CN114686778A - Weather-resistant steel and preparation method and application thereof - Google Patents

Weather-resistant steel and preparation method and application thereof Download PDF

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Publication number
CN114686778A
CN114686778A CN202210348343.1A CN202210348343A CN114686778A CN 114686778 A CN114686778 A CN 114686778A CN 202210348343 A CN202210348343 A CN 202210348343A CN 114686778 A CN114686778 A CN 114686778A
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percent
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weathering steel
steel
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周磊磊
崔凯禹
余腾义
尹晶晶
靳阳
董雪娇
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Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
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Pangang Group Panzhihua Iron and Steel Research Institute Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0006—Adding metallic additives
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/064—Dephosphorising; Desulfurising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/068—Decarburising
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • C22C33/06—Making ferrous alloys by melting using master alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium

Abstract

The invention discloses weathering steel and a preparation method and application thereof, and belongs to the technical field of steel smelting. The weathering steel comprises the following chemical components in percentage by mass: less than or equal to 0.12 percent of C, less than or equal to 0.60-1.00 percent of Si, less than or equal to 1.50 percent of Mn, 0.030-0.070 percent of P, less than or equal to 0.015 percent of S, 0.80-1.20 percent of Cr0, 0.10-0.40 percent of Ni0, 0.20-0.60 percent of Cus, more than or equal to 0.010 percent of Als, and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: molten iron desulfurization → converter smelting → LF → RH → LF → slab continuous casting → hot rolling → laminar cooling → coiling. The weather-resistant steel has the atmospheric corrosion resistance index I as high as 7.77-8.93, realizes excellent atmospheric corrosion resistance, can be used in hot and humid areas in an exposed manner, can be widely applied to the fields of buildings, bridge construction or vehicle manufacturing, and has good application value.

Description

Weather-resistant steel and preparation method and application thereof
Technical Field
The invention belongs to the technical field of steel smelting, and particularly relates to weathering resistant steel and a preparation method and application thereof.
Background
The weathering steel is also named as atmospheric corrosion resistant steel, and is a low alloy steel with good corrosion resistance in the atmosphere. Through a large amount of research at home and abroad, at present, it is generally believed that after long-time exposure to the atmosphere, a layer of compact and good-adhesion oxidation product is generated on the surface of the weathering steel, so that a steel matrix is isolated from external corrosive substances, and the corrosion resistance of the weathering steel is obviously improved.
The damage of steel corrosion to various fields of national economy and national defense construction is a common and serious problem. Statistically, in some industrially developed countries, the economic losses due to corrosion account for 2-4% of the total value of national economic production, with atmospheric corrosion being the predominant form of corrosion of steel structures, accounting for about half of the total corrosion losses. Therefore, the method has great significance for the development of weathering steel.
CN105296885A of 2016, 2 months and 3 days discloses a high chromium weathering steel containing titanium and a preparation method thereof, wherein the alloy components and the weight percentage content of the weathering steel are that C is less than or equal to 0.07%, Si is less than or equal to 0.50%, Mn is less than or equal to 1.5%, P is less than or equal to 0.02%, s is less than or equal to 0.010%, Cu is 0.20-0.55%, Cr is 3.00-5.50%, Ni is 0.10-0.65%, Ti is 0.04-0.10%, and the balance is Fe and inevitable impurities. The weathering steel has high Cr content, and although the weathering performance of the steel is improved, the high Cr content increases the smelting cost and difficulty, and also has adverse effect on the formability of steel.
At present, as the application field of weathering steel is continuously expanded, more weathering steels with excellent atmospheric corrosion resistance need to be developed to meet the market demand.
Disclosure of Invention
The invention aims to solve the technical problem that the existing weathering steel has poorer atmospheric corrosion resistance.
The technical scheme adopted by the invention for solving the technical problems is as follows: the weathering steel comprises the following chemical components in percentage by mass: less than or equal to 0.12 percent of C, 0.60 to 1.00 percent of Si, less than or equal to 1.50 percent of Mn, 0.030 to 0.070 percent of P, less than or equal to 0.015 percent of S, 0.80 to 1.20 percent of Cr, 0.10 to 0.40 percent of Ni, 0.20 to 0.60 percent of Cu, more than or equal to 0.010 percent of Als, and the balance of Fe and inevitable impurities.
Further, the weathering steel comprises the following chemical components in percentage by mass: 0.06-0.08% of C, 0.70-0.90% of Si, 0.85-1.00% of Mn, 0.040-0.060% of P, less than or equal to 0.007% of S, 0.90-1.10% of Cr, 0.20-0.30% of Ni, Cu: 0.28-0.38%, Als: 0.015-0.050%, and the balance of Fe and inevitable impurities.
The weather-resistant steel has an atmospheric corrosion resistance index I of 7.77-8.93.
The corrosion rate of the weathering steel relative to Q355B is less than or equal to 40 percent.
The yield strength of the weathering steel is 400-480MPa, the tensile strength is 550-650MPa, the elongation is more than or equal to 18 percent, and the impact value at minus 40 ℃ is more than or equal to 27J.
The invention also provides a preparation method of the weathering steel, which comprises the following steps:
molten iron desulfurization → converter smelting → LF → RH refining → LF → slab continuous casting → hot rolling → laminar cooling → coiling.
Wherein, the charging [ S ] in the molten iron desulphurization procedure is controlled to be less than or equal to 0.002%; the end point [ C ] in the smelting process of the converter is controlled to be 0.04-0.06%, the [ S ] is less than or equal to 0.005%, and the tapping temperature is more than or equal to 1700 ℃.
Wherein, the outbound temperature in the first LF procedure is controlled to be 1640-; controlling [ C ] in the RH refining procedure to be less than or equal to 0.02 percent; controlling the outlet temperature in the second LF procedure to be 1590-1600 ℃; controlling delta T in the slab continuous casting process: 20-40 ℃.
Wherein, the rough rolling full length is descaled in the hot rolling procedure, the finish rolling start temperature is less than or equal to 1020 ℃, and the finish rolling temperature is 810-850 ℃; sparse cooling is adopted in the laminar cooling process; the coiling temperature in the coiling process is controlled to be 580-620 ℃.
The invention also provides the application of the weathering steel, and the weathering steel is used in the fields of buildings, bridge construction or vehicle manufacturing and exposed in hot and humid areas.
The invention has the beneficial effects that: the weather-resistant steel prepared by the preparation method provided by the invention has the atmospheric corrosion resistance index I as high as 7.77-8.93 and far higher than 6.0, and realizes excellent atmospheric corrosion resistance of the product. Because the alloy amount is added in the alloy smelting process of the invention, the temperature drop in the process is large, the alloy carburization and heating carburization are large, and the ferrochrome melting effect is poor due to the excessive temperature drop, so that the RH procedure insert tube is seriously bonded, so that the production requirement of the steel grade of the invention can not be met by the common converter smelting-LF-RH-slab continuous casting mode. Therefore, the invention adopts double LF procedures, although one LF procedure is added, the production cost is increased, the invention has more advantages in the effective utilization of temperature, component carbon and alloy (alloy loss phenomenon caused by adhesion of an insert tube is avoided) and the refining sulfur control efficiency, and the production risk is reduced to a great extent.
The steel has good atmospheric corrosion resistance, low later maintenance cost and long service life of products, and the full-period use cost is reduced; meanwhile, the environmental pollution is reduced, and the accident risk of corrosion failure is reduced. In addition, the weathering steel can be used in hot and humid areas in an exposed manner, can be widely applied to the fields of buildings, bridge construction or vehicle manufacturing, and has good application value.
Detailed Description
The technical solution of the present invention can be specifically implemented as follows.
The weathering steel comprises the following chemical components in percentage by mass: less than or equal to 0.12 percent of C, 0.60 to 1.00 percent of Si, less than or equal to 1.50 percent of Mn, 0.030 to 0.070 percent of P, less than or equal to 0.015 percent of S, 0.80 to 1.20 percent of Cr, 0.10 to 0.40 percent of Ni, 0.20 to 0.60 percent of Cu, more than or equal to 0.010 percent of Als, and the balance of Fe and inevitable impurities.
Preferably, the weathering steel comprises the following chemical components in percentage by mass: 0.06-0.08% of C, 0.70-0.90% of Si, 0.85-1.00% of Mn, 0.040-0.060% of P, less than or equal to 0.007% of S, 0.90-1.10% of Cr, 0.20-0.30% of Ni, Cu: 0.28-0.38%, Als: 0.015-0.050%, and the balance of Fe and inevitable impurities.
Among them, C is an effective strengthening element in steel, but too high carbon content can form more coarse and coarse carbide particles in steel, which is unfavorable for plasticity and toughness, and can also be unfavorable for bending property and formability in a steel plate center segregation band, and simultaneously, the welding carbon equivalent can be increased, which is unfavorable for welding processing, so that the C is less than or equal to 0.12%, preferably 0.06-0.08% in the design of the invention.
Mn has a strong solid solution strengthening effect, can obviously reduce the phase transition temperature of steel and refine the microstructure of the steel, but the excessive content of Mn can cause casting blank cracks in the continuous casting process and can also reduce the welding performance of the steel, so that the Mn is less than or equal to 1.50 percent, and the Mn is preferably 0.85 to 1.00 percent.
S can form sulfide inclusions to deteriorate the performance of steel, and meanwhile, pitting corrosion expansion is easy to form in the corrosion process, so that the corrosion performance is adversely affected, therefore, S is less than or equal to 0.015 percent, and S is preferably less than or equal to 0.007 percent.
Al plays a role in deoxidation in steel, but the content of Al is too high, and nitrogen oxides are easy to precipitate at austenite grain boundaries to cause billet crack generation. Therefore, the invention designs Als more than or equal to 0.010 percent, and the preferred Als: 0.015-0.050%.
The contents of Si, P, Cu, Cr and Ni in the steel influence the calculated value of the atmospheric corrosion resistance index I, and the Si, P, Cu, Cr and Ni are main alloy elements for improving the atmospheric corrosion resistance of the steel; therefore, after the elements of C, Mn, S and Al are determined, the invention aims to improve the atmospheric corrosion resistance, and is based on the calculation formula of the atmospheric corrosion resistance index in appendix D of guidance for evaluating the atmospheric corrosion resistance of low alloy steel in the structural weathering steel (GB/T4171-2008): i ═ 26.01 (% Cu) +3.88 (% Ni) +1.20 (% Cr) +1.49 (% Si) +17.28 (% P) -7.29 (% Cu) (% Ni) -9.10 (% Ni) (% P) -33.39 (% Cu)2, the contents of Si, P, Cu, Cr, Ni in the steel were determined.
Wherein, Cu is beneficial to forming a compact amorphous oxide (alkyl oxide) protective layer with good adhesion on the surface of the steel, and the corrosion resistance is obvious; in addition, Cu forms insoluble sulfides with S, thereby counteracting the deleterious effects of S on steel corrosion resistance. However, when the Cu content is too high, the melting point is low and is lower than the heating temperature of the steel slab, the precipitated Cu is accumulated in the austenite grain boundary in a liquid state, and when the precipitated Cu content reaches a certain level, cracks are easily generated during heating or hot rolling. In addition, according to the calculation formula of the atmospheric corrosion resistance index I, the calculated value of the atmospheric corrosion resistance index I is reduced when the Cu content is too small or too large. Therefore, the invention designs Cu 0.20-0.60%, and preferably Cu 0.28-0.38%.
Ni can obviously improve the corrosion resistance of steel, and simultaneously Ni and Cu form a Cu-rich phase containing Ni and are retained in an external oxidation layer in a solid state, so that the enrichment amount of Cu in a matrix is reduced, the formation chance of the liquid Cu-rich phase is reduced, and the hot brittleness defect is avoided, therefore, the Ni/Cu content in the steel is generally controlled to be more than or equal to 1/2. However, too high Ni increases the adhesion of scale, hot rolling defects form on the surface when pressed into steel, Ni is a precious metal, and too high Ni content significantly increases the cost of the steel alloy. Therefore, the invention designs Ni 0.10-0.40%, preferably Ni 0.20-0.30%.
Si has higher solid solubility in steel, is beneficial to thinning rust layer tissues and reducing the overall corrosion rate of the steel. However, too high Si content makes descaling difficult during rolling and also leads to a decrease in weldability. Therefore, the invention designs Si 0.60-1.00%, preferably Si 0.70-0.90%.
P can effectively improve the atmospheric corrosion resistance of steel, when P and Cu are jointly added into the steel, a better composite effect can be displayed, according to a calculation formula of an atmospheric corrosion resistance index I, the value I can be obviously improved by high P content, but the plasticity and the low-temperature toughness of the steel can be obviously reduced by overhigh P content. The present invention therefore designs P: 0.030 to 0.070%, preferably 0.040 to 0.060%.
Cr has an obvious effect of improving the passivation capability of steel, can promote the surface of the steel to carry out a compact passivation film or a protective rust layer, the enrichment of Cr in the rust layer can effectively improve the selective permeability of the rust layer to corrosive media, and the high Cr content can obviously improve the value I according to a calculation formula of an atmospheric corrosion resistance index I. However, too high Cr content increases the production cost. Therefore, the invention designs 0.80-1.20% of Cr, and preferably 0.90-1.10% of Cr.
The weather-resistant steel has an atmospheric corrosion resistance index I of 7.77-8.93, which is far greater than 6.0, and realizes excellent atmospheric corrosion resistance of the product.
The corrosion rate of the weathering steel relative to Q355B is less than or equal to 40 percent.
The yield strength of the weathering steel is 400-480MPa, the tensile strength is 550-650MPa, the elongation is more than or equal to 18 percent, and the impact value at minus 40 ℃ is more than or equal to 27J.
The invention also provides a preparation method of the weathering steel, which comprises the following steps:
molten iron desulfurization → converter smelting → LF → RH refining → LF → slab continuous casting → hot rolling → laminar cooling → coiling.
Wherein, the main technical measures in the molten iron desulphurization procedure are deep desulphurization and desulfuration residue scraping, and the charging of [ S ] in the furnace needs to be controlled to be less than or equal to 0.002 percent; the main technical measures in the smelting process of the converter are controlling the resulfurization of the converter, controlling the end point temperature, reducing the slag discharge amount, adding ferrochromium and washing tapping slag, wherein the end point C is required to be controlled to be 0.04-0.06 percent, the S is less than or equal to 0.005 percent and the tapping temperature is more than or equal to 1700 ℃.
Wherein, the main technical measures in the first LF procedure are temperature regulation, ferrochrome addition and chromium component adjustment, and the outbound temperature needs to be controlled to be 1640-1650 ℃; the main technical measures in the RH refining procedure are vacuum decarburization and deoxidation, alloying of Als, Mn and Si, wherein [ C ] needs to be controlled to be less than or equal to 0.02 percent, and Als, Mn and Si meet the requirements; the main technical measures in the second LF procedure are temperature regulation, final alloy adjustment and refining desulfurization, the components need to be controlled to meet the requirements, and the outlet temperature is 1590-; the main technical measures in the slab continuous casting process are casting protection and low alloy steel casting powder, the casting speed needs to be controlled to be constant as much as possible, and the casting speed is delta T: 20-40 ℃.
In the smelting process of the weather-resistant steel, the alloy amount is large, the temperature drop in the process is large, so that the alloy carburization and heating carburization are large, and the ferrochrome melting effect is poor due to the excessive temperature drop, so that the RH process insert tube is seriously bonded, and therefore, the production requirement of the steel cannot be met by a common converter smelting-LF-RH-slab continuous casting mode. Therefore, the invention adopts double LF procedures, although one LF procedure is added, the production cost is increased, the invention has more advantages in the effective utilization of temperature, component carbon and alloy (alloy loss phenomenon caused by adhesion of an insert tube is avoided) and the refining sulfur control efficiency, and the production risk is reduced to a great extent. The ferrochrome entering the LF procedure for the first time is controlled by reducing the lower limit of the component requirement by 0.15 percent, and because the content of other alloy elements is low and easy to oxidize, the ferrochrome is not prepared when entering the LF for the first time, is primarily prepared after RH decarburization and deoxidation, and is finely adjusted after entering the LF for the second time.
In addition, in the hot rolling and layer cooling process of the weathering resistant steel, the casting blank is hot-fed or immediately stacked and slowly cooled and is charged in a furnace within 24 hours, the tapping temperature is 1210-1250 ℃, the rough rolling full-length descaling is realized, the finish rolling starting temperature is less than or equal to 1020 ℃, and the finish rolling temperature is 810-850 ℃; sparse cooling is adopted in the laminar cooling process; the coiling temperature in the coiling procedure is controlled to be 580-620 ℃.
For steel with high alloy content, the casting blank is easy to generate edge crack defects when the stacking time is long and the charging temperature is low, so the casting blank is subjected to hot conveying hot charging or is immediately stacked for slow cooling and is charged in 24 hours. Because the high Cr steel has strong hardenability and large cooling rate, martensite structure is easy to appear, and the toughness and plasticity of the product are adversely affected, so that cooling water between the racks is completely closed, the rolling speed can be reduced, and the cooling rate is reduced; meanwhile, sparse cooling is adopted for laminar cooling, and the cooling rate is reduced.
Based on the excellent corrosion resistance of the weathering steel, the invention also provides the application of the weathering steel, and the weathering steel is used in the fields of buildings, bridge construction or vehicle manufacturing and exposed in hot and humid areas.
The technical solutions and effects of the present invention will be further described below by practical examples.
Examples
The invention provides 3 groups of embodiments for preparing weathering steel by adopting the composition proportion and the preparation method of the weathering steel, and additionally provides 2 groups of comparative proportions, wherein the comparative example 1 is common weathering steel Q450NQR1, and the comparative example 2 is low-alloy high-strength steel Q355B. The distribution ratios of the components of the examples and the comparative examples of the invention are shown in table 1, and the prepared alloy steel is tested for corrosion resistance according to the periodic infiltration corrosion test method of weathering steel for railways TB/T2375, and the final atmospheric corrosion resistance index I and the relative Q355B corrosion rate are shown in table 1.
TABLE 1 examples and comparative examples Main Components (%) and Corrosion resistance
Categories C Si Mn P S Cr Ni Cu Als I Relative Q355B corrosion rate
Example 1 0.06 0.71 0.86 0.040 0.002 0.90 0.21 0.28 0.018 7.80 35％
Example 2 0.07 0.80 0.92 0.051 0.004 0.99 0.25 0.34 0.033 8.48 32％
Example 3 0.08 0.89 0.99 0.060 0.007 1.09 0.29 0.37 0.047 8.91 29％
Comparative example 1 0.07 0.38 0.93 0.009 0.001 0.40 0.14 0.23 0.034 5.71 48％
Comparative example 2 0.17 0.18 0.63 0.013 0.016 0.04 0.04 0.05 0.030 1.89 100％
The embodiment and the comparative example show that the weather-resistant steel has the atmospheric corrosion resistance index I of more than 6.0, is far larger than common weather-resistant steel and low-alloy high-strength steel, can realize excellent atmospheric corrosion resistance, can be used in dry areas in bare or light coating mode, reduces coating and rust removal cost, reduces failure accidents caused by corrosion, reduces environmental pollution, can be used in the fields of building, bridge construction or vehicle manufacturing, and has good application prospect.

Claims (10)

1. The weathering steel is characterized by comprising the following chemical components in percentage by mass: less than or equal to 0.12 percent of C, 0.60 to 1.00 percent of Si, less than or equal to 1.50 percent of Mn, 0.030 to 0.070 percent of P, less than or equal to 0.015 percent of S, 0.80 to 1.20 percent of Cr, 0.10 to 0.40 percent of Ni, 0.20 to 0.60 percent of Cu, more than or equal to 0.010 percent of Als, and the balance of Fe and inevitable impurities.
2. The weathering steel according to claim 1, characterized by the chemical composition, in mass percent: 0.06-0.08% of C, 0.70-0.90% of Si, 0.85-1.00% of Mn, 0.040-0.060% of P, less than or equal to 0.007% of S, 0.90-1.10% of Cr, 0.20-0.30% of Ni0.20, Cu: 0.28-0.38%, Als: 0.015-0.050%, and the balance of Fe and inevitable impurities.
3. The weathering steel of claim 2, characterized in that: the weather-resistant steel has an atmospheric corrosion resistance index I of 7.77-8.93.
4. The weathering steel of claim 2, characterized in that: the corrosion rate of the weathering steel relative to Q355B is less than or equal to 40 percent.
5. The weathering steel of claim 2, wherein: the yield strength of the weathering steel is 400-480MPa, the tensile strength is 550-650MPa, the elongation is more than or equal to 18%, and the impact value at minus 40 ℃ is more than or equal to 27J.
6. The method for preparing weathering steel according to any of claims 1 to 5, comprising the steps of:
molten iron desulfurization → converter smelting → LF → RH refining → LF → slab continuous casting → hot rolling → laminar cooling → coiling.
7. The method for producing weathering steel according to claim 6, characterized in that: controlling the [ S ] in the molten iron desulphurization procedure to be less than or equal to 0.002%; the end point C in the smelting process of the converter is controlled to be 0.04-0.06 percent, S is less than or equal to 0.005 percent, and the tapping temperature is more than or equal to 1700 ℃.
8. The method for producing weathering steel according to claim 6, characterized in that: controlling the outbound temperature to be 1640-1650 ℃ in the first LF procedure; controlling [ C ] in the RH refining procedure to be less than or equal to 0.02 percent; controlling the outlet temperature in the second LF procedure to be 1590-1600 ℃; controlling delta T in a slab continuous casting process: 20-40 ℃.
9. The method for producing weathering steel according to claim 6, characterized in that: the rough rolling full-length scale removal in the hot rolling procedure is carried out, the finish rolling initial temperature is less than or equal to 1020 ℃, and the finish rolling final temperature is 810-850 ℃; sparse cooling is adopted in the laminar cooling process; the coiling temperature in the coiling process is controlled to be 580-620 ℃.
10. Use of a weathering steel according to any of claims 1 to 5, characterized in that: the coating is used in the fields of buildings, bridge construction or vehicle manufacturing, and is exposed in hot and humid areas.
CN202210348343.1A 2022-04-01 2022-04-01 Weather-resistant steel and preparation method and application thereof Pending CN114686778A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10237543A (en) * 1997-02-25 1998-09-08 Nkk Corp Manufacture of hot rolled steel plate excellent in corrosion resistance and resistance to secondary working brittleness
CN106676427A (en) * 2015-11-06 2017-05-17 攀钢集团攀枝花钢铁研究院有限公司 Atmosphere corrosion resisting molten profile steel, atmosphere corrosion resisting vanadium-titanium-nitrogen-containing profile steel and production method of atmosphere corrosion resisting vanadium-titanium-nitrogen-containing profile steel
CN111850411A (en) * 2020-07-30 2020-10-30 攀钢集团研究院有限公司 400 MPa-grade high-chromium weathering steel and preparation method thereof
CN111926254A (en) * 2020-08-03 2020-11-13 攀钢集团研究院有限公司 440MPa grade high-phosphorus high-chromium weathering steel and preparation method and application thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10237543A (en) * 1997-02-25 1998-09-08 Nkk Corp Manufacture of hot rolled steel plate excellent in corrosion resistance and resistance to secondary working brittleness
CN106676427A (en) * 2015-11-06 2017-05-17 攀钢集团攀枝花钢铁研究院有限公司 Atmosphere corrosion resisting molten profile steel, atmosphere corrosion resisting vanadium-titanium-nitrogen-containing profile steel and production method of atmosphere corrosion resisting vanadium-titanium-nitrogen-containing profile steel
CN111850411A (en) * 2020-07-30 2020-10-30 攀钢集团研究院有限公司 400 MPa-grade high-chromium weathering steel and preparation method thereof
CN111926254A (en) * 2020-08-03 2020-11-13 攀钢集团研究院有限公司 440MPa grade high-phosphorus high-chromium weathering steel and preparation method and application thereof

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Application publication date: 20220701