CN109628854B - Method for producing steel plate by ultra-fast cooling process - Google Patents

Method for producing steel plate by ultra-fast cooling process Download PDF

Info

Publication number
CN109628854B
CN109628854B CN201910051142.3A CN201910051142A CN109628854B CN 109628854 B CN109628854 B CN 109628854B CN 201910051142 A CN201910051142 A CN 201910051142A CN 109628854 B CN109628854 B CN 109628854B
Authority
CN
China
Prior art keywords
equal
less
ultra
cooling process
steel
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
CN201910051142.3A
Other languages
Chinese (zh)
Other versions
CN109628854A (en
Inventor
杨海西
张少凯
樊利智
曹晓运
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.)
Hebei Jingye Kuanban Technology Co ltd
Original Assignee
Hebei Jingye Medium Plate 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 Hebei Jingye Medium Plate Co Ltd filed Critical Hebei Jingye Medium Plate Co Ltd
Priority to CN201910051142.3A priority Critical patent/CN109628854B/en
Publication of CN109628854A publication Critical patent/CN109628854A/en
Application granted granted Critical
Publication of CN109628854B publication Critical patent/CN109628854B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D11/00—Process control or regulation for heat treatments
    • C21D11/005—Process control or regulation for heat treatments for cooling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Abstract

A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.13-0.2% of Nb + Ti + V, less than or equal to 0.050% of Al, at least 3 of 6 of Cr, Mo, Ni, Cu, W and rare earth, and the balance of Fe and inevitable impurity elements; the ultra-fast cooling process is to cool the steel from the finishing temperature of 845-850 ℃ to 365 ℃ at the cooling speed of 80-90 ℃/s and to perform coiling at 350-355 ℃.

Description

Method for producing steel plate by ultra-fast cooling process
Technical Field
The invention belongs to the technical field of metal materials, and particularly relates to a method for producing a steel plate by an ultra-fast cooling process, in particular to a method for producing a high-strength steel plate for a bridge and a high-strength steel plate for a submarine tunnel by the ultra-fast cooling process.
Background
The low-alloy structural steel with atmospheric corrosion resistance is widely applied to the field of manufacturing of outdoor steel structures such as buildings, bridges, containers, vehicles and the like. The low-carbon manganese steel is used as a base, and a small amount of low-alloy corrosion-resistant elements such as Cr, Cu, Ni and the like are added, so that the rust layer structure of the steel is promoted to change, the atmospheric corrosion speed is favorably slowed down, and the atmospheric corrosion resistance of the steel is remarkably improved.
CN 101135029A describes atmospheric corrosion resistant steel with yield strength of 700MPa and a manufacturing method thereof, and the strength is low, so that the high strength requirement of different occasions cannot be met. CN 103114253A describes a method for producing an ultra-thin steel plate with a thickness of 3-10 mm, although yield strength Rp0.2 can reach 950-1300MPa, tensile strength Rm: 1000-1500MPa, elongation at break A: 12-20%, impact absorption energy KV2 at-40 deg.C: 80-270J, but the hot rolled substrate is subjected to two quenching and tempering heat treatment processes, so that the production efficiency is obviously influenced. CN 103302255A describes a method for manufacturing a strip-cast 700 MPa-grade high-strength atmospheric corrosion resistant steel, which has a steel strip with a yield strength of at least 700MPa, a tensile strength of at least 780MPa and an elongation of at least 18%, and is difficult to adapt to new requirements of comprehensive properties such as high strength, high elongation and impact resistance.
In addition, at present, research on the ultra-fast cooling process is mainly focused on the fields of automobile steel plates and X70 and X80 pipeline steel, and research on the comprehensive properties of improving high strength, high elongation, impact resistance and the like by using the ultra-fast cooling process in the fields of the high-strength bridge steel plate and the submarine tunnel steel plate is less.
Disclosure of Invention
The invention aims to provide a novel high-strength high-elongation high-impact-resistance high-strength high-elongation high-impact-resistance high-elongation high-impact-resistance high. In order to achieve the above object, the present invention provides a high-strength steel plate for a bridge and a steel plate for a submarine tunnel, and a method for producing the same.
The technical scheme is as follows:
a method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn1, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.13-0.2% of Nb + Ti + V, less than or equal to 0.050% of Al, at least 3 of 6 of Cr, Mo, Ni, Cu, W and rare earth, and the balance of Fe and inevitable impurity elements; the ultra-fast cooling process is to cool the steel from the finishing temperature of 845-850 ℃ to 365 ℃ at the cooling speed of 80-90 ℃/s and to perform coiling at 350-355 ℃.
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.065-0.07% of Nb, 0.02-0.025% of Ti, 0.03-0.035% of V, less than or equal to 0.050% of Al, 0.45-0.48% of Cr, 0.35-0.38% of Mo, 0.12-0.15% of Ni, 0.05-0.09% of Cu, 0.01-0.015% of W, 0.0001-0.001% of rare earth, 0.001-0.005% of N, and the balance Fe and inevitable impurity elements; the ultra-fast cooling process is to cool the steel from the finishing temperature of 845-850 ℃ to 365 ℃ at the cooling speed of 80-90 ℃/s and to perform coiling at 350-355 ℃.
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.065-0.07% of Nb, 0.02-0.025% of Ti, 0.03-0.035% of V, less than or equal to 0.050% of Al, 0.45-0.48% of Cr, 0.35-0.38% of Mo, 0.12-0.15% of Ni, 0.05-0.09% of Cu, 0.01-0.015% of W, 0.0001-0.001% of rare earth, 0.001-0.005% of N, and the balance Fe and inevitable impurity elements; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.065-0.07% of Nb, 0.02-0.025% of Ti, 0.03-0.035% of V, less than or equal to 0.050% of Al, 0.45-0.48% of Cr, 0.35-0.38% of Mo, 0.12-0.15% of Ni, 0.05-0.09% of Cu, 0.01-0.015% of W, 0.0001-0.001% of rare earth, 0.001-0.005% of N, and the balance Fe and inevitable impurity elements;
the process route comprises the following steps: molten iron pretreatment → molten steel smelting → external refining → continuous casting → heating and rolling → ultra-fast cooling process and coiling; the core steps are as follows:
(1) pretreating and desulfurizing molten iron;
(2) smelting in a converter: adopting double-slag operation, bottom blowing in a converter, wherein the carbon content target is less than or equal to 0.055%, the phosphorus content is less than or equal to 0.015%, and the tapping temperature is 1600-; carrying out double slag-blocking tapping by adopting a slag-blocking plug and a slag-blocking rod;
(3) LF + RH refining process or RH or VD vacuum degassing;
(4) the continuous casting process comprises the following steps: protective gas is blown in the whole process to avoid oxidation and nitrogen increase;
(5) heating and rolling; the method comprises the following steps of putting a steel billet into a heating furnace, heating at 1180-1220 ℃, wherein the total in-furnace time is more than or equal to 200min, the first rough rolling stage is austenite recrystallization zone rolling, the initial rolling temperature is 1050-1080 ℃, the single-pass reduction rate is more than 10%, the last-pass reduction rate is more than or equal to 25%, the second rough rolling stage is austenite non-recrystallization zone rolling, the initial rolling temperature of finish rolling is less than or equal to 890 ℃, the final rolling temperature is 840-845 ℃, the accumulated reduction rate is more than or equal to 80%, and the product thickness is 10-18mm after rolling is finished;
(6) ultra-fast cooling process and coiling; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
The method for producing the steel plate by the ultra-fast cooling process is characterized by comprising the ultra-fast cooling process and coiling in the step (6); the ultra-fast cooling process is to cool from the finish rolling temperature of 850 ℃ to 365 ℃ at a cooling rate of 90 ℃/s and to perform coiling at 355 ℃.
The method for producing the steel plate by the ultra-fast cooling process is characterized by comprising the ultra-fast cooling process and coiling in the step (6); the ultra-fast cooling process is to cool from the finishing temperature of 845 ℃ to 360 ℃ at a cooling rate of 80 ℃/s and to perform coiling at 350 ℃.
The method for producing the steel plate by the ultra-fast cooling process is characterized by comprising the following steps: the components are C0.066%, Si 0.06%, Mn 1.52%, P less than or equal to 0.01%, S less than or equal to 0.004%, Nb 0.067%, Ti 0.023%, V0.033%, Al less than or equal to 0.050%, Cr 0.46%, Mo 0.36%, Ni 0.14%, Cu 0.06%, W0.015%, rare earth 0.0005%, N0.003%, and the balance of Fe and inevitable impurity elements.
The method for producing the steel plate by the ultra-fast cooling process is characterized by comprising the following steps: the components are C0.069%, Si 0.1%, Mn 1.55%, P less than or equal to 0.01%, S less than or equal to 0.004%, Nb 0.07%, Ti 0.025%, V0.035%, Al less than or equal to 0.050%, Cr0.48%, Mo 0.38%, Ni 0.15%, Cu 0.09%, W0.01%, rare earth 0.001%, N0.005%, and the balance of Fe and inevitable impurity elements.
Compared with the prior art, the invention has the technical effects that:
1. the invention is beneficial to obtaining a specific tissue structure by accurately controlling components and a production process, particularly an ultra-fast cooling process, and is beneficial to having comprehensive properties of high strength, high elongation, impact resistance and the like.
2. The composite material has good comprehensive mechanical properties, avoids the increase of process conditions such as tempering, quenching and the like, saves the production process, does not need to rely on the production cost to obtain the properties, saves the production cost and has good adaptability.
The invention has the following chemical components in percentage by weight: (the% of the component means mass%)
C: the steel is beneficial to obtaining the required strength index; the stability of austenite is increased, the thermal stability and mechanical stability of the retained austenite can be controlled by the distribution of carbon element, but too high C causes component segregation during casting, resulting in poor welding performance. Therefore, the amount of C added is 0.066 to 0.069%.
Si has an effect of suppressing precipitation of carbide serving as a fracture origin. The heat stability of austenite is increased, the strength of the steel can be improved, and the requirements of the strength and the low cost of the invention steel are favorably realized. Si element can improve the hardenability and tempering resistance of the steel, is favorable for the comprehensive mechanical properties of the steel, particularly the elastic limit, and can also improve the yield strength and the like. Therefore, the amount of the additive is 0.05% or more. However, if the content exceeds 0.10%, the field weldability deteriorates. From the viewpoint of field weldability, Si is 0.05 to 0.10%.
Mn is a solid-solution strengthening element and can stabilize austenite. The phase transformation temperature of austenite is reduced, the crystal grain of steel is refined, the hardenability and the heat strength are improved, and enough strength and creep resistance are kept at high temperature. In addition, in the cooling after the rolling to increase the temperature of the austenite region to the low temperature side, there is an effect that the continuous cooling transformation structure, which is one of the constituent elements of the microstructure of the present invention, can be easily obtained. To obtain these effects, Mn is added in an amount of 1.5% or more. However, even if Mn is added in excess of 1.6%, the effect is saturated, so the upper limit is 1.55%. Further, Mn promotes center segregation of the continuously cast slab to form a hard phase serving as a fracture origin, so Mn is 1.5 to 1.55%.
P is an impurity, and is preferably 0.02% or less, as the content is lower, and if it exceeds 0.02%, P segregates in the central portion of the continuously cast steel sheet, causes grain boundary fracture, and significantly lowers the low-temperature toughness. Further, P is preferably 0.01% or less in view of the above problem because it adversely affects weldability.
S is an impurity, and not only causes cracking during hot rolling, but also if it is excessive, it deteriorates low-temperature toughness. Therefore, it is set to 0.004% or less. Further, S segregates near the center of the continuously cast steel sheet, and forms elongated MnS after rolling, which may not only become the starting point of hydrogen induced cracking but also cause plate cracking. Sulphur is usually present in the steel in the form of FeS. FeS has poor plasticity and low melting point. FeS is distributed around the grain boundary when the molten steel is crystallized. Therefore, S is less than or equal to 0.004%.
Nb and Ti are one of the important elements in the present invention. Nb has the following effects: the steel suppresses recovery, recrystallization and grain growth of austenite during or after rolling by a dragging effect in a solid solution state and/or a pinning effect as a carbonitride precipitate, and improves low-temperature toughness by making the effective crystal grain size fine and reducing crack propagation of brittle fracture. Further, fine carbides are generated in a coiling step, which is a characteristic of a hot-rolled steel sheet manufacturing step, and contribute to improvement in strength due to precipitation strengthening. Nb also has the following effects: the phase transition of gamma/alpha is delayed, and the phase transition temperature is lowered, whereby the microstructure after phase transition is stably changed to a continuously cooled phase transition structure even at a relatively slow cooling rate. However, in order to obtain these effects, at least 0.065% or more must be added. On the other hand, if the amount exceeds 0.075%, not only the effect is saturated, but also it is difficult to form a solid solution in the heating step before hot rolling, and coarse carbonitrides are formed as starting points of the fracture, which may deteriorate low-temperature toughness and acid resistance. Considering that the production cost and the strengthening effect are optimal, 0.065-0.07% of Nb is selected.
Ti begins to precipitate as nitrides at high temperatures immediately after solidification of an ingot obtained by continuous casting or ingot casting. The precipitates containing the Ti nitrides are stable at high temperatures, do not completely dissolve in the subsequent slab reheating, exhibit a pinning effect, suppress coarsening of austenite grains during slab reheating, refine the microstructure, and improve low-temperature toughness. Further, the generation of ferrite nuclei is suppressed in the γ/α transformation, and the generation of the continuous cooling transformation structure, which is a requirement of the present invention, is promoted. In order to obtain the above effects, at least 0.02% or more of Ti must be added. On the other hand, even if the amount exceeds 0.012%, the effect is saturated. The strength of the product is generally improved by fully utilizing the fact that N and Ti form TiN and TiC which are distributed in a fine dispersion mode. Since precipitates containing Ti nitrides are crystallized or precipitated finely with these fine oxides as nuclei, the average equivalent circle diameter of precipitates containing Ti nitrides and carbides is made small, and not only the recovery and recrystallization of austenite during or after rolling but also grain growth of ferrite after coiling are suppressed due to the effect of dense dispersion. Therefore, Ti is 0.02-0.025%.
V is also a common alloying element, V strengthens a steel matrix through precipitation strengthening and grain refinement, 0.1% of V can increase the strength of 60-100 MPa, and V is a ferrite stabilizing element, so that transformation of bainite and pearlite is inhibited, and the amount of residual austenite is increased. However, the selection of V has certain particularity in the invention, and is mainly reflected in that VC or V (C, N) can be completely dissolved in austenite at the temperature of more than 900 ℃, so that the V is mainly precipitated among phases in the austenite-ferrite phase transformation process and precipitation strengthening in ferrite. In the application, the selection of the finish rolling temperature is determined by fully considering the precipitation rule of VC or V (C, N), V is not wasted due to transitional addition, and the influence of V on the performances of strengthening, grain refining and the like is also considered, so that V is 0.03-0.035%.
Al is an element necessary for dispersing a large number of fine oxides in the molten steel during deoxidation. When the amount is excessively added, the effect is lost, so that the upper limit thereof is set to 0.05%.
N contains Ti, V, Nb nitrides and carbonitrides as described above, suppresses coarsening of austenite grains during slab reheating, and makes fine austenite grains related to effective crystal grain size in subsequent controlled rolling, thereby improving low-temperature toughness by making the microstructure into a continuous cooling transformation structure. However, if the content is less than 0.001%, the effect cannot be obtained. On the other hand, if the content exceeds 0.005%, the ductility decreases with time, and the formability during tube production decreases.
Cr is an element contributing to the improvement of the strength of the steel by precipitation strengthening, and is preferably added in an amount of 0.45% or more. On the other hand, if Cr is added in an amount exceeding 0.5%, hardenability may be increased, a bainite structure may be formed, and toughness may be impaired, so that the upper limit is preferably set to 0.48%. Therefore, Cr is 0.45-0.48%.
Mo has an effect of improving hardenability and increasing strength. In addition, Mo and Nb coexist, and have the effect of strongly suppressing recrystallization of austenite during controlled rolling, refining the austenite structure, and improving low-temperature toughness. However, even if the amount of the additive exceeds 0.35%, the effect is saturated, and therefore, the amount is 0.4% or less. Further, when 0.4% or more is added, ductility may be reduced, and formability during tube production may be reduced. Therefore, Mo is 0.35 to 0.38%.
Ni is less likely to form a hardened structure harmful to low-temperature toughness and acid resistance in a rolled structure (particularly, a center segregation zone of a slab) than Mn, Cr, and Mo, and therefore has an effect of improving strength without deteriorating low-temperature toughness and field weldability. In addition, Ni can promote rust densification on the surface of the steel plate and promote formation of a stable rust layer. However, even if the amount of Ni added exceeds 0.15%, the effect is saturated, so Ni is 0.12 to 0.15%.
Cu has the effect of improving corrosion resistance and hydrogen induced cracking resistance. At least 0.05% or more should be added, but even if the amount exceeds 0.09%, the effect is saturated. Therefore, Cu is 0.05 to 0.09%.
W is an element that improves strength, hardness, and corrosion resistance, and when W is contained, it makes rust generated on the surface of the steel sheet fine, promotes stable formation of a rust layer on the surface of the steel sheet, and thus plays a role in improving corrosion resistance. This effect tends to be stable as its content increases. Therefore W is 0.01-0.015%.
RE is an element which is commonly used for modifying nonmetallic inclusions, and can also refine grains, improve the pinning effect or lamellar tearing resistance of oxides, and improve the strength and toughness. However, even if less than 0.0001% is added, this effect is not obtained; when the amount of the additive exceeds 0.001%, the cost increases.
Detailed Description
The technical solution of the present invention will be described in detail with reference to the specific embodiments.
Example 1
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.066% of C, 0.06% of Si, 1.52% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.067% of Nb, 0.023% of Ti, 0.033% of V, less than or equal to 0.050% of Al, 0.46% of Cr, 0.36% of Mo, 0.14% of Ni, 0.06% of Cu, 0.015% of W, 0.0005% of rare earth, 0.003% of N, and the balance of Fe and inevitable impurity elements;
the process route comprises the following steps: molten iron pretreatment → molten steel smelting → external refining → continuous casting → heating and rolling → ultra-fast cooling process and coiling; the core steps are as follows:
(1) pretreating and desulfurizing molten iron;
(2) smelting in a converter: adopting double-slag operation, bottom blowing in a converter, wherein the carbon content target is less than or equal to 0.055%, the phosphorus content is less than or equal to 0.015%, and the tapping temperature is 1600-; carrying out double slag-blocking tapping by adopting a slag-blocking plug and a slag-blocking rod;
(3) LF + RH refining process or RH or VD vacuum degassing;
(4) the continuous casting process comprises the following steps: protective gas is blown in the whole process to avoid oxidation and nitrogen increase;
(5) heating and rolling; the method comprises the following steps of putting a steel billet into a heating furnace, heating at 1180-1220 ℃, wherein the total in-furnace time is more than or equal to 200min, the first rough rolling stage is austenite recrystallization zone rolling, the initial rolling temperature is 1050-1080 ℃, the single-pass reduction rate is more than 10%, the last-pass reduction rate is more than or equal to 25%, the second rough rolling stage is austenite non-recrystallization zone rolling, the initial rolling temperature of finish rolling is less than or equal to 890 ℃, the final rolling temperature is 840-845 ℃, the accumulated reduction rate is more than or equal to 80%, and the product thickness is 10-18mm after rolling is finished;
(6) ultra-fast cooling process and coiling; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
Example 2
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.068% of C, 0.08% of Si, 1.52% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.067% of Nb, 0.023% of Ti, 0.032% of V, less than or equal to 0.050% of Al, 0.47% of Cr0.47%, 0.37% of Mo, 0.13% of Ni, 0.06% of Cu, 0.011% of W, 0.0007% of rare earth, 0.005% of N, and the balance of Fe and inevitable impurity elements;
the process route comprises the following steps: molten iron pretreatment → molten steel smelting → external refining → continuous casting → heating and rolling → ultra-fast cooling process and coiling; the core steps are as follows:
(1) pretreating and desulfurizing molten iron;
(2) smelting in a converter: adopting double-slag operation, bottom blowing in a converter, wherein the carbon content target is less than or equal to 0.055%, the phosphorus content is less than or equal to 0.015%, and the tapping temperature is 1600-; carrying out double slag-blocking tapping by adopting a slag-blocking plug and a slag-blocking rod;
(3) LF + RH refining process or RH or VD vacuum degassing;
(4) the continuous casting process comprises the following steps: protective gas is blown in the whole process to avoid oxidation and nitrogen increase;
(5) heating and rolling; the method comprises the following steps of putting a steel billet into a heating furnace, heating at 1180-1220 ℃, wherein the total in-furnace time is more than or equal to 200min, the first rough rolling stage is austenite recrystallization zone rolling, the initial rolling temperature is 1050-1080 ℃, the single-pass reduction rate is more than 10%, the last-pass reduction rate is more than or equal to 25%, the second rough rolling stage is austenite non-recrystallization zone rolling, the initial rolling temperature of finish rolling is less than or equal to 890 ℃, the final rolling temperature is 840-845 ℃, the accumulated reduction rate is more than or equal to 80%, and the product thickness is 10-18mm after rolling is finished;
(6) ultra-fast cooling process and coiling; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
Example 3
A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the alloy comprises, by mass, 0.069% of C, 0.1% of Si, 1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.07% of Nb, 0.025% of Ti, 0.035% of V, less than or equal to 0.050% of Al, 0.48% of Cr0.48%, 0.38% of Mo, 0.15% of Ni, 0.09% of Cu, 0.01% of W, 0.001% of rare earth, 0.005% of N, and the balance of Fe and inevitable impurity elements;
the process route comprises the following steps: molten iron pretreatment → molten steel smelting → external refining → continuous casting → heating and rolling → ultra-fast cooling process and coiling; the core steps are as follows:
(1) pretreating and desulfurizing molten iron;
(2) smelting in a converter: adopting double-slag operation, bottom blowing in a converter, wherein the carbon content target is less than or equal to 0.055%, the phosphorus content is less than or equal to 0.015%, and the tapping temperature is 1600-; carrying out double slag-blocking tapping by adopting a slag-blocking plug and a slag-blocking rod;
(3) LF + RH refining process or RH or VD vacuum degassing;
(4) the continuous casting process comprises the following steps: protective gas is blown in the whole process to avoid oxidation and nitrogen increase;
(5) heating and rolling; the method comprises the following steps of putting a steel billet into a heating furnace, heating at 1180-1220 ℃, wherein the total in-furnace time is more than or equal to 200min, the first rough rolling stage is austenite recrystallization zone rolling, the initial rolling temperature is 1050-1080 ℃, the single-pass reduction rate is more than 10%, the last-pass reduction rate is more than or equal to 25%, the second rough rolling stage is austenite non-recrystallization zone rolling, the initial rolling temperature of finish rolling is less than or equal to 890 ℃, the final rolling temperature is 840-845 ℃, the accumulated reduction rate is more than or equal to 80%, and the product thickness is 10-18mm after rolling is finished;
(6) ultra-fast cooling process and coiling; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
Comparative example 1
The product composition and the production process steps (1) to (5) are the same as in example 1 except that the cooling process in step (6) is performed by cooling from the finish rolling temperature of 845 ℃ to 355 ℃ at a cooling rate of 5 to 15 ℃/s and coiling at 350 ℃.
Through metallographic structure analysis, the final structure is statistically 72-82% of acicular ferrite and 11-13% of bainitic ferrite by area ratio, other structures are martensite austenite, and the average width range of the formed acicular ferrite is 1.5-1.8 microns; through mechanical property analysis, the yield strength is more than or equal to 620MPa, the tensile strength is more than or equal to 760MPa, the elongation after fracture is more than or equal to 18 percent, and the impact energy at minus 40 ℃ is 220-250J.
Comparative example 2
The product components and the production process steps (1) to (5) are the same as the example 2, and the difference is that the ultra-fast cooling process and the coiling are carried out in the step (6); the ultra-fast cooling process is to cool the steel plate from the finish rolling temperature of 840-845 ℃ to 370-375 ℃ at the cooling speed of 80-90 ℃/s and to perform coiling at 345-350 ℃.
Through metallographic structure analysis, the final structure is systematically 91-92% of acicular ferrite and 3.5-5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.65-0.8 micron, and the average range of the width of the lath martensite is 0.4-0.5 micron; through mechanical property analysis, the yield strength is more than or equal to 750MPa, the tensile strength is more than or equal to 950MPa, the elongation after fracture is more than or equal to 20 percent, and the impact energy at minus 40 ℃ is 220-260J.
Comparative example 3
The product components and the production process steps (1) to (5) are the same as the example 3, and the difference is that the ultra-fast cooling process and the coiling are carried out in the step (6); the ultra-fast cooling process is to cool the steel from the finish rolling temperature of 840-845 ℃ to 350-355 ℃ at the cooling speed of 95-100 ℃/s and to perform coiling at 345-350 ℃.
Through metallographic structure analysis, the final structure is counted by area ratio to be 95.5-96.5% of acicular ferrite and 3-3.5% of lath martensite, other structures are granular bainite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 830MPa, the tensile strength is more than or equal to 950MPa, the elongation after fracture is more than or equal to 23 percent, and the impact energy at minus 40 ℃ is 210-230J.
Comparative example 4
The production process is the same as example 1, but the components are C0.05%, Si 0.05%, Mn 1.3%, P0.01% or less, S0.004% or less, Nb 0.06%, Ti 0.01%, V0.02%, Al 0.050%, Cr 0.45%, Mo 0.35%, Ni 0.12%, Cu 0.05%, W0.01%, rare earth 0.0001%, N0.0015%, and the balance of Fe and inevitable impurity elements;
through metallographic structure analysis, the final structure is statistically 85-89% of acicular ferrite and 5-8.5% of lath martensite by area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.7-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 690MPa, the tensile strength is more than or equal to 840MPa, the elongation after fracture is more than or equal to 19.5 percent, and the impact energy at minus 40 ℃ is 250-270J.
Comparative example 5
The product has the same composition as example 1, but the composition is C0.065%, Si 0.05%, Mn 1.5%, P0.01% or less, S0.004% or less, Nb 0.065%, Ti 0.02%, V0.03%, Al 0.050% or less, Cr 0.2%, Mo 0.15%, Ni 0.1%, rare earth 0.0001%, N0.0015%, and the balance of Fe and inevitable impurity elements;
through metallographic structure analysis, the final structure is 88-91% of acicular ferrite and 5-7% of lath martensite based on the area ratio, other structures are bainitic ferrite and/or martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.85 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 720MPa, the tensile strength is more than or equal to 920MPa, the elongation after fracture is more than or equal to 18 percent, and the impact energy at minus 40 ℃ is 240-260J.
Comparative example 6
The product has the same components as example 1, but the components are C0.065%, Si 0.05%, Mn 1.5%, P less than or equal to 0.01%, S less than or equal to 0.004%, Nb 0.065%, Ti 0.05%, Al less than or equal to 0.050%, Cr 0.45%, Mo 0.35%, Ni 0.12%, Cu 0.05%, rare earth 0.0001%, N0.0013%, and the balance of Fe and inevitable impurity elements;
through metallographic structure analysis, the final structure is statistically 93-95.5% of acicular ferrite and 4.5-6.5% of lath martensite in terms of area ratio, other structures are bainitic ferrite and/or martensite austenite, the average width range of the formed acicular ferrite is 0.7-0.85 micrometer, and the average width range of the lath martensite is 0.48-0.55 micrometer; through mechanical property analysis, the yield strength is more than or equal to 750MPa, the tensile strength is more than or equal to 950MPa, the elongation after fracture is more than or equal to 24 percent, and the impact energy at minus 40 ℃ is 250-270J.
The terminology used herein is for the purpose of description and illustration, rather than of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims (6)

1. A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the steel plate comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.065-0.07% of Nb, 0.02-0.025% of Ti, 0.03-0.035% of V, less than or equal to 0.050% of Al, 0.45-0.48% of Cr, 0.35-0.38% of Mo, 0.12-0.15% of Ni, 0.05-0.09% of Cu, 0.01-0.015% of W, 0.0001-0.001% of rare earth, 0.001-0.005% of N, and the balance Fe and inevitable impurity elements; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
2. A method for producing steel plates by an ultra-fast cooling process is characterized by comprising the following steps: the steel plate comprises, by mass, 0.066-0.069% of C, 0.05-0.1% of Si, 1.5-1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.065-0.07% of Nb, 0.02-0.025% of Ti, 0.03-0.035% of V, less than or equal to 0.050% of Al, 0.45-0.48% of Cr, 0.35-0.38% of Mo, 0.12-0.15% of Ni, 0.05-0.09% of Cu, 0.01-0.015% of W, 0.0001-0.001% of rare earth, 0.001-0.005% of N, and the balance Fe and inevitable impurity elements;
the process route comprises the following steps: molten iron pretreatment → molten steel smelting → external refining → continuous casting → heating and rolling → ultra-fast cooling process and coiling; the method comprises the following specific steps:
(1) pretreating and desulfurizing molten iron;
(2) smelting in a converter: adopting double-slag operation, bottom blowing in a converter, wherein the carbon content target is less than or equal to 0.055%, the phosphorus content is less than or equal to 0.015%, and the tapping temperature is 1600-; carrying out double slag-blocking tapping by adopting a slag-blocking plug and a slag-blocking rod;
(3) LF + RH refining process or RH or VD vacuum degassing;
(4) the continuous casting process comprises the following steps: protective gas is blown in the whole process to avoid oxidation and nitrogen increase;
(5) heating and rolling; the method comprises the following steps of putting a steel billet into a heating furnace, heating at 1180-1220 ℃, wherein the total in-furnace time is more than or equal to 200min, the first rough rolling stage is austenite recrystallization zone rolling, the initial rolling temperature is 1050-1080 ℃, the single-pass reduction rate is more than 10%, the last-pass reduction rate is more than or equal to 25%, the second rough rolling stage is austenite non-recrystallization zone rolling, the initial rolling temperature of finish rolling is less than or equal to 890 ℃, the final rolling temperature is 840-845 ℃, the accumulated reduction rate is more than or equal to 80%, and the product thickness is 10-18mm after rolling is finished;
(6) ultra-fast cooling process and coiling; the ultra-fast cooling process is that the steel is cooled to 365 ℃ at the cooling speed of 80-90 ℃/s from the finishing temperature of 845-850 ℃ and is coiled at 355 ℃ of 350-355 ℃;
through metallographic structure analysis, the final structure is statistically 96-97% of acicular ferrite and 1.5-2.5% of lath martensite by area ratio, other structures are bainitic ferrite and martensite austenite, the average range of the width of the formed acicular ferrite is 0.6-0.75 micrometer, and the average range of the width of the lath martensite is 0.4-0.5 micrometer; through mechanical property analysis, the yield strength is more than or equal to 850MPa, the tensile strength is more than or equal to 1050MPa, the elongation after fracture is more than or equal to 25 percent, the yield ratio is 0.79-0.82, and the impact energy at-40 ℃ is 200-250J.
3. A method for producing a steel sheet by the ultrafast cooling process as set forth in claim 2, wherein the ultrafast cooling process and the coiling are performed in the step (6); the ultra-fast cooling process is to cool from the finish rolling temperature of 850 ℃ to 365 ℃ at a cooling rate of 90 ℃/s and to perform coiling at 355 ℃.
4. A method for producing a steel sheet by the ultrafast cooling process as set forth in claim 2, wherein the ultrafast cooling process and the coiling are performed in the step (6); the ultra-fast cooling process is to cool from the finishing temperature of 845 ℃ to 360 ℃ at a cooling rate of 80 ℃/s and to perform coiling at 350 ℃.
5. A method of producing a steel sheet by the ultra-rapid cooling process according to claims 1-2, wherein: the steel plate comprises, by mass, 0.066% of C, 0.06% of Si, 1.52% of Mn, 0.01% or less of P, 0.004% or less of S, 0.067% of Nb, 0.023% of Ti, 0.033% of V, 0.050% or less of Al, 0.46% of Cr, 0.36% of Mo, 0.14% of Ni, 0.06% of Cu, 0.015% of W, 0.0005% of rare earth, 0.003% of N, and the balance of Fe and inevitable impurity elements.
6. A method of producing a steel sheet by the ultra-rapid cooling process according to claims 1-2, wherein: the steel plate comprises, by mass, 0.069% of C, 0.1% of Si, 1.55% of Mn, less than or equal to 0.01% of P, less than or equal to 0.004% of S, 0.07% of Nb, 0.025% of Ti, 0.035% of V, less than or equal to 0.050% of Al, 0.48% of Cr, 0.38% of Mo, 0.15% of Ni, 0.09% of Cu, 0.01% of W, 0.001% of rare earth, 0.005% of N, and the balance of Fe and inevitable impurity elements.
CN201910051142.3A 2019-01-17 2019-01-17 Method for producing steel plate by ultra-fast cooling process Active CN109628854B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910051142.3A CN109628854B (en) 2019-01-17 2019-01-17 Method for producing steel plate by ultra-fast cooling process

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910051142.3A CN109628854B (en) 2019-01-17 2019-01-17 Method for producing steel plate by ultra-fast cooling process

Publications (2)

Publication Number Publication Date
CN109628854A CN109628854A (en) 2019-04-16
CN109628854B true CN109628854B (en) 2021-01-29

Family

ID=66061326

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910051142.3A Active CN109628854B (en) 2019-01-17 2019-01-17 Method for producing steel plate by ultra-fast cooling process

Country Status (1)

Country Link
CN (1) CN109628854B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111975004A (en) * 2020-08-21 2020-11-24 盐城市欧特威机械科技有限公司 Manufacturing process of cutting pick for coal mining heading machine
CN112030058B (en) * 2020-08-28 2022-01-04 广州大学 Method for producing Ti microalloyed Q345B steel grade and Q345B steel grade by TMCP process

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101883875A (en) * 2007-12-04 2010-11-10 Posco公司 High-strength steel sheet with excellent low temperature toughness and manufacturing method thereof
KR20120011292A (en) * 2010-07-28 2012-02-07 현대제철 주식회사 STEEL PLATE WITH HIGH STRENGTH OF 500MPa GRADE AND LOW TEMPERATURE TOUGHNESS AND METHOD FOR MANUFACTURING THE SAME
CN106048181A (en) * 2016-07-27 2016-10-26 武汉钢铁股份有限公司 Low-temperature thick-specification pipeline steel preparing method suitable for hot continuous rolling production line
CN108103410A (en) * 2018-03-05 2018-06-01 石英楠 A kind of pipe line steel of yield strength >=910MPa and preparation method thereof
EP3385402A1 (en) * 2015-12-04 2018-10-10 Posco High-strength steel having excellent brittle crack arrestability and welding part brittle crack initiation resistance, and production method therefor

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100957970B1 (en) * 2007-12-27 2010-05-17 주식회사 포스코 High-strength and high-toughness thick steel plate and method for producing the same
CN101985725B (en) * 2010-11-27 2012-07-18 东北大学 780MPa grade low yield ratio steel plate for buildings and manufacturing method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101883875A (en) * 2007-12-04 2010-11-10 Posco公司 High-strength steel sheet with excellent low temperature toughness and manufacturing method thereof
KR20120011292A (en) * 2010-07-28 2012-02-07 현대제철 주식회사 STEEL PLATE WITH HIGH STRENGTH OF 500MPa GRADE AND LOW TEMPERATURE TOUGHNESS AND METHOD FOR MANUFACTURING THE SAME
EP3385402A1 (en) * 2015-12-04 2018-10-10 Posco High-strength steel having excellent brittle crack arrestability and welding part brittle crack initiation resistance, and production method therefor
CN106048181A (en) * 2016-07-27 2016-10-26 武汉钢铁股份有限公司 Low-temperature thick-specification pipeline steel preparing method suitable for hot continuous rolling production line
CN108103410A (en) * 2018-03-05 2018-06-01 石英楠 A kind of pipe line steel of yield strength >=910MPa and preparation method thereof

Also Published As

Publication number Publication date
CN109628854A (en) 2019-04-16

Similar Documents

Publication Publication Date Title
CN109097705B (en) 800 MPa-grade cold-rolled hot-galvanized dual-phase steel and production method thereof
CN108531808B (en) Low-yield-ratio weather-proof bridge structural steel with yield strength of more than or equal to 690MPa and production method thereof
CN101497969A (en) High-performance weather-resisting anti-seismic steel for building and production method thereof
CN101487096A (en) Low-alloy high-strength C-Mn-Al Q & P steel and method of manufacturing the same
CN104928569A (en) 800MPa grade high-ductility low-density steel and manufacturing method thereof
CN117604392A (en) Cold-rolled steel sheet and hot-dip galvanized steel sheet having excellent workability, and method for producing same
CN114134408B (en) 460 MPa-level bridge steel plate and manufacturing method thereof
CN113416889B (en) Ultrahigh-strength hot-galvanized DH1470 steel with good welding performance and preparation method thereof
CN113957346B (en) High-performance bridge steel with yield strength not less than 500MPa and preparation method and application thereof
CN112680655B (en) 700 MPa-grade low-alloy high-strength cold-rolled steel plate for automobile and preparation method thereof
CN110578085A (en) Hot-rolled steel plate with yield strength of 500MPa and atmospheric corrosion resistance
CN109023055B (en) High-strength high-formability automobile steel plate and production process thereof
KR20160079166A (en) High strength structural steel having low yield ratio and good impact toughness and preparing method for the same
JP5194572B2 (en) Method for producing high-tensile steel material with excellent weld crack resistance
CN109628854B (en) Method for producing steel plate by ultra-fast cooling process
CN114921726A (en) Low-cost high-yield-ratio cold-rolled hot-galvanized ultrahigh-strength steel and production method thereof
KR102200227B1 (en) Cord rolled steel sheet, hot-dip galvanized steel sheet having good workability, and manufacturing method thereof
JPH04325657A (en) High strength hot rolled steel sheet excellent in stretch-flanging property and its manufacture
CN109097681B (en) High-strength low-inclusion automobile steel plate and electromagnetic stirring process thereof in continuous casting process
CN114480949B (en) 690 MPa-grade low-yield-ratio weather-resistant welding structural steel, steel plate and manufacturing method thereof
CN115612934A (en) 590 MPa-level high-formability hot-dip galvanized dual-phase steel plate and preparation method thereof
JPH0413406B2 (en)
CN109252094B (en) High-strength bridge steel prepared by ultra-fast cooling process and production method thereof
CN114686762A (en) Production method of high-strength and high-toughness hot continuous rolling thin steel plate with Brinell hardness of 500HBW
JP2002363685A (en) Low yield ratio high strength cold rolled steel sheet

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
CP03 Change of name, title or address

Address after: 050409 Pingshan County, Shijiazhuang City, Hebei Province, Nan Dian town

Patentee after: Hebei Jingye Kuanban Technology Co.,Ltd.

Country or region after: China

Address before: 050409 Hebei Jingye plate Co., Ltd., No. 88, Nandian Town, Pingshan County, Shijiazhuang City, Hebei Province

Patentee before: HEBEI JINGYE PLATE Co.,Ltd.

Country or region before: China

CP03 Change of name, title or address