature is controlled to 37 ℃, and the quenching cooling time is controlled to 28min.
  6. 6. The heat treatment method according to any one of claims 1 to 5, wherein the equipment for tempering treatment is a continuous idler tempering furnace.
  7. 7. The heat treatment method according to any one of claims 1 to 5, wherein the steel material comprises the following component ,C:0.40-0.44%、Si:0.15-0.35%、Mn:0.80-1.05%、P:≤0.015%、S:≤0.015%、Cr:1.20-1.30%、Mo:0.30-0.40%、Ni:0.35-0.45%,Al:0.02-0.05%,H:≤0.0002%,O:≤0.002%,B≤0.003%, by weight and the other element is Fe.
  8. 8. The heat treatment method according to claim 7, wherein the steel material comprises the following component ,C:0.40%、Si:0.26%、Mn:0.97%、P:0.012%、S:0.002%、Cr:1.25%、Mo:0.32%、Ni:0.37%,Al:0.035%,H:0.00005%,O:≤0.00078%, in parts by weight and the other element is Fe.
  9. 9. A high-strength and high-toughness steel product, which is obtained by the heat treatment method according to any one of claims 1 to 8.
  10. 10. A stud, wherein the stud is made of the high-strength high-toughness steel according to claim 9.

Description

High-strength high-toughness steel, stud and heat treatment method Technical Field The invention belongs to the technical field of metal heat treatment processes, and particularly relates to a high-strength high-toughness steel, a stud and a heat treatment method. Background Global wind power (especially offshore wind power) is in a high-speed growth period, and larger single-machine capacity (20 MW+Mich. In the current forward direction) is a main path for cost reduction and efficiency improvement. The larger the fan power is, the higher the tower barrel is, the thicker the diameter is, and the born load is increased in geometric progression. This will continue to drive the need for ultra high strength studs of M80 and even larger gauges (e.g., M85, M90). In order to meet the limit requirements of deeper sea areas and higher tower barrels, the requirements on the comprehensive indexes of strength, toughness and corrosion resistance of the screw columns are higher. Advanced surface strengthening techniques such as novel ultra-high strength steel, more optimized heat treatment process, laser cladding and the like are applied. Meanwhile, the wind turbine is a core stress member connected with flanges at each section of the tower barrel with the height of hundred meters, so that a main backbone of the tower barrel is formed, and the wind turbine bears the total weight (including a cabin, blades and the like), huge wind load (thrust force, bending moment), dynamic load during operation and impact in extreme weather. Its failure is directly equivalent to a tower structure failure. The M80 has huge specification, and is extremely challenging to material metallurgy, forging technology, heat treatment technology and thread rolling technology to ensure high strength and good toughness of the core and high precision and high fatigue strength of the thread surface. The high-quality stud can greatly reduce the operation and maintenance requirements of detection, re-tightening, replacement and the like in the service period, avoid unplanned shutdown caused by the problem of fasteners, remarkably improve the availability of a wind farm and the economic benefit of the whole life cycle, and has extremely small occupation ratio of the stud per se in the whole wind turbine generator set, but the quality of the stud per se is directly related to hundreds of times and thousands of times of the asset safety of a tower barrel, a cabin and even the whole wind turbine generator set. In the prior art, the M80 x L high-strength wind power tower barrel stud M80 x 660 generally adoptsThe process comprises the steps of quenching and tempering hot-rolled black skin material through medium-frequency induction heat treatment, turning 1, straightening, blanking, turning 2, laser marking, cleaning, shot blasting, thread rolling, cleaning, magnetic powder inspection, cleaning, shot blasting and hot-dip galvanizing, wherein the material is 80 x 6000 in mass. The 80 x 6000 hot-rolled black skin material is a hot-rolled black skin steel bar made of 4140-FW2 material and purchased directly from a steel mill; And (3) heat treatment tempering: The 80 x 6000 hot-rolled black skin material is subjected to heat treatment tempering by adopting an intermediate frequency induction quenching furnace and a continuous carrier roller tempering furnace; Turning 1 and straightening: The 80 x 6000 quenched and tempered black skin material adopts a coreless material lathe and straightening locomotive are processed into 75.25 X 6000 quenched and tempered silver bright material; Discharging, namely adopting CNC high-speed intelligent metal circular sawing machine to discharge 75.25 X 6000 quenched and tempered silver bright material blanking is a workpiece with the length of 660 mm; Turning 2, namely Chamfering the two end blank diameters and the end faces of the 75.25-660 mm workpiece by using a numerical control lathe; Marking, namely completing laser marking on one end face of the workpiece by adopting a laser marking machine; cleaning, namely cleaning and drying the marked workpiece by adopting a spray cleaning system; Shot blasting, namely performing shot blasting on the cleaned workpiece by adopting a suspension type shot blasting machine; thread rolling, namely finishing the thread forming at two ends of a workpiece by adopting a thread rolling machine; Cleaning, namely cleaning and baking the marked workpiece by adopting a spray cleaning system; flaw detection, namely performing magnetic powder flaw detection on the rod part and the thread end of the finished thread rolling molded workpiece by adopting a fluorescent magnetic powder flaw detector; Cleaning, namely cleaning and drying the magnetic powder inspection workpiece by adopting a spray cleaning system; Shot blasting, namely performing shot blasting on the cleaned workpiece by adopting a suspension type shot blasting machine; And (3) hot dip galvanizing, namely adopting an automatic hot dip galvan