CN114875330A - High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof - Google Patents
High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 100
- 239000010959 steel Substances 0.000 title claims abstract description 100
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 27
- 238000005266 casting Methods 0.000 claims abstract description 37
- 230000007547 defect Effects 0.000 claims abstract description 11
- 238000005204 segregation Methods 0.000 claims abstract description 11
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 10
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 9
- 239000000126 substance Substances 0.000 claims abstract description 8
- 229910052718 tin Inorganic materials 0.000 claims abstract description 8
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 7
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 7
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 7
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 7
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 6
- 229910052802 copper Inorganic materials 0.000 claims abstract description 6
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 6
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 6
- 229910052785 arsenic Inorganic materials 0.000 claims abstract description 5
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims abstract description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 4
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 4
- 238000005096 rolling process Methods 0.000 claims description 25
- 230000009467 reduction Effects 0.000 claims description 14
- 238000010438 heat treatment Methods 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 11
- 239000011575 calcium Substances 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 8
- 238000009749 continuous casting Methods 0.000 claims description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 6
- 238000010583 slow cooling Methods 0.000 claims description 6
- 238000002791 soaking Methods 0.000 claims description 6
- 238000007670 refining Methods 0.000 claims description 5
- 238000003723 Smelting Methods 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 3
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052786 argon Inorganic materials 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 9
- 239000011572 manganese Substances 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 230000008859 change Effects 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 6
- 239000000956 alloy Substances 0.000 description 6
- 230000009286 beneficial effect Effects 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000005728 strengthening Methods 0.000 description 6
- 238000005496 tempering Methods 0.000 description 6
- 239000002245 particle Substances 0.000 description 5
- 238000001953 recrystallisation Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 239000006104 solid solution Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000003009 desulfurizing effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 241000519995 Stachys sylvatica Species 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000009740 moulding (composite fabrication) Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Classifications
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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
-
- 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
- B21B1/02—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 heavy work, e.g. ingots, slabs, blooms, or billets, in which the cross-sectional form is unimportant ; Rolling combined with forging or pressing
- B21B1/026—Rolling
-
- 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
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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- 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 relates to a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction and a production method thereof, wherein the steel plate consists of the following elements in percentage by mass: c: 0.102 to 0.139%, Si: 0.05-0.12%, Mn: 1.42-1.67%, P is less than or equal to 0.005%, S is less than or equal to 0.001%, Nb: 0.032-0.058%, V: 0.037-0.059%, Ti: 0.005-0.017%, Ca: 0.0007-0.0022%, Zr: 0.0007-0.0014%, O: (11-20). times.10 ‑4 %，N：（10～22）×10 ‑4 Not more than 0.10 percent of Cu, Mo and Cr, not more than 0.001 percent of As, not more than 0.001 percent of Sn, and the balance of Fe and inevitable impurities, and the chemical components also need to satisfy the formula: Zr/O = 0.61-0.75, Ti/N = 7.0-8.0; the thickness of the casting blank is 360-380 mm, the center segregation of the casting blank is less than or equal to C1.0, the center porosity is less than or equal to 0.5, and the casting blank has no defects of cracks, bubbles, alumina and silicate inclusions and the like; the thickness of the finished steel plate is 130-150 mm, ReL = 473-490 MPa, Rm = 640-658 MPa, A = 33-35%, and KV is at-40 DEG C 2 = 278-300J, and Z = 72-75% in the thickness direction, the finished steel plate has high strength and toughness, excellent performance in the thickness direction and good performance uniformity.
Description
Technical Field
The invention relates to the technical field of metal material manufacturing, in particular to a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction and a production method thereof.
Background
With the continuous progress of science and technology, important construction projects in the fields of national economy, such as building structures, ocean platforms, pressure vessels, boiler manufacturing, water/nuclear power stations, shipbuilding industry, petroleum and natural gas pipelines, bridge structures, heavy machinery manufacturing, traffic and the like, are developing towards large-scale and weight-oriented directions, the technical requirements on steel materials are higher and higher, and particularly high-strength and super-thick steel plates with the thickness of more than or equal to 100mm are required to have the characteristics of high strength, high plastic toughness, excellent lamellar tearing resistance, excellent welding performance, excellent performance uniformity and the like. Due to the lack of technical equipment and the imperfect production technology, the high-strength steel plate with the thickness of more than or equal to 100mm produced in China cannot completely meet the technical requirements of large-scale construction engineering, especially the defects of the performance in the thickness direction, the uniformity of the comprehensive performance and the welding performance restrict the development and progress of the super-thick steel plate in China, and even the super-thick steel plate depends on forging or is directly imported from abroad to meet the domestic requirements.
The manufacturing of domestic super-thick steel plates mostly adopts continuous casting blanks with the thickness of more than or equal to 300mm, the larger the thickness of the section of a casting blank is, the larger the internal and external temperature is, the more the content of elements such as carbon, phosphorus, sulfur, manganese and the like at the central part of the casting blank is higher than the surface of the casting blank, so that the casting blank has serious central component segregation, and in the cooling process of a finished steel plate, the core part of the steel plate can generate a hard martensite or bainite structure, thereby seriously damaging the performance uniformity and the thickness direction performance of the steel plate.
Before the invention, Japanese patent laid-open Nos. 6-198394 and 6-158222 can produce the thick steel plate with excellent Z-directional performance for the building structure, and have the defects that alloy elements such as Cu, Ni, Mo and the like are added during the component design of the steel plate, the production cost is high, and the thickness of the finished steel plate is only 75mm at most.
The Chinese patent application with the application number of 2009100481369.2 discloses a super-thick steel plate with excellent Z-direction performance for buildings and a production method thereof, the thickness of a finished steel plate of the patent is 60-130 mm, the Z-direction performance of an embodiment of the steel plate is 62-69%, and the super-thick steel plate has excellent lamellar tearing resistance and has the defect that the related steel plate product does not ensure impact toughness.
The Chinese patent application with the application number of 200810141457.9 obtains an ultra-thick steel plate with the thickness of 100-114 mm through quenching and tempering, but the patent has more precious elements of Mo and Cr, so that the process cost is high, and the alloy cost is also high; the Chinese invention patents with the application numbers of 200810141500.1 and 201010113835.X also obtain the super-thick steel plate by adding a large amount of precious alloys Mo and Cr and then adopting normalizing plus tempering or secondary quenching plus tempering, but the process and the alloy cost of the 2 patents are higher.
The thickness of a Q390E steel plate produced by adopting a continuous casting billet with the thickness of 260mm in the Chinese patent application with the application number of 201010159178.2 is 100mm, but the related finished steel plate cannot ensure the lamellar tearing resistance; the thickness of a Q345EZ35 steel plate produced by a Chinese patent with the application number of 201110302954.4 and a continuous casting billet with the thickness of 300mm is 140mm, the related finished steel plate has laminar tearing resistance which meets the Z35% requirement, but the yield strength and the impact energy are both in lower levels.
The Chinese patent with the application number of 202010804046.4 adopts high-temperature tempering to obtain the 100-150 mm ultra-thick high-strength steel plate for the building with excellent thickness directional performance, but the steel plate is rolled into a material in two stages, and high-temperature tempering treatment is required to be carried out, so that the manufacturing process cost is higher. The Chinese patent with the application number of 202010804760.3 discloses a method for producing a steel plate with excellent Z-direction performance for a welding structure by using a continuous casting billet under the condition of a small compression ratio, the method has excellent Z-direction performance, but the method adopts two-stage rolling and forming, quenching and tempering, and has higher manufacturing process cost.
Disclosure of Invention
The invention aims to provide a method for producing a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction aiming at the defects of the prior art.
The invention relates to a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction, which consists of the following elements in percentage by mass: c: 0.102 to 0.139%, Si: 0.05-0.12%, Mn: 1.42-1.67%, P is less than or equal to 0.005%, S is less than or equal to 0.001%, Nb: 0.032-0.058%, V: 0.037-0.059%, Ti: 0.005-0.017%, Ca: 0.0007-0.0022%, Zr: 0.0007-0.0014%, O: (11-20). times.10 -4 %，N：（10～22）×10 -4 Not more than 0.10 percent of Cu, Mo and Cr, not more than 0.001 percent of As, not more than 0.001 percent of Sn, and the balance of Fe and inevitable impurities, and the chemical components also need to satisfy the formula: Zr/O = 0.61-0.75, and Ti/N = 7.0-8.0.
The thickness of the finished steel plate is 130-150 mm, ReL = 473-490 MPa, Rm = 640-658 MPa, A = 33-35%, and KV is at-40 DEG C 2 =278 to 300J, and Z =72 to 75% in the thickness direction.
The invention relates to a production method of a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction, which comprises the following steps:
(1) smelting in a converter: the molten iron requires that P is less than or equal to 0.05 percent, S is less than or equal to 0.005 percent, As is less than or equal to 0.005 percent and Sn is less than or equal to 0.005 percent;
(2) refining outside the furnace: LF treatment time is 40-42 min, and S is less than or equal to 0.001 when the station is out; RH vacuum degree is less than 67Pa, processing time is 18-22 min, and argon is continuously blown for 12-15 min after calcium wire feeding;
(3) continuous casting: adopting full-flow protective pouring, wherein the superheat degree is 8-12 ℃, the pulling speed is 0.62-0.63 m/min, the electromagnetic stirring current intensity is 420-450A, the total amount is 8-12 mm under light reduction, and the casting blank is slowly cooled in a slow cooling pit for 68-72 h;
(4) heating: adopting a four-section heating mode, wherein the first section is heated to 1000-1100 ℃, the second section is heated to 1150-1220 ℃, the third section is heated to 1280-1300 ℃, the soaking section is heated to 1200-1220 ℃, the total heating time is 450-480 min, and the soaking section time is 62-70 min;
(5) rolling: single-stage rolling is adopted, high-pressure water dephosphorization is carried out for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then a finishing mill is immediately adopted for rolling for 5-6 times, the rolling is finished, the rolling reduction of the last time is 15-20 mm, and the rolling reduction of the rest single-time is more than or equal to 47 mm; and (3) after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, then the steel plate is air-cooled to 330-350 ℃, the steel plate is taken off line, and the steel plate is gradually cooled to room temperature by a totally-enclosed stack.
And (5) water spraying pressure for removing phosphorus from the high-pressure water is 25-26 MPa.
The thickness of the casting blank is 360-380 mm, the macrostructure defect rating center segregation of the casting blank is less than or equal to C1.0, the center porosity is less than or equal to 0.5, and the casting blank has no defects of cracks, bubbles, alumina and silicate inclusions and the like.
The reasons for the limited amounts of the chemical components in the present invention are detailed below:
the content of C is selected to be 0.102-0.139%, and C has strong interstitial solid solution strengthening effect and is an essential element for ensuring the strength of the steel plate. C is combined with Nb, V and Ti to form fine compound carbonitride particles which hinder grain boundary sliding and dislocation movement when external force is applied, thereby improving the toughness. When the C content is less than 0.102%, the strength of the steel sheet cannot be ensured, and when the C content is more than 0.139%, the center segregation of the cast slab is deteriorated, not only the plasticity and the low-temperature toughness are reduced, but also the thickness direction performance and the weldability are not facilitated. Therefore, the C content is limited to 0.102-0.139%.
The Si content of the invention is selected to be 0.05-0.12%, and Si can improve the strength but is not beneficial to low-temperature toughness and welding performance. Although Si plays a role in purifying steel as a deoxidizer in the steel-making process, the Zr and the O are added to combine to form ZrO and other fine oxides, so that the steel is purified by the deoxidizer, the Zr can change the form of inclusions, and the ZrO can be used as a structural phase change core to refine the structure and improve the low-temperature toughness and the performance in the thickness direction. Therefore, the Si content is limited to 0.05 to 0.12% in consideration of the product performance of the present invention.
The content of Mn in the steel is selected to be 1.42-1.67%, Mn has a grain refining effect and is one of important elements for ensuring the strength and toughness of steel, and Mn can also be used as a desulfurizing agent for purifying steel to improve the performance in the thickness direction and the low-temperature toughness. However, excessive Mn tends to form segregation and forms large sulfide inclusions with S, which is disadvantageous in the thickness direction performance and low-temperature toughness. Therefore, the Mn content is limited to 1.42 to 1.67%.
P is less than or equal to 0.005 percent, S is less than or equal to 0.001 percent, P, S is easy to deviate grain boundaries, S and Mn are easy to form large MnS inclusions, and the strength and toughness and the performance in the thickness direction are reduced, so the content of the S and Mn is as low as possible.
The content of Nb is selected to be 0.032-0.058%, Nb and C, N in steel are combined to form carbonitride particles to refine grains, and the strength and the toughness are improved; nb also obviously increases the recrystallization temperature, so that the product can be successfully rolled without mixed crystals at higher temperature and single-pass high reduction, and the toughness and the performance uniformity are ensured. When the Nb content is less than 0.032%, the technical requirements cannot be met, and when the Nb content is more than 0.058%, the performance requirements of the product of the invention are not influenced.
The content of V is selected to be 0.037-0.059%, and V and C, N are combined to form carbonitride particles as Nb, so that the effects of fine grain strengthening and precipitation strengthening are achieved, the strength is improved, and the low-temperature toughness is improved; v can also increase the recrystallization temperature, which is beneficial to the production and the performance of the product of the invention. In addition, more V carbonitride particles can be separated out from the central part of the steel plate during slow cooling to play a role in fine crystallization and precipitation strengthening, so that the strength of the central part slowly lost due to the cooling speed is compensated, and the performance uniformity of the steel plate at different positions is ensured. When the V content is less than 0.037%, the above effect is not significant, and when the V content is more than 0.059%, more solid solution V is disadvantageous for low-temperature toughness.
The Ti is selected to be 0.005-0.017%, the carbonitride formed by the Ti and C, N can effectively inhibit the growth of austenite grains in the heating process, the strength and the low-temperature toughness are improved, the recrystallization temperature of the Ti can also be improved, and the production and the performance of the product are facilitated. However, when the Ti content is less than 0.005%, the above effect is not significant, and when the Ti content is more than 0.017%, TiN inclusions are easily formed, which are not favorable for low-temperature toughness and thickness direction performance.
The content of Ca is selected to be 0.0007-0.0022%, the Ca can be used as a deoxidizer to purify steel, prevent casting blanks from generating air holes, and improve the internal metallurgical quality of the casting blanks; ca can also spheroidize MnS inclusions, and improve low-temperature toughness and thickness direction performance. When the content of Ca is less than 0.0007%, the above effect is not obvious, and when the content of Ca is more than 0.0022%, the grain boundary is easy to be deviated, CaO-MnS composite inclusion is easy to form, the grain boundary strength and the low-temperature toughness are reduced, and the thickness direction performance is not facilitated. Therefore, Ca is limited to 0.0007 to 0.0022%.
The Zr content of the invention is selected to be 0.0007-0.0014%, a proper amount of Zr can form ZrO and other fine oxides with O in steel, the Zr can play a role of a deoxidizer to purify steel, the Zr can change the shape of inclusions, and in addition, the ZrO and other fine oxides can be used as a structure phase change core to refine the structure and improve the low-temperature toughness and the performance in the thickness direction. When the Zr content is less than 0.0007%, the above-mentioned effect is not significant, and when the Zr content is more than 0.0014%, large-sized complex oxide inclusions containing Zr are easily formed, which are disadvantageous in low-temperature toughness and thickness direction performance. Therefore, Zr is limited to 0.0007 to 0.0014%.
The O content of the invention is selected to be (11-20). times.10 -4 Percent, O and a proper amount of Zr in steel can form ZrO and other fine oxides as a structure phase change core, the structure is refined, and the low-temperature toughness and the performance in the thickness direction are improved. Therefore, O is defined as (11-20) × 10 -4 %。
The N content of the invention is selected to be (10-22). times.10 -4 N can form carbonitride particles with Nb, V and Ti in the steel, has the functions of grain refinement and precipitation strengthening, improves the strength and toughness of the steel and improves the performance uniformity, but excessive N can form TiN inclusions with larger size with Ti, and is not beneficial to low-temperature toughness and thickness direction performance. Therefore, N is defined as (10-22) x 10 -4 %。
The Cu, Mo and Cr are not more than 0.10 percent, and the Cu, Mo and Cr are elements with strong solid solution strengthening, which are very beneficial to improving the strength but not beneficial to the impact toughness.
As is less than or equal to 0.001 percent and Sn is less than or equal to 0.001 percent, As and Sn are easy to segregate in crystal boundaries, cold brittleness is increased, low-temperature toughness and performance in the thickness direction are deteriorated, and the content of As and Sn is strictly limited in consideration of the performance requirements of the product.
Meanwhile, the chemical components also need to satisfy the formula: Zr/O = 0.61-0.75, and Ti/N = 7.0-8.0. The invention adds a proper amount of Zr to form ZrO and other fine oxides with O in steel, which not only can play a role of deoxidizer to purify steel, but also can change the shape of inclusions, and in addition, the ZrO and other fine oxides can also be used as a structure phase change core to refine the structure and improve the low-temperature toughness and the thickness direction performance, so that to obtain the product performance requirements of the invention, except for limiting Zr content, Zr and O also need to meet the formula Zr/O = 0.61-0.75, when Zr/O is less than 0.61, Zr can not play the role, and when Zr/O is more than 0.75, Zr-containing large-scale composite oxides are easy to form to be included, which is not beneficial to the low-temperature toughness and the thickness direction performance. According to the invention, the carbonitride formed by adding a proper amount of Ti and C, N can effectively inhibit austenite grains from growing in the heating process, improve the strength and the low-temperature toughness, and the Ti can also improve the recrystallization temperature, so that the production and the performance of the product are facilitated, but when the Ti/N is less than 7.0, the effect is not obvious, and when the Ti/N is more than 8.0, TiN inclusions are easily formed, so that the low-temperature toughness and the thickness direction performance are not facilitated.
The steel of the invention contains the chemical components, and the balance of Fe and inevitable impurities.
The invention also aims to provide a production method of a high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction, the produced finished steel plate has high strength and toughness, excellent performance in the thickness direction and good performance uniformity, the production process is simple and easy to implement and can be implemented on a large scale in various metallurgical enterprises, and the innovation point of the invention is that the process parameters are accurately controlled, and the specific process parameter selection reason is as follows:
(1) the converter smelting requires that P in raw material molten iron is less than or equal to 0.05 percent, S is less than or equal to 0.005 percent, As is less than or equal to 0.005 percent and Sn is less than or equal to 0.005 percent, and aims to reduce the content of easily-segregated impurity elements As far As possible, improve the metallurgical quality of casting blanks, improve the center component segregation and eliminate middle cracks, thereby ensuring the performance and the performance uniformity of the steel plate in the thickness direction.
(2) The external refining aims at degassing and desulfurizing, removing impurities, changing the form of the impurities and homogenizing the components and the temperature of the molten steel, thereby purifying the molten steel to improve the metallurgical quality of a casting blank.
(3) According to the invention, full-flow protection pouring is adopted during pouring, and the superheat degree, the pulling speed, the electromagnetic stirring current intensity, the soft reduction total amount and the slow cooling pit slow cooling time are strictly limited, so that the secondary oxidation of molten steel is prevented, the center component segregation is improved, the return of P is prevented, the surface quality is improved, H is promoted to be fully dissipated to prevent white spots, and a high-quality casting blank and a finished steel plate with uniform performance and excellent performance in the thickness direction are obtained; through the treatment of the process, the thickness of the casting blank is 360-380 mm, the macrostructure defect rating center segregation of the casting blank is less than or equal to C1.0, the center porosity is less than or equal to 0.5, and the casting blank has no defects such as cracks, bubbles, alumina and silicate inclusions.
(4) The four-section heating mode is adopted and the heating process parameters are strictly limited, so that the casting blank is promoted to be fully austenitized, the temperature uniformity of the casting blank is improved, the center component segregation is further improved, and the performance uniformity and the excellent thickness direction performance of the steel plate are ensured.
(5) The invention adopts single-stage rolling to produce the finished steel plate. The temperature of each part of a casting blank is uniform after the casting blank is heated, high-pressure water dephosphorization is carried out for 3-5 times before rolling, the surface temperature of the casting blank is 950-1000 ℃, the aim is to remove iron oxide scales on the surface of the casting blank completely, the surface quality is improved, a certain temperature difference is formed between the surface of the casting blank and the central part of the casting blank, a finishing mill is immediately adopted for rolling for 5-6 times at the moment, the single-pass reduction is more than or equal to 47mm, the deformation of the central part of the casting blank is larger than the surface by utilizing the temperature difference between the surface of the casting blank and the central part and adopting a large reduction, the crystal grains at the central part are crushed more fully, and the surface structure of a finished steel plate is relatively high in refinement degree due to the fact that the surface cooling speed is larger than the center in the cooling process. The final pass reduction is 15-20 mm, and is used for improving the plate shape and the surface quality; the surface temperature of the steel plate after laminar cooling is limited in order to ensure that the tissue types of different parts of the steel plate product are the same, if the surface temperature is too low, a medium-temperature transformation tissue appears on the surface, if the surface temperature is too high, the tissue is thick, and the mechanical property required by the product cannot be obtained; in order to reduce the degree of center segregation and obtain the mechanical property level required by the invention, the steel plate products are fully stacked and slowly cooled to room temperature at 330-350 ℃.
The thickness of a finished steel plate produced by the method is 130-150 mm, ReL = 473-490 MPa, Rm = 640-658 MPa, A =33～35%，-40℃KV 2 =278 to 300J, and Z =72 to 75% in the thickness direction.
Compared with the prior art, precious metals such as Mo, Cr, Ni and the like do not need to be added, the alloy cost is low, the production process is simple and easy to implement, and the method can be implemented on a large scale in various metallurgical enterprises; the finished steel plate produced by the method has the characteristics of high strength and toughness, excellent performance in the thickness direction, good performance uniformity and the like, and particularly has excellent performance in the thickness direction and good performance uniformity.
Detailed Description
In order to better explain the technical solution of the present invention, the technical solution of the present invention is further described below with reference to specific examples, which are only exemplary to illustrate the technical solution of the present invention and do not limit the present invention in any way.
The following table 1 is a list of values of chemical components in percentage by mass in each example and comparative example of the present invention;
table 2 below is a list of values of the main process parameters of the examples and comparative examples of the present invention;
the following table 3 shows the mechanical property test results of the examples and comparative examples of the present invention.
The thicknesses of the steel plates in the embodiments 1 to 8 and the comparative examples 1 to 3 of the invention are 130 to 150 mm.
The production method of the high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction, provided by the embodiments of the invention, comprises the following steps:
(1) smelting in a converter: the molten iron requires that P is less than or equal to 0.05 percent, S is less than or equal to 0.005 percent, As is less than or equal to 0.005 percent and Sn is less than or equal to 0.005 percent;
(2) refining outside the furnace: LF treatment time is 40-42 min, and S is less than or equal to 0.001 when the station is out; RH vacuum degree is less than 67Pa, the treatment time is 18-22 min, and argon is continuously blown for 12-15 min after calcium wires are fed;
(3) continuous casting: adopting full-flow protective pouring, wherein the superheat degree is 8-12 ℃, the pulling speed is 0.62-0.63 m/min, the electromagnetic stirring current intensity is 420-450A, the total amount is 8-12 mm under light reduction, and the casting blank is slowly cooled in a slow cooling pit for 68-72 h;
(4) heating: adopting a four-section heating mode, wherein the first section is heated to 1000-1100 ℃, the second section is heated to 1150-1220 ℃, the third section is heated to 1280-1300 ℃, the soaking section is heated to 1200-1220 ℃, the total heating time is 450-480 min, and the soaking section time is 62-70 min;
(5) rolling: single-stage rolling is adopted, high-pressure water dephosphorization is carried out for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then a finishing mill is immediately adopted for rolling for 5-6 times, the rolling is finished, the rolling reduction of the last time is 15-20 mm, and the rolling reduction of the rest single-time is more than or equal to 47 mm; and (3) after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, then the steel plate is air-cooled to 330-350 ℃, the steel plate is taken off line, and the steel plate is gradually cooled to room temperature by a totally-enclosed stack.
TABLE 1 tabulation of chemical composition (wt%) values of steel sheets of examples of the present invention and comparative examples
TABLE 2 tabulation of values of main process parameters of steel sheets of examples of the present invention and comparative examples
TABLE 3 test result list of mechanical properties of steel sheets of each example and comparative example of the present invention
The steel plate obtained in the examples 1 to 8 and the comparative examples 1 to 3 of the invention is sampled at different thickness positions at 1/4 and 1/2 of the plate width and is subjected to normal temperature tensile property, -40 ℃ longitudinal impact energy and thickness direction full thickness Z-direction property tests. The performance results of the comparative tests show that: the steel plate product has better comprehensive performance and performance uniformity, the steel plate produced by the method has the characteristics of high strength, high toughness, excellent thickness direction performance, good performance uniformity and the like, and particularly, the finished steel plate has excellent thickness direction performance and good performance uniformity. Compared with the prior art, the steel of the invention does not need to add noble metals such as Mo, Cr, Ni and the like, has low alloy cost and simple and easy production process, can be implemented on a large scale in various metallurgical enterprises, and can be widely applied to steel structure engineering in various fields such as buildings, bridges, ships, water/nuclear power stations, ocean platforms and the like.
The embodiments described above are merely specific examples of the present invention exemplified for explaining the present invention, and do not limit the present invention in any way, and any insubstantial changes from the above-described contents and forms without departing from the scope of the present invention are considered to fall within the scope of the present invention as claimed.
Claims (5)
1. The high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction is characterized by comprising the following elements in percentage by mass: c: 0.102 to 0.139%, Si: 0.05-0.12%, Mn: 1.42-1.67%, P is less than or equal to 0.005%, S is less than or equal to 0.001%, Nb: 0.032-0.058%, V: 0.037-0.059%, Ti: 0.005-0.017%, Ca: 0.0007-0.0022%, Zr: 0.0007-0.0014%, O: (11-20). times.10 -4 %，N：（10～22）×10 -4 Not more than 0.10 percent of Cu, Mo and Cr, not more than 0.001 percent of As, not more than 0.001 percent of Sn, and the balance of Fe and inevitable impurities, and the chemical components also need to satisfy the formula: Zr/O = 0.61-0.75, and Ti/N = 7.0-8.0.
2. The steel sheet according to claim 1, which has uniform properties and excellent properties in the thickness direction, and which has high toughness, is characterized in that: the thickness of the finished steel plate is 130-150 mm, ReL = 473-490 MPa, Rm = 640-658 MPa, A = 33-35%, and KV is at-40 DEG C 2 =278 to 300J, and Z =72 to 75% in the thickness direction.
3. The method for producing a high-toughness steel sheet excellent in the properties in the thickness direction and uniform in properties according to claim 1, comprising the steps of:
(1) smelting in a converter: the molten iron requires that P is less than or equal to 0.05 percent, S is less than or equal to 0.005 percent, As is less than or equal to 0.005 percent and Sn is less than or equal to 0.005 percent;
(2) refining outside the furnace: LF treatment time is 40-42 min, and S is less than or equal to 0.001 when the station is out; RH vacuum degree is less than 67Pa, the treatment time is 18-22 min, and argon is continuously blown for 12-15 min after calcium wires are fed;
(3) continuous casting: adopting full-flow protective pouring, wherein the superheat degree is 8-12 ℃, the pulling speed is 0.62-0.63 m/min, the electromagnetic stirring current intensity is 420-450A, the total amount is 8-12 mm under light reduction, and the casting blank is slowly cooled in a slow cooling pit for 68-72 h;
(4) heating: adopting a four-section heating mode, wherein the first section is heated to 1000-1100 ℃, the second section is heated to 1150-1220 ℃, the third section is heated to 1280-1300 ℃, the soaking section is heated to 1200-1220 ℃, the total heating time is 450-480 min, and the soaking section time is 62-70 min;
(5) rolling: single-stage rolling is adopted, high-pressure water dephosphorization is carried out for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then a finishing mill is immediately adopted for rolling for 5-6 times, the rolling is finished, the rolling reduction of the last time is 15-20 mm, and the rolling reduction of the rest single-time is more than or equal to 47 mm; and (3) after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, then the steel plate is air-cooled to 330-350 ℃, the steel plate is taken off line, and the steel plate is gradually cooled to room temperature by a totally-enclosed stack.
4. The method for producing a high-toughness steel sheet having uniform properties and excellent properties in the thickness direction as claimed in claim 3, wherein: and (5) water spraying pressure for removing phosphorus from the high-pressure water is 25-26 MPa.
5. The method for producing a high-toughness steel sheet having uniform properties and excellent properties in the thickness direction as claimed in claim 3, wherein: the thickness of the casting blank is 360-380 mm, the macrostructure defect rating center segregation of the casting blank is less than or equal to C1.0, the center porosity is less than or equal to 0.5, and the casting blank has no defects of cracks, bubbles, alumina and silicate inclusions and the like.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102965592A (en) * | 2012-12-11 | 2013-03-13 | 南京钢铁股份有限公司 | Method for producing ocean engineering steel plate with low compression ratio, thick specification and ultrahigh strength |
| JP2015178647A (en) * | 2014-03-19 | 2015-10-08 | Ｊｆｅスチール株式会社 | Extra thick steel plate excellent in hic resistance performance and production method thereof |
| JP2017179480A (en) * | 2016-03-30 | 2017-10-05 | 新日鐵住金ステンレス株式会社 | Ferritic stainless steel sheet for exhaust component excellent in processability, steel tube and manufacturing method therefor |
| CN108796370A (en) * | 2018-06-13 | 2018-11-13 | 武汉钢铁有限公司 | A kind of the welding structure fire-resistant and weather-resistant steel and its production method of yield strength >=690MPa |
| CN111926236A (en) * | 2020-08-12 | 2020-11-13 | 宝武集团鄂城钢铁有限公司 | Method for producing steel plate with excellent Z-direction performance for welding structure by adopting continuous casting billet under condition of small compression ratio |
-
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102965592A (en) * | 2012-12-11 | 2013-03-13 | 南京钢铁股份有限公司 | Method for producing ocean engineering steel plate with low compression ratio, thick specification and ultrahigh strength |
| JP2015178647A (en) * | 2014-03-19 | 2015-10-08 | Ｊｆｅスチール株式会社 | Extra thick steel plate excellent in hic resistance performance and production method thereof |
| JP2017179480A (en) * | 2016-03-30 | 2017-10-05 | 新日鐵住金ステンレス株式会社 | Ferritic stainless steel sheet for exhaust component excellent in processability, steel tube and manufacturing method therefor |
| CN108796370A (en) * | 2018-06-13 | 2018-11-13 | 武汉钢铁有限公司 | A kind of the welding structure fire-resistant and weather-resistant steel and its production method of yield strength >=690MPa |
| CN111926236A (en) * | 2020-08-12 | 2020-11-13 | 宝武集团鄂城钢铁有限公司 | Method for producing steel plate with excellent Z-direction performance for welding structure by adopting continuous casting billet under condition of small compression ratio |
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