WO2022083787A1 - 一种改善纯净度、可靠性的风电齿轮用钢及其冶炼方法 - Google Patents

一种改善纯净度、可靠性的风电齿轮用钢及其冶炼方法 Download PDF

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WO2022083787A1
WO2022083787A1 PCT/CN2021/132372 CN2021132372W WO2022083787A1 WO 2022083787 A1 WO2022083787 A1 WO 2022083787A1 CN 2021132372 W CN2021132372 W CN 2021132372W WO 2022083787 A1 WO2022083787 A1 WO 2022083787A1
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steel
wind power
smelting
slag
reliability
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PCT/CN2021/132372
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English (en)
French (fr)
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胡梦頔
雷应华
张洲
胡瑞海
郑文超
王占忠
周立新
刘光辉
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大冶特殊钢有限公司
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Priority to EP21882199.9A priority Critical patent/EP4092152A4/en
Priority to US17/792,473 priority patent/US11773466B2/en
Priority to JP2022542417A priority patent/JP7195487B1/ja
Publication of WO2022083787A1 publication Critical patent/WO2022083787A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/02—Dephosphorising or desulfurising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C—CHEMISTRY; METALLURGY
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    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/36—Processes yielding slags of special composition
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
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    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
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    • C21C7/064—Dephosphorising; Desulfurising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
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    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/064—Dephosphorising; Desulfurising
    • C21C7/0645—Agents used for dephosphorising or desulfurising
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    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
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    • C21C7/076—Use of slags or fluxes as treating agents
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/005—Preliminary treatment of scrap
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/006—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with use of an inert protective material including the use of an inert gas
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/04—Refining by applying a vacuum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/10—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with refining or fluxing agents; Use of materials therefor, e.g. slagging or scorifying agents
    • C22B9/106—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals with refining or fluxing agents; Use of materials therefor, e.g. slagging or scorifying agents the refining being obtained by intimately mixing the molten metal with a molten salt or slag
    • C—CHEMISTRY; METALLURGY
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    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/16—Remelting metals
    • C22B9/18—Electroslag remelting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C22C33/06—Making ferrous alloys by melting using master alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00—Refining of pig-iron; Cast iron
    • C21C1/02—Dephosphorising or desulfurising
    • C21C1/025—Agents used for dephosphorising or desulfurising
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the invention belongs to the technical field of metal smelting, and in particular relates to a steel for wind power gears with improved purity and reliability and a smelting method thereof.
  • Gears are the core material in the gearbox, and factors such as purity and compactness determine the service life of gears. , the service life of the gear often determines the overall life of a wind turbine gearbox.
  • the gear materials of the existing wind power gearboxes come from electric furnace mold ingots, and the process route is "electric furnace smelting-out-furnace refining-vacuum degassing-casting steel ingots". After years of development, this process has become mature, but the current electric furnace steel ingots.
  • the refractory materials are easily eroded and fall into the molten steel during the steelmaking process to form exogenous inclusions; Therefore, its purity cannot be effectively guaranteed, which makes it difficult to completely avoid large-particle inclusions in steel.
  • there are still various problems in the production and use of wind power gearbox gears that have not been effectively solved such as high defect detection rate, short gear fatigue life and easy breakage.
  • the purpose of the present invention is to provide a kind of steel for wind power gear and its smelting method with improved purity and reliability, in order to overcome the problem that the purity of the steel cannot be guaranteed due to the formation of inclusions in the steelmaking process in the above-mentioned prior art , the smelted steel is used for wind power gears, which greatly improves the pass rate of wind power gears and the fatigue life of gears.
  • the present invention provides the following technical solutions:
  • a steel for wind power gears with improved purity and reliability the chemical composition of the steel for wind power gears, in terms of mass percentage, includes: C: 0.15-0.19%, Si ⁇ 0.4%, Mn: 0.5-0.7%, P ⁇ 0.012%, S ⁇ 0.006%, Cr: 1.5-1.8%, Mo: 0.28-0.35%, Ni: 1.4-1.7%, Al: 0.02-0.04%, the balance is Fe and inevitable impurities.
  • the smelting method for improving the purity and reliability of wind power gear steel, as a preferred solution, the smelting method comprises the following steps:
  • Step S1 preliminary refining
  • the raw molten iron and scrap steel are added to the converter according to the ratio for primary smelting to obtain the primary molten steel;
  • Step S2 refining
  • the molten steel ladle containing the preliminary molten steel obtained in step S1 is hoisted into a refining furnace, and then premelted refining slag is added for refining, and the components in the molten steel are regulated to obtain a refined molten steel;
  • Step S3 vacuum degassing
  • the refined molten steel obtained in step S2 is subjected to vacuum degassing to remove hydrogen and oxygen in the molten steel;
  • step S3 The ladle after vacuum degassing in step S3 is hoisted into the continuous casting ladle for slag detection, the long nozzle is protected by inert gas and the immersion nozzle is protected, the tundish is protected by inert gas, the tundish is covered with slag, and the temperature is continuously measured, Using mold pre-slag protection casting, automatic liquid level control, mold electromagnetic stirring, water dynamic control in the second cooling zone, and electromagnetic stirring at the end, continuous casting billets are obtained under constant temperature and constant pulling speed;
  • Step S5 electroslag remelting in gas shielded furnace
  • step S4 The continuous casting billet obtained in step S4 is put into an electroslag furnace, a gas protection device is provided on the electroslag furnace, a protective gas is charged from the gas protection device, and then slag is added, and the slag is ignited and smelted. , feeding, to obtain wind power gear steel with improved purity and reliability.
  • the molten iron described in step S1 needs to be desulfurized using KR desulfurization equipment before being added to the converter, and the molten iron after desulfurization S accounts for the proportion of S.
  • the mass percentage ⁇ 0.003%.
  • the molten iron in step S1 accounts for 80-90% of the raw material by mass, and the balance is scrap steel;
  • the scrap is high-quality scrap, and impurities in the scrap include As ⁇ 0.04%, Sn ⁇ 0.03%, Pb ⁇ 0.002%, Sb ⁇ 0.005%, Cu ⁇ 0.20%, Ti ⁇ 0.0005 by mass percentage %; the steel scrap satisfies radiation ⁇ 0.15 ⁇ Sv/h or radioactivity ⁇ 0.1Bq/g.
  • the mass percentage of Ti in the initial molten steel obtained in step S1 is ⁇ 0.002%, and the mass of Ca is ⁇ 0.002%. Percentage ⁇ 0.001%.
  • the main components of the premelted refining slag in step S2 include Al 2 O 3 and CaF 2 ;
  • the grades of the inclusions in the refined molten steel obtained in step S2 are A fine ⁇ 1.5 grade, A coarse ⁇ 0.5 grade, B fine ⁇ 1.0 grade, B coarse ⁇ 0.5 grade, C fine grade 0, C coarse is grade 0, D fine is less than or equal to 1.0, D coarse is less than or equal to 1.0, and DS is less than or equal to 1.0.
  • the vacuum degassing treatment in step S3 is to use RH vacuum cycle degassing to achieve a degree of vacuum ⁇ 67Pa;
  • the mass percentage of hydrogen in the molten steel is less than 1.0 ppm, and the mass percentage of oxygen in the molten steel is less than or equal to 5.0 ppm.
  • the constant temperature transverse drawing speed in step S4 is specifically: the temperature is 1500-1600 °C, and the drawing speed is 0.20-0.28m/ min;
  • the central shrinkage cavity of the continuous casting slab obtained in step S4 is not greater than grade 1.0;
  • the grades of the internal inclusions of the continuous casting slab are: A type inclusions ⁇ 1.5 grades, B type inclusions ⁇ 1.0 grades, C type inclusions ⁇ 0.5 grades, D type inclusions ⁇ 1.0 grades.
  • the slag material added during electroslag remelting in step S5 is a binary slag system, and the binary slag system is composed of Ca-type slag.
  • the binary slag system is a CaF 2 and Al 2 O 3 slag system, and the mass ratio of CaF 2 and Al 2 O 3 is 7:3.
  • the melting rate of the smelting in step S5 is 12-15 kg/min;
  • the protective gas charged in step S5 is argon or nitrogen;
  • the protective gas charged in step S5 is argon.
  • the smelting method in the present invention is changed from “electric furnace smelting + die casting” to “converter smelting + continuous casting” on the basis of the existing process, and the process of "gas shielded furnace electroslag remelting" is added at the same time; the continuous casting process is adopted; A pure electroslag masterbatch is obtained.
  • an electroslag remelting process is added to further improve the purity of the material.
  • the liquid metal is covered by the slag pool to avoid re-oxidation, and at the same time, it is cooled by water.
  • the melting, refining and solidification in the mold prevents the contamination of the steel by the refractory materials; before the steel ingot is solidified, there is a molten metal pool and a slag pool at its upper end, which play the role of heat preservation and feeding to ensure the compactness of the steel ingot; in the inert gas Electroslag remelting is carried out in a protective atmosphere, and corresponding auxiliary equipment (gas shielded electroslag furnace double-layer fume hood) is added on the basis of the existing equipment, which enhances the effect of gas shielding and effectively avoids the easy burning of alloys. Excessive burning of elements keeps them within a relatively narrow range, while avoiding the generation of endogenous inclusions.
  • the steel material prepared by the smelting method of the present invention is used for wind power gears, and has excellent flaw detection performance after use. Compared with the smelting process of "electric furnace smelting + die casting" in the prior art before the process change, the qualified rate of flaw detection has been significantly improved , and also improve the production efficiency; through ASPEX scanning, compared with the smelting process of "electric furnace smelting + die casting” in the prior art, the large particle inclusions in the steel material prepared by the smelting method of the present invention are significantly reduced; Observed under a microscope, compared with the smelting process of "electric furnace smelting + die casting” in the prior art, the inclusions in the steel material prepared in the present invention are more fine and dispersed; In the smelting process of "electric furnace smelting + die casting", the low-magnification structure of the steel material prepared in the present invention is more dense.
  • Fig. 2 is the morphology of the steel material for wind power gear in the specific embodiment 1 of the present invention under a high-power microscope;
  • Fig. 3 is the morphology of the steel material for wind power gear in the specific comparative example 1 of the present invention under a high-power microscope;
  • FIG. 5 is a low-magnification microstructure diagram of the steel material for wind power gears in the specific comparative example 1 of the present invention after pickling.
  • the smelting method of steel for wind power gears with improved purity and reliability in the present invention is based on the existing process, which is changed from “electric furnace smelting + die casting” to “converter smelting + continuous casting", while adding "gas protection” Furnace electroslag remelting” process; in the electroslag remelting process, the liquid metal is covered by the slag pool to avoid re-oxidation, and at the same time, it is melted, refined and solidified in the water-cooled crystallizer, which prevents the contamination of the steel by the refractory materials; steel ingots Before solidification, there are metal molten pools and slag pools at its upper end, which play the role of heat preservation and feeding to ensure the compactness of the ingot; electroslag remelting is carried out in an inert gas protective atmosphere, and at the same time, on the basis of the existing equipment, the Corresponding auxiliary equipment (gas shielded electroslag furnace double-layer fume hood) enhances the effect of gas
  • the invention provides a wind power gear steel with improved purity and reliability.
  • the chemical composition of the wind power gear steel is C: 0.15-0.19% (for example, 0.15%, 0.155%, 0.16%, 0.165%, 0.17%, 0.175%, 0.18%, 0.185%, 0.19%), Si ⁇ 0.4% (such as 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%), Mn: 0.5 ⁇ 0.7% (such as 0.5%, 0.55%, 0.6%, 0.65%, 0.7%), P ⁇ 0.012% (such as 0, 0.002%, 0.004%, 0.006%, 0.008%, 0.01%, 0.012%) , S ⁇ 0.006% (such as 0, 0.001%, 0.002, 0.003, 0.004, 0.005, 0.006), Cr: 1.5 ⁇ 1.8% (such as 1.5%, 1.55%, 1.6%, 1.65%, 1.7%, 1.75%, 1.8 %), Mo: 0.28 ⁇ 0.35% (such as 0.28%, 0.29%,
  • the present invention also provides a smelting method of steel for wind power gears with improved purity and reliability, the smelting method comprising the following steps:
  • Step S1 preliminary refining
  • converter steelmaking uses molten iron, scrap steel, etc. as the main raw materials, and does not rely on external energy, but relies on the physical heat of the molten iron itself and the chemical reaction between the components of the molten iron to generate heat to complete the steelmaking process in the converter.
  • the molten iron needs to be desulfurized by KR desulfurization equipment before being added to the converter. 0.002%, 0.0025%, 0.003%).
  • the KR desulfurization equipment adopts a stirring paddle with aeration and stirring function. The stirring paddle enters the molten iron ladle molten pool to a certain depth. With the vortex generated by its rotation, the weighed desulfurizer is added to the surface of the molten iron by the feeder. And it is swept into the molten iron by the whirlpool to make the calcium oxide-based desulfurization powder fully contact and react with the molten iron to achieve the purpose of desulfurization.
  • the molten iron is hot charged in a large blast furnace of 1780 m 3 .
  • the mass percentage of molten iron in the raw material in step S1 is 80-90% (eg, 80%, 82%, 84%, 86%, 88%, 90%), and the balance is scrap steel.
  • the scrap steel is high-quality scrap steel, and impurities in the scrap steel are calculated by mass percentage, including As ⁇ 0.04% (such as 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%), Sn ⁇ 0.03% (eg 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.03%), Pb ⁇ 0.002% (eg 0.0005%, 0.001%, 0.0015%, 0.002%), Sb ⁇ 0.005% (eg 0.0005 %, 0.001%, 0.0015%, 0.002%, 0.0025%, 0.003%, 0.0035%, 0.004%, 0.0045%), Cu ⁇ 0.20% (such as 0.01%, 0.03%, 0.05%, 0.1%, 0.15%, 0.17% , 0.2%), Ti ⁇ 0.0005% (such as 0.0001%, 0.0002%, 0.0003%, 0.0004%, 0.0005%); scrap steel also meets radiation ⁇ 0.15 ⁇ Sv/h (such as 0.02), 0.00
  • the mass percentage of Ti in the initial molten steel obtained in step S1 is ⁇ 0.002% (for example, 0.005%, 0.01%, 0.015%, 0.02%), and the mass percentage of Ca is ⁇ 0.001 % (eg 0.0002%, 0.0004%, 0.0006%, 0.0008%, 0.001%).
  • Step S2 refining
  • the ladle containing the primary molten steel obtained in step S1 is hoisted into a refining furnace, and then pre-melted refining slag is added for refining, and the components in the molten steel are regulated to obtain a refined molten steel.
  • regulating the composition of molten steel is to fine-tune the composition of molten steel by accurately calculating the amount of alloy material to be added.
  • the main components of the pre-melted refining slag in step S2 include Al 2 O 3 and CaF 2 ; the pre-melted refining slag is used to adsorb inclusions in molten steel.
  • the melting point of the premelting type refining slag is very low, which can be melted at the fastest speed, shortening the residence time of molten steel in the refining bag, and strengthening the smelting process.
  • Pre-melting refining slag selects various raw materials for sintering or melting to generate minerals mainly 12CaO ⁇ 7Al2O3, the content of which is greater than 85%, and a large amount of calcified components can react with oxygen and sulfur in molten steel to form products with low melting point and easy to float , reduce the content of harmful elements and impurities in steel, and achieve the purpose of purifying molten steel.
  • adding pre-melting refining slag can effectively shorten the steelmaking time, has a strong ability to absorb non-metallic inclusions in steel, and has a significant effect on purifying molten steel.
  • the grades of the inclusions in the refined molten steel obtained in step S2 reach A fine ⁇ 1.5 grade, A coarse ⁇ 0.5 grade, B fine ⁇ 1.0 grade, B coarse ⁇ 0.5 grade, C fine is 0 grade, C Coarse is grade 0, D fine ⁇ 1.0 grade, D coarse ⁇ 1.0 grade, DS ⁇ 1.0 grade.
  • the evaluation method of non-metallic inclusions in steel can refer to GB/T10561-2005 standard.
  • the JK standard rating is adopted, and the inclusions are divided into four basic types: A, B, C and D, which are sulfide, alumina, silicate and spherical oxide respectively.
  • Each type of inclusion is classified according to thickness and diameter.
  • the difference is divided into two series: fine series and coarse series, and each inclusion is composed of five grades (1-5) that identify the increasing number of inclusions.
  • half-level is allowed, and the result is expressed by the number of levels of the worst field of view for each type of inclusion in each sample.
  • Step S3 vacuum degassing
  • the refined molten steel obtained in step S2 is subjected to vacuum degassing treatment to remove hydrogen and oxygen in the molten steel.
  • the vacuum degassing treatment in step S3 is to use RH vacuum cycle degassing to reach a vacuum degree of ⁇ 67Pa; under normal circumstances, the vacuum degassing treatment time in step S3 needs to exceed 20min (such as 20min, 22min, 24min, 26min, 28min, 30min, 32min, 34min, 36min, 38min, 40min).
  • the mass percentage of hydrogen in molten steel is ⁇ 1.0ppm (such as 0.1ppm, 0.2ppm, 0.3ppm, 0.4ppm, 0.5ppm, 0.6ppm, 0.7ppm, 0.8ppm, 0.9ppm),
  • the mass percentage of oxygen in molten steel is less than or equal to 5.0ppm (such as 0.5ppm, 1ppm, 1.5ppm, 2ppm, 2.5ppm, 3ppm, 3.5ppm, 4ppm, 4.5ppm, 4.8ppm).
  • step S3 The ladle after vacuum degassing in step S3 is hoisted into the continuous casting ladle for slag detection, the long nozzle is protected by inert gas and the immersion nozzle is protected (the immersion type prevents the molten steel from contacting with air), and the tundish is protected by inert gas , tundish covering slag, continuous temperature measurement, using mold pre-melting slag protection casting, liquid level automatic control, mold electromagnetic stirring, water dynamic control in the secondary cooling zone, and electromagnetic stirring at the end, under constant temperature and constant pulling speed, continuous billet.
  • the inert gas is preferably argon.
  • the continuous casting in step S4 uses the tundish induction heating measure, and the whole continuous casting process realizes constant temperature and constant pulling speed.
  • the tundish inert gas protection is to use argon for gas protection
  • the tundish covering slag is a tundish covering agent, and its main components include magnesium oxide, silicon dioxide and silicon oxide.
  • the tundish covering agent is mainly used for thermal insulation, adsorption of floating inclusions in steel, and air isolation to prevent secondary oxidation of molten steel .
  • the constant temperature transverse drawing speed in step S4 is specifically, the temperature is 1500-1600°C (for example, 1510°C, 1520°C, 1530°C, 1540°C, 1550°C, 1560°C, 1570°C, 1580°C, 1590°C), the pulling speed is 0.20 ⁇ 0.28m/min (such as 0.21m/min, 0.22m/min, 0.23m/min, 0.24m/min, 0.25m/min, 0.26m/min, 0.27m/min) .
  • the central shrinkage cavity of the continuous casting billet obtained in step S4 is not greater than level 1.0;
  • the surface of the continuous casting billet is not allowed to have transverse cracks, slag pits, heavy skin and other defects; the level of the internal inclusions of the continuous casting billet is: Type A inclusions ⁇ 1.5, Type B inclusions ⁇ 1.0, Type C inclusions ⁇ 0.5 grade, D-type inclusions ⁇ 1.0 grade.
  • Step S5 electroslag remelting in gas shielded furnace
  • step S4 The continuous casting billet obtained in step S4 is put into an electroslag furnace, a gas protection device is provided on the electroslag furnace, a protective gas is charged from the gas protection device, and then slag is added, and the slag is ignited and smelted. , feeding, to obtain wind power gear steel with improved purity and reliability.
  • Electroslag remelting is a secondary refining technology, which is a comprehensive metallurgical casting process that combines secondary refining and directional solidification of molten steel.
  • the principle is that the current passes through the liquid slag pool slag to resist heat, melts the metal electrode, and the molten metal collects into molten droplets, which pass through the slag layer and enter the metal molten pool when dripping, and then crystallize and solidify into a steel ingot in a water-cooled crystallizer.
  • the liquid metal is covered by the slag pool to avoid re-oxidation, and at the same time, it is melted, refined and solidified in the water-cooled crystallizer, which prevents the refractory material from polluting the steel; the steel ingot solidifies Before, there are metal molten pool and slag pool at its upper end, which play the role of heat preservation and feeding, and ensure the compactness of the ingot.
  • argon gas is selected as the protective gas, and corresponding auxiliary equipment is added to the equipment at the same time, and the "gas shielded electroslag furnace double-layer fume hood" with the application number of 201320698946.0 is used to enhance the effect of gas shielding and effectively It avoids the excessive burning loss of the easy-to-burn alloy elements, so that it can be controlled within a relatively narrow range, and at the same time, the generation of endogenous inclusions is avoided.
  • the slag material added during electroslag remelting in step S5 is a binary slag system, and the binary slag system is composed of Ca-type compounds and Al-type compounds.
  • the binary slag system is a CaF 2 and Al 2 O 3 slag system, and the mass ratio of CaF 2 and Al 2 O 3 is 7:3.
  • the frequency of the power supply in the electroslag remelting in step S5 is 10-12 Hz (for example, 10 Hz, 10.5 Hz, 11 Hz, 11.5 Hz, 12 Hz). Since the power frequency has an impact on the crystallization quality of the ingot, low frequency is good for the crystallization of the ingot, but it will increase the oxygen content in the ingot. Therefore, the frequency of the power supply needs to be strictly controlled during the electroslag remelting process.
  • the melting rate of smelting in step S5 is 12-15kg/min (eg 12.5kg/min, 13kg/min, 13.5kg/min, 14kg/min, 14.5kg/min).
  • the protective gas charged in step S5 is argon or nitrogen.
  • the shielding gas is argon.
  • the impurities in the scrap steel used in the following examples and comparative examples are calculated by mass percentage, including As ⁇ 0.04%, Sn ⁇ 0.03%, Pb ⁇ 0.002%, Sb ⁇ 0.005%, Cu ⁇ 0.20%, Ti ⁇ 0.0005%; At the same time, the scrap steel also meets the radiation ⁇ 0.15 ⁇ Sv/h or the radioactivity ⁇ 0.1Bq/g.
  • This embodiment provides a wind power gear steel with improved purity and reliability.
  • the chemical composition of the wind power gear steel is C: 0.17%, Si ⁇ 0.3%, Mn: 0.6%, P ⁇ 0.01% in terms of mass percentages , S ⁇ 0.006%, Cr: 1.6%, Mo: 0.30%, Ni: 1.5%, Al: 0.03%, the balance is Fe and inevitable impurities.
  • a forging plant A adopts a smelting method for improving the purity and reliability of steel for wind power gears to manufacture steel for wind power gears, and the specific smelting method includes the following steps:
  • Step S1 preliminary refining
  • the molten iron is charged in a 1780m3 large blast furnace, and desulfurized until the mass percentage of S in the molten iron is ⁇ 0.003%.
  • the mass percentage is 80%, and the balance is high-quality scrap) into the converter for primary smelting to obtain primary molten steel;
  • Step S2 refining
  • the molten steel ladle containing the preliminary molten steel obtained in step S1 is hoisted into a refining furnace, and then pre-melting type refining slag is added for refining, and the components in the molten steel are fine-tuned and controlled by ladle refining to obtain a refined molten steel, Make the grade of inclusions in the refined molten steel reach A fine ⁇ 1.5 grade, A coarse ⁇ 0.5 grade, B fine ⁇ 1.0 grade, B coarse ⁇ 0.5 grade, C fine grade 0, C coarse grade 0, D fine ⁇ 1.0 grade, D coarse ⁇ 1.0 grade, DS ⁇ 1.0 grade;
  • Step S3 vacuum degassing
  • the refined molten steel obtained in step S2 is degassed by RH vacuum cycle, so that the mass percentage of hydrogen in the molten steel is ⁇ 1.0 ppm, and the mass percentage of oxygen in the molten steel is less than or equal to 5.0 ppm;
  • step S3 The ladle after vacuum degassing in step S3 is hoisted into the continuous casting ladle for slag detection, the long nozzle is protected by argon gas and the immersion nozzle is protected, the tundish is protected by gas, the tundish is covered with slag, and the temperature is continuously measured.
  • Step S5 electroslag remelting in gas shielded furnace
  • the continuous casting billet obtained in step S4 is put into an electroslag furnace, which is provided with a "gas shielded electroslag furnace double-layer fume hood" with the application number of 201320698946.0, filled with argon, and then at a frequency of 10Hz Add binary slag system (the mass ratio of CaF 2 and Al 2 O 3 is 7:3), ignite the slag, smelt and feed at a melting rate of 14kg/min, and obtain wind power with improved purity and reliability Steel for gears.
  • an electroslag furnace which is provided with a "gas shielded electroslag furnace double-layer fume hood" with the application number of 201320698946.0, filled with argon, and then at a frequency of 10Hz
  • Add binary slag system the mass ratio of CaF 2 and Al 2 O 3 is 7:3
  • a forging plant A uses the steel manufactured by the smelting method in this example for the production of wind power gearboxes, and conducts a flaw detection test on it.
  • the results show that when the detection amount is 1,000 pieces, the number of flat-bottom holes 0.8 FBH for flaw detection is 997.
  • the qualified rate of 0.8FBH for flaw detection flat bottom hole is 99.7%.
  • the steel produced in this example is observed under a microscope of 1000 times magnification, and the result is shown in FIG. 2 , the inclusions in the steel produced in this example are more fine and dispersed.
  • the low-magnification structure of the steel produced in this example is compared with pickling, and the result is shown in FIG. 4 , the low-magnification structure of the steel prepared in this example is more dense.
  • This embodiment provides a steel for wind power gears with improved purity and reliability.
  • the chemical composition of the steel for wind power gears is calculated by mass percentage, C: 0.15%, Si ⁇ 0.4%, Mn: 0.5%, P ⁇ 0.012% , S ⁇ 0.006%, Cr: 1.5%, Mo: 0.28%, Ni: 1.4%, Al: 0.02%, the balance is Fe and inevitable impurities.
  • a certain B forging plant adopts a smelting method for wind power gear steel with improved purity and reliability to manufacture wind power gear steel.
  • the raw materials added in step S1 are desulfurized molten iron and High-quality scrap steel is added to the converter according to the mass ratio of 9:1 (the mass percentage of molten iron accounting for raw materials is 90%, and the balance is high-quality scrap steel) to carry out primary smelting to obtain primary molten steel; other steps are the same as in Example 1, here No longer.
  • a B forging plant uses the steel manufactured by the smelting method in this embodiment for the production of wind power gearboxes, and conducts a flaw detection test on it.
  • the results show that when the detection amount is 1,000 pieces, the number of flat-bottom holes 0.8 FBH for flaw detection is 1,000. pieces, that is, the qualified rate of 0.8FBH for flaw detection flat-bottomed holes is 100%.
  • This comparative example provides a kind of steel for wind power gear, which is manufactured by a forging plant A using the same raw materials as in Example 1, and using the smelting process of "electric furnace smelting + die casting" in the prior art, The specific smelting process is not repeated here.
  • the chemical composition of the steel for wind power gear manufactured in this comparative example is calculated by mass percentage, including C: 0.16%, Si ⁇ 0.25%, Mn: 0.7%, P ⁇ 0.015%, S ⁇ 0.010%, Cr: 1.5%, Mo: 0.27%, Ni: 1.52%, Al: 0.035%, and the balance is Fe and inevitable impurities.
  • a forging plant A uses the steel produced by the smelting method in this comparative example for the production of wind power gearboxes, and conducts a flaw detection test on it.
  • the results show that when the detection amount is 1,000 pieces, the number of flat-bottom holes 0.8 FBH for flaw detection is 876 The qualified rate of 0.8FBH for flaw detection flat bottom hole is 87.6%.
  • the low-magnification structure of the steel produced in this comparative example is compared with pickling, and the results are shown in Figure 5.
  • the low-magnification structure of the steel prepared in this comparative example is compared with that of the steel prepared in Example 1. Organization is rough.
  • This comparative example provides a kind of steel for wind power gear, which is manufactured by a B forging plant using the same raw materials as in Example 2, and using the smelting process of "electric furnace smelting + die casting" in the prior art, The specific smelting process is not repeated here.
  • the chemical composition of the steel for wind power gear manufactured in this comparative example is calculated by mass percentage, including C: 0.16%, Si ⁇ 0.25%, Mn: 0.65%, P ⁇ 0.015%, S ⁇ 0.010%, Cr: 1.5%, Mo: 0.29%, Ni: 1.50%, Al: 0.035%, and the balance is Fe and inevitable impurities.
  • a B forging plant uses the steel produced by the smelting method in this comparative example for the production of wind power gearboxes, and conducts a flaw detection test on it.
  • the results show that when the detection amount is 1,000 pieces, the number of flat-bottom holes 0.8 FBH for flaw detection is 883 The qualified rate of 0.8FBH for flaw detection flat bottom hole is 88.3%.
  • the steel material prepared by the smelting method of the present invention is used for wind power gears, and the flaw detection performance after use is superior.
  • the flaw detection is qualified Through ASPEX scanning, compared with the smelting process of "electric furnace smelting + die casting" in the prior art, the steel material prepared by the smelting method of the present invention contains large particles of inclusions.
  • the inclusions in the steel material prepared in the present invention are more fine and dispersed; after pickling, the low-magnification structure is compared , and the smelting process of "electric furnace smelting + die casting" in the prior art, the low-magnification structure of the steel material prepared in the present invention is more dense.

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Abstract

本发明提供一种改善纯净度、可靠性的风电齿轮用钢，化学成分按照质量百分比计，包括，C：0.15～0.19％，Si≤0.4％，Mn：0.5～0.7％，P≤0.012％，S≤0.006％，Cr：1.5～1.8％，Mo：0.28～0.35％，Ni：1.4～1.7％，Al：0.02～0.04％，余量为Fe和不可避免的杂质。冶炼方法为将原料加入转炉中初炼，转至精炼炉中精炼，经真空脱气后进行连铸，转入气体保护炉中电渣重熔。本发明连铸得到纯净的电渣母料，经电渣重熔工序，使材料的纯净度进一步提升；所制备的钢材料用于风电齿轮，探伤合格率显著提升，且钢材料中大颗粒夹杂物明显减少，夹杂物更加细小且弥散。

Description

一种改善纯净度、可靠性的风电齿轮用钢及其冶炼方法 技术领域
本发明属于金属冶炼技术领域，具体涉及一种改善纯净度、可靠性的风电齿轮用钢及其冶炼方法。
背景技术
目前国内风电行业发展越来越迅速，风电机组安装之处往往处于戈壁、荒漠、海洋等自然条件较为恶劣的区域，若齿轮箱发生故障，维护极为困难，所以其可靠性要求比一般机械高很多。齿轮箱的造价通常占风电设备总造价的15％-20％，它的研究和开发是风电技术的核心。
行业内对风电齿轮材料的纯净度、使用寿命以及变速齿轮箱的维护、更换周期提出了更高的要求，齿轮作为齿轮箱中的核心材料，纯净度、致密性等因素决定了齿轮的使用寿命，齿轮的使用寿命往往决定了一台风电齿轮箱的总体寿命。
现有风电齿轮箱齿轮材料都来自于电炉模铸锭，工艺路线为“电炉冶炼-炉外精炼-真空脱气-浇铸钢锭”，该工艺经过多年的发展，已趋于成熟，但目前电炉钢锭的炼钢工艺，一直存在两个问题未能得到有效解决：炼钢过程中耐火材料容易被侵蚀落入钢水中形成外生夹杂物；冶炼过程无法全程处于气体保护中，容易形成内生夹杂物；因而其纯净度无法得到有效的保障，导致钢中大颗粒夹杂物很难完全避免。除此之外，目前风电齿轮箱齿轮的生产和使用过程中依然存在各种各样的问题未能有效解决，如探伤不合格率高、齿轮疲劳寿命短导致容易断裂等问题。
因此，需要提供一种针对上述现有技术不足的改进技术方案，寻找一种高纯净度、高可靠性的齿轮材料，成为未来风电行业发展的一种趋势。
发明内容
本发明的目的是提供一种改善纯净度、可靠性的风电齿轮用钢及其冶炼方法，用以克服上述现有技术中在炼钢过程中形成夹杂物使得钢的纯净度无 法得到保障的问题，将所冶炼的钢用于风电齿轮大大提高了风电齿轮的探伤合格率和齿轮的疲劳寿命。
为了实现上述目的，本发明提供如下技术方案：
一种改善纯净度、可靠性的风电齿轮用钢，所述风电齿轮用钢的化学成分按照质量百分比计，包括，C：0.15～0.19％，Si≤0.4％，Mn：0.5～0.7％，P≤0.012％，S≤0.006％，Cr：1.5～1.8％，Mo：0.28～0.35％，Ni：1.4～1.7％，Al：0.02～0.04％，余量为Fe和不可避免的杂质。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，所述冶炼方法包括以下步骤：
步骤S1、初炼；
将原料铁水和废钢按照配比加入转炉中进行初炼，得到初炼钢液；
步骤S2、精炼；
将步骤S1中得到的装有所述初炼钢液的钢水包吊至精炼炉中，然后加入预熔型精炼渣进行精炼，调控钢液中的成分，得到精炼钢液；
步骤S3、真空脱气；
将步骤S2中得到的精炼钢液进行真空脱气处理，脱除钢液中的氢和氧；
步骤S4、连铸；
将步骤S3中真空脱气后的钢水包吊至连铸大包中进行下渣检测，长水口惰性气体保护和浸入式水口进行保护，中间包惰性气体保护、中间包覆盖渣、连续测温，采用结晶器预熔渣保护浇铸、液面自动控制、结晶器电磁搅拌，二冷区水动态控制、末段电磁搅拌，在恒温恒拉速下，得到连铸坯；
步骤S5、气体保护炉电渣重熔
将步骤S4中得到的所述连铸坯放入电渣炉中，电渣炉上设置有气体保护装置，从气体保护装置中充入保护气体，然后加入渣料，化渣后引燃、熔炼、补缩，得到改善纯净度、可靠性的风电齿轮用钢。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S1中所述铁水在加入转炉前需要采用KR脱硫设备进行脱硫，经过脱硫后的铁水中S所占的质量百分比≤0.003％。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S1中所述铁水占原料的质量百分比为80～90％，余量为废钢；
优选地，所述废钢为优质废钢，所述废钢中的杂质按照质量百分比计，包括As≤0.04％，Sn≤0.03％，Pb≤0.002％，Sb≤0.005％，Cu≤0.20％，Ti≤0.0005％；所述废钢满足辐射≤0.15μSv/h或放射性≤0.1Bq/g。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S1中得到的所述初炼钢液中Ti所占的质量百分比≤0.002％，Ca所占的质量百分比≤0.001％。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S2中的预熔型精炼渣的主要成分包括Al 2O 3和CaF 2；
优选地，步骤S2中得到的所述精炼钢液中夹杂物的级别达到A细≤1.5级，A粗≤0.5级，B细≤1.0级，B粗≤0.5级，C细为0级，C粗为0级，D细≤1.0级，D粗≤1.0级，DS≤1.0级。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S3中的所述真空脱气处理是采用RH真空循环脱气，达到真空度≤67Pa；
经过所述真空脱气处理后，钢液中的氢所占的质量百分比＜1.0ppm，钢液中的氧所占的质量百分比≤5.0ppm。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S4中所述恒温横拉速具体为：温度为1500～1600℃，拉速为0.20～0.28m/min；
优选地，步骤S4中得到的所述连铸坯中心缩孔不大于1.0级；
更优选地，所述连铸坯的内部夹杂物的级别为：A类夹杂物≤1.5级，B类夹杂物≤1.0级，C类夹杂物≤0.5级，D类夹杂物≤1.0级。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S5中电渣重熔时加入的渣料为二元渣系，所述二元渣系由Ca类化合物和Al类化合物组成；
优选地，所述二元渣系为CaF 2和Al 2O 3渣系，CaF 2和Al 2O 3的质量比为7：3。
如上所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，作为优选方案，步骤S5中所述熔炼的熔速为12～15kg/min；
优选地，步骤S5中充入的所述保护气体为氩气或氮气；
优选地，步骤S5中充入的所述保护气体为氩气。
与最接近的现有技术相比，本发明提供的技术方案具有如下优异效果：
本发明中的冶炼方法是在现有工序的基础上由“电炉冶炼+模铸”改为“转炉冶炼+连铸”，同时增加了“气体保护炉电渣重熔”工序；采用连铸工艺得到纯净的电渣母料，连铸后增加了电渣重熔工序，使得材料的纯净度进一步提升；电渣重熔过程中，液态金属在渣池覆盖下，避免了再氧化，同时在水冷结晶器内熔化、精炼、凝固，杜绝了耐火材料对钢的污染；钢锭凝固前，在它上端有金属熔池和渣池，起到保温和补缩作用，保证钢锭的致密性；在惰性气体保护气氛中进行电渣重熔，同时在现有设备的基础上增加了相应的辅助设备(气体保护电渣炉双层烟罩)，增强了气体保护的效果，有效的避免了易烧损合金元素的过度烧损，使其控制在比较窄的范围内，同时避免了内生夹杂物的产生。
本发明中的冶炼方法所制备的钢材料用于风电齿轮，使用后探伤检测表现优越，较工艺变更之前的现有技术中“电炉冶炼+模铸”的冶炼工艺，探伤合格率有了显著提升，也提高了生产效率；通过ASPEX扫描，与现有技术中“电炉冶炼+模铸”的冶炼工艺相比，本发明中的冶炼方法所制备的钢材料中大颗粒夹杂物明显减少；在高倍显微镜下观察，与现有技术中“电炉冶炼+模铸”的冶炼工艺相比，本发明中所制备的钢材料中夹杂物更加细小且弥散；经过酸洗低倍组织对比，与现有技术中“电炉冶炼+模铸”的冶炼工艺，本发明中所制备的钢材料低倍组织更加致密。
附图说明
构成本申请的一部分的说明书附图用来提供对本发明的进一步理解，本发明的示意性实施例及其说明用于解释本发明，并不构成对本发明的不当限定。其中：
图1为本发明具体实施例1和对照例1中冶炼出的风电齿轮用钢的钢中最大夹杂物的尺寸ASPEX扫描测试结果对比图；
图2为本发明具体实施例1中风电齿轮用钢材料在高倍显微镜下的形貌；
图3为本发明具体对照例1中风电齿轮用钢材料在高倍显微镜下的形貌；
图4为本发明具体实施例1中风电齿轮用钢材料经过酸洗低倍组织图；
图5为本发明具体对照例1中风电齿轮用钢材料经过酸洗低倍组织图。
具体实施方式
下面将对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员所获得的所有其他实施例，都属于本发明保护的范围。
下面将参考附图并结合实施例来详细说明本发明。需要说明的是，在不冲突的情况下，本发明中的实施例及实施例中的特征可以相互组合。
本发明中的改善纯净度、可靠性的风电齿轮用钢的冶炼方法是在现有工序的基础上由“电炉冶炼+模铸”改为“转炉冶炼+连铸”，同时增加了“气体保护炉电渣重熔”工序；电渣重熔过程中，液态金属在渣池覆盖下，避免了再氧化，同时在水冷结晶器内熔化、精炼、凝固，杜绝了耐火材料对钢的污染；钢锭凝固前，在它上端有金属熔池和渣池，起到保温和补缩作用，保证钢锭的致密性；在惰性气体保护气氛中进行电渣重熔，同时在现有设备的基础上增加了相应的辅助设备(气体保护电渣炉双层烟罩)，增强了气体保护的效果，有效的避免了易烧损合金元素的过度烧损，使其控制在比较窄的范围内，同时避免了内生夹杂物的产生。
本发明提供一种改善纯净度、可靠性的风电齿轮用钢，该风电齿轮用钢的化学成分按照质量百分比计，C：0.15～0.19％(比如0.15％、0.155％、0.16％、0.165％、0.17％、0.175％、0.18％、0.185％、0.19％)，Si≤0.4％(比如0％、0.05％、0.1％、0.15％、0.2％、0.25％、0.3％、0.35％、0.4％)，Mn：0.5～0.7％(比如0.5％、0.55％、0.6％、0.65％、0.7％)，P≤0.012％(比如0、0.002％、0.004％、0.006％、0.008％、0.01％、0.012％)，S≤0.006％(比如0、0.001％、0.002、0.003、0.004、0.005、0.006)，Cr：1.5～1.8％(比如1.5％、1.55％、1.6％、1.65％、1.7％、1.75％、1.8％)，Mo：0.28～0.35％(比如0.28％、0.29％、0.30％、0.31％、0.32％、0.33％、0.34％、0.35％)，Ni：1.4～1.7％(比如1.4％、1.45％、1.5％、1.55％、1.6％、1.65％、1.7％)，Al：0.02～0.04％(比如0.02％、 0.025％、0.03％、0.035％、0.04％)，余量为Fe和不可避免的杂质。
为了更好的理解本发明中改善纯净度、可靠性的风电齿轮用钢，本发明还提供一种改善纯净度、可靠性的风电齿轮用钢的冶炼方法，该冶炼方法包括以下步骤：
步骤S1、初炼；
将原料铁水和优质废钢按照配比加入转炉中进行初炼，得到初炼钢液。其中，转炉炼钢是以铁水、废钢等为主要原料，不借助外加能源，靠铁液本身的物理热和铁液组分间化学反应产生热量而在转炉中完成炼钢过程。
在本发明具体实施例中，步骤S1中铁水在加入转炉前需要采用KR脱硫设备进行脱硫，经过脱硫后的铁水中S所占的质量百分比≤0.003％(比如0.0005％、0.001％、0.0015％、0.002％、0.0025％、0.003％)。其中KR脱硫设备是采用一种带有通气搅拌功能的搅拌桨，将搅拌桨进入铁水包熔池一定深度，借其旋转产生的漩涡，经过称量的脱硫剂由给料器加入到铁水表面，并被漩涡卷入铁水中使氧化钙基脱硫粉剂与铁水充分接触反应，达到脱硫目的。
优选地，铁水采用1780m 3的大高炉铁水热装。
在本发明具体实施例中，步骤S1中铁水占原料的质量百分比为80～90％(比如80％、82％、84％、86％、88％、90％)，余量为废钢。
优选地，废钢为优质废钢，废钢中的杂质按照质量百分比计，包括As≤0.04％(比如0.005％、0.01％、0.015％、0.02％、0.025％、0.03％、0.035％、0.04％)，Sn≤0.03％(比如0.005％、0.01％、0.015％、0.02％、0.025％、0.03％)，Pb≤0.002％(比如0.0005％、0.001％、0.0015％、0.002％)，Sb≤0.005％(比如0.0005％、0.001％、0.0015％、0.002％、0.0025％、0.003％、0.0035％、0.004％、0.0045％)，Cu≤0.20％(比如0.01％、0.03％、0.05％、0.1％、0.15％、0.17％、0.2％)，Ti≤0.0005％(比如0.0001％、0.0002％、0.0003％、0.0004％、0.0005％)；废钢还满足辐射≤0.15μSv/h(比如0.02μSv/h、0.04μSv/h、0.06μSv/h、0.08μSv/h、0.1μSv/h、0.12μSv/h、0.14μSv/h、0.15μSv/h)或放射性≤0.1Bq/g(比如0.01Bq/g、0.02Bq/g、0.03Bq/g、0.04Bq/g、0.05Bq/g、0.06Bq/g、0.07Bq/g、0.08Bq/g、0.09Bq/g)。
在本发明具体实施例中，步骤S1中得到的初炼钢液中Ti所占的质量百分比≤0.002％(比如0.005％、0.01％、0.015％、0.02％)，Ca所占的质量百 分比≤0.001％(比如0.0002％、0.0004％、0.0006％、0.0008％、0.001％)。
步骤S2、精炼；
将步骤S1中得到的装有所述初炼钢液的钢水包吊至精炼炉中，然后加入预熔型精炼渣进行精炼，调控钢液中的成分，得到精炼钢液。其中，调控钢液中的成分是通过精确计算需要添加的合金料的量，对钢液中的成分进行微调。
在本发明具体实施例中，步骤S2中的预熔型精炼渣的主要成分包括Al 2O 3和CaF 2；预熔型精炼渣用于吸附钢液中的夹杂物。
预熔型精炼渣的熔点很低，能够以最快的速度熔化，缩短了钢水在精炼包中的停留时间，强化了冶炼的进行。预熔型精炼渣精选各种原料烧结或熔融，生成以12CaO·7Al2O3为主的矿物，其含量大于85％，大量的钙化成份能与钢水中的氧、硫反应生成低熔点易于上浮的产物，降低钢种的有害元素及杂质的含量，达到净化钢液的目的。在钢水包精炼中，加入预熔型精炼渣可以有效缩短炼钢时间，具有较强吸收钢中非金属夹杂物的能力，对净化钢液有显著作用。
更优选地，步骤S2中得到的精炼钢液中夹杂物的级别达到A细≤1.5级，A粗≤0.5级，B细≤1.0级，B粗≤0.5级，C细为0级，C粗为0级，D细≤1.0级，D粗≤1.0级，DS≤1.0级。
钢中非金属夹杂物的评定方法可以参照GB/T10561-2005标准。本发明中采用JK标准评级，将夹杂物分为A、B、C和D四个基本类型，它们分别是硫化物、氧化铝、硅酸盐和球状氧化物，每类夹杂物按照厚度和直径的不同分为细系和粗系两个系列，每个夹杂物由标识夹杂物数量递增的五级(1～5)组成。其中，评定夹杂物级别时，允许评半级，结果是用每个试样每类夹杂物最恶劣视场的级别数表示。
步骤S3、真空脱气；
将步骤S2中得到的精炼钢液进行真空脱气处理，脱除钢液中的氢和氧。
在本发明具体实施例中，步骤S3中的真空脱气处理是采用RH真空循环脱气，达到真空度≤67Pa；通常情况下，步骤S3中的真空脱气处理时间需要超过20min(比如20min、22min、24min、26min、28min、30min、32min、34min、36min、38min、40min)。
经过真空脱气处理后，钢液中的氢所占的质量百分比＜1.0ppm(比如0.1ppm、0.2ppm、0.3ppm、0.4ppm、0.5ppm、0.6ppm、0.7ppm、0.8ppm、0.9ppm)，钢液中的氧所占的质量百分比≤5.0ppm(比如0.5ppm、1ppm、1.5ppm、2ppm、2.5ppm、3ppm、3.5ppm、4ppm、4.5ppm、4.8ppm)。
步骤S4、连铸；
将步骤S3中真空脱气后的钢水包吊至连铸大包中进行下渣检测，长水口惰性气体保护和浸入式水口进行保护(浸入式防止钢液与空气接触)，中间包惰性气体保护、中间包覆盖渣、连续测温，采用结晶器预熔渣保护浇铸、液面自动控制、结晶器电磁搅拌，二冷区水动态控制、末段电磁搅拌，在恒温恒拉速下，得到连铸坯。其中，惰性气体优选为氩气。
步骤S4中的连铸是利用中间包感应加热措施，整个连铸过程实现恒温恒拉速。
在本发明具体实施例中，步骤S4中间包惰性气体保护是采用氩气进行气体保护；
中间包覆盖渣为中间包覆盖剂，主要成分包括氧化镁、二氧化硅和氧化硅，中间包覆盖剂是主要用于绝热保温、吸附钢中上浮的夹杂物以及隔绝空气防止钢液二次氧化。
在本发明具体实施例中，步骤S4中恒温横拉速具体为，温度为1500～1600℃(比如1510℃、1520℃、1530℃、1540℃、1550℃、1560℃、1570℃、1580℃、1590℃)，拉速为0.20～0.28m/min(比如0.21m/min、0.22m/min、0.23m/min、0.24m/min、0.25m/min、0.26m/min、0.27m/min)。
在本发明具体实施例中，步骤S4中得到的连铸坯中心缩孔不大于1.0级；
连铸坯的表面不允许有横裂、渣坑、重皮等缺陷；连铸坯的内部夹杂物的级别为：A类夹杂物≤1.5级，B类夹杂物≤1.0级，C类夹杂物≤0.5级，D类夹杂物≤1.0级。
步骤S5、气体保护炉电渣重熔；
将步骤S4中得到的所述连铸坯放入电渣炉中，电渣炉上设置有气体保护装置，从气体保护装置中充入保护气体，然后加入渣料，化渣后引燃、熔炼、补缩，得到改善纯净度、可靠性的风电齿轮用钢。
电渣重熔是一种二次精炼技术，集钢水二次精炼与定向凝固相结合的综 合冶金铸造过程。其原理是电流通过液态渣池渣阻热，将金属电极熔化，熔化的金属汇集成熔滴，滴落时穿过渣层进入金属熔池，然后于水冷结晶器中结晶凝固成钢锭。
本发明具体实施例中，电渣重熔过程中，液态金属在渣池覆盖下，避免了再氧化，同时在水冷结晶器内熔化、精炼、凝固，杜绝了耐火材料对钢的污染；钢锭凝固前，在它的上端有金属熔池和渣池，起到保温和补缩作用，保证钢锭的致密性。
另外，本发明中选择氩气作为保护性气体，同时在设备上增加了相应的辅助设备，采用申请号为201320698946.0的“气体保护电渣炉双层烟罩”，增强了气体保护的效果，有效的避免了易烧损合金元素的过度烧损，使其控制在比较窄的范围内，同时避免了内生夹杂物的产生。
在本发明具体实施例中，步骤S5中电渣重熔时加入的渣料为二元渣系，二元渣系由Ca类化合物和Al类化合物组成。
优选地，二元渣系为CaF 2和Al 2O 3渣系，CaF 2和Al 2O 3的质量比为7：3。
更优选地，步骤S5中电渣重熔中电源的频率为10～12Hz(比如10Hz、10.5Hz、11Hz、11.5Hz、12Hz)。由于电源频率对铸锭的结晶质量有影响，低频对于铸锭的结晶阻止是有好处的，但是会提高铸锭中的氧含量，所以，在电渣重熔过程中需要严格控制电源的频率。
在本发明具体实施例中，步骤S5中熔炼的熔速为12～15kg/min(比如12.5kg/min、13kg/min、13.5kg/min、14kg/min、14.5kg/min)。其中，在熔炼过程中为了维持熔速的稳定，需要根据实际使用情况，自动逐级调压。在本发明具体实施例中，步骤S5中充入的保护气体为氩气或氮气。
优选地，保护气体为氩气。
以下实施例和对照例中所用到的废钢中的杂质按照质量百分比计，包括As≤0.04％，Sn≤0.03％，Pb≤0.002％，Sb≤0.005％，Cu≤0.20％，Ti≤0.0005％；同时废钢还满足辐射≤0.15μSv/h或放射性≤0.1Bq/g。
实施例1
本实施例提供一种改善纯净度、可靠性的风电齿轮用钢，该风电齿轮用钢的化学成分按照质量百分比计，C：0.17％，Si≤0.3％，Mn：0.6％，P≤0.01％，S≤0.006％，Cr：1.6％，Mo：0.30％，Ni：1.5％，Al：0.03％，余量为Fe和 不可避免的杂质。
本实施例为某A锻造厂采用改善纯净度、可靠性的风电齿轮用钢的冶炼方法来制造风电齿轮用钢，具体冶炼方法包括以下步骤：
步骤S1、初炼；
铁水采用1780m 3的大高炉铁水热装，并脱硫处理至铁水中S所占的质量百分比≤0.003％，然后将脱硫处理后的铁水和优质废钢按照8：2的质量比(铁水占原料的质量百分比为80％，余量为优质废钢)加入转炉中进行初炼，得到初炼钢液；
步骤S2、精炼；
将步骤S1中得到的装有所述初炼钢液的钢水包吊至精炼炉中，然后加入预熔型精炼渣进行精炼，通过钢包精炼微调控制钢液中的成分，得到精炼钢液，使得精炼钢液中夹杂物的级别达到A细≤1.5级，A粗≤0.5级，B细≤1.0级，B粗≤0.5级，C细为0级，C粗为0级，D细≤1.0级，D粗≤1.0级，DS≤1.0级；
步骤S3、真空脱气；
将步骤S2中得到的精炼钢液采用RH真空循环脱气处理，使得钢液中的氢所占的质量百分比＜1.0ppm，钢液中的氧所占的质量百分比≤5.0ppm；
步骤S4、连铸；
将步骤S3中真空脱气后的钢水包吊至连铸大包中进行下渣检测，长水口氩气保护和浸入式水口进行保护，中间包气体保护、中间包覆盖渣、连续测温，采用结晶器预熔渣保护浇铸、液面自动控制、结晶器电磁搅拌，二冷区水动态控制、末段电磁搅拌，在温度为1550℃，拉速为0.24m/min的恒温恒速下，得到中心缩孔不大于1.0级的连铸坯；
步骤S5、气体保护炉电渣重熔；
将步骤S4中得到的连铸坯放入电渣炉中，该电渣炉上设置有申请号为201320698946.0的“气体保护电渣炉双层烟罩”，充入氩气，然后以10Hz的频率加入二元渣系(CaF 2和Al 2O 3的质量比为7：3)，化渣后引燃、以14kg/min的熔速进行熔炼、补缩，得到改善纯净度、可靠性的风电齿轮用钢。
性能测试：
某A锻造厂将采用本实施例中的冶炼方法制造的钢用于风电齿轮箱的生 产，并对其进行探伤测试，结果表明，检测量为1000件时，满足探伤平底孔0.8FBH数量为997件，即满足探伤平底孔0.8FBH合格率为99.7％。
将本实施例中所制造的钢的圆截面，沿直径方向分别取8个点，分别标记为1#、2#、3#、4#、5#、6#、7#、8#，然后进行ASPEX扫描，结果如图1所示，本实施例中所制造的钢中最大夹杂物的尺寸较小，且远小于对照例1中的。
将本实施例中所制造的钢在1000倍显微镜下观察，结果如图2所示，本实施例中所制备的钢中的夹杂物更加细小且弥散。
将本实施例中所制造的钢进行酸洗低倍组织对比，结果如图4所示，本实施例中所制备的钢的低倍组织更加致密。
实施例2
本实施例提供一种改善纯净度、可靠性的风电齿轮用钢，该风电齿轮用钢的化学成分按照质量百分比计，C：0.15％，Si≤0.4％，Mn：0.5％，P≤0.012％，S≤0.006％，Cr：1.5％，Mo：0.28％，Ni：1.4％，Al：0.02％，余量为Fe和不可避免的杂质。
本实施例为某B锻造厂采用改善纯净度、可靠性的风电齿轮用钢的冶炼方法来制造风电齿轮用钢，本实施例的冶炼方法中步骤S1中加入的原料为脱硫处理后的铁水和优质废钢按照9：1的质量比(铁水占原料的质量百分比为90％，余量为优质废钢)加入转炉中进行初炼，得到初炼钢液；其他步骤与实施例1中相同，在此不再赘述。
性能测试：
某B锻造厂将采用本实施例中的冶炼方法制造的钢用于风电齿轮箱的生产，并对其进行探伤测试，结果表明，检测量为1000件时，满足探伤平底孔0.8FBH数量为1000件，即满足探伤平底孔0.8FBH合格率为100％。
对照例1
本对照例提供一种风电齿轮用钢，该风电齿轮用钢为某A锻造厂采用同实施例1中相同的原料，采用现有技术中“电炉冶炼+模铸”的冶炼工艺制造而成，具体冶炼工艺在此不再赘述。
本对照例中所制造的风电齿轮用钢的化学成分按照质量百分比计，包括C：0.16％，Si≤0.25％，Mn：0.7％，P≤0.015％，S≤0.010％，Cr：1.5％，Mo：0.27％，Ni：1.52％，Al：0.035％，余量为Fe和不可避免的杂质。
性能测试：
某A锻造厂将采用本对照例中的冶炼方法制造的钢用于风电齿轮箱的生产，并对其进行探伤测试，结果表明，检测量为1000件时，满足探伤平底孔0.8FBH数量为876件，即满足探伤平底孔0.8FBH合格率为87.6％。
将本对照例中所制造的钢的圆截面，沿直径方向分别取8个点，分别标记为1#、2#、3#、4#、5#、6#、7#、8#，然后进行ASPEX扫描，结果如图1所示，本对照例中所制造的钢中最大夹杂物的尺寸较大。
将本对照例中所制造的钢在1000倍显微镜下观察，结果如图3所示，本对照例中所制备的钢中的夹杂物相比与实施例1中所制备的钢中的夹杂物大很多。
将本对照例中所制造的钢进行酸洗低倍组织对比，结果如图5所示，本对照例中所制备的钢的低倍组织相比与实施例1中所制备的钢的低倍组织较粗疏。
对照例2
本对照例提供一种风电齿轮用钢，该风电齿轮用钢为某B锻造厂采用同实施例2中相同的原料，采用现有技术中“电炉冶炼+模铸”的冶炼工艺制造而成，具体冶炼工艺在此不再赘述。
本对照例中所制造的风电齿轮用钢的化学成分按照质量百分比计，包括C：0.16％，Si≤0.25％，Mn：0.65％，P≤0.015％，S≤0.010％，Cr：1.5％，Mo：0.29％，Ni：1.50％，Al：0.035％，余量为Fe和不可避免的杂质。
性能测试：
某B锻造厂将采用本对照例中的冶炼方法制造的钢用于风电齿轮箱的生产，并对其进行探伤测试，结果表明，检测量为1000件时，满足探伤平底孔0.8FBH数量为883件，即满足探伤平底孔0.8FBH合格率为88.3％。
综上所述，本发明中的冶炼方法所制备的钢材料用于风电齿轮，使用后探伤检测表现优越，较工艺变更之前的现有技术中“电炉冶炼+模铸”的冶 炼工艺，探伤合格率有了显著提升，也提高了生产效率；通过ASPEX扫描，与现有技术中“电炉冶炼+模铸”的冶炼工艺相比，本发明中的冶炼方法所制备的钢材料中大颗粒夹杂物明显减少；在高倍显微镜下观察，与现有技术中“电炉冶炼+模铸”的冶炼工艺相比，本发明中所制备的钢材料中夹杂物更加细小且弥散；经过酸洗低倍组织对比，与现有技术中“电炉冶炼+模铸”的冶炼工艺，本发明中所制备的钢材料低倍组织更加致密。
以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均在本发明待批权利要求保护范围之内。

Claims (10)

  1. 一种改善纯净度、可靠性的风电齿轮用钢，其特征在于，所述风电齿轮用钢的化学成分按照质量百分比计，包括，C：0.15～0.19％，Si≤0.4％，Mn：0.5～0.7％，P≤0.012％，S≤0.006％，Cr：1.5～1.8％，Mo：0.28～0.35％，Ni：1.4～1.7％，Al：0.02～0.04％，余量为Fe和不可避免的杂质。
  2. 一种如权利要求1所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，所述冶炼方法包括以下步骤：
    步骤S1、初炼；
    将原料铁水和废钢按照配比加入转炉中进行初炼，得到初炼钢液；
    步骤S2、精炼；
    将步骤S1中得到的装有所述初炼钢液的钢水包吊至精炼炉中，然后加入预熔型精炼渣进行精炼，调控钢液中的成分，得到精炼钢液；
    步骤S3、真空脱气；
    将步骤S2中得到的精炼钢液进行真空脱气处理，脱除钢液中的氢和氧；
    步骤S4、连铸；
    将步骤S3中真空脱气后的钢水包吊至连铸大包中进行下渣检测，长水口惰性气体保护和浸入式水口进行保护，中间包惰性气体保护、中间包覆盖渣、连续测温，采用结晶器预熔渣保护浇铸、液面自动控制、结晶器电磁搅拌，二冷区水动态控制、末段电磁搅拌，在恒温恒拉速下，得到连铸坯；
    步骤S5、气体保护炉电渣重熔；
    将步骤S4中得到的所述连铸坯放入电渣炉中，电渣炉上设置有气体保护装置，从气体保护装置中充入保护气体，然后加入渣料，化渣后引燃、熔炼、补缩，得到改善纯净度、可靠性的风电齿轮用钢。
  3. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S1中所述铁水在加入转炉前需要采用KR脱硫设备进行脱硫，经过脱硫后的铁水中硫所占的质量百分比≤0.003％。
  4. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S1中所述铁水占原料的质量百分比为80～90％，余量为废钢；
    优选地，所述废钢为优质废钢，所述废钢中的杂质按照质量百分比计，包括As≤0.04％，Sn≤0.03％，Pb≤0.002％，Sb≤0.005％，Cu≤0.20％，Ti≤0.0005％；所述废钢满足辐射≤0.15μSv/h或放射性≤0.1Bq/g。
  5. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S1中得到的所述初炼钢液中Ti所占的质量百分比≤0.002％，Ca所占的质量百分比≤0.001％。
  6. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S2中的预熔型精炼渣的主要成分包括Al 2O 3和CaF 2；
    优选地，步骤S2中得到的所述精炼钢液中夹杂物的级别达到A细≤1.5级，A粗≤0.5级，B细≤1.0级，B粗≤0.5级，C细为0级，C粗为0级，D细≤1.0级，D粗≤1.0级，DS≤1.0级。
  7. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S3中的所述真空脱气处理是采用RH真空循环脱气，达到真空度≤67Pa；
    经过所述真空脱气处理后，钢液中的氢所占的质量百分比＜1.0ppm，钢液中的氧所占的质量百分比≤5.0ppm。
  8. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S4中所述恒温恒拉速具体为：温度为1500～1600℃，拉速为0.20～0.28m/min；
    优选地，步骤S4中得到的所述连铸坯中心缩孔不大于1.0级；
    更优选地，所述连铸坯的内部夹杂物的级别为：A类夹杂物≤1.5级，B类夹杂物≤1.0级，C类夹杂物≤0.5级，D类夹杂物≤1.0级。
  9. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S5中电渣重熔时加入的渣料为二元渣系，所述二元渣系由Ca类化合物和Al类化合物组成；
    优选地，所述二元渣系为CaF 2和Al 2O 3渣系，CaF 2和Al 2O 3的质量比为7：3。
  10. 如权利要求2所述的改善纯净度、可靠性的风电齿轮用钢的冶炼方法，其特征在于，步骤S5中所述熔炼的熔速为12～15kg/min；
    优选地，步骤S5中充入的所述保护气体为氩气或氮气；
    更优选地，步骤S5中充入的所述保护气体为氩气。
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SHAO SHUYAN, LIAO SHU-QUAN,MENG YU: "A Study on Processing About Carbonitriding Pinion Steel for Heavy Load", CAILIAO YANJIU YU YINGYONG, vol. 4, no. 3, 30 September 2010 (2010-09-30), pages 188 - 191, XP055923442, ISSN: 1673-9981 *

Cited By (5)

* Cited by examiner, † Cited by third party
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CN113699384A (zh) * 2021-08-05 2021-11-26 河南中原特钢装备制造有限公司 一种恒熔速电渣炉自动补缩工艺
CN113699384B (zh) * 2021-08-05 2023-03-31 河南中原特钢装备制造有限公司 一种恒熔速电渣炉自动补缩工艺
CN115198166A (zh) * 2022-06-28 2022-10-18 山东钢铁股份有限公司 一种提高履带钢钢水洁净度的生产方法
CN115491511A (zh) * 2022-09-01 2022-12-20 大冶特殊钢有限公司 一种高韧性超高强度钢及其制备方法
CN115491511B (zh) * 2022-09-01 2023-11-28 大冶特殊钢有限公司 一种高韧性超高强度钢及其制备方法

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US20230054329A1 (en) 2023-02-23
US11773466B2 (en) 2023-10-03
JP7195487B1 (ja) 2022-12-23
JP2023506089A (ja) 2023-02-14
CN112853206A (zh) 2021-05-28
CN112853206B (zh) 2021-11-09
EP4092152A1 (en) 2022-11-23

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