CN112159931B - 1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof - Google Patents
1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof Download PDFInfo
- Publication number
- CN112159931B CN112159931B CN202011041211.1A CN202011041211A CN112159931B CN 112159931 B CN112159931 B CN 112159931B CN 202011041211 A CN202011041211 A CN 202011041211A CN 112159931 B CN112159931 B CN 112159931B
- Authority
- CN
- China
- Prior art keywords
- steel
- continuous
- medium manganese
- cold
- equal
- 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
Links
Images
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
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- 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
- C21D8/0236—Cold rolling
-
- 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
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- C—CHEMISTRY; METALLURGY
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses 1000 MPa-grade medium manganese TRIP steel with continuous yield, which comprises the following chemical components in percentage by mass: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8% -3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, and the balance is Fe and inevitable impurities. The invention also discloses a preparation method: smelting by adopting the chemical components, and obtaining a plate blank through continuous casting or die casting; heating, rough rolling, finish rolling and coiling the plate blank in sequence to obtain a hot rolled plate; cold rolling the hot rolled plate to obtain cold rolled strip steel, wherein the total cold rolling reduction rate is 40-60%; and carrying out continuous annealing or continuous hot galvanizing on the cold-rolled strip steel to obtain the cold-rolled strip steel. The invention ensures the tensile strength of more than 1000MPa, the elongation after fracture exceeds 37 percent, and the mechanical property is very excellent; the uniaxial tension curve has no yield platform, and the difficulty in the process is reduced.
Description
Technical Field
The invention relates to the technical field of steel preparation, in particular to 1000 MPa-grade medium manganese TRIP steel with continuous yield and a preparation method thereof.
Background
The rapid development of the automobile industry brings great pressure to energy and environment. In order to achieve the aims of energy conservation, emission reduction and environmental protection, the light weight of the automobile body and the high strengthening of the steel for the automobile body are not slow enough. Currently, automotive steels have been developed to the third generation, wherein medium manganese steels are favored with superior overall mechanical properties and low cost advantages. The most significant difference between medium manganese TRIP steels and conventional TRIP steels is that conventional TRIP steels utilize C, Si and Al to improve austenite stability, with a Mn content of about 1.5%. This combination of elements gives a low austenite content, about 5% to 15%, with the remainder of the structure being ferrite (55% to 65%), bainite (25% to 35%), and therefore the TRIP effect is relatively weak. In order to fully enhance the TRIP effect of the steel plate, the medium-manganese TRIP steel enables the austenite content to be more than 30% at room temperature and even more than half of the austenite becomes a matrix structure by adding 5% -12% of Mn, so that the continuous and remarkable TRIP effect is obtained in the deformation process. The definition of Mn in this context is distinguished from the TWIP steel high Mn content design (W) Mn ≥15％)。
However, medium manganese steel is still in a state of 'hot and cold research', and key technologies of industrial production and application are not broken through. One of the important reasons is that the high content of alloy elements in the medium manganese steel causes difficulty in the preparation process: the smelting, continuous casting, rolling and heat treatment under the traditional manufacturing flow are provided with great challenges. Such as: the high alloy content increases the hardenability of the steel, so that the hot rolled plate is in a full martensite structure or a martensite structure mainly, C, Mn is highly saturated and has extremely high hardness, large-compression-ratio cold rolling cannot be realized, intermediate annealing is often required before cold rolling, the cost is increased, and the production efficiency is reduced. This also becomes a significant obstacle to the popularization and application of medium manganese steel.
Mn is an important alloy element in the medium manganese steel, has the highest content and is mainly used for enriching reverse transformed austenite in a continuous annealing soaking section so as to improve the austenite stability; in order to obtain higher residual austenite content and higher strength, the Mn content in the current medium manganese steel generally reaches 5-12%, which causes the problems of continuous casting segregation, uneven structure, difficult cold rolling, unmatched long-time proportioning and short-time annealing and the like commonly existing in the current high Mn content medium manganese steel; if the Mn content is reduced, there are problems of insufficient austenite stability, insufficient strength and/or long yield elongation. The common cold rolling medium manganese steel has longer yield extension during tensile deformation, and the stamping quality of the sheet material is seriously influenced. The patent document with the publication number of 'CN 110408861A', named as 'cold-rolled high-strength-product medium manganese steel with lower Mn content and a preparation method thereof' properly reduces the Mn content, so that the ubiquitous problems of continuous casting segregation, uneven structure, difficult cold rolling, mismatching of long-time distribution and short-time annealing and the like are solved, but the cold-rolled finished product still has longer yield extension and causes the difficulty in the process: the hot rolled sheet is also subjected to softening annealing before cold rolling.
How to develop medium manganese TRIP steel which has high strength and no yield point and does not cause difficulty in the preparation process becomes a technical problem to be solved urgently.
Disclosure of Invention
The invention aims to provide 1000 MPa-grade medium manganese TRIP steel with continuous yield and a preparation method thereof, on the basis of ensuring the tensile strength of more than 1000MPa, the elongation after breakage exceeds 37 percent, and the mechanical property is very excellent; more importantly, the uniaxial tension curve has no yield platform, the common Luders strip in the stamping process of the cold-rolled medium manganese steel is avoided, the application feasibility is improved, and the process difficulty is reduced.
In order to achieve the aim, the invention provides 1000 MPa-grade medium manganese TRIP steel with continuous yield, which comprises the following chemical components in percentage by mass: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8% -3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, and the balance is Fe and inevitable impurities.
Further, the 1000 MPa-grade medium manganese TRIP steel with continuous yield comprises the following chemical components in percentage by mass: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8% -3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, Cu is less than or equal to 0.01%, Ni is less than or equal to 0.01%, Cr is less than or equal to 0.003%, Mo is less than or equal to 0.003%, Nb is less than or equal to 0.002%, V is less than or equal to 0.002%, Ti is less than or equal to 0.002%, B is less than or equal to 0.0004%, N is less than or equal to 0.008%, and the balance of Fe and inevitable impurities.
Further, the internal microstructure of the 1000MPa grade medium manganese TRIP steel with continuous yield comprises, in volume percent: 60-80% of ferrite, 20-32% of retained austenite and 0-8% of martensite; and the retained austenite volume fraction (f gamma) R ) The mass fraction (C) of the C element, and the measured and calculated average concentration of carbon atoms (Cgamma) in the retained austenite R ) Satisfies the following conditions: f gamma R ×Cγ R >0.85×C。
The invention also provides a preparation method of the 1000 MPa-grade medium manganese TRIP steel with continuous yield, which comprises the following steps:
smelting by adopting the chemical components of the 1000 MPa-grade medium manganese TRIP steel with continuous yield to obtain molten steel, and continuously casting or die casting the molten steel to obtain a plate blank;
sequentially heating, rough rolling, finish rolling and coiling the plate blank to obtain a hot rolled plate;
cold rolling the hot rolled plate, wherein the total cold rolling reduction rate is 40-60%, and obtaining cold rolled strip steel;
and continuously annealing or continuously hot-galvanizing the cold-rolled strip steel to obtain 1000 MPa-grade medium-manganese TRIP steel with continuous yield.
Further, heating, rough rolling, finish rolling and coiling are sequentially carried out on the plate blank to obtain a hot rolled plate, and the method comprises the following steps:
heating the plate blank to 1230-1280 ℃, soaking for 60-100 min, then carrying out rough rolling, finish rolling and coiling, wherein the inlet temperature of the finish rolling is 1050-1080 ℃, the finish rolling temperature of the finish rolling is 850-930 ℃, the coiling temperature is 620-680 ℃, and then air cooling to room temperature to obtain the hot rolled plate.
Further, the continuous annealing comprises: annealing the cold-rolled strip steel sequentially through a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section, and then cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 690-730 ℃ from 210-230 ℃ at the rate of 1-2 ℃/s, the soaking section is kept at 690-730 ℃ and is kept at the temperature for 100-180 s, the slow cooling section is cooled to 610-650 ℃ from 690-730 ℃ at the rate of 2-5 ℃/s, and the fast cooling section is cooled to 240-280 ℃ from 610-650 ℃ at the rate of 20-40 ℃/s and is kept at the temperature for 80-240 s.
Further, the continuous hot galvanizing comprises: annealing the cold-rolled strip steel sequentially through a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section, then galvanizing, and cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 720-760 ℃ from 210-230 ℃ at the rate of 2 ℃/s-4 ℃/s, the soaking section is kept at 720-760 ℃ and is kept at the temperature for 60-120 s, the slow cooling section is cooled to 640-680 ℃ from 720-760 ℃ at the rate of 2 ℃/s-3 ℃/s, and the fast cooling section is cooled to 450-470 ℃ from 640-680 ℃ at the rate of 8 ℃/s-20 ℃/s.
Further, the obtaining of the hot-rolled sheet comprises: obtaining the hot rolled plate with the thickness of 2.5 mm-3.5 mm.
Further, the obtaining of the cold-rolled steel strip includes: obtaining the cold-rolled strip steel with the thickness of 1.0 mm-2.0 mm.
One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:
the 1000 MPa-grade medium manganese TRIP steel with continuous yield breaks through the traditional alloy component design thought of the medium manganese steel, reduces the Mn content to be 3.5% or below, does not add any other noble alloy element, greatly reduces the material cost through chemical component reduction design, avoids the generation of continuous casting segregation, and properly improves the C element content, thereby reducing the difficulty of C, Mn supersaturated martensite cold rolling, and the obtained 1000 MPa-grade medium manganese TRIP steel with continuous yield has the elongation of over 37% after breakage on the basis of ensuring the tensile strength of over 1000MPa, and has excellent mechanical properties; more importantly, the uniaxial tension curve has no yield platform, the common Luders strip in the stamping process of the cold-rolled medium manganese steel is avoided, and the application feasibility is improved.
According to the preparation method of 1000 MPa-grade medium manganese TRIP steel with continuous yield, the Mn content is reduced to 3.5% or below due to the adoption of the chemical components in mass fraction, and no other noble alloy element is added, so that the material cost is greatly reduced, and the generation of continuous casting segregation is avoided; because the C content with higher partition rate is properly increased, the Mn partition is not required to be strengthened by twice critical region annealing processes, and the difficulty of C, Mn supersaturated martensite cold rolling is reduced. The total cold rolling reduction is controlled to be 40-60% so as to ensure better mechanical property and reduce the difficulty of cold rolling; the intermediate cover type annealing process which is required to be adopted by the existing high Mn content medium manganese steel is saved, and the hot rolled coil can be directly cold rolled after being uncoiled; through the reduction of the process flow, the manufacturing cost is greatly reduced, and the production efficiency is improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is an internal microstructure diagram of a 1000MPa medium manganese TRIP steel with continuous yield according to an embodiment of the present invention;
fig. 2 is a uniaxial tensile stress-strain curve of 1000MPa grade medium manganese TRIP steel with continuous yield provided by the embodiment of the invention.
Detailed Description
The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.
Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be obtained by an existing method.
The technical scheme provided by the embodiment of the invention is to provide 1000 MPa-grade medium manganese TRIP steel with continuous yield, and the general idea is as follows:
in order to achieve the above purpose, the embodiment of the invention provides a 1000MPa grade medium manganese TRIP steel with continuous yield, and the 1000MPa grade medium manganese TRIP steel with continuous yield comprises the following chemical components in percentage by mass: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8-3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, and the balance is Fe and inevitable impurities.
The invention further provides 1000 MPa-grade medium manganese TRIP steel with continuous yield, which is formed by optimizing the composition elements and is based on the following principle:
the control principle in the chemical composition design of the invention is as follows:
c: 0.18 to 0.30 percent, and C is a strong austenite stabilizing element and can be enriched to austenite in the continuous annealing and subsequent aging or galvanizing processes to improve the residual austenite content at room temperature; meanwhile, C is a solid solution strengthening element and can improve the hardness and strength of a matrix structure. In the continuous annealing process of the medium manganese steel, the retention time of the strip steel in the soaking section is short, so that the C content with a high diffusion rate needs to be properly increased to quickly diffuse to reverse transformed austenite and improve the stability of the reverse transformed austenite, which is beneficial to solving the problem that the long-time austenite stabilization and short-time continuous annealing of the traditional medium manganese steel are difficult to match, and therefore, the C content needs to reach 0.18 percent. However, if the C content exceeds 0.30%, the hot rolled structure strength becomes too high, direct cold rolling becomes difficult, and the strip weldability is impaired. The content of C is preferably 0.20-0.28%.
Si: 0.5 to 1.5 percent of the total weight of the steel, and Si is a solid solution strengthening element and can improve the strength of the medium manganese steel matrix structure. Meanwhile, Si is insoluble in cementite, can effectively inhibit the decomposition of retained austenite in the aging or galvanizing stage of medium manganese steel, and is vital to the retention of austenite at room temperature. However, too high a Si content results in severe deterioration of the surface quality of the galvanized steel strip. Therefore, the Si is limited to a range of 0.5% to 1.5%, preferably 0.6% to 1.4%.
Mn: 2.8 to 3.5 percent of Mn is an important alloy element in the medium manganese steel, has the highest content and is mainly used for enriching reverse transformed austenite in a continuous annealing soaking section so as to improve the stability of the austenite; meanwhile, Mn is also a solid solution strengthening element and is beneficial to ensuring the strength of the medium manganese steel matrix structure. In order to obtain the above effects, the Mn content should be controlled to 2.8% or more. However, in order to obtain higher residual austenite content and higher strength, the Mn content in the current medium manganese steel usually reaches more than 5%, which causes the problems of continuous casting segregation, nonuniform structure, difficult cold rolling, mismatch between long-term distribution and short-term annealing, and the like commonly existing in the current high Mn content medium manganese steel, so the invention controls the upper limit Mn content to be 3.5%, and enhances the distribution effect by increasing the C content. The Mn content is preferably 2.9 to 3.4%.
Al: 0-1.5%, similar to Si, Al can effectively inhibit the decomposition of residual austenite and the precipitation of carbide; for the continuous hot-dip galvanized strip steel, Al is adopted to replace partial Si, so that the surface quality of the galvanized strip steel can be effectively improved. Therefore, the proper addition of certain Al to the continuous hot galvanizing medium manganese TRIP steel can obtain good technical effect. However, since the Al content is too high to ensure the strength of the steel sheet and to easily cause clogging of the nozzle in the continuous casting process, the upper limit of the Al content is set to 1.5%.
P is not more than 0.01%, and P is not more than 0.01% because P can suitably improve the strength of the steel sheet but tends to form segregation at grain boundaries to deteriorate plasticity, and the P content is preferably 0.005% to 0.01%.
S is not more than 0.005%, S is easily combined with Mn to form coarse MnS inclusions to deteriorate formability of a steel sheet such as punching, and therefore, the S content is controlled to 0.005% or less, and is preferably 0.0003% to 0.005% in order to avoid an increase in cost due to excessive S removal.
Therefore, the 1000 MPa-grade medium manganese TRIP steel with continuous yield provided by the embodiment of the invention breaks through the traditional alloy component design idea of the medium manganese steel, reduces the Mn content to be 3.5% or below, does not add any other noble alloy element, greatly reduces the material cost through chemical component reduction design, avoids the generation of continuous casting segregation, and properly improves the C element content, thereby reducing the difficulty of C, Mn supersaturated martensite cold rolling. On the basis of ensuring the tensile strength of more than 1000MPa, the obtained 1000 MPa-grade medium manganese TRIP steel with continuous yield has the elongation after breakage of more than 37 percent and very excellent mechanical property; more importantly, the uniaxial tension curve has no yield platform, the common Luders belt in the stamping process of the cold-rolled medium manganese steel is avoided, and the application feasibility is improved.
Further, in order to control the material cost, the present invention does not intentionally add the following elements, and if they are inevitably present in an impurity state, their contents are limited to the following ranges: cu is less than or equal to 0.01 percent, Ni is less than or equal to 0.01 percent, Cr is less than or equal to 0.003 percent, Mo is less than or equal to 0.003 percent, Nb is less than or equal to 0.002 percent, V is less than or equal to 0.002 percent, Ti is less than or equal to 0.002 percent, B is less than or equal to 0.0004 percent, and N is less than or equal to 0.008 percent. The hardenability of Cu, Ni, Cr, Mo and B can be improved, the martensite generation in the hot-rolled manganese steel is promoted, the strength of the steel plate is improved, and the cold rolling difficulty is greatly increased. In addition, they are expensive alloying elements and must be limited in view of the principle of reduction of the alloy composition. Therefore, the content of these elements which may be present is limited to Cu ≦ 0.01%, Ni ≦ 0.01%, Cr ≦ 0.003%, Mo ≦ 0.003%, and B ≦ 0.0004%.
Nb, V and Ti are easy to form carbonitrides, consume C in the medium manganese steel, reduce the enrichment degree of C in austenite, are unfavorable for retaining residual austenite, and further influence the strong plasticity of the medium manganese steel. In addition, these microalloying elements are expensive and will undoubtedly increase the material cost. Therefore, these elements are not intentionally added in the present invention, and if they exist in the form of impurity elements, the contents thereof are limited to Nb 0.002% or less, V0.002% or less, and Ti 0.002% or less.
N is a harmful impurity element in the medium manganese steel, and in order to reduce the adverse effect of N on the performance, the content thereof is preferably limited to 0.008% or less, more preferably N.ltoreq.0.005%.
Preferably, the internal microstructure of the 1000MPa grade medium manganese TRIP steel with continuous yield according to the invention is defined, the limits are described below and the reasons for the limits are explained.
The internal microstructure of the 1000 MPa-grade medium-manganese TRIP steel with continuous yield comprises the following components in percentage by volume: 60-80% of ferrite, 20-32% of retained austenite and 0-8% of martensite;
the reason why the volume fraction of the ferrite is controlled to be 60-80% in the invention is as follows:
ferrite belongs to a soft phase structure in the medium manganese steel and is formed after alloy elements such as C, Mn in martensite and the like are diffused to reverse austenite in the annealing process of a two-phase region. Ferrite in the medium manganese steel bears most of strain in the deformation process and is an important composition phase for ensuring the plasticity of the medium manganese steel except residual austenite. In addition, ferrite may also play a role in cooperative deformation when the retained austenite is transformed into hard martensite during the tensile deformation. When the medium manganese steel is continuously annealed, only ferrite and reverse transformation austenite exist in the two-phase region, so the content and the stability of the reverse transformation austenite in the two-phase region can be adjusted to a certain degree by adjusting the proportion of the ferrite in the medium manganese steel. Therefore, in order to obtain the proper residual austenite content and stability of the manganese TRIP steel, the volume fraction of ferrite in the steel needs to be controlled between 60% and 80%.
The reason why the volume fraction of the retained austenite is controlled to be 20-32% in the invention is as follows:
the retained austenite is an important composition phase for regulating plasticity in the medium manganese steel, the content and stability of the retained austenite in the medium manganese steel are regulated and controlled in an optimal range, the TRIP effect of the retained austenite is maximized, and the condition that the optimal strong plasticity is obtained is provided. In the present invention, the content of the retained austenite is at least 20% or more in order to ensure that the deformation process has enough retained austenite to generate the TRIP effect. However, when the content of the retained austenite exceeds 32%, the average C, Mn enrichment therein is significantly reduced, resulting in insufficient stability, easy transformation into martensite at the early stage of the subsequent cooling process and tensile deformation, and rather failure to provide a sustained TRIP effect. Therefore, the residual austenite content is limited to 20% to 32%.
The reason why the volume fraction of martensite is controlled to be 0-8% is as follows:
martensite does not belong to the essential constituent phase in medium manganese steels and is generally formed in the rapid cooling stage or post-galvanization cooling stage of the continuous annealing process. The martensite appears in the medium manganese steel, which means that the stability of the reverse transformation austenite in the two-phase region is insufficient, and the phase transformation occurs in the cooling process, which is not beneficial to the plasticity of the medium manganese steel. In the case of the manganese TRIP steel of the present invention, when the martensite content exceeds 8%, it indicates that the stability of the room-temperature residual austenite is seriously insufficient, and the transformation is completed at an early stage of the deformation, thereby failing to provide a sustained TRIP effect. Therefore, the content of martensite in the present invention cannot exceed 8%.
And the retained austenite volume fraction (f gamma) R ) The mass fraction (C) of the C element, and the measured and calculated average concentration of carbon atoms (Cgamma) in the retained austenite R ) Satisfies the following conditions: f gamma R ×Cγ R >0.85 XC. The average concentration of carbon atoms (Cgamma) in the retained austenite R ) Mainly determined by the carbon content of the steel and the heat treatment process. The average concentration of carbon atoms (Cgamma) in the retained austenite R ) The test method of (2) was obtained by calculation using an X-ray diffractometer (XRD).
The austenite stabilization of the medium manganese steel mainly depends on the C, Mn element to be fully and uniformly enriched in the medium manganese steel. However, in the production of manganese steel in an industrial continuous annealing line or a continuous hot dip galvanizing line, the residence time of the strip steel in the soaking zone (two-phase zone) is short, so that the Mn element having a slow diffusion rate cannot be sufficiently distributed and homogenized in the austenite. Therefore, it is necessary to enhance the stability of reverse transformation austenite by strengthening the C partition so that a sufficient amount of austenite can be stabilized to room temperature. This requires that more than 85% of the C in the finished strip has diffused into the retained austeniteIn vivo, i.e. satisfies f γ R ×Cγ R >0.85×C。
The invention also provides a preparation method of the 1000 MPa-grade medium manganese TRIP steel with continuous yield, which comprises the following steps:
smelting by adopting the chemical components of the 1000 MPa-grade medium manganese TRIP steel with continuous yield to obtain molten steel, and continuously casting or die casting the molten steel to obtain a plate blank;
sequentially heating, rough rolling, finish rolling and coiling the plate blank to obtain a hot rolled plate;
cold rolling the hot rolled plate, wherein the total cold rolling reduction rate is 40-60%, and obtaining cold rolled strip steel;
and continuously annealing or continuously hot-galvanizing the cold-rolled strip steel to obtain 1000 MPa-grade medium-manganese TRIP steel with continuous yield.
The preparation method of the 1000 MPa-grade medium manganese TRIP steel with continuous yield is based on the following principle:
due to the adoption of the chemical components with the mass fractions, the Mn content is reduced to 3.5 percent or below, no other noble alloy element is added, and the material cost is greatly reduced and the generation of continuous casting segregation is avoided through the chemical component reduction design; because the C content with higher partition rate is properly increased, the Mn partition is not required to be strengthened by twice critical region annealing processes, and the difficulty of C, Mn supersaturated martensite cold rolling is reduced. The preparation method omits the intermediate cover type annealing procedure which is required to be adopted by the prior high Mn content medium manganese steel, and the hot rolled coil can be directly cold rolled after being uncoiled; through the reduction of the process flow, the manufacturing cost is greatly reduced, and the production efficiency is improved.
The total cold rolling reduction is controlled to be 40-60% so as to ensure better mechanical property and reduce the difficulty of cold rolling: if the cold rolling reduction rate is less than 40 percent, the recrystallization in the annealing process is insufficient, more tissues which are not recrystallized appear, and the uniformity of the tissue and the mechanical property of the finished product strip steel is poor. If the cold rolling reduction is more than 60%, the difficulty of cold rolling increases and edge crack defects are easily caused.
Preferably, the slab is sequentially heated, rough rolled, finish rolled and coiled to obtain a hot rolled plate, comprising:
heating the plate blank to 1230-1280 ℃, soaking for 60-100 min, then carrying out rough rolling, finish rolling and coiling, and then carrying out air cooling to room temperature to obtain a hot rolled plate; the inlet temperature of the finish rolling is 1050-1080 ℃, the finish rolling temperature of the finish rolling is 850-930 ℃, and the coiling temperature is 620-680 ℃.
The finishing temperature is controlled to be 850-930 ℃ so as to achieve better surface quality, if the finishing temperature is higher than 930 ℃, a higher slab tapping temperature must be ensured, so that not only is energy consumption increased, but also hot rolled structure grains are coarse; if the finishing temperature is lower than 850 ℃, the deformation resistance of the hot rolled plate is improved, and the rolling load of the hot rolling mill is increased.
The coiling temperature is controlled to be 620-680 ℃ so as to achieve better surface quality, and if the coiling temperature is higher than 680 ℃, the problems of coil collapse and surface quality are easy to occur; if the coiling temperature is lower than 620 ℃, the load of the coiler is increased.
The 1000 MPa-grade medium manganese TRIP steel with continuous yield comprises 1000 MPa-grade continuously annealed medium manganese TRIP steel with continuous yield and 1000 MPa-grade continuously hot-dip galvanized medium manganese TRIP steel with continuous yield.
And after the continuous annealing, the obtained continuous annealing medium manganese TRIP steel with continuous yield and 1000MPa grade is obtained.
The continuous annealing includes: annealing the cold-rolled strip steel in a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section in sequence, and then cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield, namely the cold-rolled continuous annealed medium manganese TRIP steel; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 690-730 ℃ from 210-230 ℃ at the rate of 1-2 ℃/s, the soaking section is kept at 690-730 ℃ and is kept at the temperature for 100-180 s, the slow cooling section is cooled to 610-650 ℃ from 690-730 ℃ at the rate of 2-5 ℃/s, and the fast cooling section is cooled to 240-280 ℃ from 610-650 ℃ at the rate of 20-40 ℃/s and is kept at the temperature for 80-240 s.
The reason why the soaking temperature is controlled to be 690 ℃ -730 ℃ is as follows:
if the soaking temperature is lower than 690 ℃, the recrystallization of the cold-rolled structure is insufficient, and the proportion of reverse transformation austenite in the two-phase region is low, so that the content of residual austenite of the final finished product is insufficient, and the mechanical property is influenced; if the soaking temperature is higher than 730 ℃, the proportion of reverse transformation austenite in the two-phase region is too high, the average enrichment degree of C, Mn in the two-phase region is low, and the grain size is obviously increased, so that the stability of the reverse transformation austenite is insufficient, the martensite phase transformation can be generated in the cooling process, and the stability of the retained austenite in the finished strip steel can be influenced.
The reason why the soaking time is controlled to be 100s to 180s is as follows:
if the soaking time is too short, the recrystallization of the cold-rolled structure is insufficient, and the diffusion of Mn element from ferrite to reverse transformed austenite is insufficient, so that the stability of austenite is insufficient; if the soaking time is too long, the reverse austenite grains grow too large, which also results in the stability of the steel being reduced.
The reason for keeping the isothermal temperature of 240-280 ℃ for 80-240 s is as follows:
the temperature of 240-280 ℃ is an aging stage, and the aging stage is used for eliminating internal stress and continuously strengthening C, Mn element distribution. The aging temperature is too high, so that the austenite is easily decomposed and the tensile strength is easily reduced; when the aging temperature is too low, the C, Mn element diffuses slowly into austenite, and the stability of austenite is affected.
The continuous hot galvanizing is to obtain 1000MPa continuous hot galvanizing medium manganese TRIP steel with continuous yield.
Preferably, the continuous hot galvanizing comprises: annealing the cold-rolled strip steel sequentially through a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section, then galvanizing, and cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield, namely the continuous hot-galvanized medium manganese TRIP steel; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 720-760 ℃ from 210-230 ℃ at the rate of 2 ℃/s-4 ℃/s, the soaking section is kept at 720-760 ℃ and is kept at the temperature for 60-120 s, the slow cooling section is cooled to 640-680 ℃ from 720-760 ℃ at the rate of 2 ℃/s-3 ℃/s, and the fast cooling section is cooled to 450-470 ℃ from 640-680 ℃ at the rate of 8 ℃/s-20 ℃/s.
The reason for limiting parameters such as soaking temperature, soaking time and the like in the continuous hot galvanizing process is similar to that of the continuous annealing process, but due to the adjustment of the alloy components of the galvanized strip steel, the applicant finely adjusts the limited range of the relevant parameters according to the actual situation so as to improve the stability of austenite.
Preferably, a finishing machine is used after the continuous annealing or the continuous hot galvanizing, and the finishing elongation is controlled to be 0.4-0.8%. The execution range of the finishing elongation is limited, mainly in order to adjust the yield property of the strip steel and obtain good surface roughness and plate shape quality.
Preferably, said obtaining a hot-rolled sheet comprises: obtaining the hot rolled plate with the thickness of 2.5 mm-3.5 mm. The thickness of the hot rolled plate is too small, the hot rolled plate can be rolled close to the limit specification, and the load of a hot rolling mill is increased; the too large thickness of the hot rolled plate increases the difficulty of the reduction of the strip steel in the cold rolling stage.
Preferably, the obtaining of the cold rolled steel strip comprises: obtaining the cold-rolled strip steel with the thickness of 1.0 mm-2.0 mm. The thickness of the cold-rolled strip steel is less than 1.0mm, and is close to the limit of the capability of a cold-rolling mill for rolling the ultrahigh-strength steel; the thickness of the strip steel exceeds 2.0mm, and the cooling rate in the continuous annealing and hot galvanizing stages is difficult to ensure.
From the above, the invention provides 1000 MPa-grade medium manganese TRIP steel with continuous yield and the preparation method thereof,
(1) in terms of components, the traditional alloy component design idea of medium manganese steel is broken through, the content of Mn is reduced to 3.5% or below, the content of C is properly increased, and other components are reasonably designed;
(2) in the method, the total rolling reduction rate of the cold rolling is controlled to be 40-60% so as to ensure better mechanical property and reduce the difficulty of the cold rolling; the intermediate cover type annealing process which is required to be adopted by the prior high Mn content medium manganese steel is saved, and the hot rolled coil can be directly cold rolled after being uncoiled.
Through the improvement of the components and the method, the prepared 1000 MPa-grade medium manganese TRIP steel with continuous yield has the advantages that on the basis of ensuring the tensile strength of more than 1000MPa, the elongation after breakage exceeds 37 percent, and the mechanical property is very excellent; more importantly, the uniaxial tension curve has no yield platform, the common Luders belt in the stamping process of the cold-rolled medium manganese steel is avoided, the application feasibility is improved, and the process difficulty is reduced.
The following will explain in detail a 1000MPa grade medium manganese TRIP steel with continuous yield and its preparation method of the present application with reference to examples, comparative examples and experimental data.
(1) Molten steels of examples 1 to 7 and comparative examples 1 to 5 were prepared, and the molten steels had the chemical compositions shown in fig. 1, and were produced by converter steelmaking and were cast into slabs by continuous casting.
TABLE 1 mass fraction of chemical components of each of examples and comparative examples
| Group of | C | Si | Mn | P | S | Al | Remarks for note |
| Example 1 | 0.21 | 1.3 | 3.4 | 0.009 | 0.0005 | 0.03 | Continuous annealed medium manganese TRIP steel |
| Example 2 | 0.24 | 1.2 | 3.2 | 0.008 | 0.0005 | 0.04 | Continuous annealed medium manganese TRIP steel |
| Example 3 | 0.27 | 0.9 | 3.4 | 0.008 | 0.0008 | 0.55 | Continuous annealed medium manganese TRIP steel |
| Example 4 | 0.23 | 0.6 | 3.3 | 0.009 | 0.0005 | 1.10 | Continuous hot-dip galvanized medium manganese TRIP steel |
| Example 5 | 0.25 | 0.6 | 3.2 | 0.009 | 0.0004 | 1.05 | Continuous hot-dip galvanized medium manganese TRIP steel |
| Example 6 | 0.27 | 0.8 | 3.0 | 0.008 | 0.0005 | 1.40 | Continuous hot-dip galvanized medium manganese TRIP steel |
| Example 7 | 0.28 | 0.7 | 3.4 | 0.008 | 0.0005 | 1.20 | Continuous hot-dip galvanized medium manganese TRIP steel |
| Comparative example 1 | 0.15 | 0.8 | 3.0 | 0.007 | 0.0005 | 1.35 | Continuous hot galvanizing process |
| Comparative example 2 | 0.27 | 0.8 | 3.4 | 0.008 | 0.0005 | 0.60 | Continuous annealing process |
| Comparative example 3 | 0.24 | 0.6 | 3.3 | 0.008 | 0.0006 | 1.15 | Continuous hot galvanizing process |
| Comparative example 4 | 0.25 | 1.4 | 5.0 | 0.009 | 0.0004 | 0.02 | Continuous annealing process (high Mn content) |
| Comparative example 5 | 0.21 | 1.3 | 3.4 | 0.009 | 0.0005 | 0.03 | Continuous annealing process |
(2) Heating the plate blank to 1250 +/-20 ℃, soaking for 60-100 min, then carrying out rough rolling and finish rolling, wherein the inlet temperature of the finish rolling is 1050-1080 ℃, the finish rolling temperature is 850-930 ℃, the coiling temperature is 620-680 ℃, and then carrying out air cooling to room temperature to obtain a hot rolled plate with the thickness of 2.5-3.5 mm;
(3) rolling the hot rolled plate on an acid rolling production line to obtain cold-hard strip steel with the thickness of 1.0-2.0 mm, wherein the total cold rolling reduction rate is 40-60%; specific process parameters for each example and comparative example are shown in table 2.
TABLE 2 Process parameters for the examples and comparative examples
(4) And annealing or galvanizing the cold-hard strip steel on a continuous annealing production line or a continuous hot galvanizing production line to obtain cold-rolled continuous annealed manganese TRIP steel or continuous hot galvanized manganese TRIP steel.
In the manufacturing method step (4), the continuous annealing process comprises the following steps: preheating the strip steel to 210-230 ℃, heating to 690-730 ℃ at a heating rate of 1-2 ℃/s, soaking for 100-180 s, then slowly cooling to 610-650 ℃, and slowly cooling at a slow cooling rate of 2-5 ℃/s; after slow cooling, under the condition of 40 percent high hydrogen, the mixture is rapidly cooled to 240-280 ℃ at the cooling rate of 20-40 ℃/s, isothermal aging is carried out for 80-240 s, and then the mixture is cooled to room temperature in an air cooling or water quenching mode.
In the step (4) of the above production method, the continuous hot dip galvanizing process includes: preheating the strip steel to 210-230 ℃, heating to 720-760 ℃ at the heating rate of 2-4 ℃/s, soaking for 60-120 s, then slowly cooling to 640-680 ℃, and slowly cooling at the slow cooling rate of 2-3 ℃/s; after slow cooling, rapidly cooling to 450-470 ℃ at a cooling rate of 8-20 ℃/s under the condition of 20% high hydrogen, and then putting the strip steel into a zinc pot for galvanizing; after the galvanization is finished, the strip steel is cooled to 410-430 ℃, then air cooling is adopted, the temperature of a cooling tower top roller is 250-290 ℃, and finally the strip steel is cooled to room temperature in an air cooling or water quenching mode.
In the step (4), the steel strip has a temper rolling elongation of 0.4 to 0.8% after continuous annealing or hot dip galvanizing.
The continuous annealing or galvanizing process parameters of each example and comparative example are shown in table 3.
TABLE 3 continuous annealing or Hot galvanizing Process parameters for the examples and comparative examples
The samples of each example and comparative example were subjected to microstructure and mechanical property examination, and the results are shown in Table 4.
TABLE 4 statistics of microstructure and mechanical Properties of the examples and comparative examples
In conclusion, the yield strength of the medium manganese TRIP steel with continuous yield can be controlled to be 725 MPa-755 MPa, the tensile strength can be controlled to be 1015 MPa-1065 MPa, and the elongation (A50) after fracture is more than 37%. FIG. 1 is a graph of the internal microstructure of a 1000MPa medium manganese TRIP steel with continuous yield, provided in example 1, and it can be seen that the steel is composed of ferrite + retained austenite. As shown in the attached figure 2, the uniaxial tensile stress-strain curve of the medium manganese TRIP steel with continuous yield has no yield platform, so that the common Luders strip in the stamping process of cold-rolled medium manganese steel is avoided, and the application feasibility is improved. The invention optimizes the production process flow of the traditional high Mn content medium manganese steel by reduced components and process design, greatly reduces the manufacturing cost and improves the production efficiency.
Finally, it should be further noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (8)
1. The 1000 MPa-grade medium manganese TRIP steel with continuous yield is characterized by comprising the following chemical components in percentage by mass: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8% -3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, and the balance is Fe and inevitable impurities;
smelting chemical components of the 1000 MPa-grade medium manganese TRIP steel with continuous yield to obtain molten steel, and continuously casting or die casting the molten steel to obtain a plate blank;
sequentially heating, rough rolling, finish rolling and coiling the plate blank to obtain a hot rolled plate;
cold rolling the hot rolled plate to obtain cold rolled strip steel, wherein the total cold rolling reduction rate is 40-60%;
continuously annealing or continuously hot-galvanizing the cold-rolled strip steel to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield;
the continuous annealing includes: annealing the cold-rolled strip steel sequentially through a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section, and then cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 690-730 ℃ from 210-230 ℃ at the rate of 1-2 ℃/s, the soaking section is kept at 690-730 ℃ and is kept at the temperature for 100-180 s, the slow cooling section is cooled to 610-650 ℃ from 690-730 ℃ at the rate of 2-5 ℃/s, and the fast cooling section is cooled to 240-280 ℃ from 610-650 ℃ at the rate of 20-40 ℃/s and is kept at the temperature for 80-240 s.
2. The 1000MPa class medium manganese TRIP steel with continuous yield according to claim 1, characterized in that the continuous hot galvanizing comprises: annealing the cold-rolled strip steel sequentially through a preheating section, a heating section, a soaking section, a slow cooling section and a fast cooling section, then galvanizing, and cooling to room temperature to obtain 1000 MPa-grade medium manganese TRIP steel with continuous yield; wherein the content of the first and second substances,
the preheating section is heated to 210-230 ℃ from room temperature, the heating section is heated to 720-760 ℃ from 210-230 ℃ at the rate of 2 ℃/s-4 ℃/s, the soaking section is kept at 720-760 ℃ and is kept at the temperature for 60-120 s, the slow cooling section is cooled to 640-680 ℃ from 720-760 ℃ at the rate of 2 ℃/s-3 ℃/s, and the fast cooling section is cooled to 450-470 ℃ from 640-680 ℃ at the rate of 8 ℃/s-20 ℃/s.
3. The 1000MPa class medium manganese TRIP steel with continuous yield according to claim 1 or 2, characterized in that the chemical composition mass fraction of the 1000MPa class medium manganese TRIP steel with continuous yield is as follows: c: 0.18% -0.30%, Si: 0.5% -1.5%, Mn: 2.8% -3.5%, Al: 0-1.5%, P is less than or equal to 0.01%, S is less than or equal to 0.005%, Cu is less than or equal to 0.01%, Ni is less than or equal to 0.01%, Cr is less than or equal to 0.003%, Mo is less than or equal to 0.003%, Nb is less than or equal to 0.002%, V is less than or equal to 0.002%, Ti is less than or equal to 0.002%, B is less than or equal to 0.0004%, N is less than or equal to 0.008%, and the balance of Fe and inevitable impurities.
4. The 1000MPa grade medium manganese TRIP steel with continuous yield according to claim 1 or 2, characterized in that the internal microstructure of the 1000MPa grade medium manganese TRIP steel with continuous yield comprises, in volume percentages: 60-80% of ferrite, 20-32% of retained austenite and 0-8% of martensite; and the volume fraction of the retained austenite, the mass fraction of the element C, and the measured and calculated average carbon atom concentration in the retained austenite satisfy the following conditions:
fγ R ×Cγ R >0.85×C；
wherein, f gamma R Is the volume fraction of retained austenite, C is the mass fraction of C element, Cgamma R Is the determined and calculated average carbon atom concentration inside the retained austenite.
5. The 1000MPa class medium manganese TRIP steel with continuous yield according to claim 1 or 2, characterized in that the slab is subjected to heating, rough rolling, finish rolling and coiling in sequence to obtain a hot rolled plate comprising:
heating the plate blank to 1230-1280 ℃, soaking for 60-100 min, then carrying out rough rolling, finish rolling and coiling, and then air cooling to room temperature to obtain a hot rolled plate; the inlet temperature of the finish rolling is 1050-1080 ℃, the finish rolling temperature of the finish rolling is 850-930 ℃, and the coiling temperature is 620-680 ℃.
6. The 1000MPa grade medium manganese TRIP steel with continuous yield according to claim 1 or 2, characterized in that the continuous annealing or continuous hot galvanizing is controlled to have a temper elongation of 0.4-0.8% by a temper mill.
7. The 1000MPa grade medium manganese TRIP steel with continuous yield according to claim 1 or 2, characterized in that said obtaining of hot rolled sheet comprises: obtaining the hot rolled plate with the thickness of 2.5 mm-3.5 mm.
8. The medium manganese TRIP steel in the 1000MPa class with continuous yield according to claim 1 or 2, characterized in that said obtaining of cold-rolled steel strip comprises: obtaining the cold-rolled strip steel with the thickness of 1.0 mm-2.0 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011041211.1A CN112159931B (en) | 2020-09-28 | 2020-09-28 | 1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011041211.1A CN112159931B (en) | 2020-09-28 | 2020-09-28 | 1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112159931A CN112159931A (en) | 2021-01-01 |
| CN112159931B true CN112159931B (en) | 2022-08-12 |
Family
ID=73861791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011041211.1A Active CN112159931B (en) | 2020-09-28 | 2020-09-28 | 1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112159931B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112853224B (en) * | 2021-01-06 | 2021-11-05 | 东北大学 | High-strength high-plasticity low-carbon medium-manganese TRIP steel and preparation method thereof |
| CN113249646B (en) * | 2021-04-15 | 2022-08-05 | 首钢集团有限公司 | High-strength-plasticity hot-base galvanized medium manganese steel sheet and preparation method thereof |
| CN114032475B (en) * | 2021-10-15 | 2022-12-16 | 首钢集团有限公司 | High-strength cold-rolled hot-galvanized medium manganese steel, preparation method thereof and hot-formed part |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5586007B2 (en) * | 2007-02-23 | 2014-09-10 | タタ、スティール、アイモイデン、ベスローテン、フェンノートシャップ | Cold rolled and continuously annealed high strength steel strip and method for producing the steel |
| EP1990431A1 (en) * | 2007-05-11 | 2008-11-12 | ArcelorMittal France | Method of manufacturing annealed, very high-resistance, cold-laminated steel sheets, and sheets produced thereby |
| CN101928875A (en) * | 2009-06-22 | 2010-12-29 | 鞍钢股份有限公司 | High-strength cold-rolled plate with favorable forming property and preparation method thereof |
| CN102409235A (en) * | 2010-09-21 | 2012-04-11 | 鞍钢股份有限公司 | High-strength cold rolling transformation induced plasticity steel plate and preparation method thereof |
| CN103805838B (en) * | 2012-11-15 | 2017-02-08 | 宝山钢铁股份有限公司 | High formability super strength cold-roll steel sheet and manufacture method thereof |
| JP5884210B1 (en) * | 2014-07-25 | 2016-03-15 | Ｊｆｅスチール株式会社 | Method for producing high-strength hot-dip galvanized steel sheet |
| JP6187710B2 (en) * | 2015-06-11 | 2017-08-30 | 新日鐵住金株式会社 | Alloyed hot-dip galvanized steel sheet and method for producing the same |
| CN106244923B (en) * | 2016-08-30 | 2018-07-06 | 宝山钢铁股份有限公司 | A kind of phosphorus characteristic and the excellent cold rolling high strength steel plate of forming property and its manufacturing method |
-
2020
- 2020-09-28 CN CN202011041211.1A patent/CN112159931B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112159931A (en) | 2021-01-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108504958B (en) | 690 MPa-grade hot-rolled thick-specification low-yield-ratio automobile spoke steel and preparation method thereof | |
| US10227683B2 (en) | High strength cold rolled steel sheet | |
| US8679265B2 (en) | High-strength cold-rolled steel sheet | |
| JP7150022B2 (en) | High-strength steel sheet with excellent workability and its manufacturing method | |
| CN112159931B (en) | 1000 MPa-grade medium manganese TRIP steel with continuous yield and preparation method thereof | |
| CN102586688B (en) | A kind of dual phase sheet steel and manufacture method thereof | |
| US20100330392A1 (en) | Galvanized steel sheet excellent in uniformity and method for producing the same | |
| JP4650006B2 (en) | High carbon hot-rolled steel sheet excellent in ductility and stretch flangeability and method for producing the same | |
| JP6248207B2 (en) | Hot-dip galvanized steel sheet excellent in hole expansibility, alloyed hot-dip galvanized steel sheet, and manufacturing method thereof | |
| JP2011208226A (en) | Steel sheet with high tensile strength and superior ductility and method for producing the same | |
| CN107502819B (en) | A kind of 600MPa grades of 0.6mm or less thin gauge cold-rolled biphase steel and preparation method thereof | |
| EP4159886A1 (en) | Ultrahigh-strength dual-phase steel and manufacturing method therefor | |
| CN109321839B (en) | 240 MPa-grade bake-hardening steel and manufacturing method thereof | |
| JP5363922B2 (en) | High-strength cold-rolled steel sheet with an excellent balance between elongation and stretch flangeability | |
| CN107739981A (en) | Baking hardening hot-dip galvanizing sheet steel and preparation method thereof | |
| CN109930068A (en) | A kind of 800MPa grades of ultra-thin specification cold-rolled biphase steel and preparation method thereof | |
| US20220010394A1 (en) | High-yield-ratio cold-rolled dual-phase steel and manufacturing method therfor | |
| CN113403529B (en) | 1470 MPa-level alloyed galvanized steel plate for cold stamping and preparation method thereof | |
| US20180179610A9 (en) | High-strength steel sheet and production method therefor | |
| RU2478729C2 (en) | Method of making steel strip (versions) | |
| JP2019512600A (en) | Hot-dip galvanized steel sheet excellent in bake hardenability and aging resistance and method for producing the same | |
| JP2009035816A (en) | Process for producing high-strength cold rolled steel sheet with low yield strength and with less material quality fluctuation | |
| CN109518080A (en) | Strong dual phase steel of cold rolling low cost superelevation and preparation method thereof | |
| CN110343971A (en) | Superhigh intensity hot galvanizing Multiphase Steel and its production method | |
| JP2023547102A (en) | Ultra-high strength steel plate with excellent ductility and its manufacturing method |
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 |