CN115094346A - Hot rolled strip steel with tensile strength not lower than 1200MPa produced by TSR production line and method - Google Patents
Hot rolled strip steel with tensile strength not lower than 1200MPa produced by TSR production line and method Download PDFInfo
- Publication number
- CN115094346A CN115094346A CN202210781466.4A CN202210781466A CN115094346A CN 115094346 A CN115094346 A CN 115094346A CN 202210781466 A CN202210781466 A CN 202210781466A CN 115094346 A CN115094346 A CN 115094346A
- Authority
- CN
- China
- Prior art keywords
- steel
- hot
- tsr
- equal
- 1200mpa
- 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.)
- Granted
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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
- B21B1/463—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/58—Roll-force control; Roll-gap control
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/74—Temperature control, e.g. by cooling or heating the rolls or the product
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/18—Controlling or regulating processes or operations for pouring
-
- 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
- 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
- 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
- C22C38/06—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
- C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium 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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
-
- 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
- C21D2211/002—Bainite
-
- 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
-
- 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 hot-rolled thin strip steel with the tensile strength of more than or equal to 1200MPa produced by a TSR production line comprises the following components in percentage by weight: c: 0.12 to 0.20%, Mn: 1.8-3.0%, P is less than or equal to 0.01%, S is less than or equal to 0.01%, Als: 0.015-0.050%, Cr is not more than 1.0%, N is not more than 0.005%, Nb: 0.01-0.05% or V: 0.06-0.20% of one or two of the components are added in a composite manner; the production method comprises the following steps: conventional smelting and refining; casting into a blank; hot rolling; cooling; naturally cooling to room temperature after coiling; and (5) cold forming after uncoiling and blanking. According to the invention, through adding Nb or V or compounding of the Nb and the V and adopting TSR short-flow process production, the mechanical property of the steel strip is ensured, the repeated heating, multiple dephosphorization, multiple rolling and the like of the steel strip can be reduced, cold rolling and heat treatment can be omitted, the energy consumption can be reduced by more than 80%, the carbon dioxide emission can be reduced by more than 70%, the surface roughness of the product is reduced to within 1 mu m from 1.5-3 mu m, and a user does not need to carry out acid pickling before forming.
Description
Technical Field
The invention relates to a steel and a manufacturing method thereof, and particularly belongs to a hot-rolled thin strip steel with the tensile strength of more than or equal to 1200MPa and the method for producing the hot-rolled thin strip steel with the tensile strength of 0.5-2.0 mm by adopting a double-roller thin strip casting and rolling (TSR) production line.
Background
The light weight is an important way for realizing green low-carbon development of the automobile industry. The lightweight design and manufacture of the safety structural member of the vehicle body are carried out by adopting advanced high-strength steel and ultrahigh-strength steel, so that the collision safety of the whole vehicle can be improved, the oil consumption or the energy consumption can be reduced, and the lightweight design and manufacture method is deeply favored by domestic and foreign automobile companies. The martensite steel belongs to super-high strength steel and can be directly used for parts such as automobile anti-collision beams, doorsills, carriages and the like; in recent years, steel companies at home and abroad start the research and development work of the ultra-high strength martensitic steel based on respective production lines.
The tensile strength of a typical martensitic thin steel plate is generally in the range of 1000-1800 MPa, and the production process route thereof is generally as follows: molten steel smelting → continuous casting → cooling → casting blank heating → hot continuous rolling → cooling → coiling → uncoiling → acid pickling → cold rolling → coiling → uncoiling → heating → annealing → cooling → coiling. Such as chinese patent publication No. CN 109898018A, CN 114086071A, CN 111519109B. In the production line, the raw materials need to be repeatedly coiled and uncoiled, heated and cooled, hot rolled and cold rolled and the like, and the production line has the characteristics of complex process flow, long production period and high energy consumption, so that the production and manufacturing cost of the material is greatly increased. At present, the development of ultra-high strength thin steel plates with low energy consumption, low cost and high quality is the key research direction of steel companies.
The near-net-shape steel production technology cancels the cold rolling and annealing heat treatment procedures of the traditional sheet, directly uses the hot rolled sheet obtained by continuous casting and rolling of a thin slab or continuous casting and rolling of a thin strip to replace the traditional cold rolled sheet, has the obvious advantages of simple process flow, consumption reduction, energy conservation and low production cost, and draws wide attention in the industry. However, due to the technical characteristics of the rapid solidification process, the structural uniformity of the produced thin strip steel is easily influenced by the design of material components; meanwhile, because the continuous casting and rolling production is carried out by adopting thin slabs or thin strips, the total reduction rate of the material thickness is far smaller than that of the traditional process, and the fine grain strengthening effect of the structure of the steel is greatly different from that of the traditional process. Therefore, the ultra-high strength automobile thin steel plate produced by adopting the near net shape technology cannot simply and directly adopt the traditional product technology, and innovative breakthroughs in component design and production process are needed. For example, chinese patent publication No. CN 106381451B discloses a CSP thin slab continuous casting and rolling process for producing 1000 MPa-grade hot-rolled martensitic steel and a production method thereof, but the tensile strength of the martensitic steel is low (only 1000 MPa). Chinese patent publication No. CN 112522571 a discloses a method for producing a martensitic steel strip by strip continuous casting, but it requires rapid cooling (cooling rate >120 ℃/s) of a hot-rolled strip, and has great practical production difficulty and difficult guarantee of uniformity of product performance. Aiming at the problems in the prior art, a novel low-cost 1200 MPa-grade ultra-high-strength martensitic steel near net shape manufacturing method is researched and designed, so that the problems in the prior art are very necessary to be overcome.
Disclosure of Invention
The invention aims to overcome the defects of complex process, high energy consumption and large product performance uniformity fluctuation in the prior art, and provides hot-rolled thin strip steel which can reduce the energy consumption by more than 70% and reduce the carbon dioxide emission by more than 60% on the premise of ensuring the strength level, has the surface quality roughness of the product reduced from 1.5-3 mu m to less than 1 mu m, further simplifies the production flow, and is produced by adopting a TSR production line, wherein the tensile strength of the hot-rolled thin strip steel is more than or equal to 1200MPa, and a method thereof are not required to be pickled by users before forming.
The measures for realizing the aim are as follows:
the hot-rolled thin strip steel with the tensile strength of more than or equal to 1200MPa produced by a TSR production line comprises the following components in percentage by weight: c: 0.12 to 0.20%, Mn: 1.8-3.0%, P is less than or equal to 0.01%, S is less than or equal to 0.01%, Als: 0.015-0.050%, Cr is not more than 1.0%, N is not more than 0.005%, Nb: 0.01-0.05% or V: 0.06-0.20% of one or two of the above components are added in a composite manner, and the balance is Fe and inevitable impurities; the metallographic structure is full martensite or martensite plus bainite with the volume ratio not more than 10%.
Preferably: the Cr content is 0.46-0.95 wt%.
Further: the weight percentage content of the added B is not more than 0.001 percent.
The production method of hot-rolled thin strip steel with tensile strength of more than or equal to 1200MPa produced by a TSR production line comprises the following steps:
1) conventionally smelting and refining to obtain molten steel with the components;
2) casting to form a blank: strip casting with a twin roll casting plant to obtain a cast strip, during which: controlling the molten steel to carry out thin-strip continuous casting under the protection of conventional inert gas, wherein the blank drawing speed is 46-117 m/min, and the thickness of a continuous casting strip is 1.0-2.5 mm;
3) hot rolling: hot rolling the cast strip to a product thickness of 0.5-2.0 mm, during which: controlling the single-pass reduction rate to be 20-60% and the final rolling temperature to be 850-1000 ℃;
4) cooling, namely cooling to the coiling temperature at a cooling speed of not less than 50 ℃/s by adopting laminar or aerosol cooling;
5) naturally cooling to room temperature after coiling, and controlling the coiling temperature not to exceed 270 ℃;
6) and (5) carrying out cold forming after uncoiling and blanking.
Further, the method comprises the following steps: the coiling temperature is 180-265 ℃.
The action and mechanism of each element and the main process in the invention are as follows:
c: carbon is an essential element in steel and is also the most economical and effective strengthening element. The carbon content is designed to be lower, and the strength is reduced after hot stamping forming; however, too high a carbon content lowers the plasticity of the steel and is disadvantageous in weldability. Therefore, in the consideration of economy and comprehensive performance, the control range of the percentage content of carbon is 0.12-0.20%.
Mn: manganese has a solid solution strengthening effect and is one of important elements for improving the strength of the material; however, too high manganese content tends to adversely affect weldability. Therefore, the upper limit of manganese is set to be 3.0%, and the content of manganese added in the invention is 1.8-3.0%.
P: phosphorus is a harmful element in steel and is easy to cause center segregation of a casting blank. The steel is easy to be deviated to a grain boundary in the subsequent hot continuous rolling heating process, so that the brittleness of the steel is obviously increased. Meanwhile, the content is controlled to be below 0.01 percent based on the consideration of cost and without influencing the performance of steel.
S sulfur is a very harmful element. Sulfur in steel often exists in the form of sulfide of manganese, and this sulfide inclusion deteriorates toughness of steel and causes anisotropy of properties, so that the lower the sulfur content in steel, the better. The sulfur content in steel is controlled to 0.01% or less in consideration of the manufacturing cost.
And Als: aluminum is added for deoxidation, and when the content of Als is less than 0.015%, the effect thereof cannot be exerted; on the other hand, alumina agglomerate inclusions are easily formed due to the addition of a large amount of aluminum; therefore, the control range of the aluminum content is 0.015 to 0.050 percent.
Cr is an important element for improving the hardenability of the steel, is dissolved into austenite to improve the stability of the austenite, and is beneficial to improving the hardenability of the steel; meanwhile, the chromium can improve the tempering stability of the steel. When the chromium content exceeds 1.0%, the hardenability is improved with a surplus, and a cast strip obtained by continuous casting is easy to generate surface cracks at a high drawing speed, so that strip breakage and steel leakage are caused or the surface quality of a product is influenced. Therefore, the chromium content in the invention is controlled below 1.0%, and the Cr content is preferably 0.46-0.95% by weight.
N can improve the strength of the steel; however, the bonding force of nitrogen with niobium and vanadium is strong, and coarse niobium nitride and vanadium nitride particles can be formed in the steel at high temperature, so that the plasticity and the toughness of the steel are seriously damaged; in addition, higher nitrogen content increases the amount of micro-alloying elements needed to stabilize the nitrogen element, thereby increasing costs. Therefore, the content of nitrogen should be reduced as much as possible, and nitrogen is controlled to 0.005% or less in the present invention.
Nb: niobium is a strong C, N-compound forming element. A certain amount of niobium carbide and nitride can be formed by adding a small amount of niobium into the steel, so that austenite grains are prevented from growing and refined, and the strength and toughness of the steel after hot forming and quenching are greatly improved; the purpose of adding a small amount of titanium to the steel is to fix the N element in the steel and avoid the combination of B and N. However, excess niobium combines with C to form coarse carbonitrides, thereby reducing the hardness and strength of the martensite after quenching of the test steel. Therefore, the total content is controlled to be in the range of 0.01 to 0.05 percent.
V is also a strong C, N compound forming element and can play a role in refining austenite grains, and a certain amount of niobium carbon and nitride can be formed by adding a small amount of vanadium into steel, so that the austenite grains are prevented from growing, therefore, the quenched martensite lath has a smaller size, and the strength of the steel is greatly improved. Therefore, the content is controlled to be 0.06-0.20%.
B, the element can be added or not added in the invention. Boron is an element for strongly improving hardenability, and obvious influence can be caused only by adding trace amount of boron, and the hardenability can be improved by times, so that other expensive metal elements are saved. The hardenability of the steel can be obviously improved by adding trace boron element into the steel; but the boron content is higher than 0.001 percent, and the cast strip obtained by continuous casting is easy to generate surface cracks at high drawing speed, thereby causing strip breakage and steel leakage or influencing the poor surface quality of products. Therefore, the boron content in the present invention is controlled to 0.001% or less.
According to the invention, the molten steel is controlled to carry out thin-strip continuous casting under the protection of conventional inert gas, the thickness of the cast strip is 1.0-2.5 mm, and because of the thinner original thickness of the cast strip, the subsequent hot rolling reduction passes can be effectively reduced, and the production energy consumption is reduced; however, the thickness of the cast strip is too thin, and the strip is easy to break under the condition of high stretching of cast rolling, so that the continuity of production is influenced. The molten steel is controlled to carry out thin-strip continuous casting under the protection of conventional inert gas, so that the surface oxidation of the continuous casting thin strip can be avoided, the phenomenon that the production of the continuous casting thin strip is broken due to the pressing of oxides into the continuous casting thin strip is prevented, and the improvement of the surface quality of a product is facilitated.
The invention controls the single-pass reduction rate to be 20-60% and the final rolling temperature to be 850-1000 ℃, because the larger hot rolling reduction rate can refine the grains of the strip steel, which is beneficial to improving the strength of the material. However, the single-pass rolling reduction rate is too large, which is unfavorable for controlling the plate shape and increases the rolling load; considering that the method only adopts single-pass hot rolling, the reduction rate is controlled within 60 percent to ensure that the shape and thickness precision of the product plate is controllable. In order to avoid the influence of mixed crystals in the hot rolling stage on the material performance, the finish rolling temperature cannot be lower than the temperature for cooling and recrystallization of high-temperature austenite; meanwhile, the oxidation thickness of the surface of the strip steel is increased along with the rise of the finishing temperature, so the finishing temperature of the invention is controlled within 850-1000 ℃.
The casting speed of the present invention is preferably 46 to 117m/min because the casting speed is related to the strip drawing speed and the steel production efficiency of the continuous casting. The high drawing speed is beneficial to improving the production efficiency, but molten steel can not be solidified in time in the twin-roll casting machine easily, and the cast strip is broken and steel leakage is induced; lower elongation will affect production efficiency, increase production cost, and at the same time will result in cold hardening of the cast strip, increase subsequent rolling load and energy consumption, and is detrimental to controlling the strip shape.
The invention controls the cooling speed to be lower than 50 ℃/s to be lower than 270 ℃, preferably the cooling coiling temperature is 180-265 ℃, because the steel sheet developed by the invention is converted into the critical cooling speed and the critical finishing temperature of martensite in the cooling process, otherwise, the steel sheet cannot be sufficiently cooled to the required strength; the plate belt waste heat can be used for self-tempering treatment of the plate temperature, so that the internal stress generated in cooling can be reduced or eliminated, and the plasticity of the strip steel is improved; meanwhile, the strip steel can utilize waste heat to reduce the deformation resistance of the strip steel, so that the strip steel is convenient to curl.
Compared with the prior art, the martensite steel with the tensile strength of 1200MPa is produced by adding Nb, V or the compound addition of the Nb and the V, controlling the elements such as Cr, B and the like in the components and adopting a TSR short-flow process, not only can the mechanical property be ensured, but also the working procedures of repeated heating, multiple dephosphorization, multiple rolling and the like of the strip steel in the production process can be reduced, and the working procedures of cold rolling and annealing heat treatment can be cancelled, so that the energy consumption can be reduced by more than 80 percent and the emission of carbon dioxide can be reduced by more than 70 percent, the roughness of the surface quality of the product can be reduced to within 1 mu m from the traditional 1.5-3 mu m, and a user does not need to carry out acid cleaning before forming.
Drawings
FIG. 1 is a diagram showing that the metallographic structure of the steel sheet of the invention is fully martensitic.
Detailed Description
The present invention is described in detail below:
table 1 is a list of chemical compositions for each example of the present invention and comparative example;
table 2 is a table of the main process parameters of each example of the present invention and comparative example;
table 3 is a table showing the results of the performance tests of the examples of the present invention and the comparative examples.
The production of each embodiment of the invention is carried out according to the following steps:
1) conventionally smelting and refining to obtain molten steel with the components;
2) casting to form a blank: strip casting with a twin roll casting plant to obtain a cast strip, during which: controlling the molten steel to carry out thin-strip continuous casting under the protection of conventional inert gas, wherein the blank drawing speed is 46-117 m/min, and the thickness of a continuous casting strip is 1.0-2.5 mm;
3) hot rolling: hot rolling the cast strip to a thickness of 0.5-2.0 mm, during which: controlling the single-pass reduction rate to be 20-60% and the final rolling temperature to be 850-1000 ℃;
4) cooling, namely cooling to the coiling temperature at a cooling speed of not less than 50 ℃/s by adopting laminar flow type or aerosol type cooling;
5) naturally cooling to room temperature after coiling, and controlling the coiling temperature not to exceed 270 ℃;
6) and (5) cold forming after uncoiling and blanking.
TABLE 1 chemical composition (wt.%) of inventive and comparative examples
TABLE 2 tabulation of values of main process parameters for each example of the invention and comparative example
TABLE 3 results of testing the properties of the inventive and comparative examples
As can be seen from Table 3, the tensile strength of the direct cold forming of the thin steel plate of the invention reaches the hot rolled thin steel plate of more than 1200MPa through the TSR double-roll thin strip casting and rolling process, which is much higher than the product strength of the existing TSR production line; the method has important significance for promoting the light weight level of the automobile and reducing the energy consumption and carbon emission in steel production.
The present embodiments are merely preferred examples, and are not intended to limit the scope of the present invention.
Claims (5)
1. The hot-rolled thin strip steel with the tensile strength of more than or equal to 1200MPa produced by a TSR production line comprises the following components in percentage by weight: c: 0.12 to 0.20%, Mn: 1.8-3.0%, P is less than or equal to 0.01%, S is less than or equal to 0.01%, Als: 0.015-0.050%, Cr is not more than 1.0%, N is not more than 0.005%, Nb: 0.01-0.05% or V: 0.06-0.20% of one or two of the above components are added in a composite manner, and the balance is Fe and inevitable impurities; the metallographic structure is full martensite or martensite plus bainite with the volume ratio not more than 10%.
2. The hot-rolled thin strip steel with tensile strength of more than or equal to 1200MPa produced by the TSR production line according to claim 1, wherein the hot-rolled thin strip steel comprises the following components in percentage by weight: the Cr content is 0.46-0.95 wt%.
3. The hot-rolled thin strip steel with tensile strength of more than or equal to 1200MPa produced by the TSR production line as claimed in claim 1, wherein: the weight percentage content of the added B is not more than 0.001 percent.
4. The production method of hot-rolled thin strip steel with tensile strength of more than or equal to 1200MPa produced by the TSR production line according to claim 1, comprising the following steps:
1) conventionally smelting and refining to obtain molten steel with the components;
2) casting to form a blank: strip casting with a twin roll casting plant to obtain a cast strip, during which: controlling the molten steel to carry out thin-strip continuous casting under the protection of conventional inert gas, wherein the blank drawing speed is 46-117 m/min, and the thickness of a continuous casting strip is 1.0-2.5 mm;
3) hot rolling: hot rolling the cast strip to a product thickness of 0.5-2.0 mm, during which: controlling the single-pass reduction rate to be 20-60% and the final rolling temperature to be 850-1000 ℃;
4) cooling, namely cooling to the coiling temperature at a cooling speed of not less than 50 ℃/s by adopting laminar flow type or aerosol type cooling;
5) naturally cooling to room temperature after coiling, and controlling the coiling temperature not to exceed 270 ℃;
6) and (5) carrying out cold forming after uncoiling and blanking.
5. The method for producing hot-rolled thin strip steel with tensile strength of more than or equal to 1200MPa by using TSR production line according to claim 4, characterized in that: the coiling temperature is 180-265 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210781466.4A CN115094346B (en) | 2022-07-04 | 2022-07-04 | Hot rolled strip steel with tensile strength more than or equal to 1200MPa and produced by adopting TSR production line and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210781466.4A CN115094346B (en) | 2022-07-04 | 2022-07-04 | Hot rolled strip steel with tensile strength more than or equal to 1200MPa and produced by adopting TSR production line and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115094346A true CN115094346A (en) | 2022-09-23 |
| CN115094346B CN115094346B (en) | 2023-06-20 |
Family
ID=83297127
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210781466.4A Active CN115094346B (en) | 2022-07-04 | 2022-07-04 | Hot rolled strip steel with tensile strength more than or equal to 1200MPa and produced by adopting TSR production line and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115094346B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1840723A (en) * | 2005-03-30 | 2006-10-04 | 宝山钢铁股份有限公司 | Superhigh strength steel plate with yield strength more than 1100Mpa and method for producing same |
| CN1840724A (en) * | 2005-03-30 | 2006-10-04 | 宝山钢铁股份有限公司 | Superhigh strength steel plate with yield strength more than 960Mpa and method for producing same |
| JP2008208454A (en) * | 2007-01-31 | 2008-09-11 | Jfe Steel Kk | High-strength steel excellent in delayed fracture resistance and its production method |
| CN103305755A (en) * | 2012-03-14 | 2013-09-18 | 宝山钢铁股份有限公司 | Manufacturing method of thin-strip continuous casting low-carbon micro-alloy high-strength steel strip |
| CN103302255A (en) * | 2012-03-14 | 2013-09-18 | 宝山钢铁股份有限公司 | Manufacturing method of thin-strip casting 700 MPa grade high-strength weather resisting steel |
| WO2014187193A1 (en) * | 2013-05-22 | 2014-11-27 | 宝山钢铁股份有限公司 | Ultra-high strength cold-rolled corten steel plate and method of fabricating same |
| CN106222555A (en) * | 2016-08-24 | 2016-12-14 | 武汉钢铁股份有限公司 | By tensile strength >=1300MPa thin hot forming steel and the production method of sheet billet Direct Rolling |
| CN112522571A (en) * | 2019-09-19 | 2021-03-19 | 宝山钢铁股份有限公司 | Method for producing martensite steel strip by twin-roll thin-strip continuous casting |
| CN112522576A (en) * | 2019-09-19 | 2021-03-19 | 宝山钢铁股份有限公司 | Thin-gauge high-corrosion-resistance steel and production method thereof |
-
2022
- 2022-07-04 CN CN202210781466.4A patent/CN115094346B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1840723A (en) * | 2005-03-30 | 2006-10-04 | 宝山钢铁股份有限公司 | Superhigh strength steel plate with yield strength more than 1100Mpa and method for producing same |
| CN1840724A (en) * | 2005-03-30 | 2006-10-04 | 宝山钢铁股份有限公司 | Superhigh strength steel plate with yield strength more than 960Mpa and method for producing same |
| JP2008208454A (en) * | 2007-01-31 | 2008-09-11 | Jfe Steel Kk | High-strength steel excellent in delayed fracture resistance and its production method |
| CN103305755A (en) * | 2012-03-14 | 2013-09-18 | 宝山钢铁股份有限公司 | Manufacturing method of thin-strip continuous casting low-carbon micro-alloy high-strength steel strip |
| CN103302255A (en) * | 2012-03-14 | 2013-09-18 | 宝山钢铁股份有限公司 | Manufacturing method of thin-strip casting 700 MPa grade high-strength weather resisting steel |
| WO2014187193A1 (en) * | 2013-05-22 | 2014-11-27 | 宝山钢铁股份有限公司 | Ultra-high strength cold-rolled corten steel plate and method of fabricating same |
| CN106222555A (en) * | 2016-08-24 | 2016-12-14 | 武汉钢铁股份有限公司 | By tensile strength >=1300MPa thin hot forming steel and the production method of sheet billet Direct Rolling |
| CN112522571A (en) * | 2019-09-19 | 2021-03-19 | 宝山钢铁股份有限公司 | Method for producing martensite steel strip by twin-roll thin-strip continuous casting |
| CN112522576A (en) * | 2019-09-19 | 2021-03-19 | 宝山钢铁股份有限公司 | Thin-gauge high-corrosion-resistance steel and production method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115094346B (en) | 2023-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10995380B2 (en) | 1500 MPa grade press hardening steel by thin slab casting and direct rolling and method for producing the same | |
| US10988820B2 (en) | 1500 MPa grade press hardening steel by medium thin slab casting and direct rolling and method for producing the same | |
| US20190169708A1 (en) | 1900 MPa GRADE PRESS HARDENING STEEL BY MEDIUM THIN SLAB CASTING AND DIRECT ROLLING AND METHOD FOR PRODUCING THE SAME | |
| US11124851B2 (en) | 1900 MPa grade press hardening steel by thin slab casting and directly rolling and method for producing the same | |
| CN101701316B (en) | Automobile beam steel with tensile strength of 590MPa and manufacturing method thereof | |
| CN106191678B (en) | With the tensile strength >=1700MPa hot formings steel and production method of medium thin slab Direct Rolling | |
| CN107557692B (en) | 1000MPa grade analysis of producing hot rolled TRIP and manufacturing method based on CSP process | |
| WO2019218135A1 (en) | Ultra high strength steel having yield strength of 1,000 mpa and low yield-tensile ratio, and preparation method thereof | |
| CN106086683B (en) | With the thin hot forming steel of tensile strength >=1700MPa of sheet billet Direct Rolling and production method | |
| CN109023055B (en) | High-strength high-formability automobile steel plate and production process thereof | |
| CN114150227B (en) | High-toughness hot stamping steel rolled by medium and thin slabs with Rm more than or equal to 1500MPa and production method | |
| CN114214563B (en) | High-toughness hot stamping steel rolled by sheet billet with Rm more than or equal to 1500MPa and production method | |
| CN105543666A (en) | Automobile beam steel with 960 MPa yield strength and production method thereof | |
| CN109097681B (en) | High-strength low-inclusion automobile steel plate and electromagnetic stirring process thereof in continuous casting process | |
| CN112795731A (en) | Cold-rolled steel plate for lampshade and production method thereof | |
| CN106086686A (en) | By the tensile strength of medium thin slab Direct Rolling >=2100MPa hot forming steel and production method | |
| CN115491593B (en) | Hot rolled thin strip steel with tensile strength more than or equal to 1800MPa and produced by adopting TSR production line and method | |
| CN114990432B (en) | Hot rolled strip steel with tensile strength not lower than 1500MPa produced by TSR production line and method | |
| CN113403541A (en) | 550 MPa-level low-alloy high-strength cold-rolled steel plate and production method thereof | |
| CN108546872B (en) | Hot-rolled dual-phase thin steel plate with tensile strength not lower than 600MPa produced by CSP production line and method | |
| CN106222556A (en) | By the tensile strength of medium thin slab Direct Rolling >=1300MPa hot forming steel and production method | |
| CN115094346B (en) | Hot rolled strip steel with tensile strength more than or equal to 1200MPa and produced by adopting TSR production line and method | |
| CN113403540A (en) | 500 MPa-level low-alloy high-strength cold-rolled steel plate and production method thereof | |
| CN115287551A (en) | Hot rolled strip steel with tensile strength of more than or equal to 1800MPa produced by TSR production line and method | |
| CN115029627B (en) | Hot forming steel with tensile strength more than or equal to 1500MPa produced by TSR production line and 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 |