CN109402508B - Low-carbon microalloyed Q690-grade high-strength weathering steel and preparation method thereof - Google Patents
Low-carbon microalloyed Q690-grade high-strength weathering steel and preparation method thereof Download PDFInfo
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Abstract
The low-carbon microalloyed Q690-grade high-strength weathering steel comprises, by weight, 0.03-0.10% of C, 0.10-0.50% of Si, 1.20-2.00% of Mn, 0.002-0.010% of S, 0.003-0.015% of P, 0.01-0.05% of Al, 0.05-0.15% of V, 0.01-0.02% of N, 0.30-0.80% of Cr, 0.30-0.80% of Ni, 0.15-0.55% of Cu, 0.15-0.55% of Mo, and the balance of Fe, the yield strength is 700-798 MPa, the tensile strength is 795-950 MPa, and the elongation is 15.5-18.6%; the preparation method comprises the following steps: (1) smelting molten steel, casting and forging; (2) heating to 1100-1200 ℃, and preserving heat for solid solution; (3) carrying out rough rolling and finish rolling; then cooling to 400-520 ℃ with water; (4) and slowly cooling the heat preservation felt groove to room temperature. The steel grade rolling process is simple, does not need quenching and tempering treatment, is resistant to atmospheric corrosion, has good comprehensive properties of strength and toughness, and has good low-temperature impact property.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to low-carbon microalloyed Q690-grade high-strength weathering steel and a preparation method thereof.
Background
The weathering steel widely accepted in the market in recent years is mainly of 295MPa grade 09CuPTiRE, 345MPa grade 09CuPCrNi and 450MPa grade Q450NQR1, is widely applied to multiple fields of railways, buildings, bridges and the like, and can resist corrosion of industrial atmosphere, acid rain, ocean atmosphere and seawater. However, the strength of the weathering steel plate needs to be improved, and because the traditional high-strength steel has poor impact toughness, weldability and fatigue property and cannot resist corrosion of atmosphere and marine environment, the potential market demand prompts development of thin strip steel with high strength and good weathering resistance to replace low-strength thick strip steel to become a main research and development direction, and the concept of high-performance weathering steel is provided at home and abroad; the weathering steel is low-alloy structural steel with a rust protection layer and atmospheric corrosion resistance; compared with plain carbon steel, the weathering steel has better corrosion resistance in atmospheric environment, and compared with stainless steel, the weathering steel can greatly reduce the addition amount of alloy elements, and the total amount of the alloy elements such as P, Cu, Cr, V, Mo and the like only accounts for a few percent, thereby effectively reducing the cost of steel.
So far, various domestic applications have been made on high-strength and high-weather-resistance weathering steel and a method for manufacturing the same; the patent with application number 200710045329.X introduces a high corrosion-resistant high-strength weathering steel and a manufacturing method thereof, the method adopts the Cr-Ni-Cu series component design of ultra-low carbon, low manganese and medium chromium, utilizes Ti micro-alloying to produce the high-weather-resistance high-strength weathering steel with yield strength more than 700MPa and 72h period infiltration corrosion rate less than 25 percent (compared with Q345 plain carbon steel); however, the Cr content in the scheme is up to more than 4.50 percent, so that the alloy cost is high and the welding performance is poor; the patent of application No. 201010246778.2 introduces a low-cost yield strength 700MPa grade non-quenched and tempered high-strength weathering steel and a manufacturing method thereof, the method adopts high Ti component design to increase the strengthening effect; the patent of application number 201410236616.9 introduces a 700 MPa-grade industrial atmosphere corrosion resistant martensite steel plate and a preparation method thereof; the method adopts Nb-Ti series component design, so that the yield strength range of the prepared steel plate is 695-720 MPa, the tensile strength is more than or equal to 800MPa, the elongation is more than or equal to 18 percent, the low-temperature impact energy at minus 40 ℃ is more than 100J, and the annual corrosion loss of the industrial atmosphere resistance is less than 350g/m2。
The high-strength atmospheric corrosion resistant steel with the yield strength of 700MPa is based on low-carbon (or ultra-low-carbon) -silicon-manganese steel, and is added with a proper amount of alloying elements such as Cu, Ni, Cr and the like for a microalloying route, and the final product is obtained by combining Nb-Ti microalloying with TMCP process technology; however, the high-strength steel plate produced by adopting the Nb-Ti microalloy component system has the disadvantages of heavy load of hot rolling, high difficulty in controlling the hot rolling process, high yield ratio of steel and high alloy cost, and the production cost can be increased by the heat treatment process after the rolling of the strip steel.
Disclosure of Invention
Aiming at the problems of the existing weathering steel preparation technology, the invention provides low-carbon microalloyed Q690-grade high-strength weathering steel and a preparation method thereof, the V-N-Cr microalloying technology is utilized, the content of alloy components is reduced through component design, meanwhile, the nucleation of intragranular ferrite is promoted in the billet rolling process, the toughness of the core part of a plate is improved, and the Q690-grade high-strength weathering steel is prepared through grain refinement and precipitation strengthening.
The low-carbon microalloyed Q690-grade high-strength weathering steel comprises, by weight, 0.03-0.10% of C, 0.10-0.50% of Si, 1.20-2.00% of Mn, 0.002-0.010% of S, 0.003-0.015% of P, 0.01-0.05% of Al, 0.05-0.15% of V, 0.01-0.02% of N, 0.30-0.80% of Cr, 0.30-0.80% of Ni, 0.15-0.55% of Cu, 0.15-0.55% of Mo, and the balance Fe and other inevitable impurities; the yield strength is 700-798 MPa, the tensile strength is 795-950 MPa, the elongation is 15.5-18.6%, the impact energy at the temperature of minus 60 ℃ is more than or equal to 100J, and the yield ratio is 0.84-0.88.
The thickness of the low-carbon microalloyed Q690-grade high-strength weathering steel is 4-14 mm.
The structure of the low-carbon microalloyed Q690-grade high-strength weathering steel is polygonal ferrite, acicular ferrite and granular bainite.
The preparation method of the low-carbon microalloyed Q690-grade high-strength weathering steel comprises the following steps:
1. smelting molten steel according to set components, casting and forging to the thickness of 60-140 mm to obtain a steel billet, wherein the steel billet comprises, by weight, 0.03-0.10% of C, 0.10-0.50% of Si, 1.20-2.00% of Mn, 0.002-0.010% of S, 0.003-0.015% of P, 0.01-0.05% of Al, 0.05-0.15% of V, 0.01-0.02% of N, 0.30-0.80% of Cr0.30-0.80% of Ni, 0.15-0.55% of Cu, 0.15-0.55% of Mo, and the balance of Fe and other inevitable impurities;
2. heating the steel billet to 1100-1200 ℃ along with the heating furnace, and preserving heat for 2-4 h to ensure full austenitization of the steel billet and full solid solution of microalloy elements;
3. carrying out rough rolling and finish rolling on the heat-preserved steel billet; wherein the initial rolling temperature of rough rolling is 1050-1160 ℃, and the final rolling temperature is 960-1080 ℃; the start rolling temperature of finish rolling is 860-900 ℃, and the finish rolling temperature is 810-850 ℃; after finishing finish rolling, cooling the steel plate to 400-520 ℃ by water to obtain a hot rolled plate;
4. and (3) putting the hot rolled plate into a heat preservation felt groove, and slowly cooling to room temperature to prepare the low-carbon microalloyed Q690-grade high-strength weathering steel.
In the method, the rolling passes of rough rolling are 2-4 times, and the reduction rate of each pass is 24-28.6%.
In the method, the rolling pass of finish rolling is 6-7 times, and the reduction rate of each pass is 13-28%.
In the method, the cooling speed is controlled at 25-45 ℃/s during water cooling.
The weathering steel is required to have higher strength and atmospheric corrosion resistance, and simultaneously has good impact toughness and welding performance; the method adopts a mode of compositely adding alloy elements to obtain the best effect of the steel, obviously improves the atmospheric corrosion resistance of the steel by adding elements such as Cr, Mo and the like, and simultaneously improves the toughness of the steel by adding trace alloy elements; the principle of the invention is as follows:
c: c is the most economic and effective strengthening element in steel, the strength level of steel is directly influenced by the content of C, but the atmospheric corrosion resistance of the steel is damaged by excessively high C content, and the welding performance, the toughness, the stamping performance and the like of the steel are also influenced; therefore, the content range of the adopted C is 0.03-0.10%, and the strength is compensated by adding other alloy elements such as Si, Mn and the like;
si: si is beneficial to improving the strength, yield point and wear resistance of the steel, has higher solubility in alpha-Fe and gamma-Fe, plays a role in solid solution strengthening, can increase the volume fraction of ferrite in the steel, refines grains and is beneficial to improving the toughness; si can also improve the resistivity of the steel, form a Si-rich protective film on the surface of the steel, improve the corrosion resistance, and can improve the corrosion resistance of the steel by being matched with other elements such as Cu, Cr and P; the Si content range is 0.10-0.50%, and the toughness and plasticity of the weld metal are adversely affected when the Si content is lower than or higher than the range;
mn: mn is one of the most effective elements for compensating the strength of steel under the condition of reducing the content of C, and a proper amount of Mn is added into the steel, so that the hardenability of the steel can be increased, the effects of solid solution strengthening and grain refinement are achieved, the brittle transition temperature can be reduced while the strength is improved, the medium-temperature transition is facilitated, but the excessive increase of the content of Mn can deteriorate the weldability of steel and the toughness of a welding heat affected zone; the Mn content range is 1.20-2.00% to obtain the optimal acicular ferrite content and the optimal toughness matching;
s: the existence of S can deteriorate the atmospheric corrosion resistance of the steel, and the lower the S content is under the same condition, the better the corrosion resistance of the steel is; but Cu can obviously offset the harmful effect of S in steel, the higher the content of S is, the more obvious the effect of Cu on reducing corrosion rate is, and the combination of the S and the Cu can form a refractory compound to fill the pores of the rust layer and prevent further corrosion; therefore, the range of S content is controlled to be 0.002-0.01%;
p: p is one of the most effective alloy elements for improving the weather resistance of the steel, and Fe for promoting the rust layer of the weather-resistant steel to have amorphous property3O4Has special effect; however, high P content increases the cold brittleness of steel, and deteriorates welding performance and cold bending performance; under the condition of atmospheric corrosion, P in the steel is an anode depolarizer and can accelerate the uniform dissolution of the steel and Fe2+The oxidation rate of (A) contributes to the formation of a uniform FeOOH rust layer on the steel surface and promotes the formation of FeO rich in amorphous iron oxyhydroxideX(OH)3-2xSo as to become a protective barrier for the tissue corrosion medium to enter the steel matrix and prevent the interior of the steel from atmospheric corrosion, therebyThe content range of the adopted P is between 0.003 and 0.01 percent.
Al: the aluminum alloy mainly plays roles of nitrogen fixation and deoxidation, AlN formed by the joint of Al and N can effectively refine grains, but the toughness of steel can be damaged due to the excessively high Al content, so that the content of the aluminum alloy is controlled to be within the range of 0.01-0.05%;
cu: cu is a key element for improving the atmospheric corrosion resistance of steel, and shows excellent synergistic weather-resistant effect when being combined with P to be added into the steel, so that the atmospheric corrosion resistance of the steel is improved; the addition of the Cu with the face-centered cubic structure can improve the cold-brittleness transformation temperature of the steel, increase the Cu content and correspondingly increase the yield strength of the weathering steel; therefore, the Cu content is 0.15-0.55%;
v: compared with Nb, the micro-alloy continuous casting billet has low probability of cracking, strong affinity of V and N, easy combination, promotion of VN precipitation, conversion of V in steel from a solid solution state to a precipitation state, remarkable improvement of strength, and precipitation strengthening of 250-300 MPa; v is the most economical microalloying element, can convert the originally harmful N element into useful cheap alloy elements, and can effectively reduce the cost, so the content of V is 0.05-0.15%;
n: similar to the action of C element, the strength of steel can be improved by a mode of interstitial solid solution, but the N in a solid solution state has great harm to the plasticity and toughness of the steel, so the content range of the N is 0.01-0.02%;
ni: ni is a relatively stable element, and the addition of Ni can change the self-corrosion potential of the steel to the positive direction, increase the stability of the steel, improve the toughness and the hardenability while improving the strength, and can effectively prevent the network cracking phenomenon caused by the hot brittleness of Cu; however, too high Ni increases the cost and increases the adhesion of the scale, so that the N content is controlled to be in the range of 0.30 to 0.80%.
Cr: cr has an obvious effect on improving the passivation capability of steel, can promote the surface of the steel to form a compact passivation film or a protective rust layer, can effectively improve the selective permeability of the rust layer to corrosive media by enriching in the rust layer, and has an obvious effect when being added into the steel with Cu at the same time, wherein the Cr content in the weathering steel is generally 0.4-1.0 percent (the highest content is 1.3 percent); the increase of the Cr content can promote the yield strength of the steel to be slightly increased, but the strengthening effect is not as good as that of Cu, and the addition of Cr can improve the cold-brittleness transition temperature of the alloy, so the Cr content ranges from 0.30% to 0.80%.
Mo: the Mo element can improve the brittleness of the steel and reduce the toughness of the steel while increasing the strength; when the steel contains 0.4 to 0.5 percent of Mo, the atmospheric corrosion rate of the steel can be reduced by less than one half; preferably, when Mo is within the range of 0.1-0.25%, the steel has excellent strength and plasticity proportion; by combining various conditions, the content range of the adopted Mo is 0.15-0.55%.
Compared with the prior art, the invention has the advantages that:
(1) by utilizing a V-N-Cr microalloying technology, VN and V (C, N) nanometer-sized precipitates can promote the nucleation of ferrite in crystal during the billet rolling process, the strength and toughness of the core of the plate are improved, and Q690-grade high-strength weathering steel is produced by the refining effect of crystal grains and the precipitation strengthening principle; the weathering steel has low carbon content of 0.03-0.10 wt%, the carbon equivalent is reduced by low carbon design, the welding performance can be improved, the formation of coarse cementite in the steel plate structure is avoided by controlled rolling and controlled cooling, and the steel plate has good low-temperature impact toughness. For steel plates with different thickness specifications, the contents of Cr, Ni, V, Mo and other alloys are optimized and adjusted, the cost is saved, and the method has great significance for upgrading products of steel enterprises, saving energy and reducing consumption;
(2) the rolling operation process is simple, two-stage rolling is adopted, the rolled state is delivered, quenching and tempering treatment is not needed, the requirements on equipment and technology are not strict, the atmospheric corrosion resistance is realized, the comprehensive performance of toughness is good, the low-temperature impact performance is good, and the industrial production and popularization are easy to realize.
After 360-hour periodic infiltration corrosion experiment of simulating industrial atmospheric environment, the corrosion weight loss rate of the steel prepared by the method is slower than that of plain carbon steel Q345B, the difference is obvious in the initial stage of the corrosion period, and the relative corrosion rate of 72 hours with Q345B as a comparison sample is reduced by 50%.
The steel grade rolling has simple operation process, does not need quenching and tempering treatment, is resistant to atmospheric corrosion, has good comprehensive performance of obdurability and good low-temperature impact performance, is easy to realize industrial production, and can be used in the manufacturing industry of railway vehicles.
Drawings
FIG. 1 is a schematic flow chart of a preparation method of low-carbon microalloyed Q690-grade high-strength weathering steel of the invention;
FIG. 2 is an OM structure diagram of a low carbon microalloyed Q690 grade high strength weathering steel of example 1;
FIG. 3 is a transmission profile of a low-carbon microalloyed Q690 grade high strength weathering steel of example 2;
fig. 4 is a structure diagram of a low-carbon microalloyed Q690-grade high-strength weathering steel OM in example 3.
Detailed Description
The following non-limiting examples are presented to enable those of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.
The test methods described in the examples of the present invention are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
The hot rolling mill adopted by the embodiment of the invention is a phi 450mm hot rolling mill in the northeast university rolling technology and the continuous rolling automation national key laboratory.
In the embodiment of the invention, the heating furnace adopted during furnace cooling is a high-temperature box type resistance furnace with the model number of RX4-85-13B。
The transmission electron microscope used in the examples of the present invention is FEI Tecnai G2F20 field emission transmission electron microscope;
the scanning electron microscope used in the examples of the present invention was a LEICA-DMIRM optical electron microscope.
The atmospheric corrosion resistance test in the embodiment of the invention is a periodic infiltration corrosion test method of weathering resistant steel for railways according to the standard of the railway industry, TB/T2375-93.
The standard of the welding crack sensitivity index in the embodiment of the invention is GB/T1591-2008.
Example 1
The flow is shown in figure 1;
smelting molten steel according to set components, casting and forging the molten steel to the thickness of 140mm to obtain a steel billet, wherein the steel billet comprises 0.03% of C, 0.50% of Si, 2.00% of Mn, 0.002% of S, 0.010% of P, 0.04% of Al, 0.15% of V, 0.02% of N, 0.80% of Cr, 0.80% of Ni, 0.45% of Cu, 0.55% of Mo and the balance of Fe and other inevitable impurities by weight percentage;
heating the steel billet to 1200 ℃ along with the furnace by adopting a heating furnace and preserving heat for 2 hours to ensure that the steel billet is fully austenitized and microalloy elements are fully dissolved in solution;
carrying out rough rolling and finish rolling on the heat-preserved steel billet; wherein the initial rolling temperature of rough rolling is 1160 ℃, and the final rolling temperature is 1080 ℃; the rolling passes of rough rolling are 2, the reduction rate of each pass is 24 percent and 28.6 percent respectively, and the thickness of the rough rolling plate is 76 mm; the start rolling temperature of finish rolling is 900 ℃, and the finish rolling temperature of finish rolling is 850 ℃; the rolling pass of finish rolling is 6, the reduction rate of each pass is 13-28%, and the total reduction rate is 81%; after finishing the finish rolling, cooling the steel plate to 520 ℃ (the temperature of returning red), and controlling the average cooling speed to be 25 ℃/s during water cooling to obtain a hot rolled plate with the thickness of 14 mm;
putting the hot rolled plate into a heat preservation felt groove, and slowly cooling to room temperature to prepare low-carbon microalloyed Q690-grade high-strength weathering steel;
the yield strength of the low-carbon microalloyed Q690-grade high-strength weathering steel is 700MPa, the tensile strength is 795MPa, the elongation is 18.6 percent, the impact energy is 188J at the temperature of minus 60 ℃, and the yield ratio is 0.88; the structure is polygonal ferrite, acicular ferrite and granular bainite, and the OM structure is shown in figure 2; the weld crack sensitivity index Pcm is 0.27%;
carrying out an atmospheric corrosion resistance test, taking common carbon steel Q345B as a comparison, selecting 3 samples of each steel type to carry out a parallel test, calculating the corrosion weight loss of each sample in unit area and unit time, and calculating the average value to obtain the average corrosion rate; comparing the average corrosion rate of the weathering steel with that of Q345B to obtain the relative corrosion rate; the average corrosion weight loss ratio of the weathering steel is 2.896 g/(m)2H), the average corrosion weight loss ratio of the Q345B plain carbon steel is 6.102 g/(m)2H) relative corrosion rate of 47.5%, indicating that the above weathering steel is largeThe strength is greatly improved, and the corrosion resistance is obvious, and is about twice of that of the Q345B plain carbon steel.
Example 2
The method is the same as example 1, except that:
(1) the thickness of the steel billet is 90mm, and the components comprise 0.06 percent of C, 0.40 percent of Si, 1.60 percent of Mn, 0.005 percent of S, 0.015 percent of P, 0.05 percent of Al, 0.11 percent of V, 0.015 percent of N, 0.60 percent of Cr, 0.50 percent of Ni, 0.55 percent of Cu and 0.35 percent of Mo according to weight percentage;
(2) heating to 1150 ℃ along with the furnace and preserving heat for 3 hours;
(3) the initial rolling temperature of rough rolling is 1080 ℃, and the final rolling temperature is 980 ℃; the rolling passes of rough rolling are 3, the reduction rate of each pass is 25%, 26% and 27%, and the thickness of the rough rolling plate is 36.5 mm; the start rolling temperature of finish rolling is 900 ℃, and the finish rolling temperature is 810 ℃; the rolling pass of finish rolling is 6, the reduction rate of each pass is 13-28%, and the total reduction rate is 78%; after finishing the finish rolling, cooling the steel plate to 460 ℃, controlling the average cooling speed to be 36 ℃/s during water cooling, and controlling the thickness of the hot rolled plate to be 8 mm;
(4) the yield strength of the low-carbon microalloyed Q690-grade high-strength weathering steel is 769MPa, the tensile strength is 910MPa, the elongation is 16.2 percent, the impact energy is 161J at minus 60 ℃, and the yield ratio is 0.85; the transmission profile is shown in FIG. 3; the weld crack sensitivity index Pcm is 0.25%;
(5) the test result of the atmospheric corrosion resistance is as follows: the average corrosion weight loss ratio of the weathering steel is 2.655 g/(m)2H) the relative corrosion rate was 43.5%.
Example 3
The method is the same as example 1, except that:
(1) the thickness of the steel billet is 60mm, and the components comprise 0.10 percent of C, 0.10 percent of Si, 1.20 percent of Mn, 0.010 percent of S, 0.003 percent of P, 0.01 percent of Al, 0.05 percent of V, 0.01 percent of N, 0.30 percent of Cr, 0.30 percent of Ni, 0.15 percent of Cu and 0.15 percent of Mo according to weight percentage;
(2) heating to 1100 ℃ along with the furnace and preserving heat for 4 hours;
(3) the initial rolling temperature of rough rolling is 1050 to DEG C, and the final rolling temperature is 960 ℃; the rolling passes of rough rolling are 4 times, the reduction rate of each pass is 28%, 25% and 25%, and the thickness of the rough rolling plate is 18 mm; (ii) a The initial rolling temperature of finish rolling is 860 ℃, and the finish rolling temperature of finish rolling is 810 ℃; the rolling passes of finish rolling are 7, the reduction rate of each pass is 13-28%, and the total reduction rate is 78%; after finishing the finish rolling, cooling the steel plate to 400 ℃ by water, controlling the average cooling speed to be 45 ℃/s during water cooling, and controlling the thickness of the hot rolled plate to be 4 mm;
(4) the yield strength of the low-carbon microalloyed Q690-grade high-strength weathering steel is 798MPa, the tensile strength is 950MPa, the elongation is 15.5 percent, the impact energy is 100J at the temperature of minus 60 ℃, and the yield ratio is 0.84; OM organization as shown in fig. 4; the weld crack sensitivity index Pcm is 0.21%;
(5) the test result of the atmospheric corrosion resistance is as follows: the average corrosion weight loss ratio of the weathering steel is 2.504 g/(m)2H) the relative corrosion rate was 41.0%.
Claims (2)
1. A preparation method of low-carbon microalloyed Q690-grade high-strength weathering steel is characterized by comprising the following steps:
(1) smelting molten steel according to set components, casting and forging to the thickness of 60-140 mm to obtain a steel billet, wherein the steel billet comprises, by weight, 0.03-0.10% of C, 0.10-0.50% of Si, 1.20-2.00% of Mn, 0.002-0.010% of S, 0.003-0.015% of P, 0.01-0.05% of Al, 0.05-0.15% of V, 0.01-0.02% of N, 0.30-0.80% of Cr, 0.30-0.80% of Ni, 0.15-0.55% of Cu, 0.15-0.55% of Mo, and the balance of Fe and other inevitable impurities;
(2) heating the steel billet to 1100-1200 ℃ along with the heating furnace, and preserving heat for 2-4 h to ensure full austenitization of the steel billet and full solid solution of microalloy elements;
(3) carrying out rough rolling and finish rolling on the heat-preserved steel billet; wherein the initial rolling temperature of rough rolling is 1050-1160 ℃, and the final rolling temperature is 960-1080 ℃; the start rolling temperature of finish rolling is 860-900 ℃, and the finish rolling temperature is 810-850 ℃; after finishing finish rolling, cooling the steel plate to 400-520 ℃ by water to obtain a hot rolled plate; the rolling passes of rough rolling are 2-4 times, and the reduction rate of each pass is 24-28.6%; the rolling pass of finish rolling is 6-7 times, and the reduction rate of each pass is 13-28%;
(4) and (3) putting the hot rolled plate into a heat-insulating felt groove, slowly cooling to room temperature, and preparing the low-carbon microalloyed Q690-grade high-strength weathering steel, wherein the yield strength is 700-798 MPa, the tensile strength is 795-950 MPa, the elongation is 15.5-18.6%, the impact energy at the temperature of minus 60 ℃ is more than or equal to 100J, and the yield ratio is 0.84-0.88.
2. The preparation method of the low-carbon microalloyed Q690-grade high-strength weathering steel as claimed in claim 1, characterized in that the cooling speed is controlled to be 25-45 ℃/s during water cooling in the step (3).
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101892431A (en) * | 2010-07-07 | 2010-11-24 | 江苏省沙钢钢铁研究院有限公司 | Hot-rolled weather-proof bridge steel with yield strength of 500MPa and manufacturing method thereof |
| CN102534417A (en) * | 2012-02-08 | 2012-07-04 | 东北大学 | High-performance bridge weathering steel containing Mo and preparation method thereof |
| JP2015516505A (en) * | 2012-03-14 | 2015-06-11 | バオシャン アイアン アンド スティール カンパニー リミテッド | Manufacturing method of 700MPa class high strength weathering steel by continuous strip casting method |
| CN106947913A (en) * | 2017-03-21 | 2017-07-14 | 马钢(集团)控股有限公司 | A kind of high-strength high-toughness hot rolls weather-resistant steel plate and preparation method thereof |
| CN108193141A (en) * | 2017-12-29 | 2018-06-22 | 东北大学 | A kind of Q550 rank hot-strips of V-N-Cr microalloyings and preparation method thereof |
-
2018
- 2018-11-12 CN CN201811338543.9A patent/CN109402508B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101892431A (en) * | 2010-07-07 | 2010-11-24 | 江苏省沙钢钢铁研究院有限公司 | Hot-rolled weather-proof bridge steel with yield strength of 500MPa and manufacturing method thereof |
| CN102534417A (en) * | 2012-02-08 | 2012-07-04 | 东北大学 | High-performance bridge weathering steel containing Mo and preparation method thereof |
| JP2015516505A (en) * | 2012-03-14 | 2015-06-11 | バオシャン アイアン アンド スティール カンパニー リミテッド | Manufacturing method of 700MPa class high strength weathering steel by continuous strip casting method |
| CN106947913A (en) * | 2017-03-21 | 2017-07-14 | 马钢(集团)控股有限公司 | A kind of high-strength high-toughness hot rolls weather-resistant steel plate and preparation method thereof |
| CN108193141A (en) * | 2017-12-29 | 2018-06-22 | 东北大学 | A kind of Q550 rank hot-strips of V-N-Cr microalloyings and preparation method thereof |
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