CN115948697B - 500 MPa-level weather-resistant coating-free hot rolled rod wire and rolling process thereof - Google Patents
500 MPa-level weather-resistant coating-free hot rolled rod wire and rolling process thereof Download PDFInfo
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- 238000001816 cooling Methods 0.000 claims abstract description 28
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 15
- 229910052802 copper Inorganic materials 0.000 claims abstract description 12
- 239000000126 substance Substances 0.000 claims abstract description 12
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 12
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 11
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 9
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 5
- 229910000831 Steel Inorganic materials 0.000 claims description 52
- 238000010438 heat treatment Methods 0.000 claims description 52
- 239000010959 steel Substances 0.000 claims description 52
- 238000000034 method Methods 0.000 claims description 18
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- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 8
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- 229910001563 bainite Inorganic materials 0.000 description 4
- 238000005728 strengthening Methods 0.000 description 4
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Abstract
The invention discloses a 500 MPa-level weather-proof coating-free hot rolled rod wire and a rolling process thereof, wherein the chemical components of the hot rolled rod wire are ：C：＜0.14wt％、Si：0.3～0.6wt％、Mn：0.5～0.75wt％、P＜0.03wt％、S＜0.02wt％、Cu：0.1～1.0wt％、Cr：1.0～4.5wt％、Cr/Cu＝5～11, and the balance of Fe and unavoidable impurities in percentage by weight; and can be added with Nb by microalloying according to the actual capacity of the production line: 0.015 to 0.035wt percent, V:0.04 to 0.07wt%, nb/v=1/3 to 2/3; the invention can meet the requirements of cold working, coating-free plating and bare wire for more than 25 years, adopts a brand new super weather-proof component system aiming at the deep processing requirement of the industrial rod and wire for drawing, and forms a microstructure favorable for cold working on the basis of meeting weather resistance by matching with a rolling control and cooling control technical scheme.
Description
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to a weather-proof coating-free hot rolled rod and wire and a rolling process thereof.
Background
Industrial wires and bars are numerous (such as spring steel, bridge cable steel, cord steel, cold heading steel, free cutting steel, bearing steel and the like), and in order to meet the requirements of different service performances, hot rolled wires and bars often need to be processed by a plurality of working procedures (such as cold drawing, cold heading, tempering, weaving, stranding and the like), so that the requirements on tissues and performances are strict.
Currently, the upgrading and upgrading of industrial lines and bars mainly focuses on the improvement of intensity levels (for example, cord steel is developed from 70 levels to 80 levels and 90 levels, bridge steel is developed from 1860MPa to 1960MPa, 2000MPa and 2100 MPa), and the attention to weather resistance capable of prolonging service life is less, which mainly has two reasons:
(1) The steel mainly depends on the addition of weather-resistant elements (such as Cu, cr, ni, P and the like) to improve the weather resistance, and the weather-resistant elements can obviously increase the hardenability of the steel, so that abnormal structures such as bainite, martensite and the like appear in the steel, and compared with the existing industrial wire and bar microstructures mainly comprising ferrite and pearlite, the structures such as bainite, martensite and the like are not beneficial to deep processing such as drawing, cold heading and the like, so that the addition of elements such as Cu, cr, ni, P and the like is often strictly limited in the steel in order to ensure the service performance of the industrial wire and bar.
(2) In some wire and bar products with weather resistance requirements on final products, means such as galvanization, copper plating and the like are often adopted to realize high weather resistance of the final products, such as: galvanized steel stranded wires, copper plated steel cords and the like, which can effectively avoid the influence of weather-resistant alloy elements on steel performance, but the plating process has large pollution and high energy consumption and processing cost.
Weather resistant steel with coating free and long service life is becoming a development hot spot of current green steel products; at present, most of weather-resistant steel produced at home and abroad is plate material, and because of the completely different deep processing flow and application scene of wire rod and plate material, hot rolled wire rods and round steel for weather-resistant steel structures with multiple continuous rolling passes, high requirement on organization performance and large cold processing deformation are reported in China.
CN108396238 discloses a 1860MPa grade corrosion-resistant steel wire rod and a production method thereof, wherein the chemical components are C0.80-0.85%, si 0.15-0.35%, mn 0.60-0.70%, P is less than or equal to 0.025%, S is less than or equal to 0.015%, cr 0.35-0.40%, cu 0.21-0.27%, ca (40-80) multiplied by 10-4%, and the continuous casting superheat degree is not more than 30 ℃, and the crystallizer is subjected to electromagnetic stirring; continuously rolling into square billets with the diameter of 100-200 mm; the temperature difference of the pass strip during rolling is less than or equal to 30 ℃; controlling the initial rolling temperature, the finish rolling inlet temperature, the reducing sizing inlet temperature and the spinning temperature; cooling by a stelmor air cooling line by a cooling speed control method of strong cooling and weak cooling, and naturally cooling after cooling to 500 ℃. The phi (8-13) mm wire rod produced by the invention has the tensile strength of 1150-1250 MPa, the elongation of 10-16% and the surface shrinkage of 18-32%, and the corrosion speed is lower than 70% of the corrosion speed of the wire rod for YL82B steel strand under the condition of full immersion corrosion of 5% NaCl solution at the temperature of 23 ℃ and 15 d. Although the patent is a wire rod product, the weather resistance of the wire rod product cannot meet the long-term bare and maintenance-free requirements due to the high carbon content and the low Cr content.
XG835NH steel wire rods developed by North Korea and Xing Gang are used for producing 10.9 MPa-level atmospheric corrosion resistant bolts, the steel is medium carbon alloy steel, mn, mo, cr, si and other alloy elements are added in the steel, the alloy elements increase the incubation period of austenite transformation, and the supercooled austenite stability of the material is improved, but the wire rods are cooled too fast after rolling, martensite structures are easy to appear, the strength of the martensite structures is high, the hardness is high, and the drawing and cold heading deep processing of the wire rods are not facilitated.
Currently, industrial rod and wire materials mainly obtain weather resistance through a galvanization process such as galvanization, which has two main problems: the hot galvanizing process has large pollution and high cost; the weather-resistant layer on the surface of the second coating product is often thinner, and is easy to damage in the process of transportation, installation and use, so that the corrosion-resistant effect cannot be achieved; in addition, the current weathering steel is fully developed in the plates, but for industrial rod wires which need cold drawing and large deformation, the weathering steel is slow to develop due to the obvious difference between the processing flow and the application scene of the weathering steel and the plates.
Disclosure of Invention
The invention aims to provide a 500 MPa-level weather-proof coating-free hot rolled rod wire and a rolling process thereof, which can meet the requirements of cold working, coating-free coating and bare wire for more than 25 years, and adopts a brand new super weather-proof component system to form a microstructure which is beneficial to cold working on the basis of meeting weather resistance by matching with a rolling control and cooling control technical scheme aiming at the deep processing requirements of the industrial rod wire for drawing.
In order to achieve the above purpose, the following technical scheme is adopted:
a500 MPa-level weather-proof coating-free hot rolled rod wire comprises the following chemical components in percentage by mass:
C: < 0.14wt%, si:0.3 to 0.6 weight percent of Mn:0.5 to 0.75 weight percent, P is less than 0.03 weight percent, S is less than 0.02 weight percent, cu:0.1 to 1.0 weight percent of Cr:1.0 to 4.5wt%, cr/Cu=5 to 11, and the balance of Fe and unavoidable impurities.
According to the scheme, the chemical components comprise the following components in percentage by mass:
c: < 0.14wt%, si:0.4 to 0.5 weight percent of Mn:0.6 to 0.7 weight percent, P is less than 0.03 weight percent, S is less than 0.02 weight percent, cu:0.3 to 0.7 weight percent of Cr:2 to 3.5wt%, cr/Cu=7 to 9, and the balance being Fe and unavoidable impurities.
According to the scheme, the micro-alloying is carried out, and the chemical components further comprise Nb in mass percent: 0.015 to 0.035wt percent, V:0.04 to 0.07wt% Nb/v=1/3 to 2/3.
The 500 MPa-level weather-proof coating-free hot rolled rod and wire rolling process comprises the following steps of:
Heating a steel billet; comprises a preheating section, a heating section and a soaking section;
rolling; adopting low-temperature controlled rolling, wherein the whole process adopts austenite unrecrystallized rolling;
Cooling control is performed; cooling the wire rod by adopting a Steyr process control; the cooling bed on the bar is slowly cooled by a heat-preserving cover.
According to the scheme, in the billet heating process, the billet is a small square billet or a rectangular billet, and the section (140-220 mm) is x (140-220 mm); heating temperature in the preheating section is less than or equal to 600 ℃ and heating time is 10-15 min; the heating section is divided into a heating section 1 and a heating section 2, wherein the heating temperature of the heating section 1 is 600-1000 ℃, the heating time is 10-15 min, the heating temperature of the heating section 2 is 1000-1200 ℃, and the heating time is 40-50 min; the heating temperature of the soaking section is 1100-1200 ℃ and the heating time is 10-20 min.
According to the scheme, the finish rolling temperature in the rolling process is 850+/-10 ℃, the reduced sizing temperature is 840+/-10 ℃, and the finish rolling temperature is 830+/-10 ℃.
According to the scheme, in the controlled cooling process, the wire is cooled by adopting a Steyr process, the speed of a 0# roller way is 0.2-1 m/s, and the speed of the rest 8 groups of roller ways is improved by 3% relative to that of the former group of roller ways (extremely bad); the air quantity of the 13 groups of fans is 210000m 3/h, the 1# fan to the 2# fan is opened by 5% -25%, the heat preservation cover is opened, the temperature of the outlet 2# fan is 650+/-20 ℃, the 3# fan to the 13# fan is fully closed, and the heat preservation cover is closed, so that the temperature of the outlet 13# fan is more than 300 ℃.
According to the scheme, in the controlled cooling process, the temperature of a cooling bed on the bar is more than 600 ℃, a heat preservation cover is adopted for slow cooling, and the temperature of a heat preservation cover is more than 330 ℃.
Compared with the prior art, the invention has the following beneficial effects:
The invention develops a 500 MPa-level weather-proof coating-free hot rolled rod wire and a rolling process thereof, can meet the requirements of cold working, coating-free and bare steel for more than 25 years, thoroughly changes the steel condition of the traditional zinc-plated rod wire product, realizes the simplification of downstream processing flow (coating-free) and maintenance-free of an application end, reduces the total flow cost of downstream users, has good market application prospect, and is hopeful to completely replace the traditional coating-plated product.
Drawings
Fig. 1: example 1 microstructure in hot rolled state: ferrite + pearlite, 200X.
Fig. 2: example 1 microstructure in hot rolled state: ferrite + pearlite, 500X.
Detailed Description
The following examples further illustrate the technical aspects of the present invention, but are not intended to limit the scope of the present invention.
The specific embodiment provides a 500 MPa-level weather-proof coating-free hot rolled rod wire, which comprises the following chemical components in percentage by mass:
C: < 0.14wt%, si:0.3 to 0.6 weight percent of Mn:0.5 to 0.75 weight percent, P is less than 0.03 weight percent, S is less than 0.02 weight percent, cu:0.1 to 1.0 weight percent of Cr:1.0 to 4.5wt%, cr/Cu=5 to 11, and the balance of Fe and unavoidable impurities.
In an optimized scheme, the chemical components comprise the following components in percentage by mass:
c: < 0.14wt%, si:0.4 to 0.5 weight percent of Mn:0.6 to 0.7 weight percent, P is less than 0.03 weight percent, S is less than 0.02 weight percent, cu:0.3 to 0.7 weight percent of Cr:2 to 3.5wt%, cr/Cu=7 to 9, and the balance being Fe and unavoidable impurities.
In the optimized scheme, the method further comprises the step of performing microalloying, wherein the chemical components further comprise Nb in mass percent: 0.015 to 0.035wt percent, V:0.04 to 0.07wt% Nb/v=1/3 to 2/3.
The specific embodiment also provides a rolling process of the 500 MPa-level weather-resistant coating-free hot rolled rod and wire, which comprises the following steps:
Heating a steel billet; comprises a preheating section, a heating section and a soaking section;
rolling; adopting low-temperature controlled rolling, wherein the whole process adopts austenite unrecrystallized rolling;
Cooling control is performed; cooling the wire rod by adopting a Steyr process control; the cooling bed on the bar is slowly cooled by a heat-preserving cover.
Specifically, in the billet heating process, the billet is a small square billet or a rectangular billet, and the section (140-220 mm) is x (140-220 mm); heating temperature in the preheating section is less than or equal to 600 ℃ and heating time is 10-15 min; the heating section is divided into a heating section 1 and a heating section 2, wherein the heating temperature of the heating section 1 is 600-1000 ℃, the heating time is 10-15 min, the heating temperature of the heating section 2 is 1000-1200 ℃, and the heating time is 40-50 min; the heating temperature of the soaking section is 1100-1200 ℃ and the heating time is 10-20 min.
Specifically, the finish rolling temperature in the rolling process is 850+/-10 ℃, the reduced sizing temperature is 840+/-10 ℃, and the finish rolling temperature is 830+/-10 ℃.
Specifically, in the controlled cooling process, the wire is cooled by adopting a Steyr process, the speed of a 0# roller way is 0.2-1 m/s, and the speed of the rest 8 groups of roller ways is improved by 3% relative to that of the previous group of roller ways (extremely bad); the air quantity of the 13 groups of fans is 210000m 3/h, the 1# fan to the 2# fan is opened by 5% -25%, the heat preservation cover is opened, the temperature of the outlet 2# fan is 650+/-20 ℃, the 3# fan to the 13# fan is fully closed, and the heat preservation cover is closed, so that the temperature of the outlet 13# fan is more than 300 ℃.
Specifically, in the controlled cooling process, the temperature of a cooling bed on a bar is more than 600 ℃, a heat preservation cover is adopted for slow cooling, and the temperature of a heat preservation cover is more than 330 ℃.
In the specific embodiment of the invention, C: carbon element is detrimental to corrosion of steel and has an effect on welding performance, cold embrittlement performance and stamping performance; the carbon has the most remarkable influence on the strength and the plasticity of the wire rod, and as the carbon content increases, the strength of the wire rod is continuously improved, the plasticity is rapidly reduced, and the carbon content also influences the drawability of a final finished product. Comprehensively, the carbon content of the invention is less than 0.14 weight percent.
Si: the silicon element is an important strengthening element in steel, is favorable for corrosion resistance, can obviously improve the elastic limit of the steel wire after drawing, but the excessively high Si content increases the brittleness of ferrite and is unfavorable for cold heading. Comprehensively considering the silicon content of the invention to be 0.3 to 0.6 weight percent.
Mn: manganese and sulfur are combined to generate MnS so as to reduce the harm of sulfur, refine pearlite and improve the strength of the steel wire; however, mn tends to be biased in steel, which causes uneven structure and performance, and too high Mn content will increase production cost; in addition, in the case of weathering steel, the influence of manganese on corrosion resistance in academia is not uniform, and most students believe that manganese can improve corrosion resistance of steel to the ocean atmosphere, but has little effect on corrosion resistance in the industrial atmosphere. Comprehensively considering the manganese content of the invention to be 0.5 to 0.75 weight percent.
P: phosphorus is one of the most effective alloying elements for improving the atmospheric corrosion resistance of steel, and can be uniformly dissolved in the steel, so that a compact protective film is formed on the surface of the steel, the inside of the steel is not corroded by the atmosphere, and the corrosion resistance is optimal when w (P) =0.08-0.15% in the steel; however, for industrial wire rods requiring deep cold working, phosphorus tends to be cold brittle, and has a great influence on steel quality, particularly cold workability, and strict control is required for this purpose. In comprehensive consideration, the phosphorus content P of the invention is less than 0.03 weight percent.
S: sulfur belongs to harmful elements in the steel, and is easy to generate thermal embrittlement, so that the steel wire drawing and heat treatment processing conditions are further deteriorated, and if the mass fraction of residual sulfur in the steel is reduced to 0.01%, the weather resistance of the carbon steel can be greatly improved. In general terms, the sulfur content S of the invention is less than 0.02 wt.%.
Cu: copper is an alloying addition element commonly used for producing corrosion-resistant steel materials, cu is a metal element with slower chemical reaction speed, and the strength of the steel can be improved by adding Cu, but if the Cu content is too high, the low-temperature toughness of the steel can be directly affected. Notably, the effect of copper on counteracting the deleterious effects of sulfur in steel is evident, and the effect is characterized by the higher sulfur content in steel and the more pronounced the relative effect of copper on reducing corrosion rate. This is because copper forms poorly soluble sulfides with sulfur. In general, the copper content of the invention is 0.1 to 1.0 wt.%.
Cr: chromium is a main element for improving the weather resistance of steel, and can form a compact oxide film on the surface of the steel, so that the passivation capability of the steel is improved, and the growth speed of a rust layer is reduced. However, chromium can greatly improve the hardenability of the steel, and excessive chromium can cause abnormal structures such as bainite, martensite and the like to be formed in the steel, which is disadvantageous to the cold workability of the steel. Considering comprehensively, the chromium content of the invention is 1.0 to 4.5 weight percent.
Cr/Cu: the invention has synergistic strengthening effect on the weather-resistant elements copper and chromium, and Cr/Cu=5-11 based on the most economic cost.
Nb, V: niobium and vanadium are common microalloy strengthening elements, can prevent austenite grains from growing, refine and reheat the austenite grains, improve uniformity of structure and performance, but excessive addition can obviously improve production cost, and the Nb and V composite microalloy strengthening effect is superior to that of single element. Comprehensively considering that the content of niobium and vanadium is respectively 0.015-0.035 wt percent and 0.04-0.07 wt percent, and Nb/V=1/3-2/3.
As high alloy steel, the casting blank heating process needs to avoid crack generation, so that a special sectional heating process needs to be established; meanwhile, the invention is also low-carbon steel, and in order to further improve the toughness, low-temperature controlled rolling is adopted, and a microstructure suitable for drawing is obtained through proper controlled cooling, so that a large number of abnormal structures such as martensite, bainite and the like are avoided.
The chemical compositions of the examples and comparative examples of the present invention are shown in Table 1; the heating process parameters of each example and comparative example are shown in Table 2; the rolling process parameters of each example and comparative example are shown in Table 3; the process parameters for the cooling control of each example and comparative example are shown in Table 4. The test results (toughness, cold heading property, weather resistance) of each example and comparative example are shown in Table 5.
The microstructure in example 1 is shown in fig. 1 and fig. 2, wherein fig. 1 is a microstructure in a hot rolled state: ferrite + pearlite, 200X; FIG. 2 shows a microstructure in a hot rolled state: ferrite + pearlite, 500X.
TABLE 1 chemical composition wt%
TABLE 2 heating process parameters
TABLE 3 Rolling Process parameters
Table 4 controlled cooling process parameters
TABLE 5 test effect
As can be seen from Table 5, the comparative examples 1 to 3, which are the current conventional products, have significantly lower toughness and corrosion resistance than the examples, and do not meet the plating-free use requirements; the 500 MPa-level weather-resistant coating-free hot rolled rod wire rod and the rolling process thereof have excellent toughness, cold heading property and weather resistance (relative corrosion rate is less than or equal to 25%), can meet the requirements of deep drawing and cold heading processing, and the manufactured product can meet the requirements of cold processing, coating-free and bare use for more than 25 years, thereby simplifying the downstream processing flow and application end maintenance, reducing the total flow purchasing cost of downstream users, having good market application prospect and being hopeful to comprehensively replace the traditional coating-plating products.
Claims (2)
1. A500 MPa-level weather-proof coating-free hot rolled rod wire is characterized by comprising the following chemical components in percentage by mass:
C：＜0.14wt%、Si：0.3～0.6wt%、Mn：0.5～0.75wt%、P＜0.03wt%、S＜0.02wt%、Cu：0.1～1.0wt%、Cr：1.0～4.5wt%、Cr/Cu=5～11、Nb：0.015～0.035wt%、V：0.04～0.07wt%、Nb/V=1/3～2/3, The balance of Fe and unavoidable impurities;
the 500 MPa-level weather-proof coating-free hot rolled rod and wire rolling process comprises the following steps of:
Heating a steel billet; comprises a preheating section, a heating section and a soaking section; the billet adopts a small square billet or a rectangular billet, and the section (140-220 mm) is x (140-220 mm); heating temperature in the preheating section is less than or equal to 600 ℃ and heating time is 10-15 min; the heating section is divided into a heating section 1 and a heating section 2, wherein the heating temperature of the heating section 1 is 600-1000 ℃, the heating time is 10-15 min, the heating temperature of the heating section 2 is 1000-1200 ℃, and the heating time is 40-50 min; the heating temperature of the soaking section is 1100-1200 ℃ and the heating time is 10-20 min
Rolling; adopting low-temperature controlled rolling, wherein the whole process adopts austenite unrecrystallized rolling; the finish rolling temperature in the rolling process is 850+/-10 ℃, the reduced sizing temperature is 840+/-10 ℃, and the finish rolling temperature is 830+/-10 ℃;
Cooling control is performed; cooling the wire rod by adopting a Steyr process control; the bar is slowly cooled by a heat-preserving cover on the cooling bed; wherein, the wire is cooled by adopting a Steyr process control, the speed of a 0# roller way is 0.2-1 m/s, and the speed of the rest 8 groups of roller ways is improved by 3% relative to the previous group of roller ways; the air quantity of the 13 groups of fans is 210000m 3/h, the 1# fan to the 2# fan is opened by 5% -25%, the heat preservation cover is opened, the temperature of the outlet 2# fan is 650+/-20 ℃, the 3# fan to the 13# fan is fully closed, and the temperature of the outlet 13# fan is higher than 300 ℃; the temperature of the cooling bed on the bar is more than 600 ℃, the heat preservation cover is adopted for slow cooling, and the temperature of the heat preservation cover is more than 330 ℃.
2. The 500 MPa-level weather-resistant coating-free hot rolled rod and wire as claimed in claim 1, wherein the chemical components comprise, in mass fraction:
C：＜0.14wt%、Si：0.4～0.5wt%、Mn：0.6～0.7wt%、P＜0.03wt%、S＜0.02wt%、Cu：0.3～0.7wt%、Cr：2～3.5wt%、Cr/Cu=7～9。
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07268467A (en) * | 1994-03-30 | 1995-10-17 | Nippon Steel Corp | Production of hot coil for steel tube having high toughness and sour resistance |
| KR20020040213A (en) * | 2000-11-24 | 2002-05-30 | 이구택 | A METHOD FOR MANUFACTURING HOT ROLLED STEEL SHEET OF TENSILE STRENGTH 80kg/㎟ GRADE WITH EXCELLENT WEATHER RESISTANCE AND WORKABILITY |
| KR20110076148A (en) * | 2009-12-29 | 2011-07-06 | 주식회사 포스코 | Hot rolled steel sheet having excellent corrosion resistance and impcat toughness and manufacturing method thereof |
| CN115161552A (en) * | 2022-06-15 | 2022-10-11 | 宝山钢铁股份有限公司 | High-strength hot-rolled strip steel with high weather resistance and manufacturing method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100517674B1 (en) * | 2000-04-04 | 2005-09-29 | 신닛뽄세이테쯔 카부시키카이샤 | Hot rolled wire or steel bar for machine structural use capable of dispensing with annealing, and method for producing the same |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07268467A (en) * | 1994-03-30 | 1995-10-17 | Nippon Steel Corp | Production of hot coil for steel tube having high toughness and sour resistance |
| KR20020040213A (en) * | 2000-11-24 | 2002-05-30 | 이구택 | A METHOD FOR MANUFACTURING HOT ROLLED STEEL SHEET OF TENSILE STRENGTH 80kg/㎟ GRADE WITH EXCELLENT WEATHER RESISTANCE AND WORKABILITY |
| KR20110076148A (en) * | 2009-12-29 | 2011-07-06 | 주식회사 포스코 | Hot rolled steel sheet having excellent corrosion resistance and impcat toughness and manufacturing method thereof |
| CN115161552A (en) * | 2022-06-15 | 2022-10-11 | 宝山钢铁股份有限公司 | High-strength hot-rolled strip steel with high weather resistance and manufacturing method thereof |
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