CN117004868B - High-conductivity wire rod and production method thereof - Google Patents
High-conductivity wire rod and production method thereof Download PDFInfo
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- CN117004868B CN117004868B CN202311273428.9A CN202311273428A CN117004868B CN 117004868 B CN117004868 B CN 117004868B CN 202311273428 A CN202311273428 A CN 202311273428A CN 117004868 B CN117004868 B CN 117004868B
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- 239000002893 slag Substances 0.000 claims abstract description 100
- 238000001816 cooling Methods 0.000 claims abstract description 76
- 238000005096 rolling process Methods 0.000 claims abstract description 68
- 238000000034 method Methods 0.000 claims abstract description 40
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 26
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 26
- 239000010703 silicon Substances 0.000 claims abstract description 26
- 238000003723 Smelting Methods 0.000 claims abstract description 24
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 133
- 229910000831 Steel Inorganic materials 0.000 claims description 118
- 239000010959 steel Substances 0.000 claims description 118
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 58
- 238000010079 rubber tapping Methods 0.000 claims description 54
- 229910052742 iron Inorganic materials 0.000 claims description 51
- 238000009749 continuous casting Methods 0.000 claims description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- 229910052786 argon Inorganic materials 0.000 claims description 29
- 230000008569 process Effects 0.000 claims description 27
- 229910052760 oxygen Inorganic materials 0.000 claims description 26
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 23
- 239000001301 oxygen Substances 0.000 claims description 23
- 238000005266 casting Methods 0.000 claims description 19
- 229910052698 phosphorus Inorganic materials 0.000 claims description 17
- 238000011282 treatment Methods 0.000 claims description 17
- 239000000843 powder Substances 0.000 claims description 16
- 238000009987 spinning Methods 0.000 claims description 16
- 229910052717 sulfur Inorganic materials 0.000 claims description 16
- 239000012535 impurity Substances 0.000 claims description 15
- 239000000126 substance Substances 0.000 claims description 15
- 239000003595 mist Substances 0.000 claims description 13
- 229910001566 austenite Inorganic materials 0.000 claims description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims description 12
- 238000007664 blowing Methods 0.000 claims description 11
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 claims description 10
- 238000007670 refining Methods 0.000 claims description 10
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 9
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 9
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 9
- 238000005261 decarburization Methods 0.000 claims description 9
- 230000004907 flux Effects 0.000 claims description 9
- 239000004571 lime Substances 0.000 claims description 9
- 230000009467 reduction Effects 0.000 claims description 9
- 229910000859 α-Fe Inorganic materials 0.000 claims description 9
- 239000007788 liquid Substances 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims description 8
- 238000009863 impact test Methods 0.000 claims description 4
- 238000009864 tensile test Methods 0.000 claims description 4
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 abstract description 6
- 238000001556 precipitation Methods 0.000 abstract description 5
- 230000001276 controlling effect Effects 0.000 description 63
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 18
- 239000011572 manganese Substances 0.000 description 14
- 230000006872 improvement Effects 0.000 description 12
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical group C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 10
- 229910001567 cementite Inorganic materials 0.000 description 9
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 8
- 239000011574 phosphorus Substances 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000011593 sulfur Substances 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 238000004321 preservation Methods 0.000 description 6
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000013078 crystal Substances 0.000 description 4
- 239000005864 Sulphur Substances 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 230000000875 corresponding effect Effects 0.000 description 3
- 230000009931 harmful effect Effects 0.000 description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 229910019142 PO4 Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 230000005496 eutectics Effects 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 2
- 239000010452 phosphate Substances 0.000 description 2
- 238000010583 slow cooling Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 206010067484 Adverse reaction Diseases 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000006838 adverse reaction Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010622 cold drawing Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000009713 electroplating Methods 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 150000004763 sulfides Chemical class 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
- B21B37/76—Cooling control on the run-out table
-
- 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
- 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
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
-
- 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
Abstract
The invention provides a high-conductivity wire rod and a production method thereof, wherein the high-conductivity wire rod is characterized in that the total content, the manganese-sulfur ratio, the silicon equivalent and the like of all added elements are controlled, and in the production method, the high-temperature wire rod inclusion, the grain size, the precipitation of triple carburization and the comprehensive cooperative control of the structure of oxide skin on the surface of the wire rod are realized by adopting a double slag method in converter smelting, adopting high Wen Zhongga high-temperature wire-laying and sectional cooling methods in high-line rolling and the like, so that the wire rod has good tissue performance and higher conductivity.
Description
Technical Field
The invention relates to the field of alloy materials, in particular to a high-conductivity wire rod and a production method thereof.
Background
The wire rod for the ultralow-carbon copper-clad steel wire is subjected to deep processing treatments such as acid washing, drawing, annealing, electroplating and the like to prepare the copper-clad steel wire, and is mainly used as a lead wire of an electronic component, a central conductor of a communication cable, a twisted grounding wire, a shielding braided wire and the like. The guarantee and improvement of the conductivity of the wire rod for the copper-clad steel wire are always difficult problems puzzling the steel enterprises, and the cold drawing performance and the mechanical property of the wire rod for the copper-clad steel wire are strictly required.
The existing wire rod for the ultralow-carbon copper-clad steel wire is mainly characterized in that components are reasonably designed, and the production process is adjusted, so that the control of the microstructure inside the wire rod is realized, and the required performance is achieved. The components are reasonably designed, such as adding a proper amount of boron element and a proper amount of zirconium element, so that crystal grains are stabilized at a proper level, and the wire rod has good tensile strength and elongation and good conductivity. For the production process, the existing wire rod rolling process for the ultralow-carbon copper-clad steel wire mainly controls the grain size of the wire rod through high Wen Zhongga and high Wen Tu wires and slow cooling after rolling, so as to control the conductivity of the wire rod.
However, the factors affecting the conductivity are not only grain size, inclusion size, composition and the like, which affect the conductivity of the wire rod, but also high conductivity and good drawing performance are required for the wire rod for the ultralow-carbon copper-clad steel wire, so that the comprehensive structural performance and the good surface quality of the wire rod are required to be regulated and controlled.
Disclosure of Invention
The invention aims to provide a high-conductivity wire rod and a production method thereof.
The invention provides a production method of a high-conductivity wire rod, which is characterized by comprising the following chemical components in percentage by mass: c: 0.001-0.005%, si less than or equal to 0.005%, P less than or equal to 0.010%, S less than or equal to 0.005%, and O: 0.005-0.015%, N is less than or equal to 0.002%, mn, and the balance of Fe and unavoidable impurities;
and satisfies the following:
except Fe, the total content of other elements is 0.008-0.13%,
Mn/S＞10.5，
silicon equivalent Sieq is less than or equal to 0.06 percent, silicon equivalent Si eq The calculation formula is as follows:
Si eq =(34*C+13*Si+6*Mn+16*P+12*S)/13,
wherein, the element symbols are mass percentages of the corresponding elements;
the production method comprises the following steps:
according to the chemical composition ratio, after molten iron pretreatment, converter smelting and RH vacuum refining are carried out to obtain molten steel;
casting the molten steel through a continuous casting process to form a continuous casting blank;
cogging the continuous casting billet;
rolling the continuous casting billet to obtain a wire rod, wherein in the rolling process, the temperature of a finish rolling inlet is controlled to be 950-970 ℃, and the spinning temperature is controlled to be 930-950 ℃;
and cooling the wire rod, wherein when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 0.5-1 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 5-8 ℃/s, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 1-3 ℃/s.
As a further improvement of the present invention, the converter smelting after the molten iron pretreatment specifically includes:
after pretreatment, the S content of the molten iron is controlled to be less than or equal to 0.002 percent,
adding molten iron into a converter for smelting, wherein the proportion of the molten iron is 85-90%, and the balance is recoverable iron;
pouring slag within 10-12 min after blowing is started, controlling the slag pouring rate to be more than or equal to 55%, adding a slag former to perform slag formation, controlling the final slag alkalinity of a converter to be 3.5-4, and controlling the mass percentage of MgO in the slag to be 8% -10%;
tapping when the temperature of molten steel reaches 1670-1690 ℃, and adding lime of 2 kg/ton molten steel when tapping reaches 1/3;
after tapping, adding 1.3-1.8 kg/ton of calcium aluminate synthetic slag of molten steel to the slag surface, and controlling the oxygen content in the molten steel to be 0.030-0.060%.
As a further improvement of the present invention, in the converter smelting process, further comprising:
in the tapping process, argon is blown into the ladle at the bottom, the argon pressure is controlled to be 0.5-0.6 mpa before the tapping amount is 3/4, and the argon pressure is controlled to be 0.4-0.5 mpa after the tapping amount is 3/4.
As a further improvement of the present invention, the RH vacuum refining comprises the steps of:
when the vacuum pressure is lower than 100Pa, decarburizing the molten steel, and controlling the C content of the molten steel to be less than or equal to 0.0030% after decarburization is finished;
al is added into the molten steel for deoxidization treatment, wherein the addition amount of the Al is as follows: [ (11-13) ×oxygen content×10 4 ]kg, when deoxidation is finished, controlling the Al mass content of molten steel to be less than 0.002%;
and carrying out clean circulation and air breaking treatment.
As a further improvement of the present invention, the continuous casting process specifically includes:
adding mold flux into the mold, controlling the thickness of the liquid slag layer to be 3-5 mm,
performing primary cooling and secondary cooling after continuous casting, adopting four-zone water mist cooling in a secondary cooling section, wherein the water quantity of the four-zone water mist cooling is 120-125, 50-60, 30-35 and 25-30L/min respectively, the lowest water quantity of each zone is 25, 20, 18 and 15L/min respectively,
and carrying out rolling treatment on the continuous casting tail end, wherein the rolling reduction is 25-26 mm.
As a further improvement of the present invention, the components of the mold flux include, in mass percent: siO (SiO) 2 ：37±3%，CaO：30±5%，Al 2 O 3 ：7±2.5%，Na 2 O：5.6±2.5%，MgO：4±2%，F - : 7+/-3%, the basicity R of the crystallizer casting powder is 0.81+/-0.06, and the viscosity of the crystallizer casting powder is 0.46+/-0.12.
As a further improvement of the present invention, the cogging treatment specifically includes:
and (3) adopting 9 frames for continuous rolling cogging, controlling the area shrinkage of the billets between each pass to be 16-22%, controlling the linear speed ratio of the outlet and inlet of the rolling mill to be 1.2-1.3, and controlling the austenite grain size of the billets of the last rolling mill to be 95-100 mu m.
As a further improvement of the present invention, the coil rod obtained after rolling the continuous casting billet further includes: and controlling the temperature difference between the surface and the core of the wire rod to be less than or equal to 60 ℃ when the finish rolling outlet is used for spinning.
The invention also provides a high-conductivity wire rod, which is manufactured by adopting the high-conductivity wire rod production method.
As a further improvement of the invention, the thickness of the surface oxide scale of the wire rod is 15-20 mu m, and the wire rod is oxidizedThe iron sheet structure sequentially comprises FeO and Fe from inside to outside 3 O 4 、Fe 2 O 3 Wherein the FeO amount is the largest, feO and Fe 3 O 4 The number ratio is 4-6.
As a further improvement of the invention, according to the standard GB/T30834-2022, the class A inclusions are less than or equal to 0.5 level, the class B inclusions are less than or equal to 0.5 level, the class C inclusions are less than or equal to 0.5 level, the class D inclusions are less than or equal to 0.5 level, the maximum inclusion size is less than or equal to 15 mu m in the cross section of the wire rod and the longitudinal section of the wire rod, and the wire breakage rate of drawing is less than 1 time/ton of 0.10 mm.
As a further improvement of the invention, tensile and impact tests are carried out according to the standards GB/T228 and GB/T229, when the specification of the wire rod is 5.0-14 mm, the tensile strength of the wire rod is 260-300 MPa, and the elongation is more than or equal to 50%; when the specification of the wire rod is 7-14 mm, the tensile strength is 240-280 MPa, and the elongation is 45%.
As a further improvement of the invention, when the specification of the wire rod is 5.0-14 mm, the conductivity is more than or equal to 16.3%, and the ferrite grain size is 5.5-6 grade; when the specification of the wire rod is 7-14 mm, the conductivity is more than or equal to 16.5%, and the ferrite grain size is 5-5.5 grade.
The beneficial effects of the invention are as follows: the invention provides a high-conductivity wire rod and a production method thereof, wherein the high-conductivity wire rod is characterized in that the total content of all added elements, the manganese-sulfur ratio, the silicon equivalent and the like are controlled, and the method adopts a double slag method in converter smelting, adopts high Wen Zhongga and high-temperature wire-spinning and sectional cooling methods in high-line rolling, so that the comprehensive cooperative control of wire rod inclusion, grain size, precipitation of triple carburization and the structure of wire rod surface oxide skin is realized, and the wire rod has good tissue property and higher conductivity.
Drawings
Fig. 1 is a schematic diagram showing steps of a method for producing a high conductivity wire rod according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below in conjunction with the detailed description of the present invention and the corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and are not to be construed as limiting the present invention.
The high-conductivity wire rod provided by the embodiment of the invention is characterized in that the total content of all added elements, the manganese-sulfur ratio, the silicon equivalent and the like are controlled in terms of components, and the method for producing the high-conductivity wire rod comprises the steps of adopting a double slag method in converter smelting, adopting high Wen Zhongga and high-temperature wire-laying and sectional cooling and the like in high-line rolling, so that the comprehensive cooperative control of wire rod inclusion, grain size, precipitation of triple carburization and the structure of the surface oxide skin of the wire rod is realized, and the wire rod has good organization property and higher conductivity.
The wire rod comprises the following chemical components in percentage by mass: c: 0.001-0.005%, si less than or equal to 0.005%, P less than or equal to 0.010%, S less than or equal to 0.005%, and O: 0.005-0.015%, N is less than or equal to 0.002%, mn, and the balance of Fe and unavoidable impurities;
specifically, the design principle of the chemical components of the wire rod is described as follows:
carbon (C): carbon is the most important constituent element in steel, the carbon content directly determines the strength and plasticity thereof, the strength, hardness and plasticity and toughness of steel are improved along with the increase of the carbon content, but carbon is a nonmetallic element, when the carbon exists in steel, electrons are introduced to scatter and block, so that the resistance is increased, the conductivity of the material is obviously reduced, and the conductivity is reduced, so that the carbon content is controlled to be 0.001-0.005% in the embodiment.
Silicon (Si): the silicon is easy to form nonmetallic inclusion in the steel, the elongation and drawing performance of the material are reduced, and similar to C, the existence of the silicon also seriously affects the conductivity of the steel, and the higher the silicon content is, the lower the conductivity of the steel is, so that the silicon content is controlled to be less than or equal to 0.005 percent in the embodiment.
Phosphorus (P): phosphorus is a harmful impurity element, reduces the plasticity and toughness of steel, and can improve the cold brittleness of steel. The presence of phosphorus affects the conductivity of the steel, and the higher the phosphorus content, the lower the conductivity of the steel, so that the phosphorus content is controlled to be 0.010% or less in this embodiment.
Sulfur (S): sulfur can cause cracking of the material during hot working, creating thermal embrittlement. The high sulfur content in the steel increases the content of sulfide inclusions, resulting in reduced plasticity and toughness of the steel. Therefore, the sulfur content is controlled to 0.005% in this embodiment.
Manganese (Mn): the addition of Mn can raise the strength of wire rod, and is a good deoxidizer, and at the same time, mn can be combined with S to form Mn sulfide, so that the harmful effect of S in steel can be eliminated, but the Mn element is obviously negatively correlated with conductivity, and its Mn content is raised and conductivity is lowered.
In addition to Fe as a basic element, the addition of other elements forms inclusions that hinder the free conduction of electrons in the crystal lattice, resulting in an increase in resistivity, and thus the total content of other elements and the conductivity are inversely related. The total content of elements is reduced, and the conductivity is improved, so that the total content of other elements is controlled to be 0.008-0.13% except Fe which is taken as a basic element.
Oxygen (O): oxygen exists in the form of oxide or silicate inclusions in steel, so that the plasticity, toughness and strength of the steel are reduced, and therefore, the oxygen content needs to be controlled to be 0.005-0.015%.
Nitrogen (N): nitrogen can strengthen the steel, but can significantly reduce the plasticity and toughness of the steel, and increase the aging tendency and cold brittleness. Therefore, the nitrogen content should be controlled to be not more than 0.002%
Further, in the steel, mn/S is more than 10.5, and by controlling Mn/S, the hot embrittlement tendency of sulfur can be reduced, thereby reducing cracks at the corners of the cast slab. Meanwhile, mn/S influences the size, morphology and distribution of inclusions of sulfide, when the Mn/S ratio is high, sulfur element is more easily combined with manganese to form manganese sulfide instead of forming sulfide in steel, and the formation of manganese sulfide can avoid the formation of sulfide. When Mn/S is small, sulfur forms Fe+FeS+FeO eutectic in steel, these eutectic inclusions can induce brittle fracture at high temperature, and as a defect source, the wire rod is cracked at the time of rolling, thus Mn/S is controlled to be > 10.5.
Silicon equivalent Si eq Less than or equal to 0.06 percent, silicon equivalent Si eq The calculation formula is as follows:
Si eq =(34*C+13*Si+6*Mn+16*P+12*S)/13，
wherein the element symbols are mass percentages of the corresponding elements.
The silicon equivalent is a method for quantifying the effect of each element in the alloy on the conductivity, and compares the effect of each element on the conductivity with the effect of the silicon element, and converts the effect to the effect of the silicon element on the conductivity. The alloy composition can be reasonably designed according to the linear relation between the silicon equivalent and the conductivity, so that the silicon equivalent Si eq The content is controlled to be less than or equal to 0.06 percent.
As shown in fig. 1, the production method includes the steps of:
s1: according to the chemical composition ratio, after molten iron pretreatment, converter smelting and RH vacuum refining are carried out to obtain molten steel.
S2: and casting the molten steel through a continuous casting process to form a continuous casting blank.
S3: and cogging the continuous casting billet.
S4: and rolling the continuous casting billet to obtain the wire rod, wherein in the rolling process, the temperature of a finish rolling inlet is controlled to be 950-970 ℃, and the spinning temperature is controlled to be 930-950 ℃.
S5: and cooling the wire rod, wherein when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 0.5-1 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 5-8 ℃/s, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 1-3 ℃/s.
In step S1, the smelting process includes the steps of:
s11: after pretreatment, controlling the S content of molten iron to be less than or equal to 0.002%, adding the molten iron into a converter for smelting, wherein the proportion of the molten iron is 85-90%, and the balance is recoverable iron.
S12: pouring slag 10-12 min after blowing is started, controlling the slag pouring rate to be more than or equal to 55%, adding a slag former to perform slag formation, controlling the final slag alkalinity of the converter to be 3.5-4, and controlling the mass percentage of MgO in the slag to be 8% -10%.
S13: tapping when the temperature of molten steel reaches 1670-1690 ℃, and adding lime of 2 kg/ton molten steel when tapping reaches 1/3.
S14: after tapping, adding 1.3-1.8 kg/ton of calcium aluminate synthetic slag of molten steel to the slag surface, and controlling the oxygen content in the molten steel to be 0.030-0.060%.
In converter smelting, molten iron is pretreated to ensure that the chemical components and the quality of the molten iron meet the requirements of the smelting process. Recoverable iron is a material extracted and recovered from scrap steel and scrap iron.
The deslagging is carried out 10-12 minutes after the blowing is started, and waste residues or unnecessary substances generated in the smelting process are discharged from the converter. And controlling the alkalinity of the final slag to be 3.5-4 so as to ensure the stability and consistency of the waste slag.
After tapping, the addition of calcium aluminate synthetic slag is continued, and two different slags are used to treat impurities in steel in cooperation with alkaline slags used in tapping. The acidic slag added after tapping can remove impurities such as phosphorus, and under acidic conditions, the phosphorus reacts with silicon dioxide in the slag to form phosphate and is adsorbed into the slag, so that the phosphate is removed from the steel. The alkaline slag used in tapping can be used for desulphurisation, and the alkaline slag can form sulfides with the sulphur, transferring the sulphur from the steel into the slag, thus reducing the sulphur content in the steel. By reasonably controlling the addition amount and the composition of the acid slag and the alkaline slag, harmful elements such as phosphorus, sulfur and the like are effectively removed.
Further, in the tapping process, argon is blown to the ladle at the bottom, the argon pressure is controlled to be 0.5-0.6 mpa before the tapping amount is 3/4, and the argon pressure is controlled to be 0.4-0.5 mpa after the tapping amount is 3/4. In the smelting process, argon is blown in to form a gas curtain to prevent oxygen in air from entering molten steel, so that oxidation of the molten steel is reduced. The pressure is controlled to be 0.5-0.6 MPa in the early stage of tapping, so that the stability of gas curtain is ensured, molten steel is fully protected, and the temperature is controlled. After tapping 3/4, the flow rate of bottom blowing argon needs to be adjusted along with the reduction of molten steel, and the flow rate is reduced so as to maintain the control of the molten steel.
In the RH refining process, the method includes the steps of:
s15: when the vacuum pressure is lower than 100Pa, decarburizing the molten steel, and controlling the C content of the molten steel to be less than or equal to 0.0030% after decarburization is finished.
S16: al is added into the molten steel for deoxidization treatment, wherein the addition amount of the Al is as follows: [ (11-13) ×oxygen content×10 4 ]kg, when the deoxidation is finished, controlling the Al mass content of the molten steel to be less than 0.002 percent.
S17: and carrying out clean circulation and air breaking treatment.
The RH refining is performed to remove gas and dissolved gas in a vacuum environment, so as to purify molten steel and improve the purity and uniformity of the molten steel. The degree of deoxidation is generally controlled according to the oxygen content, and at the end of the deoxidation, the aluminum content of the molten steel is ensured to be lower than 0.002% so as to ensure the uniformity and purity of the steel. In the final stage of RH refining, gas is pumped from the refining chamber by a vacuum pump to clean the working environment and remove residual gases and impurities, eliminating bubbles or other impurities that may accumulate in the refining chamber.
In step S2, the continuous casting process specifically includes:
s21: and adding mold flux, and controlling the thickness of the liquid slag layer to be 3-5 mm.
S22: and after continuous casting, performing primary cooling and secondary cooling, wherein four-region water mist cooling is adopted in the secondary cooling section, wherein the water quantity of the four-region water mist cooling is 120-125, 50-60, 30-35 and 25-30L/min respectively, and the lowest water quantity of each region is 25, 20, 18 and 15L/min respectively.
S23: and carrying out rolling treatment on the continuous casting tail end, wherein the rolling reduction is 25-26 mm.
The mold flux is used for protecting molten steel from being damaged in continuous casting processThe important material influenced by the external environment can prevent the molten steel from contacting with the external air and prevent adverse reactions such as oxidation and the like by forming a slag layer on the surface of the crystallizer. In this embodiment, the mold flux comprises the following components: siO (SiO) 2 ：37±3%，CaO：30±5%，Al 2 O 3 ：7±2.5%，Na 2 O：5.6±2.5%，MgO：4±2%，F - : 7+/-3%, the basicity R of the crystallizer casting powder is 0.81+/-0.06, and the viscosity of the crystallizer casting powder is 0.46+/-0.12.
In the continuous casting process, the molten steel is gradually solidified and forms a solid structure through primary cooling and secondary cooling. Primary cooling is typically the initial stage in the continuous casting process where the hot molten steel is cooled to some extent by cooling water or cooling nozzles to form the outer shell of the billet. Thereafter, the secondary cooling further reduces the temperature of the billet, causing the interior to gradually solidify. In the secondary cooling section of continuous casting, four-zone water mist cooling is adopted to quickly absorb heat and reduce the temperature.
In step S3, the cogging step specifically includes:
and (3) adopting 9 frames for continuous rolling cogging, controlling the area shrinkage of the billets between each pass to be 16-22%, controlling the linear speed ratio of the outlet and inlet of the rolling mill to be 1.2-1.3, and controlling the austenite grain size of the billets of the last rolling mill to be 95-100 mu m.
In the cogging process, the austenite grain size is precisely controlled by precisely controlling the area shrinkage and the linear velocity ratio of the outlet to the inlet. The larger the grain size, the fewer the grain boundaries, the less the electrons are hindered by passing through the grain boundaries, the less the scattering, the less the lost energy, the less the resistance, and the higher the conductivity. However, the size of the crystal grains is too large, the tensile strength and the elongation of the wire rod are also obviously reduced, and the crystal grains of the wire rod cannot be too large in order to ensure the mechanical property of the wire rod. In the cogging step, the grain size is first controlled in cooperation with the subsequent rolling step.
In the step S4, the temperature of the finish rolling inlet is controlled to be 950-970 ℃, the temperature difference between the surface of the wire rod and the core is less than or equal to 60 ℃ when the finish rolling outlet is used for spinning, and the spinning temperature is controlled to be 930-950 ℃.
In the step S5, the wire rod is cooled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 0.5-1 ℃/S, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 5-8 ℃/S, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 1-3 ℃/S.
In the rolling and cooling process, high Wen Zhongga and high-temperature spinning and sectional cooling are adopted to further control the grain size of the wire rod, the precipitation of tertiary cementite and the structure of iron scale on the surface of the wire rod, so that the wire rod has good tissue performance and higher conductivity.
The tertiary cementite is formed under relatively low temperature conditions, typically in the quenching or tempering temperature range. At the temperature of above 650 ℃, the size of the cubic cementite is smaller, the cubic cementite is dispersed and distributed at the grain boundary position, at the temperature of 600-650 ℃, the size of the cubic cementite is obviously increased from the original spherical shape to the rod shape or the strip shape, and at the temperature of below 600 ℃, the number of the cubic cementite is continuously increased, and the cubic cementite is in the shape of the strip shape, is larger in size and is close to a half net shape.
And the forming temperature range of the iron scale is mainly in the wire rod spinning temperature range of 800-900 ℃. When the wire rod is cooled to 570 ℃, feO in the inner layer of the iron oxide scale starts to move to Fe 3 O 4 At the moment, the cooling speed is properly increased to control the FeO conversion of the inner layer of the iron scale, and the iron scale is easier to clean as the FeO ratio in the iron scale is larger.
By combining the generation temperature characteristics of the tertiary cementite and the iron scale, a rolling method with high Wen Tusi and high Wen Zhongga is adopted, slow cooling is adopted at the temperature of more than 650 ℃, rapid cooling is adopted at the temperature of 600-650 ℃, and proper rapid cooling is adopted at the temperature of less than 600 ℃, so that the control of grain size, the tertiary cementite and the iron scale is realized, a tertiary cementite structure with relatively coarse grains, less and dispersed and an iron scale structure with large FeO ratio is formed, and the tissue performance and the conductivity of the wire rod are improved.
The embodiment also provides a high-conductivity wire rod, which is manufactured by adopting the high-conductivity wire rod production method.
Obtained by the above production methodThe thickness of the iron scale on the surface of the wire rod is 15-20 mu m, and the iron scale structure sequentially comprises FeO and Fe from inside to outside 3 O 4 、Fe 2 O 3 Wherein the FeO amount is the largest, feO and Fe 3 O 4 The number ratio is 4-6.
According to the standard GB/T30834-2022, the class A inclusions are less than or equal to 0.5 level, the class B inclusions are less than or equal to 0.5 level, the class C inclusions are less than or equal to 0.5 level, the class D inclusions are less than or equal to 0.5 level, the maximum inclusion size is less than or equal to 15 mu m in the cross section of the wire rod and the longitudinal section of the wire rod, and the wire breakage rate of drawing is less than 1 time/ton when 0.10 mm.
Carrying out tensile and impact tests according to the standards GB/T228 and GB/T229, wherein when the specification of the wire rod is 5.0-14 mm, the tensile strength of the wire rod is 260-300 MPa, and the elongation is more than or equal to 50%; when the specification of the wire rod is 7-14 mm, the tensile strength of the wire rod is 240-280 MPa, and the elongation is more than or equal to 45%.
When the specification of the wire rod is 5.0-14 mm, the conductivity is more than or equal to 16.3%, and the ferrite grain size is 5.5-6 grades; when the specification of the wire rod is 7-14 mm, the conductivity is more than or equal to 16.5%, and the ferrite grain size is 5-5.5 grade.
In summary, the present embodiment provides a high conductivity wire rod and a production method thereof, in which the total content of all additive elements, the manganese-sulfur ratio, the silicon equivalent and the like are controlled in terms of components, in the production process, the converter smelting is performed by adopting a double slag method, the surface shrinkage and the linear speed are controlled in the cogging process, and the measures of high Wen Zhongga in combination with high Wen Tusi, sectional cooling and the like are adopted to realize the precipitation of wire rod inclusions, grain size and third carburization and the control of the structure of the surface oxide scale of the wire rod, so that the wire rod has good tissue performance and higher conductivity.
The following describes the embodiments of the present invention further by way of 3 examples and 3 comparative examples.
The composition percentages of examples 1 to 3 and comparative examples 1 to 3 are shown in tables 1 and 2, and the balance not shown in tables 1 and 2 is Fe and unavoidable impurities.
Example 1
The specification of the wire rod is 5.5mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.001%, si:0.002%, P:0.005%S:0.003%, mn:0.036%, the total content of other elements except Fe as basic element is 0.047%, mn/S=12, silicon equivalent Si eq =0.03%, oxygen content: 0.007%, nitrogen content: 0.0008%, the balance being Fe and unavoidable impurities.
Adding pretreated molten iron with S content of 0.001% into a converter for smelting, wherein the molten iron ratio is 90%, the balance is recoverable iron, and carrying out slag pouring operation 12min after blowing is started, wherein the slag pouring rate is 60%. Continuously adding a slag former to carry out slag formation, controlling the final slag alkalinity of the converter to be 3.6, and carrying out tapping operation when the mass percentage of MgO in the slag reaches 1670 ℃. When tapping to 1/3, adding lime of 2 kg/ton molten steel, and adding calcium aluminate synthetic slag of 1.4 kg/ton molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.040%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.5Mpa, and the pressure of the argon after tapping is 3/4 Mpa is controlled to be 0.4Mpa.
When the vacuum pressure is lower than 100Pa, decarburizing the molten steel, ensuring that the C content of the molten steel is 0.0010% when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the Al addition is 72kg, and performing clean circulation and air breaking treatment after deoxidization is finished and the Al content is 0.0012%.
The thickness of the slag layer of the casting powder liquid of the crystallizer is controlled to be 3.5mm in the continuous casting process, four areas of water mist cooling are adopted in the secondary cooling section, the water quantity is 122, 53, 32 and 27L/min, the lowest water quantity in each section is 25, 20, 18 and 15L/min, and the light end rolling reduction is 25mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：37%，CaO：30%，Al 2 O 3 ：8%，Na 2 O：5.8%，MgO：5%，F - :8%, basicity R:0.81, viscosity: 0.5.
and adopting 9 frames for continuous rolling cogging, controlling the surface shrinkage of billet pass to be 18 percent, controlling the linear speed ratio of the outlet to the inlet of the rolling mill to be 1.2, and controlling the austenite grain size of the last rolling mill billet to be 95 mu m.
When the temperature of the finish rolling inlet is controlled to 960 ℃, the temperature difference between the surface and the core of the wire rod is controlled to 40 ℃, the wire rod spinning temperature is controlled to 935 ℃, the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover are controlled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to 0.5 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to 6 ℃/s, and when the surface temperature of the wire rod is reduced to less than 600 ℃, the surface cooling speed of the wire rod is controlled to 1.5 ℃/s.
Example 2
The specification of the wire rod is 7mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.003%, si:0.003%, P:0.007%, S:0.004%, mn:0.052%, the total content of other elements except Fe as basic element is 0.069%, mn/S=13, silicon equivalent Si eq =0.047%, oxygen content: 0.008% of nitrogen content: 0.001%, the balance being Fe and unavoidable impurities.
Adding pretreated molten iron with S content of 0.0015% into a converter for smelting, wherein the ratio of molten iron to recoverable iron is 88%, pouring slag after 11min from the beginning of blowing, pouring slag with slag rate of 60%, continuously adding a slag former for slag formation, controlling the final slag alkalinity of the converter to be 3.8, and tapping when the mass percentage of MgO in the slag reaches 1680 ℃. When tapping to 1/3, adding lime of 2 kg/ton molten steel, and adding calcium aluminate synthetic slag of 1.5 kg/ton molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.05%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.55Mpa, and the pressure of the argon after tapping is 3/4 is controlled to be 0.45Mpa.
When the vacuum pressure is below 100Pa, decarburizing the molten steel, ensuring that molten steel C is 0.002% when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the addition amount of Al is 84kg, controlling the Al content to be 0.0015% after deoxidization is finished, and finally carrying out clean circulation and air breaking treatment.
The thickness of the mold flux liquid slag layer is controlled to be 4mm during continuous casting, four areas of water mist cooling are adopted in the secondary cooling section, the water quantity is 123, 55, 33 and 28L/min, the lowest water quantity in each section is 25, 20, 18 and 15L/min, and the light end reduction is 25.5mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：39%，CaO：32%，Al 2 O 3 ：8.5%，Na 2 O：6.5%，MgO：3%，F - :6, basicity R:0.82, viscosity: 0.55.
and adopting 9 frames for continuous rolling cogging, controlling the surface shrinkage of billet pass to be 20 percent, controlling the linear speed ratio of the outlet to the inlet of the rolling mill to be 1.25, and controlling the austenite grain size of the last rolling mill billet to be 98 mu m.
When the temperature of the finish rolling inlet is 960 ℃, the temperature difference between the surface and the core of the wire rod is 30 ℃, the wire rod spinning temperature is 940 ℃, the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover are controlled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 0.8 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 7 ℃/s, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 2 ℃/s.
Example 3
The specification of the wire rod is 12mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.005%, si:0.004%, P:0.008%, S:0.003%, mn:0.042%, the total content of other elements except Fe as the basic element is 0.062%, mn/S=14, silicon equivalent Si eq =0.049%, oxygen content: 0.01%, nitrogen content: 0.0015% of Fe and the balance of unavoidable impurities.
Adding pretreated molten iron with S content of 0.001% into a converter for smelting, wherein the molten iron ratio is 90%, the balance is recoverable iron, carrying out slag pouring operation after 12min after blowing is started, wherein the slag pouring rate is 65%, continuously adding a slag former for slag formation, controlling the final slag alkalinity of the converter to be 4, and carrying out tapping operation when the MgO mass percentage in the slag is 9% and the temperature reaches 1685 ℃. When tapping to 1/3, adding lime of 2 kg/ton molten steel, and adding calcium aluminate synthetic slag of 1.6 kg/ton molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.05%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.6Mpa, and the pressure of the argon after tapping is 3/4 is controlled to be 0.5Mpa.
When the vacuum pressure is below 100Pa, decarburizing the molten steel, ensuring that the molten steel C is 0.0025% when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the addition amount of Al is 88kg, controlling the Al content to be 0.0016% after deoxidization is finished, and finally carrying out clean circulation and air breaking treatment.
The thickness of the liquid slag layer of the crystallizer casting powder is controlled to be 5mm during continuous casting, four-zone water mist cooling is adopted in the secondary cooling section, the water quantity is 125, 60, 35 and 30L/min respectively, and the lowest water in each sectionThe amounts were 25, 20, 18, 15L/min, respectively, and the tip light depression was 26mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：38%，CaO：32%，Al 2 O 3 ：6.5%，Na 2 O：5%，MgO：5.5%，F - :8.5%, basicity R:0.84, viscosity: 0.52.
and adopting 9 frames for continuous rolling cogging, controlling the billet pass area shrinkage rate to be 21%, controlling the linear speed ratio of a rolling mill outlet to an inlet to be 1.28, and controlling the austenite grain size of the last rolling mill billet to be 98 mu m.
When the temperature of the finish rolling inlet is 965 ℃, the temperature difference between the surface of the wire rod and the core is 55 ℃, the wire-spinning temperature is controlled to 945 ℃, the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover are controlled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to 1 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to 7 ℃/s, and when the surface temperature of the wire rod is reduced to less than 600 ℃, the surface cooling speed of the wire rod is controlled to 2.5 ℃/s.
Comparative example 1
The specification of the wire rod is 5.5mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.007%, si:0.009%, P:0.02%, S:0.01%, mn:0.10%, the total content of other elements except Fe as a basic element is 0.146%, mn/S=10, silicon equivalent Si eq =0.107%, oxygen content: 0.003% of nitrogen: 0.005% of Fe and the balance of unavoidable impurities.
Adding pretreated molten iron with S content of 0.005% into a converter for smelting, wherein the ratio of the molten iron is 75%, the balance is recoverable iron, carrying out slag pouring operation 8min after blowing is started, the slag pouring rate is 50%, continuously adding a slag former for slag making, controlling the final slag alkalinity of the converter to be 2.0, and carrying out tapping operation when the mass percentage of MgO in the slag reaches 1650 ℃. When tapping to 1/3, adding 3 kg/ton of lime of molten steel, and adding 1.2 kg/ton of calcium aluminate synthetic slag of molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.08%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.4Mpa, and the pressure of the argon after tapping is 3/4 Mpa is controlled to be 0.3Mpa.
When the vacuum pressure is below 100Pa, decarburizing the molten steel, ensuring that molten steel C is 0.005% when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the addition amount of Al is 54kg, controlling the Al content to be 0.005% when deoxidization is finished, and finally carrying out clean circulation and air breaking treatment.
The thickness of the slag layer of the mold flux is controlled to be 1.5mm during continuous casting, four areas of water mist cooling are adopted in the secondary cooling section, the water quantity is 110, 40, 25 and 20L/min respectively, the lowest water quantity in each section is 20, 15, 12 and 10L/min respectively, and the light end rolling reduction is 20mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：32.5%，CaO：38%，Al 2 O 3 ：10.5%，Na 2 O：8.5%，MgO：6.5%，F - :3.5%, basicity R:1.169, viscosity: 0.61.
and adopting 9 frames for continuous rolling cogging, controlling the billet pass area shrinkage rate to be 14 percent, controlling the linear speed ratio of a rolling mill outlet to an inlet to be 1.0, and controlling the austenite grain size of the last rolling mill billet to be 110 mu m.
When the temperature of the finish rolling inlet is controlled to 910 ℃, the temperature difference between the surface and the core of the wire rod is controlled to 30 ℃, the wire rod spinning temperature is controlled to 890 ℃, the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover are controlled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to 5 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to 4.5 ℃/s, and when the surface temperature of the wire rod is reduced to less than 600 ℃, the surface cooling speed of the wire rod is controlled to 4 ℃/s.
Comparative example 2
The specification of the wire rod is 7mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.0008%, si:0.012%, P:0.015%, S:0.015%, mn:0.09%, the total content of other elements except Fe as a basic element is 0.132%, mn/S=6, silicon equivalent Si eq =0.088%, oxygen content: 0.02%, nitrogen content: 0.004%, and the balance of Fe and unavoidable impurities.
Adding the pretreated molten iron with S content of 0.005% into a converter for smelting, wherein the molten iron ratio is 70%, the balance is recoverable iron, carrying out slag pouring operation 15min after blowing is started, the slag pouring rate is 40%, continuously adding a slag former for slag making, controlling the final slag alkalinity of the converter to be 4.5, controlling the MgO mass percentage in the slag to be 12%, and carrying out tapping operation when the temperature reaches 1700 ℃. When tapping to 1/3, adding 4 kg/ton of lime of molten steel, and adding 2.1 kg/ton of calcium aluminate synthetic slag of molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.08%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.3Mpa, and the pressure of the argon after tapping is 3/4 Mpa is controlled to be 0.35Mpa.
When the vacuum pressure is below 100Pa, decarburizing the molten steel, ensuring that molten steel C is 0.004% when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the addition amount of Al is 40kg, controlling the Al content to be 0.006% after deoxidization is finished, and finally carrying out clean circulation and air breaking treatment.
The thickness of the crystallizer casting powder liquid slag layer is controlled to be 6.5mm during continuous casting, four areas of water mist cooling are adopted in the secondary cooling section, the water quantity is 130, 70, 40 and 35L/min respectively, the lowest water quantity in each section is 30, 25, 20 and 18L/min respectively, and the light end reduction is 28mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：41%，CaO：37%，Al 2 O 3 ：4.0%，Na 2 O：3.0%，MgO：6.5%，F - :11%, basicity R:0.90, viscosity: 0.71.
and adopting 9 frames for continuous rolling cogging, controlling the surface shrinkage of billet pass to be 24%, controlling the linear speed ratio of a rolling mill outlet to an inlet to be 1.5, and controlling the austenite grain size of the last rolling mill billet to be 90 mu m.
Controlling the temperature of a finish rolling inlet to 980 ℃, controlling the temperature difference between the surface and the core of the wire rod to 65 ℃, controlling the spinning temperature to 960 ℃, controlling the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover, controlling the surface cooling speed of the wire rod to 5 ℃/s when the surface temperature of the wire rod is more than or equal to 650 ℃, controlling the surface cooling speed of the wire rod to 3 ℃/s when the surface temperature of the wire rod is 600-650 ℃, and controlling the surface cooling speed of the wire rod to 0.5 ℃/s when the surface temperature of the wire rod is reduced to be less than 600 ℃.
Comparative example 3
The specification of the wire rod of the comparative example is 12mm, and the chemical components of the wire rod comprise the following components in percentage by mass: c:0.01%, si:0.015%, P:0.016%, S:0.008%, mn:0.04%, the total content of other elements except Fe as a basic element is 0.089%, mn/S=5, silicon equivalent Si eq =0.087%, oxygen content: 0.018%, nitrogen content: 0.004%The balance of Fe and unavoidable impurities.
Adding pretreated molten iron with S content of 0.003% into a converter for smelting, wherein the molten iron ratio is 80%, the balance is recoverable iron, carrying out slag pouring operation 8min after blowing is started, wherein the slag pouring rate is 40%, continuously adding a slag former for slag formation, controlling the final slag alkalinity of the converter to be 2.5, and carrying out tapping operation when the MgO mass percentage in the slag is 12% and the temperature reaches 1660 ℃. When tapping to 1/3, adding 3 kg/ton of lime of molten steel, and adding 2.2 kg/ton of calcium aluminate synthetic slag of molten steel to the slag surface after tapping, so as to ensure that the oxygen content in the molten steel is 0.08%. Argon is blown to the bottom of the steel ladle in the tapping process, the pressure of the argon in the early stage is controlled to be 0.75Mpa, and the pressure of the argon after tapping is 3/4 is controlled to be 0.6Mpa.
When the vacuum pressure is below 100Pa, decarburizing the molten steel, ensuring that the molten steel C is less than or equal to 0.0030 percent when decarburization is finished, adding Al into the molten steel for deoxidization, wherein the addition amount of the Al is 104kg, controlling the Al content to be 0.0055 percent when deoxidization is finished, and finally carrying out clean circulation and air breaking treatment.
The thickness of the crystallizer casting powder liquid slag layer is controlled to be 7mm during continuous casting, four areas of water mist cooling are adopted in the secondary cooling section, the water quantity is 128, 65, 40 and 33L/min, the lowest water quantity in each section is 28, 26, 24 and 20L/min, and the light end reduction is 23mm. The components of the crystallizer casting powder are as follows: siO (SiO) 2 ：37%，CaO：30%，Al 2 O 3 ：7%，Na 2 O：5.6%，MgO：4%，F - :7%, basicity R:0.81±0.06, viscosity: 0.46 + -0.12.
And adopting 9 frames for continuous rolling cogging, controlling the surface shrinkage of billet pass to be 24%, controlling the linear speed ratio of a rolling mill outlet to an inlet to be 1.4, and controlling the austenite grain size of the last rolling mill billet to be 92 mu m.
When the temperature of the finish rolling inlet is controlled to 900 ℃, the temperature difference between the surface and the core of the wire rod is controlled to be 30 ℃, the wire rod spinning temperature is controlled to be 880 ℃, the roller speed, the air quantity of a fan and the opening degree of a heat preservation cover are controlled, when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 3 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 3 ℃/s, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 2 ℃/s.
The wire rods prepared in examples and comparative examples were subjected to measurement of the thickness and structure of the scale, ferrite grain size grade measurement, inclusion, mechanical properties, conductivity and wire breakage rate, respectively, and the test results are shown in table 1.
TABLE 1
| Specification/mm | Grade of ferrite grain | Tensile strength Rm/MPa | Elongation/% | Conductivity/% | Austenite grain size after frame 6 | Yield 12 th austenitic grain size | |
| Example 1 | 5.5 | 6.0 | 290 | 53 | 16.5 | 43.5 | 30.3 |
| Example 2 | 7 | 5.8 | 280 | 50 | 16.7 | 44.2 | 32.6 |
| Example 3 | 12 | 5.5 | 260 | 52 | 16.6 | 46.7 | 33.5 |
| Comparative example 1 | 5.5 | 7.5 | 335 | 50 | 15.0 | 35.6 | 26.4 |
| Comparative example 2 | 7 | 6.8 | 320 | 47 | 14.6 | 37.2 | 28.5 |
| Comparative example 3 | 12 | 7.0 | 330 | 48 | 14.5 | 36.8 | 27.6 |
TABLE 2
As can be seen from the table, the thickness of the surface scale of the wire rod produced in the examples is: 16-18 μm FeO/Fe 3 O 4 : 4.8-5.5, wherein according to the standard GB/T30834-2022, the inclusion grade A of the wire rod is less than or equal to 0.5 grade, the inclusion grade B is less than or equal to 0.5 grade, the inclusion grade C is less than or equal to 0.5 grade, the inclusion grade D is less than or equal to 0.5 grade, the maximum size of the cross section and the maximum width of the longitudinal section are less than or equal to 13 mu m, the ferrite grain size is 5.5-6 grade, the austenite grain size of rolled pieces after a 6 th rolling mill is produced in high-line rolling is 43.5-46.7 mu m, and the grain size of rolled pieces of a 12 th rolling mill is 30.3-33.5 mu m. Drawing until the wire breakage rate of 0.10mm is less than or equal to 0.65 times/ton. Tensile and impact tests are carried out according to the standards GB/T228 and GB/T229, the tensile strength is 260-290 MPa, the elongation is more than or equal to 50%, and the conductivity is more than or equal to 16.5%.
It should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is for clarity only, and that the skilled artisan should recognize that the embodiments may be combined as appropriate to form other embodiments that will be understood by those skilled in the art.
The above list of detailed descriptions is only specific to practical embodiments of the present invention, and is not intended to limit the scope of the present invention, and all equivalent embodiments or modifications that do not depart from the spirit of the present invention should be included in the scope of the present invention.
Claims (11)
1. The production method of the high-conductivity wire rod is characterized by comprising the following chemical components in percentage by mass: c: 0.001-0.005%, si less than or equal to 0.005%, P less than or equal to 0.010%, S less than or equal to 0.005%, and O: 0.005-0.015%, N is less than or equal to 0.002%, mn, and the balance of Fe and unavoidable impurities;
and satisfies the following:
except Fe, the total content of other elements is 0.008-0.13%,
Mn/S＞10.5，
silicon equivalent Si eq Less than or equal to 0.06 percent, silicon equivalent Si eq The calculation formula is as follows:
Si eq =(34*C+13*Si+6*Mn+16*P+12*S)/13,
wherein, the element symbols are mass percentages of the corresponding elements;
the production method comprises the following steps:
according to the chemical composition ratio, after molten iron pretreatment, converter smelting and RH vacuum refining are carried out to obtain molten steel;
after pretreatment, controlling the S content of molten iron to be less than or equal to 0.002%, adding the molten iron into a converter for smelting, wherein the proportion of the molten iron is 85-90%, and the balance is recoverable iron; pouring slag within 10-12 min after blowing is started, controlling the slag pouring rate to be more than or equal to 55%, adding a slag former to perform slag formation, controlling the final slag alkalinity of a converter to be 3.5-4, and controlling the mass percentage of MgO in the slag to be 8% -10%; tapping when the temperature of molten steel reaches 1670-1690 ℃, and adding lime of 2 kg/ton molten steel when tapping reaches 1/3; after tapping, adding 1.3-1.8 kg of calcium aluminate synthetic slag per ton of molten steel to the slag surface, and controlling the oxygen content in the molten steel to be 0.030-0.060%;
casting the molten steel through a continuous casting process to form a continuous casting blank;
cogging the continuous casting billet;
rolling the continuous casting billet to obtain a wire rod, wherein in the rolling process, the temperature of a finish rolling inlet is controlled to be 950-970 ℃, and the spinning temperature is controlled to be 930-950 ℃;
adopting 9 frames for continuous rolling cogging, controlling the area shrinkage of the blank between each pass to be 16-22%, controlling the linear speed ratio of the outlet and inlet of a rolling mill to be 1.2-1.3, and controlling the austenite grain size of the blank of the last rolling mill to be 95-100 mu m;
and cooling the wire rod, wherein when the surface temperature of the wire rod is more than or equal to 650 ℃, the surface cooling speed of the wire rod is controlled to be 0.5-1 ℃/s, when the surface temperature of the wire rod is 600-650 ℃, the surface cooling speed of the wire rod is controlled to be 5-8 ℃/s, and when the surface temperature of the wire rod is reduced to be less than 600 ℃, the surface cooling speed of the wire rod is controlled to be 1-3 ℃/s.
2. The method of producing high conductivity wire rods as recited in claim 1, further comprising, during said converter smelting:
in the tapping process, argon is blown into the ladle at the bottom, the argon pressure is controlled to be 0.5-0.6 mpa before the tapping amount is 3/4, and the argon pressure is controlled to be 0.4-0.5 mpa after the tapping amount is 3/4.
3. The method of producing a high conductivity wire rod according to claim 1, wherein said RH vacuum refining comprises the steps of:
when the vacuum pressure is lower than 100Pa, decarburizing the molten steel, and controlling the C content of the molten steel to be less than or equal to 0.0030% after decarburization is finished;
al is added into the molten steel for deoxidization treatment, wherein the addition amount of the Al is as follows: [ (11-13) ×oxygen content×10 4 ]kg, when the deoxidation is finished, controlling the Al mass content of molten steel to be less than 0.002%;
and carrying out clean circulation and air breaking treatment.
4. The method for producing a high-conductivity wire rod according to claim 2, wherein the continuous casting process specifically comprises:
adding mold flux into the mold, controlling the thickness of the liquid slag layer to be 3-5 mm,
performing primary cooling and secondary cooling after continuous casting, adopting four-zone water mist cooling in a secondary cooling section, wherein the water quantity of the four-zone water mist cooling is 120-125, 50-60, 30-35 and 25-30L/min respectively, the lowest water quantity of each zone is 25, 20, 18 and 15L/min respectively,
and carrying out rolling treatment on the continuous casting tail end, wherein the rolling reduction is 25-26 mm.
5. The method of producing a high conductivity wire rod according to claim 4, wherein the composition of the mold flux, in mass percent, comprises: siO (SiO) 2 ：37±3%，CaO：30±5%，Al 2 O 3 ：7±2.5%，Na 2 O：5.6±2.5%，MgO：4±2%，F - : 7+/-3%, the basicity R of the crystallizer casting powder is 0.81+/-0.06, and the viscosity of the crystallizer casting powder is 0.46+/-0.12.
6. The method of producing a high conductivity wire rod according to claim 1, wherein said rolling said continuous casting slab to obtain a wire rod, further comprising: and controlling the temperature difference between the surface and the core of the wire rod to be less than or equal to 60 ℃ when the finish rolling outlet is used for spinning.
7. A high conductivity wire rod manufactured by the method of any one of claims 1 to 6.
8. The high conductivity wire rod according to claim 7, wherein the surface iron scale of the wire rod has a thickness of 15-20 μm, and the iron scale structure comprises FeO and Fe from inside to outside in sequence 3 O 4 、Fe 2 O 3 Wherein the FeO amount is the largest, feO and Fe 3 O 4 The number ratio is 4-6.
9. The high conductivity wire rod according to claim 7, wherein the class a inclusions are equal to or less than 0.5, the class B inclusions are equal to or less than 0.5, the class C inclusions are equal to or less than 0.5, the class D inclusions are equal to or less than 0.5, the maximum inclusion size is equal to or less than 15 μm in the cross section of the wire rod and the longitudinal section of the wire rod, and the wire breakage rate of 0.10mm is less than 1 time per ton in the inclusion class of the wire rod according to standard GB/T30834-2022.
10. The high conductivity wire rod of claim 7, wherein the tensile strength of the wire rod is 260-300 mpa and the elongation is more than or equal to 50% when the wire rod specification is 5.0-14 mm by performing tensile and impact tests according to standards GB/T228, GB/T229; when the specification of the wire rod is 7-14 mm, the tensile strength is 240-280 MPa, and the elongation is 45%.
11. The high conductivity wire rod of claim 7, wherein when the wire rod specification is 5.0-14 mm, the conductivity is not less than 16.3%, and the ferrite grain size is 5.5-6 grade; when the specification of the wire rod is 7-14 mm, the conductivity is more than or equal to 16.5%, and the ferrite grain size is 5-5.5 grade.
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| CN106906410A (en) * | 2017-02-13 | 2017-06-30 | 邢台钢铁有限责任公司 | A kind of Ultra-low carbon wire rod and its production method with high conductivity |
| CN112122338A (en) * | 2020-09-16 | 2020-12-25 | 广东韶钢松山股份有限公司 | Ultra-low carbon steel wire rod for steel ladle steel wire and production process thereof |
| CN113073268A (en) * | 2021-03-29 | 2021-07-06 | 江苏省沙钢钢铁研究院有限公司 | Wire rod for copper-clad steel wire and production method thereof |
| CN114892069A (en) * | 2022-05-21 | 2022-08-12 | 湖南华菱湘潭钢铁有限公司 | Method for producing copper-clad wire rod without molten iron pretreatment process |
| CN116770184A (en) * | 2023-08-17 | 2023-09-19 | 江苏省沙钢钢铁研究院有限公司 | Corrosion-resistant welding wire steel wire rod and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106906410A (en) * | 2017-02-13 | 2017-06-30 | 邢台钢铁有限责任公司 | A kind of Ultra-low carbon wire rod and its production method with high conductivity |
| CN112122338A (en) * | 2020-09-16 | 2020-12-25 | 广东韶钢松山股份有限公司 | Ultra-low carbon steel wire rod for steel ladle steel wire and production process thereof |
| CN113073268A (en) * | 2021-03-29 | 2021-07-06 | 江苏省沙钢钢铁研究院有限公司 | Wire rod for copper-clad steel wire and production method thereof |
| CN114892069A (en) * | 2022-05-21 | 2022-08-12 | 湖南华菱湘潭钢铁有限公司 | Method for producing copper-clad wire rod without molten iron pretreatment process |
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