CN112251570A - Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt - Google Patents
Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt Download PDFInfo
- Publication number
- CN112251570A CN112251570A CN202010976705.2A CN202010976705A CN112251570A CN 112251570 A CN112251570 A CN 112251570A CN 202010976705 A CN202010976705 A CN 202010976705A CN 112251570 A CN112251570 A CN 112251570A
- Authority
- CN
- China
- Prior art keywords
- wind power
- heat treatment
- power bolt
- hardness difference
- cross
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010438 heat treatment Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000005496 tempering Methods 0.000 claims abstract description 16
- 238000010791 quenching Methods 0.000 claims abstract description 8
- 230000000171 quenching effect Effects 0.000 claims abstract description 8
- 238000004321 preservation Methods 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 239000002904 solvent Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 4
- 239000002184 metal Substances 0.000 abstract description 2
- 238000004886 process control Methods 0.000 abstract description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003125 aqueous solvent Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
- C21D1/60—Aqueous agents
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D11/00—Process control or regulation for heat treatments
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0093—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for screws; for bolts
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
The invention discloses a heat treatment process for reducing the core surface hardness difference of a cross section of a wind power bolt, which belongs to the technical field of metal heat treatment, wherein the heat treatment process controls quenching and tempering parameters, so that the core surface hardness difference of a large-size bolt cross section above M56 is obviously reduced, and after the large-size bolt cross section is treated by a reasonable gradient tempering process, the maximum core surface hardness difference of the bolt is 20HV, and the requirement that the core surface hardness difference of a 10.9-grade wind power bolt is less than or equal to 30HV is met. And the secondary heat treatment is not needed for saving, so that the secondary heat treatment cost and the loss of material scrap are reduced.
Description
Technical Field
The invention belongs to the technical field of metal heat treatment, and particularly relates to a heat treatment process for reducing the hardness difference of a cross section core surface of a wind power bolt.
Background
With the high performance of wind turbine generators and the improvement of material use stress, higher design stress and weight reduction requirements are put on bolts, and the most effective measure is to improve the strength of steel for the bolts. At present, most of wind power high-strength bolts are 10.9 grades, the tensile strength Rm of the bolts is more than or equal to 1040Mpa, the elongation A after fracture is more than or equal to 9 percent, the reduction of area Z is more than or equal to 48 percent, and the low-temperature impact absorption energy (-40 ℃) KV2 is more than or equal to 27J. In order to ensure that the wind power fastening piece can obtain higher strength, steel grades such as 42CrMo, B7 and the like are generally selected to manufacture the wind power bolt. However, the existing quenching and tempering heat treatment process parameters are controlled more coarsely, the problems of high surface hardness and low core hardness are easy to occur, the core surface hardness difference is larger than 30HV, and the secondary heat treatment can be only adopted for saving and can also be scrapped in whole batch.
Disclosure of Invention
The purpose of the invention is as follows: in order to overcome the defects of the prior art, the invention provides a heat treatment process for reducing the surface hardness difference of the cross section center of a wind power bolt, which can reduce the surface hardness difference of the cross section center of a large-size wind power bolt and reduce the secondary heat treatment cost and the material scrapping loss.
The technical scheme is as follows: the invention relates to a heat treatment process for reducing the surface hardness difference of a cross section center of a wind power bolt, which comprises the following steps of:
(1) heating the wind power bolt to 880 +/-5 ℃, preserving heat for 180min, and carrying out hydrosolvent quenching;
(2) carrying out sectional gradient tempering on the quenched wind power bolt, wherein the tempering temperature of the first section and the second section is 540 +/-5 ℃, the heat preservation time is 90-120min, the tempering temperature of the third section and the fourth section is 565 +/-5 ℃, and the heat preservation time is 60-90 min;
(3) and cooling the tempered wind power bolt with water.
Specifically, the wind power bolt is a 42CrMo wind power bolt.
Has the advantages that: compared with the prior art, the heat treatment process controls quenching and tempering parameters, so that the hardness difference of the cross section core surface of the large-size bolt with the diameter of more than M56 is obviously reduced, the maximum hardness difference of the core surface of the bolt is 20HV after the large-size bolt is treated by the reasonable gradient tempering process, and the requirement that the hardness difference of the core surface of a 10.9-grade wind power bolt is less than or equal to 30HV is met. And the secondary heat treatment is not needed for saving, so that the secondary heat treatment cost and the loss of material scrap are reduced.
Detailed Description
The specific technical effects which can be produced by the process are further described in detail by combining the case that a certain factory in China adopts the process method to carry out heat treatment on the wind power bolt.
Specifically, the 42CrMo wind power bolt with the specification of M56mm or above is subjected to heat treatment in three furnaces, wherein the furnace numbers of the three furnaces are 1, 2 and 3 respectively. And the wind power bolt is heated by adopting a mesh belt furnace, and sectional gradient tempering is carried out by adopting a mesh belt tempering furnace.
The heating temperature of the furnace number 1 is 880 ℃, the amplitude of the wave is 5 ℃, the heat preservation time is 150min, and then PIG hydrosolvent with the concentration of 5 percent is adopted for quenching. Feeding the quenched wind power bolt into a mesh belt tempering furnace, controlling the temperature of 1-2 sections at 540 ℃, controlling the wave amplitude of the upper and lower sections at 5 ℃, and respectively keeping the temperature of 1-2 sections for 90min and 120 min. Controlling the temperature of 3-4 sections at 565 ℃, the amplitude of waves at 5 ℃ above and below, keeping the temperature of 3-4 sections for 60min and 90min respectively, and discharging and cooling.
The process and temperature control of the furnace No. 2 are the same as those of the furnace No. 1, and the different parts comprise that PIG aqueous solvent with the concentration of 6.7% is adopted for quenching, the heat preservation time in 1-2 sections is respectively controlled to be 100min and 110min, and the heat preservation time in 3-4 sections is respectively controlled to be 75min and 86 min.
The process and temperature control of the furnace No. 3 are the same as those of the furnace No. 1, and different parts comprise that PIG water solvent with the concentration of 8% is adopted for quenching, the heat preservation time in the 1-2 sections is respectively controlled to be 98min and 106min, and the heat preservation time in the 3-4 sections is respectively controlled to be 70min and 80 min.
The three-furnace wind-power bolt was tested, and the results are shown in table 1:
TABLE 1 wind power bolt hardness data
| Furnace number 1 | Furnace number 2 | Furnace number 3 | |
| Cross section core hardness/HV | 335 | 340 | 331 |
| Cross sectional surface hardness/HV | 346 | 359 | 350 |
| Hardness difference/HV of heart surface | 11 | 19 | 19 |
As can be seen from the above table, by adopting the process method, the core surface hardness difference of the 42CrMo wind power bolt with the specification of more than M56mm can be effectively controlled, so that the core surface hardness difference does not exceed 20HV and meets the standard requirement of less than or equal to 30 HV. In addition, the cross section core hardness and the surface hardness also meet the technical requirements.
Claims (6)
1. A heat treatment process for reducing the hardness difference of a cross section core surface of a wind power bolt is characterized by comprising the following steps of:
(1) heating the wind power bolt to 880 +/-5 ℃, preserving heat for 180min, and carrying out hydrosolvent quenching;
(2) carrying out sectional gradient tempering on the quenched wind power bolt, wherein the tempering temperature of the first section and the second section is 540 +/-5 ℃, the heat preservation time is 90-120min, the tempering temperature of the third section and the fourth section is 565 +/-5 ℃, and the heat preservation time is 60-90 min;
(3) and cooling the tempered wind power bolt with water.
2. The heat treatment process for reducing the hardness difference of the cross section center surface of the wind power bolt as claimed in claim 1, wherein the specification of the wind power bolt is more than M56 mm.
3. The heat treatment process for reducing the hardness difference of the cross section core surface of the wind power bolt as claimed in claim 1, wherein the concentration of the water solvent in the step (1) is 5-8%.
4. The heat treatment process for reducing the hardness difference of the cross section center surface of the wind power bolt as claimed in claim 1, wherein the wind power bolt is heated by a mesh belt furnace in the step (1).
5. The heat treatment process for reducing the hardness difference of the cross section center surface of the wind power bolt as claimed in claim 1, wherein a mesh belt tempering furnace is adopted in the step (2) to perform sectional gradient tempering on the wind power bolt.
6. The heat treatment process for reducing the hardness difference of the cross section center surface of the wind power bolt according to any one of claims 1 to 5, wherein the wind power bolt is a 42CrMo wind power bolt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010976705.2A CN112251570A (en) | 2020-09-16 | 2020-09-16 | Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010976705.2A CN112251570A (en) | 2020-09-16 | 2020-09-16 | Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112251570A true CN112251570A (en) | 2021-01-22 |
Family
ID=74231805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010976705.2A Pending CN112251570A (en) | 2020-09-16 | 2020-09-16 | Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112251570A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114737039A (en) * | 2022-03-28 | 2022-07-12 | 嘉兴恒瑞金属科技股份有限公司 | Heat treatment process for reducing hardness difference of wind power bolt |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101186963A (en) * | 2007-12-17 | 2008-05-28 | 国网北京电力建设研究院 | Heat treatment technique of high strength anchor bolt for extra-high voltage transmission line rod tower |
| CN102601597A (en) * | 2012-04-01 | 2012-07-25 | 株洲春华实业有限责任公司 | Machining process for railway riveting fastener molds |
| CN102943207A (en) * | 2012-11-09 | 2013-02-27 | 谢亚平 | High-strength fastener and processing method thereof |
| CN106148663A (en) * | 2016-07-06 | 2016-11-23 | 常熟市常力紧固件有限公司 | A kind of Technology for Heating Processing of automobile tire high rigidity bolt |
| CN109531063A (en) * | 2018-11-27 | 2019-03-29 | 重庆旺达汽车零部件有限公司 | A kind of processing method of high-strength bolts |
-
2020
- 2020-09-16 CN CN202010976705.2A patent/CN112251570A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101186963A (en) * | 2007-12-17 | 2008-05-28 | 国网北京电力建设研究院 | Heat treatment technique of high strength anchor bolt for extra-high voltage transmission line rod tower |
| CN102601597A (en) * | 2012-04-01 | 2012-07-25 | 株洲春华实业有限责任公司 | Machining process for railway riveting fastener molds |
| CN102943207A (en) * | 2012-11-09 | 2013-02-27 | 谢亚平 | High-strength fastener and processing method thereof |
| CN106148663A (en) * | 2016-07-06 | 2016-11-23 | 常熟市常力紧固件有限公司 | A kind of Technology for Heating Processing of automobile tire high rigidity bolt |
| CN109531063A (en) * | 2018-11-27 | 2019-03-29 | 重庆旺达汽车零部件有限公司 | A kind of processing method of high-strength bolts |
Non-Patent Citations (1)
| Title |
|---|
| 张先鸣: ""风电用高强度螺栓调质处理及质量控制"", 《电气制造》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114737039A (en) * | 2022-03-28 | 2022-07-12 | 嘉兴恒瑞金属科技股份有限公司 | Heat treatment process for reducing hardness difference of wind power bolt |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104946870A (en) | Heat treatment method for strength of 28CrMoNiV steel capable of improving industrial steam turbine rotor forge piece | |
| CN112322867B (en) | Heat treatment process for improving comprehensive mechanical properties of Cr-Ni-Mo large-scale forging for nuclear power | |
| CN102943169A (en) | Quenching and annealing preparation method of ultrahigh-strength thin steel plate for automobiles | |
| CN108441615B (en) | Hardening and tempering method of 12Cr13 stainless steel bar | |
| CN101660036B (en) | Heat treating method of high strength and high ductility steel tube | |
| CN106811580A (en) | A kind of annealing process of H13 hot die steels | |
| CN106048152B (en) | A kind of heat treatment method improving bar low-temperature impact toughness | |
| CN111020405A (en) | High-strength steel plate for pressurized water reactor nuclear power station containment shell head and manufacturing method thereof | |
| CN116622948B (en) | Stainless steel with equiaxial austenite-deformed austenite lamellar interphase heterostructure | |
| CN103320591A (en) | Heat treatment method of 30GrNi3MoV forged pieces | |
| CN105886717A (en) | Normalizing method for forging waste heat of steel | |
| CN104593573A (en) | Combined thermomechanical treatment strengthening method for efficiently improving strength and toughness of non-quenched and tempered steel | |
| CN109837379B (en) | Heat treatment process for thin-wall flexible gear of harmonic reducer | |
| CN113801978B (en) | Heat treatment method for improving strength and toughness of bearing steel 8Cr4Mo4V | |
| CN110684885B (en) | Forging control method for uniformly refining grain size of forge piece | |
| CN112251570A (en) | Heat treatment process for reducing hardness difference of cross section core surface of wind power bolt | |
| CN106435405A (en) | 42CrMo4 wind power main shaft after-forging heat treatment method of low-wind-speed wind turbine generator | |
| CN110551880A (en) | softening heat treatment process for small-size 22Si2MnCrNi2MoA steel rolled material | |
| WO2022166038A1 (en) | Hot rolled high strength steel long-shank bolt and manufacturing method therefor | |
| CN113186373A (en) | Preparation method of ultrahigh-strength ultrafine-grain steel plate | |
| CN103667615A (en) | heat treatment method of 42CrMo workpiece | |
| CN115927805B (en) | Heat treatment method for improving grain size of 10Cr11Co3W3NiMoVNbNB martensitic stainless steel forging | |
| CN114752855B (en) | 460 MPa-grade economical low-yield-ratio low-crack-sensitivity structural steel and manufacturing method thereof | |
| CN206052090U (en) | A kind of prestressed anchor annealing device | |
| CN105112634A (en) | Heat treatment process for hot-working die |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210122 |
|
| RJ01 | Rejection of invention patent application after publication |