CN114875330B - 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 PDF

Info

Publication number
CN114875330B
CN114875330B CN202210572116.7A CN202210572116A CN114875330B CN 114875330 B CN114875330 B CN 114875330B CN 202210572116 A CN202210572116 A CN 202210572116A CN 114875330 B CN114875330 B CN 114875330B
Authority
CN
China
Prior art keywords
equal
less
steel plate
percent
thickness direction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202210572116.7A
Other languages
Chinese (zh)
Other versions
CN114875330A (en
Inventor
童明伟
张莉芹
易勋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Baowu Group Echeng Iron and Steel Co Ltd
Original Assignee
Baowu Group Echeng Iron and Steel Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Baowu Group Echeng Iron and Steel Co Ltd filed Critical Baowu Group Echeng Iron and Steel Co Ltd
Priority to CN202210572116.7A priority Critical patent/CN114875330B/en
Publication of CN114875330A publication Critical patent/CN114875330A/en
Application granted granted Critical
Publication of CN114875330B publication Critical patent/CN114875330B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21BROLLING OF METAL
    • B21B1/00Metal-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
    • B21B1/02Metal-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
    • B21B1/026Rolling
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C33/00Making ferrous alloys
    • C22C33/04Making ferrous alloys by melting
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/001Ferrous alloys, e.g. steel alloys containing N
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/04Ferrous alloys, e.g. steel alloys containing manganese
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/12Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/14Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00Technologies related to metal processing
    • Y02P10/20Recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)

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 to 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 to 0.0022%, zr:0.0007 to 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 130-150mm, reL = 473-490MPa, rm = -640-658MPa, A = -33-35%, KV at-40 DEG C 2 = 278-300J, and Z = 72-75% in the thickness direction, and the finished steel plate has high strength and toughness, excellent thickness direction performance and good performance uniformity.

Description

High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof
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 sections of the casting blanks is, the higher the internal and external temperatures are, the higher the contents of elements such as carbon, phosphorus, sulfur, manganese and the like in the central parts of the casting blanks are, so that the casting blanks have serious central component segregation, and in the cooling process of finished steel plates, hard martensite or bainite structures can be generated in the cores of the steel plates, so that the performance uniformity and the thickness direction performance of the steel plates are seriously damaged.
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 for buildings with excellent Z-direction performance and a production method thereof, the thickness of a finished steel plate of the patent is 60-130 mm, the Z-direction performance of the 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 have the guarantee of impact toughness.
The Chinese patent application with the application number of 200810141457.9 obtains the super-thick steel plate with the thickness of 100-114 mm through quenching and tempering, but the patent has more contents of precious elements Mo and Cr, thereby not only having high process cost, but also having higher alloy cost; 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 a continuous casting slab 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 300mm thick continuous casting billet in Chinese patent with application number 201110302954.4 is 140mm, and the related finished steel plate has lamellar tearing resistance which meets the Z35% requirement, but the yield strength and the impact energy are both in a lower level.
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 directivity, but the steel plate is rolled into a material in two stages, high-temperature tempering treatment is required to be carried out, and the manufacturing process cost is high. The Chinese patent with the application number of 202010804760.3 discloses a method for producing a steel plate for a welded structure with excellent Z-direction performance 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 the manufacturing process cost is high.
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 to 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 to 0.0022%, zr:0.0007 to 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 finished steel plate is 130-150mm, reL = 473-490MPa, rm = 640-658MPa, A = 33-35%, and KV 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 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 wire feeding;
(3) Continuous casting: adopting full-flow protection 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 soft 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: adopting single-stage rolling, performing high-pressure water descaling for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then immediately adopting a finishing mill to perform rolling for 5-6 times, wherein the rolling reduction of the final time is 15-20 mm, and the rolling reduction of the rest single time is more than or equal to 47mm; and after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, and then the steel plate is cooled to 330-350 ℃ by air and is discharged, and the steel plate is closely and fully stacked and slowly cooled to the room temperature.
And (5) the water spraying pressure for high-pressure water descaling 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 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 micro composite 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 to 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 properties of the product of the present invention.
The content of Mn in the steel is selected to be 1.42-1.67%, mn has the function of refining crystal grains and is one of important elements for ensuring the strength and the 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-sized sulfide inclusions with S, which are 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 and S are easy to deviate from grain boundaries, S and Mn are easy to form large MnS inclusions, and the toughness and the performance in the thickness direction are reduced, so the content of the Mn-S inclusions is as low as possible.
The content of Nb is selected to be 0.032-0.058%, nb in steel is combined with C and N 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 of the invention can be successfully rolled without mixed crystals at higher temperature and single-pass high reduction, thereby ensuring the obdurability and the performance uniformity. 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 is combined with C and N 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 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%, carbonitride formed by Ti, C and N can effectively inhibit austenite grains from growing in the heating process, strength and low-temperature toughness are improved, and the Ti can also improve recrystallization temperature, so that the production and 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 Ca content of the invention 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; the Ca can also spheroidize MnS inclusions, and improve the low-temperature toughness and the performance in the thickness direction. 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 not only play a role of a deoxidizer to purify steel, but also 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 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) multiplied by 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 to 20). Times.10 -4 %。
The N content of the invention is selected to be (10-22) multiplied by 10 -4 Percent, N can form carbon nitrogen with Nb, V and Ti in steelThe compound points have the functions of grain refinement and precipitation strengthening, improve the toughness of the steel and improve the performance uniformity, but too much N can form TiN inclusions with larger size with Ti, and the low-temperature toughness and the thickness direction performance are not facilitated. Therefore, N is defined as (10-22). Times.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 a crystal boundary, the cold brittleness is increased, the low-temperature toughness and the 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 have to satisfy the formula: zr/O = 0.61-0.75, ti/N = 7.0-8.0. The invention adds proper amount of Zr to form ZrO and other fine oxides with O in steel, which can purify steel and change inclusion shape as deoxidizer, besides, zrO and other fine oxides can be used as structure phase change core to refine structure and improve low temperature toughness and thickness direction performance, therefore, to obtain product performance requirement of the invention, except limiting Zr content, zr and O must meet the formula Zr/O = 0.61-0.75, when Zr/O < 0.61, zr can not play the above-mentioned role, when Zr/O > 0.75, zr containing large-scale composite oxide inclusion is easy to form, which is not good for low temperature toughness and thickness direction performance. According to the invention, the carbonitride formed by adding a proper amount of Ti, C and N can effectively inhibit austenite grains from growing in the heating process, improve the strength and 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 performance in the thickness direction 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 purpose of the external refining is 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 of cracks, bubbles, alumina, silicate inclusions and the like.
(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 the casting blank is uniform after heating, high-pressure water descaling 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, 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 large reduction, the crystal grains at the central part are crushed more fully, and the surface cooling speed of the finished steel plate is higher than that of the center in the cooling process, so that the relative refinement degree of the surface structure is higher. The final pass reduction is 15-20 mm, which is to improve the plate shape and 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 stacked in a totally-closed way at 330-350 ℃ and slowly cooled to room temperature.
The thickness of the finished steel plate produced by the invention is 130-150mm, reL = 473-490MPa, rm = 640-658MPa, A = 33-35%, and-40 ℃ KV 2 =278 to 300J, and Z =72 to 75% in the thickness direction.
Compared with the prior art, 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, and can be implemented on a large scale in each metallurgical enterprise; the finished steel plate produced by the method has the characteristics of high strength and toughness, excellent thickness direction performance, good performance uniformity and the like, and particularly has excellent thickness direction performance 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 each example and comparative example 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 of examples 1 to 8 and comparative examples 1 to 3 of the present invention were 130 to 150mm.
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, 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 protection 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 soft 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: adopting single-stage rolling, performing high-pressure water descaling for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then immediately adopting a finishing mill to perform rolling for 5-6 times, wherein the rolling reduction of the final time is 15-20 mm, and the rolling reduction of the rest single time is more than or equal to 47mm; and after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, and then the steel plate is cooled to 330-350 ℃ by air and is discharged, and the steel plate is closely and fully stacked and slowly cooled to the room temperature.
TABLE 1 tabulation of chemical composition (wt%) values of steel sheets of examples of the present invention and comparative examples
Figure 101299DEST_PATH_IMAGE001
TABLE 2 tabulation of values of main process parameters of steel sheets of examples of the present invention and comparative examples
Figure 346336DEST_PATH_IMAGE002
TABLE 3 test result list of mechanical properties of steel sheets of each example and comparative example of the present invention
Figure 657232DEST_PATH_IMAGE003
The steel plates of the products of examples 1-8 and comparative examples 1-3 of the invention are respectively sampled at different thickness positions at the 1/4 part of the plate width and the 1/2 part of the plate width to carry out 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 of the invention has better comprehensive performance and performance uniformity, the steel plate produced by the method has the characteristics of high strength, high toughness, excellent performance in the thickness direction, good performance uniformity and the like, and particularly the finished steel plate has excellent performance in the thickness direction 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 in 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 plants, 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 to 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 to 0.059%, ti: 0.005-0.017%, ca:0.0007 to 0.0022%, zr: 0.0007E0.0014%,O:(11~20)×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 production method of the high-strength and high-toughness steel plate with uniform performance and excellent performance in the thickness direction comprises the following 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 wire feeding;
(3) Continuous casting: adopting full-flow protection 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 soft 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: adopting single-stage rolling, performing high-pressure water descaling for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then immediately adopting a finishing mill to perform rolling for 5-6 times, wherein the rolling reduction of the final time is 15-20 mm, and the rolling reduction of the rest single time is more than or equal to 47mm; and after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, and then the steel plate is cooled to 330-350 ℃ by air and is discharged, and the steel plate is closely and fully stacked and slowly cooled to the room temperature.
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 130-150mm eL =473~490MPa,R m =640~658MPa,A=33~35%,-40℃KV 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 is required to have P less than or equal to 0.05 percent, S less than or equal to 0.005 percent, as less than or equal to 0.005 percent and Sn 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 wire feeding;
(3) Continuous casting: adopting full-flow protection 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 soft 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: adopting single-stage rolling, performing high-pressure water descaling for 3-5 times before rolling to ensure that the surface temperature of a casting blank is 950-1000 ℃, then immediately adopting a finishing mill to perform rolling for 5-6 times, wherein the rolling reduction of the final time is 15-20 mm, and the rolling reduction of the rest single time is more than or equal to 47mm; and after laminar cooling, the surface temperature of the steel plate is 620-680 ℃, and then the steel plate is cooled to 330-350 ℃ by air and is discharged, and the steel plate is closely and fully stacked and slowly cooled to the room temperature.
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) the water spraying pressure for high-pressure water descaling 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 crack, bubble and alumina and silicate inclusion defects.
CN202210572116.7A 2022-05-25 2022-05-25 High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof Active CN114875330B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210572116.7A CN114875330B (en) 2022-05-25 2022-05-25 High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210572116.7A CN114875330B (en) 2022-05-25 2022-05-25 High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof

Publications (2)

Publication Number Publication Date
CN114875330A CN114875330A (en) 2022-08-09
CN114875330B true CN114875330B (en) 2022-10-18

Family

ID=82678578

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210572116.7A Active CN114875330B (en) 2022-05-25 2022-05-25 High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof

Country Status (1)

Country Link
CN (1) CN114875330B (en)

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102965592B (en) * 2012-12-11 2014-05-28 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
JP6086086B2 (en) * 2014-03-19 2017-03-01 Jfeスチール株式会社 Ultra-thick steel plate with excellent HIC resistance and manufacturing method thereof
JP6261640B2 (en) * 2016-03-30 2018-01-17 新日鐵住金ステンレス株式会社 Ferritic stainless steel sheet and steel pipe for exhaust parts with excellent workability and manufacturing method thereof
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
CN111926236B (en) * 2020-08-12 2021-11-23 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

Also Published As

Publication number Publication date
CN114875330A (en) 2022-08-09

Similar Documents

Publication Publication Date Title
CN111441000A (en) 690 MPa-yield-strength low-yield-ratio high-strength steel plate and manufacturing method thereof
CN109136738B (en) High-strength low-temperature-resistant hull structure steel plate and preparation method thereof
CN109628828B (en) Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof
CN114645183B (en) Production method of high-toughness low-yield-ratio low-alloy high-strength steel plate
CN110735085A (en) Manufacturing method of thin Q345qE and Q370qE steel plates
CN114134406B (en) Spherical tank steel plate with thickness of 20-50mm and excellent low-temperature toughness of core and manufacturing method thereof
CN110983187A (en) Novel high-strength weather-resistant pipeline steel X80 steel plate and production method thereof
CN111926236B (en) Method for producing steel plate with excellent Z-direction performance for welding structure by adopting continuous casting billet under condition of small compression ratio
CN110184534B (en) 100-150 mm thick super-thick steel plate with excellent performance after die welding treatment and production method thereof
CN108588569B (en) Ocean engineering steel with yield strength of more than or equal to 450MPa and preparation method thereof
CN116716544B (en) Round steel for ocean engineering and preparation method thereof
CN112779456A (en) Method for manufacturing steel plate SM490B for welded structure
CN111763880A (en) Low-yield-ratio ultra-thick hydroelectric high-strength steel plate and manufacturing method thereof
CN114622135B (en) Micro-niobium alloyed Q355B low-alloy high-strength structural steel plate and manufacturing method thereof
CN114875330B (en) High-strength and high-toughness steel plate with uniform performance and excellent performance in thickness direction and production method thereof
CN113151740B (en) VL4-4L steel plate with good low-temperature toughness for ship and manufacturing method thereof
CN110747390B (en) High-strength corrosion-resistant steel for ships and preparation method thereof
CN115572911B (en) 350MPa grade sulfuric acid dew point corrosion resistant rare earth steel and manufacturing method thereof
CN115652209B (en) 650MPa grade sulfuric acid dew point corrosion resistant rare earth steel and manufacturing method thereof
CN115637391B (en) 550MPa grade sulfuric acid dew point corrosion resistant rare earth steel and manufacturing method thereof
CN116145017B (en) Production method of high-toughness wear-resistant steel plate with uniform hardness in thickness direction
CN116005071B (en) X80 crack-arrest steel plate and production method thereof
CN114182166B (en) 390 MPa-grade low-alloy corrosion-resistant steel and preparation method thereof
CN115652208B (en) 450MPa grade sulfuric acid dew point corrosion resistant rare earth steel and manufacturing method thereof
CN113186460B (en) 820 MPa-level large-thickness steel plate for ships and manufacturing method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant