CN112126863A - Marine climate-resistant easily-welded weather-resistant steel plate for bridge and production method thereof - Google Patents

Marine climate-resistant easily-welded weather-resistant steel plate for bridge and production method thereof Download PDF

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Publication number
CN112126863A
CN112126863A CN202010833260.2A CN202010833260A CN112126863A CN 112126863 A CN112126863 A CN 112126863A CN 202010833260 A CN202010833260 A CN 202010833260A CN 112126863 A CN112126863 A CN 112126863A
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resistant
weather
steel plate
equal
bridge
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谷盟森
李建朝
李�杰
龙杰
于红伟
吴天育
高雅
张志军
徐腾飞
王晓书
靳兴亚
程海林
王少义
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Wuyang Iron and Steel Co Ltd
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Wuyang Iron and Steel 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • 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
    • 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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Abstract

The invention discloses a weather-resistant steel plate for a marine climate resistant easy-welding bridge and a production method thereof, wherein the weather-resistant steel plate comprises the following chemical components in percentage by mass: c: 0.06-0.10%, Mn: 1.30-1.50%, P is less than or equal to 0.010%, S is less than or equal to 0.002%, Nb: 0.015-0.035%, Ni: 1.25-1.50%, Al: 0.015 to 0.040%, Cu: 0.30-0.40%, Mo: 0.06-0.10% of Fe and inevitable impurities as the rest; the production method comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and controlled cooling. The invention designs by innovative components, controls rolling and cooling control modes, produces the steel plate with uniform and consistent overall performance and organization, ensures that the strength and the low-temperature impact at minus 20 ℃ meet the requirements, reduces the production cost, achieves the international advanced level of product performance, and is deeply trusted by customers.

Description

Marine climate-resistant easily-welded weather-resistant steel plate for bridge and production method thereof
Technical Field
The invention belongs to the technical field of metallurgy, and particularly relates to a marine climate-resistant easily-welded weather-resistant steel plate for a bridge and a production method thereof.
Background
With the rapid development of bridge steel, the steel consumption of weather-resistant bridge steel in inland and ocean areas is gradually increased, the quality requirements of products are more and more strict, and particularly, the weather-resistant bridge steel has special requirements on weather resistance, environmental protection, easy welding property and the like.
In general, in order to ensure seawater corrosion resistance of steel for bridges, the conventional method adopts the surface of a common bridge steel plate to be coated with a corrosion-resistant coating, so that the construction quantity is large, and meanwhile, certain pollution is caused to the environment. The surface of the marine steel plate is seriously flaked, bubbled and corroded in a long-term service in a marine environment, and needs to be maintained regularly. Particularly, the maintenance cost of the seawater corrosion resistant treatment in coastal areas or cross-sea bridges is high and the difficulty is high in the middle and later service period of bridges. Therefore, it is particularly important to improve the marine climate corrosion resistance of the steel for bridges.
A patent with application number 201210055632.9 of Wuhan iron and Steel (group) company in 2012 discloses 'clean corrosion-resistant ocean engineering steel and a production method thereof', wherein the steel comprises the following chemical components in percentage by weight: c: 0.01 to 0.03%, Si: 0.28 to 0.95%, Mn: 0.10-0.50%, P: 0.010-0.10%, Ni: 0.10-0.90%, Cu: 0.05-0.25%, and controlling: s is less than or equal to 0.006 percent, Nb is less than or equal to 0.005 percent, V is less than or equal to 0.005 percent, Ti is less than or equal to 0.005 percent, and the following relations are satisfied: cu and Ni are more than or equal to 3C and less than or equal to 1.15 percent, and Ni and Mn are more than or equal to 1.5Cu and less than or equal to 1.28 percent. The patent has the advantages that the content of Nb is low, the content of P is high, and the toughness of a parent metal and a welding heat affected zone is not facilitated; accelerated cooling is required, residual stress is easily generated, and the corrosion resistance is not good.
A patent with application number 201310398905.4 of saddle steel member limited in 2013 discloses steel for welding structures with excellent marine environment corrosion resistance and a manufacturing method thereof, wherein the steel comprises the following chemical components in percentage by weight: c: 0.015 to 0.060%, Si: 0.30-0.70%, Mn: 0.51-1.20%, P is less than or equal to 0.025%, S is less than or equal to 0.005%, Nb: 0.020 to 0.090%, Ti: 0.010-0.050%, Ni: 0.91-1.20%, Cu: 0.26-0.90%, Mo: 0.10-0.60%, ALs: 0.005-0.060%, while ensuring that Cu/Mo is 1.30-1.70, Si, Mn/Nb is 5.0-9.0, and the rest is Fe and inevitable impurity elements. According to the method, more Cu and Mo are added, Cu increases casting blank cracks in the continuous casting process, the cleaning amount of steel billets and the waste amount of steel plates caused by cracks are increased, the production cost of raw materials is increased due to excessive Mo, and meanwhile, the hardness after welding is increased and the crack sensitivity after welding is increased; in addition, Mo exceeds 0.5%, and the toughness of the weld joint begins to deteriorate; when Ti is added more than 0.040%, large-particle TiN inclusions are easily formed, and the impact toughness of the mother plate is adversely affected.
A patent with application number 201811014026 of Handan iron and Steel company in 2018 discloses a weather-resistant steel Q345qDNH steel strip for bridges, which comprises the following chemical components in percentage by mass: c: 0.07 to 0.11%, Si: 0.31 to 0.37%, Mn: 0.55-0.65%, P: 0.015-0.025%, S is less than or equal to 0.006%, Cu: 0.31-0.35%, Cr: 0.41 to 0.47%, Ni: 0.32-0.36%, ALs: 0.02 to 0.03%, Nb: 0.004 to 0.010%, Ca: 0.0010-0.0040%, B is less than or equal to 0.0005%, H is less than or equal to 0.0002%, N is less than or equal to 0.008%, and the balance is Fe and inevitable residual elements. The patent refers to the fact that the rolling process of the plate strip and the medium plate is different, the patent refers to the fact that the steel is low in Ni content, is general atmospheric corrosion resistant steel, and is based on ASTMG101 as a standard reference of a corrosion performance detection method, and the marine climate corrosion resistance effect is not ideal.
Disclosure of Invention
The invention aims to provide a weather-resistant steel plate for a marine climate resistant easy-welding type bridge, and also provides a production method of the weather-resistant steel plate for the marine climate resistant easy-welding type bridge.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the weather-resistant steel plate for the marine climate-resistant easy-welding bridge comprises the following chemical components in percentage by mass: c: 0.06-0.10%, Mn: 1.30-1.50%, P is less than or equal to 0.010%, S is less than or equal to 0.002%, Nb: 0.015-0.035%, Ni: 1.25-1.50%, Al: 0.015 to 0.040%, Cu: 0.30-0.40%, Mo: 0.06-0.10% and the balance of Fe and inevitable impurities.
The thickness of the weather-resistant steel plate is 20-65 mm.
The weather-resistant steel plate structure consists of 85-90% of ferrite and 10-15% of granular bainite, and the grain size is more than or equal to grade 9.
The weather-resistant steel plate of the invention comprises: the yield strength Re0.2 is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the yield ratio is less than or equal to 0.85, the elongation is more than or equal to 20 percent, the transverse impact energy at minus 20 ℃ is more than or equal to 47J, and the weather resistance index V value is more than or equal to 1.20.
The weather resistance index V value of the weather-resistant steel plate is calculated by smelting analysis:
V=1/{(1.0-0.16[C])*(1.05-0.05[Si])*(1.04-0.016[Mn])*(1.0-0.5[P])*(1.0+1.9[S])*(1.0-0.1[Cu])*(1.0-0.12[Ni])*(1.0-0.12[Ni])*(1.0-0.3[Mo])*(1.0-I.7[Ti])}
the invention also provides a production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge, which comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control; and in the rolling procedure, II-type controlled rolling is adopted.
According to the initial smelting process, the tapping molten steel C is less than or equal to 0.05%, the early preparation is made for ensuring the control of the final component C, and the failure of the whole furnace molten steel smelting caused by the increase of C in the subsequent process is avoided.
According to the LF refining process, 1.5-1.9 kg/t of Al wire (the purity is more than or equal to 99.9%) of steel is added for deep deoxidation after primary refining is finished, 0.5-1.0 kg/t of Al particles (the purity is more than or equal to 99.9%) of steel are added for slag-changing deoxidation, the white slag holding time is more than or equal to 30min, oxides in molten steel are fully adsorbed by refined slag, the high purity of the molten steel is ensured, sulfides are reduced, and ultralow-S smelting is realized.
According to the Ca treatment process, 0.07-0.14 kg/t of solid pure calcium cored wires (calcium purity is more than or equal to 97%) of steel are added for Ca treatment, so that O and S can be further removed, the form of inclusions can be changed, the purity of molten steel can be improved, the formation of MnS inclusions can be reduced, and the performance of a steel plate can be improved.
In the rolling procedure, the initial rolling temperature at the stage I is 1000-1050 ℃, and the final rolling temperature is 950-980 ℃; and in the second stage, the steel airing thickness is more than or equal to 100mm, the initial rolling temperature is 850-880 ℃, the final rolling temperature is 790-800 ℃, and the steel plate grains are fully refined through large reduction, so that the structure performance of the steel plate is ensured.
The controlled cooling process adopts air cooling after rolling, reduces the structural stress and avoids the tempering process.
The invention relates to a method for detecting weather-resistant steel plates for marine climate resistant and easily welded Q345qDNHY-I bridges, which is subject to GB/T2975, GB/T228 and GB/T6394 in standard reference.
Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: 1. the invention adopts the component design of low C content and trace Nb, thus ensuring the easy weldability and low welding crack sensitivity of the steel plate; the weather resistance of the steel plate is ensured by adding Cu, Ni and Mo elements, and the weather resistance index V value is more than or equal to 1.20. 2. The invention obtains ferrite and granular bainite structures by controlling rolling and cooling modes, the overall performance and the structures of the produced steel plates are uniform, the strength and the low-temperature impact at minus 20 ℃ meet the requirements, and the production cost is reduced. 3. The yield strength Re0.2 of the steel plate produced by the method is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the yield ratio is less than or equal to 0.85, the elongation is more than or equal to 20 percent, and the transverse impact energy at the temperature of minus 20 ℃ is more than or equal to 47J. 4. The weather-resistant steel plate for the marine climate resistant easy-welding Q345qDNHY-I bridge, which is produced by the invention, has the performance reaching the international advanced level and is deeply trusted by customers.
Drawings
FIG. 1 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant easy-to-weld Q345qDNHY-I bridge in example 1;
FIG. 2 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant weldable Q345qDNHY-I bridge in example 2;
FIG. 3 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant weldable Q345qDNHY-I bridge in example 3;
FIG. 4 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant weldable Q345qDNHY-I bridge in example 4;
FIG. 5 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant easy-to-weld Q345qDNHY-I bridge in example 5;
FIG. 6 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant easy-to-weld Q345qDNHY-I bridge in example 6;
FIG. 7 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant weldable Q345qDNHY-I bridge in example 7;
FIG. 8 is a metallographic structure diagram of a weather-resistant steel plate for a marine climate resistant weldable Q345qDNHY-I bridge in example 8.
Detailed Description
The present invention will be described in further detail with reference to the following drawings and specific examples.
Example 1
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 20mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.22.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.04 percent;
(2) an LF refining process, namely adding 1.5kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.8kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 35 min;
(3) a Ca treatment process, wherein 0.14kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts II type controlled rolling, wherein the initial rolling temperature in the first stage is 1000 ℃, and the final rolling temperature is 960 ℃; in the second stage, the steel airing thickness is 100mm, the initial rolling temperature is 860 ℃, and the final rolling temperature is 790 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge obtained in the embodiment are shown in table 2, and the metallographic structure is shown in fig. 1.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 89% of ferrite and 11% of granular bainite, and the grain size is 10 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 2
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 30mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.22.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.05 percent;
(2) an LF refining process, namely adding 1.9kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.7kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 30 min;
(3) a Ca treatment process, wherein 0.10kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts II type controlled rolling, wherein the initial rolling temperature in the stage I is 1050 ℃, and the final rolling temperature is 980 ℃; in the second stage, the steel airing thickness is 100mm, the initial rolling temperature is 850 ℃, and the final rolling temperature is 795 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties and metallographic structure of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge are shown in Table 2.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 87 percent of ferrite and 13 percent of granular bainite, and the grain size is 10 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 3
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 50mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.23.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.03 percent;
(2) an LF refining process, namely adding 1.7kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.9kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 40 min;
(3) a Ca treatment process, wherein 0.07kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts type II controlled rolling, wherein the initial rolling temperature of the stage I is 1020 ℃, and the final rolling temperature is 970 ℃; in the second stage, the steel airing thickness is 110mm, the initial rolling temperature is 865 ℃, and the final rolling temperature is 790 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge obtained in the embodiment are shown in Table 2, and the metallographic structure is shown in FIG. 3.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 86 percent of ferrite and 14 percent of granular bainite, and the grain size is 9 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 4
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 65mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.24.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.05 percent;
(2) an LF refining process, namely adding 1.5kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.6kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 35 min;
(3) a Ca treatment process, wherein 0.14kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) rolling, wherein II-type controlled rolling is adopted, the initial rolling temperature of the stage I is 1035 ℃, and the final rolling temperature is 972 ℃; in the stage II, the steel airing thickness is 130mm, the initial rolling temperature is 875 ℃, and the final rolling temperature is 800 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge are shown in Table 2, and the metallographic structure is shown in FIG. 4.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 89% of ferrite and 11% of granular bainite, and the grain size is 9 grades; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 5
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 40mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.23.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.035%;
(2) an LF refining process, namely adding 1.8kg/t of steel Al wire into steel for deep deoxidation after primary refining is finished, adding 0.65kg/t of steel Al particles for slag-changing deoxidation, and keeping the white slag for 38 min;
(3) a Ca treatment process, wherein 0.12kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts II type controlled rolling, the initial rolling temperature of the stage I is 1012 ℃, and the final rolling temperature is 978 ℃; in the stage II, the steel airing thickness is 120mm, the initial rolling temperature is 856 ℃, and the final rolling temperature is 797 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties and metallographic structure of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge are shown in Table 2 and the metallographic structure is shown in FIG. 5.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 87 percent of ferrite and 13 percent of granular bainite, and the grain size is 10 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 6
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 26mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.22.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.042;
(2) an LF refining process, namely adding 1.6kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.85kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 32 min;
(3) a Ca treatment process, wherein 0.12kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts II type controlled rolling, wherein the initial rolling temperature of the stage I is 1045 ℃, and the final rolling temperature is 980 ℃; II, airing the steel at 110mm thickness, wherein the initial rolling temperature is 870 ℃, and the final rolling temperature is 792 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge obtained in the embodiment are shown in Table 2, and the metallographic structure is shown in FIG. 6.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 90 percent of ferrite and 10 percent of granular bainite, and the grain size is 9 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 7
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 48mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.24.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.047;
(2) an LF refining process, namely adding 1.8kg/t of Al wire into steel for deep deoxidation after initial refining, adding 1.0kg/t of Al grains into the steel for slag-changing deoxidation, and keeping the white slag for 36 min;
(3) a Ca treatment process, wherein 0.08kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) the rolling procedure adopts II type controlled rolling, wherein the initial rolling temperature of the stage I is 1009 ℃, and the final rolling temperature is 955 ℃; in the II stage, the steel airing thickness is 120mm, the initial rolling temperature is 862 ℃, and the final rolling temperature is 796 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge are shown in Table 2, and the metallographic structure is shown in FIG. 7.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 85 percent of ferrite and 15 percent of granular bainite, and the grain size is 10 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Example 8
The thickness of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge is 36mm, the chemical component composition and the mass percentage content are shown in Table 1, and the weather-resistant index V value of the weather-resistant steel plate is 1.21.
The production method of the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge comprises the working procedures of primary smelting, LF refining, Ca treatment, rolling and cooling control, and comprises the following specific process steps:
(1) primary smelting, tapping molten steel C: 0.038;
(2) an LF refining process, namely adding 1.6kg/t of Al wire into steel for deep deoxidation after initial refining, adding 0.5kg/t of Al grains into the steel for slag-changing deoxidation, and keeping white slag for 33 min;
(3) a Ca treatment process, wherein 0.09kg/t of steel solid pure calcium cored wire is added for Ca treatment;
(4) rolling, wherein type II controlled rolling is adopted, the initial rolling temperature of the stage I is 1040 ℃, and the final rolling temperature is 950 ℃; in the second stage, the steel airing thickness is 115mm, the initial rolling temperature is 880 ℃, and the final rolling temperature is 798 ℃;
(5) and a controlled cooling process, namely air cooling after rolling.
The mechanical properties and metallographic structure of the weather-resistant steel plate for the marine climate resistant weldable Q345qDNHY-I bridge are shown in Table 2 and the metallographic structure is shown in FIG. 8.
In conclusion, the weather-resistant steel plate for the marine climate-resistant and easily-welded Q345qDNHY-I bridge, which is obtained in the embodiment, has large margin in yield strength and tensile strength, and good elongation and impact toughness at-20 ℃; the steel plate structure consists of 88 percent of ferrite and 12 percent of granular bainite, and the grain size is 9 grade; the steel plate has uniform structure and performance, the yield ratio is less than or equal to 0.85, and the special performance requirements of customers are completely met.
Table 1 examples 1-8 marine climate resistant weldable type weather-resistant steel sheet for Q345qDNHY-I bridge, chemical composition and mass% thereof (%)
Figure DEST_PATH_IMAGE001
In table 1, the balance is Fe and inevitable impurities.
TABLE 2 examples 1-8 Marine climate resistant easy-to-weld type weather-resistant steel plate for Q345qDNHY-I bridge
Figure 677853DEST_PATH_IMAGE002
Although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: modifications and equivalents may be made thereto without departing from the spirit and scope of the invention and it is intended to cover in the claims the invention as defined in the appended claims.

Claims (10)

1. The marine climate-resistant easy-welding type weather-resistant steel plate for the bridge is characterized by comprising the following chemical components in percentage by mass: c: 0.06-0.10%, Mn: 1.30-1.50%, P is less than or equal to 0.010%, S is less than or equal to 0.002%, Nb: 0.015-0.035%, Ni: 1.25-1.50%, Al: 0.015 to 0.040%, Cu: 0.30-0.40%, Mo: 0.06-0.10% and the balance of Fe and inevitable impurities.
2. The marine climate resistant easy-welding type weather-resistant steel plate for the bridge according to claim 1, wherein the thickness of the weather-resistant steel plate is 20-65 mm.
3. The weather-resistant steel plate for the marine climate resistant easy-welding bridge as claimed in claim 1, wherein the weather-resistant steel plate structure consists of 85-90% of ferrite and 10-15% of granular bainite, and the grain size is not less than 9 grade.
4. The weather-resistant steel plate for the marine climate-resistant easy-welding bridge as claimed in claim 1, wherein the weather-resistant steel plate comprises: the yield strength Re0.2 is more than or equal to 345MPa, the tensile strength is more than or equal to 490MPa, the yield ratio is less than or equal to 0.85, the elongation is more than or equal to 20 percent, the transverse impact energy at minus 20 ℃ is more than or equal to 47J, and the weather resistance index V value is more than or equal to 1.20.
5. The production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge is characterized by comprising the working procedures of primary smelting, LF refining, Ca treatment, rolling and controlled cooling; and in the rolling procedure, II-type controlled rolling is adopted.
6. The production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge as claimed in claim 5, wherein in the primary smelting process, the molten steel tapping C is less than or equal to 0.05%.
7. The production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge as claimed in claim 5, wherein in the LF refining process, 1.5-1.9 kg/t of Al wire of steel is added for deep deoxidation after primary refining, 0.5-1.0 kg/t of Al grains of steel are added for slag-changing deoxidation, and the white slag holding time is not less than 30 min.
8. The production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge as claimed in claim 5, wherein in the Ca treatment step, 0.07-0.14 kg/t of solid pure calcium cored wire of steel is added for Ca treatment.
9. The production method of the weather-resistant steel plate for the marine climate resistant easy-welding bridge according to any one of claims 5 to 8, characterized in that in the rolling procedure, the initial rolling temperature in the stage I is 1000-1050 ℃, and the final rolling temperature is 950-980 ℃; and in the second stage, the steel airing thickness is more than or equal to 100mm, the initial rolling temperature is 850-880 ℃, and the final rolling temperature is 790-800 ℃.
10. The method for producing the marine climate resistant easy-welding type weather-resistant steel plate for the bridge according to any one of claims 5 to 8, wherein the controlled cooling process adopts air cooling after rolling.
CN202010833260.2A 2020-08-18 2020-08-18 Marine climate-resistant easily-welded weather-resistant steel plate for bridge and production method thereof Pending CN112126863A (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6052522A (en) * 1983-08-31 1985-03-25 Nippon Steel Corp Manufacture of weather-resistant steel material
JPH0820838A (en) * 1994-07-07 1996-01-23 Sumitomo Metal Ind Ltd Atmospheric corrosion resisting refractory steel material excellent in weldability and its production
CN105331880A (en) * 2015-11-12 2016-02-17 江阴兴澄特种钢铁有限公司 High-strength weather-proof bridge steel and preparation method thereof
CN108707829A (en) * 2018-05-30 2018-10-26 舞阳钢铁有限责任公司 Low-welding crack-sensitive Q420qF bridge steel plates and its production method
CN111218613A (en) * 2020-01-08 2020-06-02 河北华进贸易有限公司 Marine weather-proof bridge steel plate

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6052522A (en) * 1983-08-31 1985-03-25 Nippon Steel Corp Manufacture of weather-resistant steel material
JPH0820838A (en) * 1994-07-07 1996-01-23 Sumitomo Metal Ind Ltd Atmospheric corrosion resisting refractory steel material excellent in weldability and its production
CN105331880A (en) * 2015-11-12 2016-02-17 江阴兴澄特种钢铁有限公司 High-strength weather-proof bridge steel and preparation method thereof
CN108707829A (en) * 2018-05-30 2018-10-26 舞阳钢铁有限责任公司 Low-welding crack-sensitive Q420qF bridge steel plates and its production method
CN111218613A (en) * 2020-01-08 2020-06-02 河北华进贸易有限公司 Marine weather-proof bridge steel plate

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Application publication date: 20201225