CN114182165A - Low-yield-ratio high-toughness Q500qE bridge steel and production method thereof - Google Patents
Low-yield-ratio high-toughness Q500qE bridge steel and production method thereof Download PDFInfo
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- 239000010959 steel Substances 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 20
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- 238000000034 method Methods 0.000 claims abstract description 12
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- 239000012535 impurity Substances 0.000 claims abstract description 9
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 9
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 9
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 7
- 229910001563 bainite Inorganic materials 0.000 claims abstract description 5
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 5
- 238000005096 rolling process Methods 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 17
- 238000001816 cooling Methods 0.000 claims description 16
- 238000003723 Smelting Methods 0.000 claims description 6
- 238000009749 continuous casting Methods 0.000 claims description 6
- 238000003466 welding Methods 0.000 claims description 5
- 238000005266 casting Methods 0.000 claims description 4
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- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel 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
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- 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
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- 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
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- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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Abstract
The invention discloses low-yield-ratio high-toughness Q500qE bridge steel and a production method thereof, relating to the technical field of steel production, wherein the bridge steel comprises the following chemical components in percentage by mass: c: 0.04 to 0.07 percent of Si: 0.15-0.25%, Mn: 1.40-1.55%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, Nb: 0.03-0.05%, Ti: 0.008% -0.02%, Alt: 0.020% -0.040%, Cu: 0.10% -0.20%, Ni: 0.20-0.30%, Cr: 0.25% -0.40%, Mo: 0.10% -0.20%, carbon equivalent CEV: 0.38% -0.45%, weld crack susceptibility Pcm: 0.15 to 0.23 percent, and the balance of Fe and a small amount of inevitable impurities. The steel with the thickness specification of 10-60 mm is obtained by adopting a TMCP + tempering process, a metallographic structure mainly comprising bainite and ferrite is obtained, and good matching of high strength, low yield ratio and high low-temperature toughness is realized.
Description
Technical Field
The invention relates to the technical field of steel production, in particular to low-yield-ratio high-toughness Q500qE bridge steel and a production method thereof.
Background
With the continuous improvement of the bridge construction level in China, the requirement for high reliability of a steel bridge structure is not strict from highway, railway to highway and railway dual-purpose bridge even across river and sea, from large span of the bridge to heavy load, so that higher requirements are provided for the quality of bridge steel, the bridge steel is required to have high strength and low yield ratio, and good low-temperature toughness, plasticity, weldability and the like, so that the working conditions of light weight, large span and heavy load of the structure are met, and the safety and the service life of the steel bridge structure are improved.
The yield ratio of the material is closely related to the plastic deformation capacity and the work hardening capacity, and the high-yield-ratio steel has small plastic deformation and is easy to brittle fracture after yielding; the reliability of the material of the low yield ratio steel is higher, if the steel is overloaded, the steel firstly yields, and then the material is hardened due to plastic deformation, so that the strength is improved, and the fracture is delayed. Therefore, to improve the safety of the steel bridge, a low yield ratio bridge steel is preferred.
The yield ratio of the steel is generally improved along with the improvement of the strength of the steel, when the strength reaches 500MPa, the lower yield ratio needs to be controlled, and particularly, the difficulty is great when the requirements on the transverse direction and the longitudinal direction are met. The high impact fiber section ratio and the low yield ratio are two contradictory indexes, and the requirement can make the process window of the bridge steel narrow and the production difficulty greatly increased.
The bridge steel also requires transverse and longitudinal yield ratios and impact fiber fracture surface ratios while ensuring the strength and the toughness, the technical indexes are far more strict than various bridge standards, and the prior patent on 500MPa bridge steel is rarely published.
At present, the products in the 500MPa grade bridge steel patents do not simultaneously relate to the performance requirements of transverse and longitudinal strength, yield ratio and impact fiber section ratio.
CN 108624744B discloses a Q500qE bridge steel plate and a production method thereof, wherein Mn (1.6-1.8%) and Si (0.20-0.40%) are controlled relatively high, a casting blank is easy to generate center segregation, welding crack sensitivity is increased, and weldability of the steel is affected.
CN 111057945B discloses 'a 500 MPa-grade tough weather-proof bridge steel and a preparation method thereof', the method needs to add more alloy elements such as Cr (0.40-0.50%), Ni (0.30-0.40%), Cu (0.27-0.37%) and Mo (0.2-0.7%), and the alloy cost is greatly improved.
CN 111455287A discloses '500 MPa-grade weather-proof bridge steel with low yield ratio and a manufacturing method thereof', the method also needs to control higher alloy content, such as Cr (0.45-0.60%), Ni (0.30-0.45%), Cu (0.30-0.40%), and alloy cost is increased.
CN 111155032A discloses 'a rare earth high-performance bridge steel plate with 500MPa grade yield strength and a production method thereof', which is added with V (0.05% -0.07%) and contains rare earth elements, and the cost is higher.
CN 107326304A discloses 'a TMCP type bridge steel plate with 500MPa grade yield and a production method', the heating temperature is 1240-1250 deg.C, the heating temperature is higher, and the crystal grain is easy to be coarse.
Disclosure of Invention
Aiming at the technical problems, the invention overcomes the defects of the prior art, and provides the low-yield-ratio high-toughness Q500qE bridge steel which comprises the following chemical components in percentage by mass: c: 0.04 to 0.07 percent of Si: 0.15-0.25%, Mn: 1.40-1.55%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, Nb: 0.03-0.05%, Ti: 0.008% -0.02%, Alt: 0.020% -0.040%, Cu: 0.10% -0.20%, Ni: 0.20-0.30%, Cr: 0.25% -0.40%, Mo: 0.10% -0.20%, carbon equivalent CEV: 0.38% -0.45%, weld crack susceptibility Pcm: 0.15 to 0.23 percent, and the balance of Fe and a small amount of inevitable impurities;
carbon equivalent CEV calculation formula: CEV (%) = C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15;
the formula for calculating the welding crack sensitivity coefficient Pcm is as follows: pcm = C + Si/30+ Mn/20+ Cu/20+ Ni/60+ Cr/20+ Mo/15+ V/10+ 5B.
The technical scheme of the invention is further defined as follows:
the low-yield-ratio high-toughness Q500qE bridge steel comprises the following chemical components in percentage by mass: c: 0.04-0.06%, Si: 0.15-0.20%, Mn: 1.40-1.48%, P is less than or equal to 0.014%, S is less than or equal to 0.003%, Nb: 0.030-0.040%, Ti: 0.008% -0.018%, Alt: 0.020% -0.035%, Cu: 0.10% -0.18%, Ni: 0.20-0.28%, Cr: 0.25% -0.35%, Mo: 0.10% -0.18%, carbon equivalent CEV: 0.38% -0.44%, weld crack susceptibility Pcm: 0.15 to 0.21 percent, and the balance of Fe and a small amount of inevitable impurities.
The low-yield-ratio high-toughness Q500qE bridge steel comprises the following chemical components in percentage by mass: : c: 0.045% -0.065%, Si: 0.18-0.23%, Mn: 1.41-1.52 percent, P is less than or equal to 0.013 percent, S is less than or equal to 0.003 percent, Nb: 0.035 to 0.045 percent, Ti: 0.009% -0.019%, Alt: 0.022% -0.038%, Cu: 0.11-0.20%, Ni: 0.21-0.29%, Cr: 0.28% -0.38%, Mo: 0.11% -0.19%, carbon equivalent CEV: 0.39% -0.44%, weld crack susceptibility Pcm: 0.16 to 0.22 percent, and the balance of Fe and a small amount of inevitable impurities.
The low-yield-ratio high-toughness Q500qE bridge steel comprises the following chemical components in percentage by mass: c: 0.05 to 0.07 percent, Si: 0.20-0.25%, Mn: 1.41-1.55 percent of Nb, P is less than or equal to 0.013 percent, S is less than or equal to 0.003 percent, and Nb: 0.038% -0.050%, Ti: 0.010% -0.020%, Alt: 0.025 to 0.040%, Cu: 0.11-0.20%, Ni: 0.22-0.30%, Cr: 0.30% -0.40%, Mo: 0.12% -0.20%, carbon equivalent CEV: 0.40% -0.45%, weld crack susceptibility Pcm: 0.16 to 0.23 percent, and the balance of Fe and a small amount of inevitable impurities.
The invention also aims to provide a production method of the low-yield-ratio high-toughness Q500qE bridge steel, which comprises the following steps of smelting, continuous casting, heating, rolling, cooling and tempering, and specifically comprises the following steps:
s1, smelting according to chemical components and casting to obtain a blank;
s2, heating: sending the continuous casting slab to a heating furnace, wherein the heating temperature is 1180-1220 ℃, the soaking time is not less than 36min, and the total heating time is not less than 220 min;
s3, rolling: a two-stage rolling method is adopted, high-temperature high-reduction is adopted for rough rolling, and the pass reduction rate of last 2 continuous passes is more than or equal to 20 percent; the thickness of the intermediate temperature-waiting blank is more than or equal to 1.8h, wherein h is the thickness of a finished product and is unit mm; the initial rolling temperature of the finish rolling stage is 800-930 ℃, and the final rolling temperature is 790-850 ℃;
s4, cooling: controlling the cooling water inlet temperature to be 720-760 ℃; entering laminar cooling, wherein the cooling speed is 10-20 ℃/s, and the temperature of red return is 420-620 ℃;
s5, tempering: tempering at 400-520 ℃, keeping the temperature for 14-50 min, wherein the keeping time is in direct proportion to the thickness of the finished product, and then air-cooling to room temperature.
According to the production method of the low-yield-ratio high-toughness Q500qE bridge steel, the thickness specification of the steel plate is 10-60 mm.
In the production method of the low-yield-ratio high-toughness Q500qE bridge steel, the metallographic structure of the steel plate mainly comprises bainite and ferrite.
The invention has the beneficial effects that:
(1) according to the invention, through the low C, V-removing and microalloying component design, the steel with the thickness specification of 10-60 mm is obtained by adopting a TMCP + tempering process, a metallographic structure mainly comprising bainite and ferrite is obtained, and good matching of high strength, low yield ratio and high low-temperature toughness is realized;
(2) according to the invention, by controlling the rolling temperature and the re-reddening temperature and matching with a relaxation method, namely accurately controlling the temperature of cooling inlet water, the yield strength is effectively reduced, and the tensile strength is improved, so that the low yield ratio is ensured;
(3) the invention has excellent comprehensive performance, the transverse and longitudinal yield strength is more than 500MPa, the tensile strength is more than 630MPa, the yield ratio is less than or equal to 0.86, and the elongation is more than or equal to 18 percent; akv is more than 120J at minus 40 ℃ and the fracture rate of the impact fiber is more than or equal to 80 percent; the high-carbon-equivalent-value-ratio-based high-toughness high-strength steel has low carbon equivalent and welding crack sensitivity coefficient, has good welding performance, can be better applied to bridge construction, and has high social value.
Drawings
FIG. 1 is a metallographic structure diagram of an example.
Detailed Description
The production method of the low-yield-ratio high-toughness Q500qE bridge steel provided by the following embodiments comprises smelting, continuous casting, heating, rolling, cooling and tempering, and specifically comprises the following steps:
s1, smelting according to chemical components and casting to obtain a blank;
s2, heating: sending the continuous casting slab to a heating furnace, wherein the heating temperature is 1180-1220 ℃, the soaking time is not less than 36min, and the total heating time is not less than 220 min;
s3, rolling: a two-stage rolling method is adopted, high-temperature high-reduction is adopted for rough rolling, and the pass reduction rate of last 2 continuous passes is more than or equal to 20 percent; the thickness of the intermediate temperature-waiting blank is more than or equal to 1.8h, wherein h is the thickness of a finished product and is unit mm; the initial rolling temperature of the finish rolling stage is 800-930 ℃, and the final rolling temperature is 790-850 ℃;
s4, cooling: controlling the cooling water inlet temperature to be 720-760 ℃; entering laminar cooling, wherein the cooling speed is 10-20 ℃/s, and the temperature of red return is 420-620 ℃;
s5, tempering: tempering at 400-520 ℃, keeping the temperature for 14-50 min, wherein the keeping time is in direct proportion to the thickness of the finished product, and then air-cooling to room temperature.
The chemical composition, process parameters and properties of each example are shown in tables 1, 2 and 3:
TABLE 1 chemical composition in weight percent (wt%) of examples 1-5
| Examples | C | Si | Mn | P | S | Nb | Ti | Alt | Cu | Cr | Ni | Mo | CEV | Pcm |
| 1 | 0.05 | 0.19 | 1.43 | 0.012 | 0.002 | 0.038 | 0.012 | 0.031 | 0.11 | 0.29 | 0.26 | 0.16 | 0.40 | 0.16 |
| 2 | 0.05 | 0.23 | 1.46 | 0.010 | 0.002 | 0.041 | 0.012 | 0.030 | 0.14 | 0.31 | 0.24 | 0.16 | 0.41 | 0.17 |
| 3 | 0.06 | 0.20 | 1.42 | 0.013 | 0.003 | 0.042 | 0.014 | 0.033 | 0.12 | 0.35 | 0.23 | 0.15 | 0.42 | 0.18 |
| 4 | 0.06 | 0.24 | 1.41 | 0.011 | 0.002 | 0.041 | 0.017 | 0.031 | 0.16 | 0.31 | 0.27 | 0.17 | 0.42 | 0.18 |
| 5 | 0.05 | 0.22 | 1.48 | 0.011 | 0.002 | 0.045 | 0.015 | 0.032 | 0.12 | 0.32 | 0.22 | 0.18 | 0.42 | 0.17 |
TABLE 2 specific Process parameters for examples 1-5
TABLE 3 Properties of examples 1-5
As shown in FIG. 1, the microstructure type of the steel plate is a "bainite + ferrite" structure. Therefore, the Q500qE bridge steel plate produced by the invention has excellent transverse and longitudinal tensile and impact properties, the yield strength is more than 500MPa, the tensile strength is more than 630MPa, the yield ratio is less than or equal to 0.86, and the elongation is more than or equal to 18 percent; the impact energy is more than 120J at minus 40 ℃ and the section rate of the impact fiber is more than or equal to 80 percent.
In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention.
Claims (7)
1. A low-yield-ratio high-toughness Q500qE bridge steel is characterized in that: the chemical components by mass percent are as follows: c: 0.04 to 0.07 percent of Si: 0.15-0.25%, Mn: 1.40-1.55%, P is less than or equal to 0.015%, S is less than or equal to 0.005%, Nb: 0.03-0.05%, Ti: 0.008% -0.02%, Alt: 0.020% -0.040%, Cu: 0.10% -0.20%, Ni: 0.20-0.30%, Cr: 0.25% -0.40%, Mo: 0.10% -0.20%, carbon equivalent CEV: 0.38% -0.45%, weld crack susceptibility Pcm: 0.15 to 0.23 percent, and the balance of Fe and a small amount of inevitable impurities;
carbon equivalent CEV calculation formula: CEV (%) = C + Mn/6+ (Cr + Mo + V)/5+ (Ni + Cu)/15;
the formula for calculating the welding crack sensitivity coefficient Pcm is as follows: pcm = C + Si/30+ Mn/20+ Cu/20+ Ni/60+ Cr/20+ Mo/15+ V/10+ 5B.
2. The low yield ratio, high toughness Q500qE bridge steel according to claim 1, wherein: the chemical components by mass percent are as follows: c: 0.04-0.06%, Si: 0.15-0.20%, Mn: 1.40-1.48%, P is less than or equal to 0.014%, S is less than or equal to 0.003%, Nb: 0.030-0.040%, Ti: 0.008% -0.018%, Alt: 0.020% -0.035%, Cu: 0.10% -0.18%, Ni: 0.20-0.28%, Cr: 0.25% -0.35%, Mo: 0.10% -0.18%, carbon equivalent CEV: 0.38% -0.44%, weld crack susceptibility Pcm: 0.15 to 0.21 percent, and the balance of Fe and a small amount of inevitable impurities.
3. The low yield ratio, high toughness Q500qE bridge steel according to claim 1, wherein: the chemical components by mass percent are as follows: : c: 0.045% -0.065%, Si: 0.18-0.23%, Mn: 1.41-1.52 percent, P is less than or equal to 0.013 percent, S is less than or equal to 0.003 percent, Nb: 0.035 to 0.045 percent, Ti: 0.009% -0.019%, Alt: 0.022% -0.038%, Cu: 0.11-0.20%, Ni: 0.21-0.29%, Cr: 0.28% -0.38%, Mo: 0.11% -0.19%, carbon equivalent CEV: 0.39% -0.44%, weld crack susceptibility Pcm: 0.16 to 0.22 percent, and the balance of Fe and a small amount of inevitable impurities.
4. The low yield ratio, high toughness Q500qE bridge steel according to claim 1, wherein: the chemical components by mass percent are as follows: c: 0.05 to 0.07 percent, Si: 0.20-0.25%, Mn: 1.41-1.55 percent of Nb, P is less than or equal to 0.013 percent, S is less than or equal to 0.003 percent, and Nb: 0.038% -0.050%, Ti: 0.010% -0.020%, Alt: 0.025 to 0.040%, Cu: 0.11-0.20%, Ni: 0.22-0.30%, Cr: 0.30% -0.40%, Mo: 0.12% -0.20%, carbon equivalent CEV: 0.40% -0.45%, weld crack susceptibility Pcm: 0.16 to 0.23 percent, and the balance of Fe and a small amount of inevitable impurities.
5. A production method of low-yield-ratio high-toughness Q500qE bridge steel is characterized by comprising the following steps: the method is applied to any one of claims 1 to 4, and comprises smelting, continuous casting, heating, rolling, cooling and tempering, and specifically comprises the following steps:
s1, smelting according to chemical components and casting to obtain a blank;
s2, heating: sending the continuous casting slab to a heating furnace, wherein the heating temperature is 1180-1220 ℃, the soaking time is not less than 36min, and the total heating time is not less than 220 min;
s3, rolling: a two-stage rolling method is adopted, high-temperature high-reduction is adopted for rough rolling, and the pass reduction rate of last 2 continuous passes is more than or equal to 20 percent; the thickness of the intermediate temperature-waiting blank is more than or equal to 1.8h, wherein h is the thickness of a finished product and is unit mm; the initial rolling temperature of the finish rolling stage is 800-930 ℃, and the final rolling temperature is 790-850 ℃;
s4, cooling: controlling the cooling water inlet temperature to be 720-760 ℃; entering laminar cooling, wherein the cooling speed is 10-20 ℃/s, and the temperature of red return is 420-620 ℃;
s5, tempering: tempering at 400-520 ℃, keeping the temperature for 14-50 min, wherein the keeping time is in direct proportion to the thickness of the finished product, and then air-cooling to room temperature.
6. The production method of the low-yield-ratio high-toughness Q500qE bridge steel according to claim 5, wherein the production method comprises the following steps: the thickness specification of the steel plate is 10-60 mm.
7. The production method of the low-yield-ratio high-toughness Q500qE bridge steel according to claim 5, wherein the production method comprises the following steps: the metallographic structure of the steel plate mainly comprises bainite and ferrite.
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| PCT/CN2022/087569 WO2023071079A1 (en) | 2021-10-29 | 2022-04-19 | Low-yield-ratio high-toughness q500qe bridge steel and production method thereof |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114836693A (en) * | 2022-05-20 | 2022-08-02 | 首钢京唐钢铁联合有限责任公司 | 460 MPa-grade high-performance steel for bridge U rib and production method thereof |
| CN115094340A (en) * | 2022-07-28 | 2022-09-23 | 湖南华菱湘潭钢铁有限公司 | Production method of Q500GJ steel plate with low yield strength and toughness ratio |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103352167A (en) * | 2013-07-15 | 2013-10-16 | 南京钢铁股份有限公司 | Low-yield ratio and high-strength steel for bridges and manufacturing method thereof |
| CN104195429A (en) * | 2014-05-30 | 2014-12-10 | 秦皇岛首秦金属材料有限公司 | Low-yield-ratio low-cracking-sensitivity Q550CF quenched and tempered steel and producing method |
| CN104988429A (en) * | 2015-07-13 | 2015-10-21 | 武汉钢铁(集团)公司 | Structure steel plate for bridge with yield strength being 690MPa and production method thereof |
| CN110423938A (en) * | 2019-07-24 | 2019-11-08 | 舞阳钢铁有限责任公司 | TMCP type surrenders 500MPa level structure steel plate and its production method |
| CN111979481A (en) * | 2020-07-23 | 2020-11-24 | 张家港宏昌钢板有限公司 | Thin-gauge low-yield-ratio high-strength bridge steel and production method thereof |
| CN112831717A (en) * | 2020-12-03 | 2021-05-25 | 南京钢铁股份有限公司 | 690 MPa-grade low-yield-ratio thin-specification weather-resistant bridge steel and manufacturing method thereof |
| CN113186454A (en) * | 2021-03-30 | 2021-07-30 | 湖南华菱湘潭钢铁有限公司 | Production method of tempered low-yield-ratio bridge steel |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3584742B2 (en) * | 1998-08-05 | 2004-11-04 | 住友金属工業株式会社 | High strength thick steel plate excellent in weldability and toughness and method for producing the same |
| CN105063509B (en) * | 2015-07-27 | 2017-12-08 | 武汉钢铁(集团)公司 | Yield strength 500MPa levels structural steel for bridge and its production method |
| CN105018856B (en) * | 2015-08-14 | 2017-03-01 | 武汉钢铁(集团)公司 | The vertically and horizontally little structural steel for bridge plate of mechanical property difference and its manufacture method |
| CN105779883A (en) * | 2016-05-06 | 2016-07-20 | 舞阳钢铁有限责任公司 | 485MPa level TMCP+ tempering weather-proof bridge steel plate and production method |
| CN108624744B (en) * | 2018-05-11 | 2020-02-18 | 鞍钢股份有限公司 | Q500qE bridge steel plate and production method thereof |
| CN111118401A (en) * | 2020-02-28 | 2020-05-08 | 五矿营口中板有限责任公司 | High-performance large-thickness easy-to-weld bridge structural steel and manufacturing method thereof |
| CN114182165A (en) * | 2021-10-29 | 2022-03-15 | 南京钢铁股份有限公司 | Low-yield-ratio high-toughness Q500qE bridge steel and production method thereof |
-
2021
- 2021-10-29 CN CN202111270439.2A patent/CN114182165A/en active Pending
-
2022
- 2022-04-19 WO PCT/CN2022/087569 patent/WO2023071079A1/en unknown
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103352167A (en) * | 2013-07-15 | 2013-10-16 | 南京钢铁股份有限公司 | Low-yield ratio and high-strength steel for bridges and manufacturing method thereof |
| CN104195429A (en) * | 2014-05-30 | 2014-12-10 | 秦皇岛首秦金属材料有限公司 | Low-yield-ratio low-cracking-sensitivity Q550CF quenched and tempered steel and producing method |
| CN104988429A (en) * | 2015-07-13 | 2015-10-21 | 武汉钢铁(集团)公司 | Structure steel plate for bridge with yield strength being 690MPa and production method thereof |
| CN110423938A (en) * | 2019-07-24 | 2019-11-08 | 舞阳钢铁有限责任公司 | TMCP type surrenders 500MPa level structure steel plate and its production method |
| CN111979481A (en) * | 2020-07-23 | 2020-11-24 | 张家港宏昌钢板有限公司 | Thin-gauge low-yield-ratio high-strength bridge steel and production method thereof |
| CN112831717A (en) * | 2020-12-03 | 2021-05-25 | 南京钢铁股份有限公司 | 690 MPa-grade low-yield-ratio thin-specification weather-resistant bridge steel and manufacturing method thereof |
| CN113186454A (en) * | 2021-03-30 | 2021-07-30 | 湖南华菱湘潭钢铁有限公司 | Production method of tempered low-yield-ratio bridge steel |
Non-Patent Citations (3)
| Title |
|---|
| 于峰: "抗大变形管线钢X80轧制工艺研究" * |
| 唐子金: "X80钢级Φ1 219 mm×26.4 mm大变形直缝埋弧焊管的开发" * |
| 李新宇: "在线淬火（DQ）状态Q690D钢板屈强比的研究及应用" * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023071079A1 (en) * | 2021-10-29 | 2023-05-04 | 南京钢铁股份有限公司 | Low-yield-ratio high-toughness q500qe bridge steel and production method thereof |
| CN114836693A (en) * | 2022-05-20 | 2022-08-02 | 首钢京唐钢铁联合有限责任公司 | 460 MPa-grade high-performance steel for bridge U rib and production method thereof |
| WO2024000669A1 (en) * | 2022-06-30 | 2024-01-04 | 南京钢铁股份有限公司 | Single-billet, multi-grade production method for series of high-grade grade e steels for weather-resistant bridges |
| CN115094340A (en) * | 2022-07-28 | 2022-09-23 | 湖南华菱湘潭钢铁有限公司 | Production method of Q500GJ steel plate with low yield strength and toughness ratio |
| CN115287537A (en) * | 2022-07-29 | 2022-11-04 | 南京钢铁股份有限公司 | 500 MPa-grade stainless steel composite plate with low yield ratio and preparation method thereof |
| CN115807192A (en) * | 2022-12-12 | 2023-03-17 | 湖南华菱湘潭钢铁有限公司 | Low-carbon 420 MPa-level TMCP structural steel and production method thereof |
| CN116716538A (en) * | 2023-04-26 | 2023-09-08 | 南京钢铁股份有限公司 | High-strength bridge steel and manufacturing method thereof |
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