CN115323271A - Refractory hot-rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high low-temperature toughness and preparation method thereof - Google Patents
Refractory hot-rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high low-temperature toughness and preparation method thereof Download PDFInfo
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- 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
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- 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
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- 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
- C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
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- C22C33/04—Making ferrous alloys by melting
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- 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
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
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Abstract
The invention discloses a refractory hot rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high and low temperature toughness and a preparation method thereof, and the hot rolled H-shaped steel comprises the following chemical components in percentage by mass: c:0.04-0.07%, si:0.25-0.35%, mn:0.90-1.20%, P is less than or equal to 0.020%, S is less than or equal to 0.010%, mo:0.15-0.20%, ti:0.015-0.035%, cr:0.25-0.40%, V:0.020 to 0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities. The 390 MPa-grade low-yield-ratio high-low-temperature-toughness refractory hot-rolled steel plate provided by the invention has excellent refractory performance and high low-temperature toughness, and can be used as an excellent steel material for construction.
Description
Technical Field
The invention belongs to the field of refractory steel, and particularly relates to a refractory hot rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high low-temperature toughness and a preparation method thereof.
Background
The steel structure building has huge potential and wide development prospect. Although it has many advantages, it has the disadvantage of poor fire protection properties. When the temperature of the steel for the common building reaches 400 ℃, the yield strength is reduced to half of the strength of the room temperature, and when the temperature reaches 600 ℃, the strength is basically lost, so that the fire safety of the high-rise steel structure building is highly valued by people. Therefore, when a large-scale steel structure building is built, the fire resistance of the steel structure is enhanced by coating a layer of fireproof coating on the surface of the steel structure according to the industrial specifications and standards, but the cost of the building is increased by times by spraying the fireproof material, the construction period is prolonged, the effective use area in a room is reduced, and the environment is polluted by splashing in the spraying operation. The use of the fire-resistant steel can greatly reduce the use of fire-resistant coating, and the fire-resistant steel can be recycled. Therefore, the development of constructional steels with fire resistance is a goal of many steel companies.
Disclosure of Invention
Aiming at one or more problems in the prior art, the invention provides a refractory hot-rolled steel plate with yield strength of 390MPa grade, low yield ratio and high and low temperature toughness, which comprises the following chemical components in percentage by mass: c:0.04-0.07%, si:0.25-0.35%, mn:0.90-1.20%, P is less than or equal to 0.020%, S is less than or equal to 0.010%, mo:0.15-0.20%, ti:0.015-0.035%, cr:0.25-0.40%, V:0.020-0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities.
In some embodiments, the low yield ratio high and low temperature toughness refractory hot rolled steel plate with the yield strength of 390MPa grade comprises the following chemical components in percentage by mass: c:0.043-0.068%, si:0.26-0.33%, mn:0.92-1.14%, P is less than or equal to 0.012%, S is less than or equal to 0.005%, mo:0.15-0.20%, ti:0.015-0.034%, cr:0.25-0.38%, V:0.020-0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities.
In some embodiments, the mechanical properties of the refractory hot-rolled steel plate with the yield strength of 390MPa grade and the low yield ratio and the high and low temperature toughness meet the following requirements: the normal temperature yield strength is more than or equal to 402MPa, the normal temperature tensile strength is more than or equal to 568MPa, the elongation A is more than or equal to 25 percent, the low temperature impact at minus 20 ℃ is more than or equal to 211J, the yield ratio is less than or equal to 0.71, and the high temperature tensile yield strength is more than or equal to 292MPa.
The invention provides a preparation method of a high-low temperature toughness refractory hot-rolled steel plate with a yield strength of 390MPa grade and a low yield ratio, which comprises the following steps: smelting, continuous casting, rolling and cooling; wherein:
in the smelting process, molten iron subjected to desulfurization pretreatment is refined, heated and alloyed in an LF furnace to ensure that the components and the temperature of the molten steel meet the requirements of the subsequent process; vacuum treating for more than 20 min; carrying out soft blowing on the molten steel after vacuum treatment;
in the continuous casting process, a protective casting method is adopted in the whole continuous casting process, meanwhile, a soft reduction measure is adopted, and the quality of a casting blank is controlled by using a casting blank electromagnetic stirring means, the center segregation of the casting blank is not more than 2.0 grades of B and C series, the A series segregation is not allowed to appear, and the center porosity of the casting blank is not more than 2 grades;
in the rolling and cooling process, the tapping temperature of the steel plate blank is 1180-1220 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is more than or equal to 1100 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10 percent, and the accumulated reduction rate is more than or equal to 60 percent; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the final rolling temperature of finish rolling is controlled to be 820-860 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; after rolling, the steel plate is relaxed for 20 to 30 seconds, and then the steel plate is cooled to 570 to 640 ℃ by adopting accelerated cooling.
Based on the technical scheme, the invention adopts reasonable microalloying component design of Cr, mo, nb, V and Ti and a relaxation process after rolling to obtain a 390 MPa-level low-yield-ratio fire-resistant high-low temperature toughness steel product with high safety, which can improve the fire resistance of steel structure buildings and improve the storage strength of building steel, thereby improving the safety of the steel structure buildings, simultaneously reducing or avoiding the use of fire-resistant coatings and promoting the development of the steel structure buildings. Meanwhile, the low-yield-ratio fireproof steel product with high and low temperature toughness has low production cost, improves the recycling of social resources, and saves the social resources.
Drawings
FIG. 1 is a metallographic structure photograph of a high and low temperature toughness hot rolled steel sheet having a yield strength of 390MPa grade and a low yield ratio prepared in example 1;
FIG. 2 is a metallographic structure photograph of a high and low temperature toughness hot rolled steel sheet having a yield strength of 390MPa grade and a low yield ratio prepared in example 2;
FIG. 3 is a metallographic structure photograph of a refractory hot rolled steel sheet having a yield strength of 390MPa grade prepared in example 3 and having a low yield ratio and high low temperature toughness.
Detailed Description
The invention aims to provide a 390 MPa-grade yield strength low-yield ratio high-low temperature toughness refractory hot-rolled steel plate and a preparation method of the 390 MPa-grade yield strength low-yield ratio high-low temperature toughness refractory hot-rolled steel plate.
In a first aspect of the invention, a refractory hot rolled steel plate with a yield strength of 390MPa grade, a low yield ratio and high low-temperature toughness is provided, which comprises the following chemical components in percentage by mass: c:0.04-0.07%, si:0.25-0.35%, mn:0.90-1.20%, P is less than or equal to 0.020%, S is less than or equal to 0.010%, mo:0.15-0.20%, ti:0.015-0.035%, cr:0.25-0.40%, V:0.020 to 0.025%, nb:0.04-0.07%, the balance being Fe and unavoidable impurities; can be selected as C:0.043-0.068%, si:0.26-0.33%, mn:0.92-1.14%, P is less than or equal to 0.012%, S is less than or equal to 0.005%, mo:0.15-0.20%, ti:0.015-0.034%, cr:0.25-0.38%, V:0.020 to 0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities.
In some embodiments, the mechanical properties of the provided low yield ratio high and low temperature toughness refractory hot rolled steel plate with the yield strength of 390MPa grade satisfy that: the normal temperature yield strength is more than or equal to 402MPa, the normal temperature tensile strength is more than or equal to 568MPa, the elongation A is more than or equal to 25 percent, the low temperature impact at minus 20 ℃ is more than or equal to 211J, the yield ratio is less than or equal to 0.71, and the high temperature tensile yield strength is more than or equal to 292MPa.
In a second aspect of the invention, the invention provides a preparation method of a refractory hot-rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high low-temperature toughness, which comprises the following processes: smelting, continuous casting, rolling and cooling; wherein:
in the smelting process, molten iron subjected to desulfurization pretreatment is refined, heated and alloyed in an LF furnace to ensure that the components and the temperature of the molten steel meet the requirements of the subsequent process; vacuum treating for more than 20 min; carrying out soft blowing on the molten steel after vacuum treatment, wherein during the soft blowing, the slag surface of a steel ladle is kept still, and the liquid level of the molten steel cannot be exposed in the air;
in the continuous casting process, a protective casting method is adopted in the whole continuous casting process, meanwhile, a soft reduction measure is adopted, and the quality of a casting blank is controlled by using a casting blank electromagnetic stirring means, the center segregation of the casting blank is not more than 2.0 grades of B and C series, the A series segregation is not allowed to appear, and the center porosity of the casting blank is not more than 2 grades;
in the rolling and cooling process, the tapping temperature of the steel plate blank is 1180-1220 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is more than or equal to 1100 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10 percent, and the accumulated reduction rate is more than or equal to 60 percent; the initial rolling temperature of the finish rolling is less than or equal to 950 ℃, the final rolling temperature of the finish rolling is controlled to be 820-860 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; after rolling, the steel plate relaxes for 20 to 30 seconds and then is cooled to 570 to 640 ℃.
The present invention will be described in detail below with reference to specific examples, which are intended to facilitate understanding of the present invention and are not intended to limit the present invention.
Example 1: production of high-low temperature toughness refractory hot-rolled steel plate with yield strength of 390MPa grade and low yield ratio
The embodiment aims to produce a refractory hot-rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high and low temperature toughness, the chemical components and the content of the refractory hot-rolled steel plate are shown in the following table 1, and the preparation method specifically comprises the following processes: smelting, continuous casting, rolling and cooling; wherein:
in the smelting process, molten iron subjected to desulfurization pretreatment is refined, heated and alloyed in an LF furnace to ensure that the components and the temperature of the molten steel meet the requirements of the subsequent process; vacuum treating for more than 20 min; carrying out soft blowing on the molten steel after vacuum treatment, wherein during the soft blowing, the slag surface of a steel ladle should be kept calm, and the liquid level of the molten steel cannot be exposed in air;
in the continuous casting process, a protective casting method is adopted in the whole continuous casting process, meanwhile, a soft reduction measure is adopted, the quality of a casting blank is controlled by using a casting blank electromagnetic stirring measure, the central segregation of the casting blank is not more than the grade of 2.0 of B and C series, the A series segregation is not allowed to occur, and the central porosity of the casting blank is not more than the grade of 2;
in the rolling and cooling process, the tapping temperature of a steel plate blank is about 1200 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is 1120 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10 percent, the cumulative reduction rate is more than or equal to 60 percent, and finish rolling is started when the thickness of the plate blank after the rough rolling is 3 times that of a finished product; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the final rolling temperature of finish rolling is controlled at 821 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; after relaxation for 20 seconds, the steel sheet was cooled to 578 ℃. And straightening by using a straightening machine to obtain the steel plate.
As shown in FIG. 1, a metallographic structure photograph of a high/low temperature toughness hot rolled steel sheet having a yield strength of 390MPa grade and a low yield ratio prepared in this example is shown, and a multi-phase microstructure of ferrite, a bainite structure and trace pearlite is obtained. The results of mechanical property testing are shown in table 2 below.
Examples 2 to 3
Examples 2-3 the preparation method of example 1 was followed, except that the steel sheets had different chemical compositions (as shown in table 1 below) and different parameter control in the rolling and cooling processes, specifically:
in the rolling and cooling process of the embodiment 2, the tapping temperature of a steel plate blank is about 1200 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is 1130 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10 percent, the accumulated reduction rate is more than or equal to 60 percent, and finish rolling is started when the thickness of the plate blank after the rough rolling is 3 times of the thickness of a finished product; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the final rolling temperature of finish rolling is controlled at 840 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; after relaxation for 25 seconds, the steel sheet was cooled to 610 ℃.
In the rolling and cooling process of the embodiment 3, the tapping temperature of a steel plate blank is about 1205 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is 1140 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10 percent, the accumulated reduction rate is more than or equal to 60 percent, and finish rolling is started when the thickness of the plate blank after the rough rolling is 3 times of the thickness of a finished product; the initial rolling temperature of the finish rolling is less than or equal to 950 ℃, the final rolling temperature of the finish rolling is controlled at 860 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; after relaxation for 30 seconds, the steel sheet was cooled to 637 ℃.
Metallographic structure photographs of the high and low temperature toughness hot rolled steel sheets having a yield strength of 390MPa grade and a low yield ratio prepared in examples 2 and 3 are shown in FIG. 2 and FIG. 3, respectively, and a multi-phase microstructure of ferrite, a bainite structure and trace pearlite is obtained. The results of mechanical property tests on both are shown in table 2 below.
Comparative examples 1 to 4
Comparative examples 1 to 4 the preparation process of example 1 was followed except that:
the chemical compositions of the steel sheets of comparative example 1 and example 1 are different, and are specifically shown in table 1 below;
comparative examples 2 to 4 are different from example 1 in control parameters in the rolling and cooling processes, specifically, comparative example 2 is not subjected to relaxation treatment after rolling; comparative example 3 the time for relaxation treatment after rolling was 10 seconds; comparative example 4 the time for performing the relaxation treatment after rolling was 40 seconds.
The results of measuring mechanical properties of the steel sheets prepared in comparative examples 1 to 4 are shown in table 2 below.
Table 1: chemical composition and content (%)
| Element(s) | C | Si | Mn | P | S | Nb | V | Ti | Cr | Mo |
| Example 1 | 0.058 | 0.29 | 1.02 | 0.010 | 0.003 | 0.062 | 0.025 | 0.025 | 0.38 | 0.18 |
| Example 2 | 0.043 | 0.33 | 1.14 | 0.012 | 0.003 | 0.044 | 0.020 | 0.015 | 0.25 | 0.20 |
| Example 3 | 0.068 | 0.26 | 0.92 | 0.012 | 0.005 | 0.068 | 0.025 | 0.034 | 0.32 | 0.15 |
| Comparative example 1 | 0.060 | 0.30 | 1.03 | 0.010 | 0.003 | 0.061 | 0.030 | 0.025 | 0.37 | 0.11 |
| Comparative example 2 | 0.061 | 0.29 | 1.05 | 0.010 | 0.003 | 0.066 | 0.022 | 0.025 | 0.37 | 0.19 |
| Comparative example 3 | 0.057 | 0.27 | 1.00 | 0.012 | 0.004 | 0.060 | 0.027 | 0.026 | 0.38 | 0.17 |
| Comparative example 4 | 0.056 | 0.28 | 1.05 | 0.012 | 0.003 | 0.057 | 0.025 | 0.025 | 0.33 | 0.18 |
Table 2: mechanical Properties of Steel sheets prepared in examples and comparative examples
As is clear from the contents shown in tables 1 and 2, the refractory hot-rolled steel sheets having a yield strength of 390MPa class and a low yield ratio and high and low temperature toughness obtained in examples 1 to 3 are excellent in overall mechanical properties and satisfy: the normal temperature yield strength is more than or equal to 402MPa, the normal temperature tensile strength is more than or equal to 568MPa, the elongation A is more than or equal to 25 percent, the low temperature impact at minus 20 ℃ is more than or equal to 200J, the low temperature impact at minus 40 ℃ is more than or equal to 140J, the low temperature impact at minus 60 ℃ is more than or equal to 70J, the yield ratio is less than or equal to 0.71, and the high temperature tensile yield strength is more than or equal to 290MPa. Compared with the steel produced in the example 1, the steel produced in the comparative example 1 has higher V content and lower Mo content, the strength of the prepared steel plate is similar, but the fire resistance is obviously reduced; compared with the example 1, the comparative example 2 has similar components to the example 1, and the comparative example 2 does not carry out post-rolling relaxation treatment in the rolling and cooling process for preparing the steel plate, which can improve the yield and tensile strength of the steel plate, obviously improves the yield ratio and is not beneficial to the low-temperature toughness of the steel plate; in contrast to example 1, comparative examples 3 and 4, both of which were subjected to relaxation treatment after rolling, had a shorter relaxation treatment time, resulting in higher strength-to-yield ratio and poorer low-temperature impact toughness, and lower strength and poorer fire resistance when the relaxation time was too long.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (4)
1. A refractory hot-rolled steel plate with 390 MPa-grade yield strength, low yield ratio and high and low temperature toughness comprises the following chemical components in percentage by mass: c:0.04-0.07%, si:0.25-0.35%, mn:0.90-1.20%, P is less than or equal to 0.020%, S is less than or equal to 0.010%, mo:0.15-0.20%, ti:0.015-0.035%, cr:0.25-0.40%, V:0.020 to 0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities.
2. The refractory hot-rolled steel plate with 390MPa grade yield strength and low yield ratio and high and low temperature toughness as claimed in claim 1, comprises the following chemical components by mass percent: c:0.043-0.068%, si:0.26-0.33%, mn:0.92-1.14%, P is less than or equal to 0.012%, S is less than or equal to 0.005%, mo:0.15-0.20%, ti:0.015-0.034%, cr:0.25-0.38%, V:0.020-0.025%, nb:0.04-0.07%, and the balance of Fe and inevitable impurities.
3. The refractory hot rolled steel plate with the yield strength of 390MPa grade and the low yield ratio and the high and low temperature toughness as claimed in claim 1 or 2, has the mechanical properties of: the normal-temperature yield strength is more than or equal to 402MPa, the normal-temperature tensile strength is more than or equal to 568MPa, the elongation A is more than or equal to 25 percent, the low-temperature impact at the temperature of minus 20 ℃ is more than or equal to 211J, the yield ratio is less than or equal to 0.71, and the high-temperature tensile yield strength is more than or equal to 292MPa.
4. The method for preparing the refractory hot rolled steel plate with the yield strength of 390MPa grade and the low yield ratio and the high and low temperature toughness as claimed in any one of claims 1 to 3, which comprises the following processes: smelting, continuous casting, rolling and cooling; wherein:
in the smelting process, molten iron subjected to desulfurization pretreatment is refined, heated and alloyed in an LF furnace to ensure that the components and the temperature of the molten steel meet the requirements of the subsequent process; vacuum treating for more than 20 min; carrying out soft blowing on the molten steel after vacuum treatment;
in the continuous casting process, a protective casting method is adopted in the whole continuous casting process, meanwhile, a light reduction measure is adopted, the quality of a casting blank is controlled by using a casting blank electromagnetic stirring measure, the center segregation of the casting blank is not more than the level of 2.0 of B and C series, the A series segregation is not allowed to occur, and the center porosity of the casting blank is not more than the level of 2;
in the rolling and cooling process, the tapping temperature of the steel plate blank is 1180-1220 ℃, two-stage rolling is adopted, the initial rolling temperature of rough rolling is more than or equal to 1100 ℃, the final rolling temperature of the rough rolling is 980-1050 ℃, the single-pass reduction rate is more than or equal to 10%, and the cumulative reduction rate is more than or equal to 60%; the initial rolling temperature of finish rolling is less than or equal to 950 ℃, the final rolling temperature of finish rolling is controlled to be 820-860 ℃, the single-pass reduction rate is more than or equal to 12 percent, and the cumulative reduction rate is more than or equal to 63 percent; relaxation is carried out for 20-30 seconds after rolling, and then the steel plate is cooled to 570-640 ℃ by adopting accelerated cooling.
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| JP2004204342A (en) * | 2002-10-28 | 2004-07-22 | Nippon Steel Corp | 590 MPa CLASS HIGH-TENSION STEEL EXCELLENT IN HIGH-TEMPERATURE STRENGTH AND ITS PRODUCTION METHOD |
| US20100263773A1 (en) * | 2007-11-22 | 2010-10-21 | Posco | High strength and low yield ratio steel for structure having excellent low temperature toughness |
| CN101906585A (en) * | 2009-06-08 | 2010-12-08 | 鞍钢股份有限公司 | High-performance fire-resistant steel plate for building structure and manufacturing method thereof |
| CN102400049A (en) * | 2010-09-07 | 2012-04-04 | 鞍钢股份有限公司 | 490-grade fire-resistant steel plate for building structure and manufacturing method thereof |
| EP2557185A1 (en) * | 2011-08-10 | 2013-02-13 | Swiss Steel AG | Armature en acier profilée et laminée à chaud pour pièces en béton armé dotées d'une résistance au feu améliorée et son procédé de fabrication |
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| CN111187977A (en) * | 2020-01-07 | 2020-05-22 | 北京科技大学 | 690 MPa-grade anti-seismic, corrosion-resistant and fire-resistant medium-thickness plate steel and manufacturing method thereof |
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