A high-aluminum rare earth weathering steel for bridge damper and preparation method thereof

Abstract

The invention discloses a high-aluminum rare earth weathering steel for a bridge damper and a preparation method thereof, comprising the following elements: Al: 2.0-4.0%, Si: 0.30-2.0%, Mn: 0.6-0.8%, Ti: 0.02-0.15%, V: 0.05-0.20%, Cu: 0.18-0.30%, Ni: 0.15-0.25%, B: 0.12-0.20%, C: 0.06-0.09%, P: 0.018-0.40%, S: 0.003-0.008%, Re: 0.0075-0.080%, and the remainder is Fe and unavoidable impurities. The preparation method comprises: raw material pretreatment; high temperature smelting; casting and rolling; cutting and grinding; and surface final treatment. By combining various elements and optimizing the surface treatment method, the weathering steel obtained in the present invention has the characteristics of high strength, easy welding, good weather resistance and good shock-absorbing and damping performance. It is used as the skeleton material in the bridge damper, which can significantly improve the seismic performance, durability and vibration control effect of the bridge.

Description

Technical Field

[0001] The invention relates to the technical field of bridge damper materials, and in particular to a high-aluminum rare earth weathering steel for a bridge damper and a preparation method thereof. Background Art

[0002] The raw materials of bridge dampers are usually composed of high molecular polymers (rubber), metal materials, adhesives, damping media and coatings. Among them, metal materials, as the exoskeleton of the damper, shape various bridge damping devices, provide support, energy consumption and protection capabilities in all directions, and their effectiveness and durability directly determine the performance and service life of the entire bridge damper. Traditional steel, as the main component material of the damper exoskeleton, has a certain strength, but its impact toughness, weldability, fatigue resistance, etc. are not ideal, and it performs worse in terms of resistance to atmospheric and marine corrosion, which will directly affect the service life of the damper, maintenance costs and the safety of the bridge. The research and application of bridge dampers in the existing technology focuses more on the innovation of damper structure, lacks the exploration and application of its materials. With the development of modern bridge dampers, the selection of steel materials for dampers has become particularly demanding.

[0003] As a special type of steel, rare earth weathering steel has excellent weather resistance and mechanical properties and has been widely used in the engineering field in recent years. The addition of rare earth elements and appropriate alloy design enable it to be used for a long time in harsh natural environment conditions without being easily corroded. In addition, rare earth weathering steel also has higher damping properties than ordinary steel, which can absorb and disperse the energy of vibration, thereby reducing the vibration amplitude of the structure. Therefore, the application of rare earth weathering steel in the field of bridge dampers is expected to significantly improve the seismic performance, durability and vibration control effect of bridges. Summary of the invention

[0004] The present invention is to overcome the above-mentioned problems existing in the prior art and provide a high-aluminum rare earth weathering steel for a bridge damper and a preparation method thereof. The high-aluminum rare earth weathering steel has the characteristics of high strength, easy welding, good weathering resistance and good shock-absorbing and damping performance. It is used as a skeleton material in a bridge damper and can significantly improve the seismic resistance, durability and vibration control effect of the bridge.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a high-aluminum rare earth weathering steel for a bridge damper, which comprises the following elements, measured in percentage by mass: Al: 2.0-4.0%, Si: 0.30-2.0%, Mn: 0.6-0.8%, Ti: 0.02-0.15%, V: 0.05-0.20%, Cu: 0.18-0.30%, Ni: 0.15-0.25%, B: 0.12-0.20%, C: 0.06-0.09%, P: 0.018-0.40%, S: 0.003-0.008%, Re: 0.0075-0.080%, and the remainder is Fe and unavoidable impurities; wherein Re is a rare earth element.

[0007] In the high-aluminum rare earth weathering steel of the present invention, the introduction of Al, Si and Mn plays an important role in improving corrosion resistance, reducing the density of weathering steel and refining grains. Ti and V not only play the role of strong deoxidizers in high-aluminum weathering steel, but also can regulate the density of the organization and refine the grains. The addition of Cu, Ni and B can improve the atmospheric corrosion resistance, strength and hot rolling performance of aluminum weathering steel. Trace amounts of Re can effectively control and improve the size and shape of inclusions in weathering steel, improve the cleanliness of molten steel, and effectively remove harmful impurities in steel while improving the toughness, weldability and processing performance of weathering steel, pointing out the direction for the development of green manufacturing of weathering steel in the future. Under the synergistic effect of various elements, the weathering steel in the present invention has the characteristics of high strength, easy welding, good weather resistance and good shock absorption and damping performance. It is used as a skeleton material in a bridge damper, which can significantly improve the seismic performance, durability and vibration control effect of the bridge.

[0008] Preferably, the mass percentage ratio of the Al, Ti and V elements is: Al:(Ti+V)=10-20.

[0009] Preferably, the mass percentage ratio of the Al, Cu, Ni and B elements is: Al:(Cu+Ni+B)=3-6.

[0010] The present invention controls the ratio of Al element to Ti, V element and Cu, Ni, B element within this range to control the content of intermetallic compounds in weathering steel within a certain range, which is beneficial to improving the strength, toughness and processing performance of weathering steel dampers.

[0011] Preferably, the mass percentage ratio of the Re and S elements is: Re:S=2.5-10.

[0012] Preferably, Re is one or more of Ce, La and Y.

[0013] In a second aspect, the present invention provides a method for preparing the high-aluminum rare earth weathering steel for the bridge damper, which is characterized by comprising the following steps:

[0014] S1: Raw material pretreatment: remove dust and impurities from the surface of the raw materials of each element, cut the raw materials and grind them;

[0015] S2: High temperature smelting: weigh the raw materials of each element in proportion and place them in a smelting blast furnace for heating and melting, stirring continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0016] S3: Casting and rolling: Casting and rolling the obtained molten steel mixture to form steel and cooling it, followed by quenching heat treatment;

[0017] S4: Cutting and grinding: Cut the heat-treated steel and grind the surface to remove burrs;

[0018] S5: Final surface treatment: Several carbide balls are rolled on the surface of the steel material, causing uniform plastic deformation on the surface of the steel material, thereby refining the grains on the surface of the steel material to form a gradient structure. The steel material surface is then hot-dip coated with a metal layer, coated with a passivation liquid, and painted to obtain the high-aluminum rare earth weathering steel for the bridge damper.

[0019] The present invention utilizes carbide balls to roll on the surface of the steel during the final treatment to perform surface gradient treatment on the steel, which can further refine the surface grains, thereby further improving the strength, corrosion resistance and shock absorption damping characteristics of the weathering steel damper. Using the high-aluminum rare earth weathering steel in the present invention for bridge dampers can effectively ensure the effectiveness of the bridge dampers and extend the service life of the dampers. Moreover, the method in the present invention is simple and easy to implement, has advantages in implementation cost, and can be widely used in bridge dampers.

[0020] Preferably, the heating melting temperature in S2 is 1600-1900°C.

[0021] Preferably, during the rolling process in S3, the starting rolling temperature is 1100-1200°C, the final rolling temperature is 800-900°C; the cooling time is 5-8h; the quenching heat treatment temperature is 750-800°C, and the time is 10s-5min.

[0022] Preferably, the number of cemented carbide balls in S5 is 5 to 10, and the diameter is 15 to 25 mm; the moving direction of the cemented carbide balls on the surface of the steel plate can be freely adjusted, and uniform plastic deformation on the surface of the steel plate is counted as one surface gradient treatment, and the number of treatments is 20 to 50 times; the downward pressure of the cemented carbide balls during a single treatment on the surface of the steel plate remains unchanged, and as the number of treatments increases, the downward pressure increases uniformly from 15 mm to 45 mm; during a single treatment, all the cemented carbide balls move in the same direction on the surface of the steel plate, and the moving speed is 200 to 450 mm / s.

[0023] Preferably, lubricating oil is evenly coated on the surface of the steel before S5 surface final treatment.

[0024] Preferably, the hot-dip metal layer in S5 is a zinc layer, and the thickness of the metal layer is 40 μm to 200 μm. Hot-dip galvanizing on the surface of weathering steel mainly plays the role of aesthetics and rust prevention, and can significantly improve the protection and decorative properties.

[0025] Preferably, the passivation solution in S5 is selected from chromic acid passivation solution, nitric acid passivation solution, and magnesium passivation solution, and the thickness of the passivation film is 1 to 200 nm.

[0026] Therefore, the present invention has the following beneficial effects:

[0027] (1) The introduction of Al, Si and Mn in the high-aluminum rare earth weathering steel of the present invention plays an important role in improving corrosion resistance, reducing the density of weathering steel and refining grains. Ti and V not only act as strong deoxidizers in high-aluminum weathering steel, but also can regulate the density of the organization and refine the grains; the addition of Cu, Ni and B can improve the atmospheric corrosion resistance, strength and hot rolling performance of aluminum weathering steel; trace amounts of Re can effectively control and improve the size and shape of inclusions in weathering steel, improve the cleanliness of molten steel, and effectively remove harmful impurities in the steel while also improving the toughness, weldability and processing performance of weathering steel;

[0028] (2) The present invention uses the content of Al element to control the content of Ti, V and Cu, Ni, B elements for the first time, so as to control the intermetallic compounds in the steel within a certain range, which is beneficial to improving the strength, toughness and processing performance of the weathering steel damper;

[0029] (3) During the final treatment, the surface of the steel is gradient treated by rolling a carbide ball on the surface, which can further refine the surface grains, thereby further improving the strength, corrosion resistance and shock absorption damping characteristics of the weathering steel damper. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a preparation process flow chart of the present invention.

[0031] Figure 2 It is a schematic diagram comparing the surface grain size and body-centered grain size of weathering steel before and after the surface final treatment of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art.

[0034] Overall embodiment:

[0035] A high-aluminum rare-earth weathering steel for a bridge damper comprises the following elements, measured by mass percentage: Al: 2.0-4.0%, Si: 0.30-2.0%, Mn: 0.6-0.8%, Ti: 0.02-0.15%, V: 0.05-0.20%, Cu: 0.18-0.30%, Ni: 0.15-0.25%, B: 0.12-0.20%, C: 0.06-0.09%, P: 0.018-0.40%, S: 0.003-0.008%, Re: 0.0075-0.080%, and the remainder is Fe and unavoidable impurities; wherein Re is a rare earth element.

[0036] As a preferred solution, the mass percentage ratio of the Al, Ti and V elements is: Al:(Ti+V)=10-20.

[0037] As a preferred solution, the mass percentage ratio of the Al, Cu, Ni and B elements is: Al: (Cu+Ni+B) = 3-6.

[0038] As a preferred solution, the mass percentage ratio of the Re and S elements is: Re:S=2.5-10.

[0039] As a preferred solution, Re is one or more of Ce, La, and Y.

[0040] The preparation process of the high aluminum rare earth weathering steel for the bridge damper is as follows: Figure 1 As shown in , the following steps are included:

[0041] S1: Raw material pretreatment: remove dust and impurities from the surface of the raw materials of each element, cut the raw materials and grind them;

[0042] S2: High temperature smelting: weigh the raw materials of each element in proportion and place them in a smelting blast furnace for heating and melting, stirring continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0043] S3: Casting and rolling: Casting and rolling the obtained molten steel mixture to form steel and cooling it, followed by quenching heat treatment;

[0044] S4: Cutting and grinding: Cut the heat-treated steel and grind the surface to remove burrs;

[0045] S5: Final surface treatment: Several carbide balls are rolled on the surface of the steel material, causing uniform plastic deformation on the surface of the steel material, thereby refining the grains on the surface of the steel material to form a gradient structure. The steel material surface is then hot-dip coated with a metal layer, coated with a passivation liquid, and painted to obtain the high-aluminum rare earth weathering steel for the bridge damper.

[0046] As a preferred solution, the heating and melting temperature in S2 is 1600-1900°C.

[0047] As a preferred solution, in the rolling process in S3, the starting rolling temperature is 1100-1200°C, the final rolling temperature is 800-900°C; the cooling time is 5-8h; the quenching heat treatment temperature is 750-800°C, and the time is 10s-5min.

[0048] As a preferred solution, the number of cemented carbide balls in S5 is 5 to 10, and the diameter is 15 to 25 mm; the moving direction of the cemented carbide balls on the surface of the steel plate can be freely adjusted, and uniform plastic deformation on the surface of the steel plate is counted as one surface gradient treatment, and the number of treatments is 20 to 50 times; the downward pressure of the cemented carbide balls during a single treatment of the steel plate surface remains unchanged, and as the number of treatments increases, the downward pressure increases uniformly from 15 mm to 45 mm; during a single treatment, all the cemented carbide balls move in the same direction on the surface of the steel plate, and the moving speed is 200 to 450 mm / s.

[0049] As a preferred solution, lubricating oil is evenly coated on the surface of the steel before the S5 surface final treatment.

[0050] As a preferred solution, the hot-dip metal layer in S5 is a zinc layer, and the thickness of the metal layer is 40 μm to 200 μm.

[0051] As a preferred solution, the passivation solution in S5 is selected from chromic acid passivation solution, nitric acid passivation solution, and magnesium passivation solution, and the thickness of the passivation film is 1 to 200 nm.

[0052] Embodiment 1:

[0053] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured by mass percentage: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.06%, Cu: 0.20%, Ni: 0.20%, B: 0.15%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.05%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V)=20, Al: (Cu+Ni+B)=3.64, Ce: S=10).

[0054] The preparation method of the high-aluminum rare earth weathering steel for the bridge damper comprises the following steps:

[0055] S1: Raw material processing: remove dust and impurities from the surface of the raw materials, cut the raw materials and grind them for subsequent smelting;

[0056] S2: High temperature smelting: weigh the raw materials in step S1 according to the determined mass percentage of each element, place them in a smelting blast furnace, heat them to 1650°C and melt them, and stir them continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0057] S3: Casting and rolling: Cast the molten steel mixture from step S2, with the starting rolling temperature at 1100°C and the final rolling temperature at 800°C, process it into corresponding steel and cool it for 5 hours, and then perform quenching heat treatment at a temperature of 760°C for 1 minute;

[0058] S4: Cutting and grinding: Cut the steel made in S3 into suitable and consistent sizes, and grind the surface to remove burrs;

[0059] S5: Final surface treatment: Lubricating oil is evenly applied on the steel surface, and five carbide balls with a diameter of 15 mm are used to roll along the steel surface in the same direction at a speed of 200 mm / s for surface gradient treatment. The downward pressure is adjusted after each treatment for 3 times, increasing by 5 mm at a time, and the downward pressure is gradually increased from 15 mm to 45 mm, for a total of 18 times; finally, the steel surface is hot-dip galvanized, coated with passivation liquid, and painted; the thickness of the zinc layer is 100μm; the passivation liquid is chromic acid passivation liquid, and the coating thickness is 100nm; JN55 type Ocean Old Man (HYLR) weather-resistant polyurethane topcoat is used for painting.

[0060] Embodiment 2:

[0061] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured by mass percentage: Al: 3.5%, Si: 0.60%, Mn: 0.80%, Ti: 0.15%, V: 0.2%, Cu: 0.30%, Ni: 0.20%, B: 0.20%, C: 0.08%, P: 0.03%, S: 0.005%, La: 0.025%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V)=10, Al: (Cu+Ni+B)=5, La: S=5).

[0062] The preparation method of the high-aluminum rare earth weathering steel for the bridge damper comprises the following steps:

[0063] S1: Raw material processing: remove dust and impurities from the surface of the raw materials, cut the raw materials and grind them for subsequent smelting;

[0064] S2: High temperature smelting: weigh the raw materials in step S1 according to the determined mass percentage of each element, place them in a smelting blast furnace, heat them to 1650°C and melt them, and stir them continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0065] S3: Casting and rolling: Cast the molten steel mixture from step S2, with the starting rolling temperature at 1150°C and the final rolling temperature at 850°C, process it into the corresponding steel material and cool it for 6 hours, and then perform quenching heat treatment at a temperature of 760°C for 1 minute;

[0066] S4: Cutting and grinding: Cut the steel made in S3 into suitable and consistent sizes, and grind the surface to remove burrs;

[0067] S5: Final surface treatment: Lubricating oil is evenly applied on the surface of the steel, and 10 carbide balls with a diameter of 20 mm are used to roll along the same direction of the steel surface at a speed of 300 mm / s for surface gradient treatment. The downward pressure is adjusted after each treatment for 3 times, increasing by 3 mm at a time, and the downward pressure is gradually increased from 15 mm to 45 mm, and a total of 30 treatments are performed; finally, the same materials and methods as in Example 1 are used to perform hot-dip metal coating, apply passivation liquid, and paint on the surface of the steel.

[0068] Embodiment 3:

[0069] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 4.0%, Si: 0.90%, Mn: 0.80%, Ti: 0.12%, V: 0.18%, Cu: 0.28%, Ni: 0.24%, B: 0.18%, C: 0.08%, P: 0.08%, S: 0.008%, Y: 0.064%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V)=13.33, Al: (Cu+Ni+B)=5.71, Y: S=8).

[0070] The preparation method of the high-aluminum rare earth weathering steel for the bridge damper comprises the following steps:

[0071] S1: Raw material processing: remove dust and impurities from the surface of the raw materials, cut the raw materials and grind them for subsequent smelting;

[0072] S2: High temperature smelting: weigh the raw materials in step S1 according to the determined mass percentage of each element, place them in a smelting blast furnace, heat them to 1650°C and melt them, and stir them continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0073] S3: Casting and rolling: Cast the molten steel mixture from step S2, with the starting rolling temperature at 1100°C and the final rolling temperature at 900°C, process it into corresponding steel and cool it for 8 hours, and then perform quenching heat treatment at a temperature of 760°C for 1 minute;

[0074] S4: Cutting and grinding: Cut the steel made in S3 into suitable and consistent sizes, and grind the surface to remove burrs;

[0075] S5: Final surface treatment: Lubricating oil is evenly applied on the surface of the steel, and 8 carbide balls with a diameter of 25 mm are used to roll along the same direction of the steel surface at a speed of 280 mm / s for surface gradient treatment. The pressure is adjusted after each treatment for 3 times, increasing by 3 mm at a time, and the pressure is gradually increased from 15 mm to 45 mm, and a total of 30 treatments are performed; finally, the same materials and methods as in Example 1 are used to perform hot-dip metal coating, apply passivation liquid, and paint on the surface of the steel.

[0076] Embodiment 4:

[0077] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured by mass percentage: Al: 3.5%, Si: 0.60%, Mn: 0.65%, Ti: 0.15%, V: 0.20%, Cu: 0.30%, Ni: 0.20%, B: 0.20%, C: 0.08%, P: 0.03%, S: 0.005%, La: 0.0125%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V)=10, Al: (Cu+Ni+B)=5, La: S=2.5).

[0078] The preparation method of the high-aluminum rare earth weathering steel for the bridge damper comprises the following steps:

[0079] S1: Raw material processing: remove dust and impurities from the surface of the raw materials, cut the raw materials and grind them for subsequent smelting;

[0080] S2: High temperature smelting: weigh the raw materials in step S1 according to the determined mass percentage of each element, place them in a smelting blast furnace, heat them to 1650°C and melt them, and stir them continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture;

[0081] S3: Casting and rolling: Cast the molten steel mixture from step S2, with the starting rolling temperature at 1100°C and the final rolling temperature at 900°C, process it into corresponding steel and cool it for 8 hours, and then perform quenching heat treatment at a temperature of 760°C for 1 minute;

[0082] S4: Cutting and grinding: Cut the steel made in S3 into suitable and consistent sizes, and grind the surface to remove burrs;

[0083] S5: Final surface treatment: Lubricating oil is evenly applied on the surface of the steel, and 8 carbide balls with a diameter of 25 mm are used to roll along the same direction of the steel surface at a speed of 280 mm / s for surface gradient treatment. The pressure is adjusted after each treatment for 3 times, increasing by 3 mm at a time, and the pressure is gradually increased from 15 mm to 45 mm, and a total of 30 treatments are performed; finally, the same materials and methods as in Example 1 are used to perform hot-dip metal coating, apply passivation liquid, and paint on the surface of the steel.

[0084] Comparative Example 1:

[0085] A weathering steel for a bridge damper comprises the following elements by mass percentage: 0.1% C, 0.5% Si, 0.15% P, 0.45% Cu, 0.05% Ti, and the balance is Fe and unavoidable impurities.

[0086] The preparation method is the same as that in Example 1.

[0087] Comparative Example 2 (without gradient treatment):

[0088] The difference between Comparative Example 2 and Example 1 is that no surface gradient treatment is performed in S5, and the surface of the steel material polished in S4 is directly subjected to hot-dip metal coating, passivation liquid coating, and painting treatment; the rest is the same as in Example 1.

[0089] Comparative Example 3 (the ratio of Al:(Ti+V) is too high):

[0090] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.04%, Cu: 0.20%, Ni: 0.20%, B: 0.15%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.05%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 25, Al: (Cu+Ni+B) = 3.64, Ce: S = 10); the preparation method is the same as that in Example 1.

[0091] Comparative Example 4 (the ratio of Al:(Ti+V) is too low):

[0092] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.2%, V: 0.2%, Cu: 0.20%, Ni: 0.20%, B: 0.15%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.05%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 5, Al: (Cu+Ni+B) = 3.64, Ce: S = 10); the preparation method is the same as that in Example 1.

[0093] Comparative Example 5 (the ratio of Al:(Cu+Ni+B) is too high):

[0094] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.06%, Cu: 0.05%, Ni: 0.10%, B: 0.05%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.05%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 20, Al: (Cu+Ni+B) = 10, Ce: S = 10); the preparation method is the same as that in Example 1.

[0095] Comparative Example 6 (the ratio of Al:(Cu+Ni+B) is too low):

[0096] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.06%, Cu: 0.60%, Ni: 0.80%, B: 0.60%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.05%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 20, Al: (Cu+Ni+B) = 1, Ce: S = 10); the preparation method is the same as that in Example 1.

[0097] Comparative Example 7 (Re:S ratio is too high):

[0098] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.06%, Cu: 0.20%, Ni: 0.20%, B: 0.15%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.1%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 20, Al: (Cu+Ni+B) = 3.64, Ce: S = 20); the preparation method is the same as that in Example 1.

[0099] Comparative Example 8 (Re:S ratio is too low):

[0100] A high-aluminum rare earth weathering steel for a bridge damper comprises the following elements, measured in percentage by mass: Al: 2.0%, Si: 0.80%, Mn: 0.70%, Ti: 0.04%, V: 0.06%, Cu: 0.20%, Ni: 0.20%, B: 0.15%, C: 0.06%, P: 0.03%, S: 0.005%, Ce: 0.005%, and the remainder is Fe and unavoidable impurities (Al: (Ti+V) = 20, Al: (Cu+Ni+B) = 3.64, Ce: S = 1); the preparation method is the same as that in Example 1.

[0101] The properties of the weathering steels obtained in the above embodiments and comparative examples were tested, and the results are shown in Table 1.

[0102] The test method for mechanical properties refers to GB / T 228-2002. During the test, each sample was cut into at least three uniaxial tensile specimens to ensure the repeatability of the data. The experiment adopted a uniaxial tensile test at room temperature, and an extensometer was used to monitor the tensile displacement of the sample during the entire test. The tensile rate was set to 5× -3 s -1 .

[0103] The test method for grain size on the surface and core of steel refers to GB / T 6394-2017.

[0104] Table 1: Weathering steel performance test results.

[0105]

[0106] It can be seen from the results in Table 1 that the high aluminum rare earth weathering steels prepared by the formula and method of the present invention in Examples 1 to 3 have finer grains, stronger strength, toughness and shock-absorbing damping performance than the traditional steel in Comparative Example 1.

[0107] from Figure 2It can be seen from the data comparison between Example 1 and Comparative Example 2 that the method of plastic deformation of the material by uniformly rolling the cemented carbide ball on the steel surface at high speed in the present invention further refines the grains on the steel surface. This shows that the high-aluminum rare earth weathering steel with this composition and surface treatment has good structural safety and good seismic performance, and has excellent engineering application prospects in the field of bridge dampers.

[0108] In Comparative Example 3, the ratio of Al: (Ti+V) is too high, which exceeds the range of the present invention, resulting in a decrease in the yield strength and tensile strength of the weathering steel. This is because the Ti element and the V element cannot inhibit the oxidation of the Al element in the weathering steel; in Comparative Example 4, the ratio of Al: (Ti+V) is too low, which will lead to a decrease in the yield strength and tensile strength of the weathering steel. This is because the Ti and V elements have extremely strong affinity with carbon and oxygen, and their excessive content changes the element ratio in the weathering steel.

[0109] In Comparative Example 5, the ratio of Al: (Cu+Ni+B) is too high, which exceeds the scope of the present invention, resulting in a decrease in yield strength and tensile strength. This is because the content of Cu, Ni, and B elements is too low, which reduces the hardenability of weathering steel; in Comparative Example 6, the ratio of Al: (Cu+Ni+B) is too low, which will lead to a decrease in the elongation of weathering steel. This is because the content of Cu, Ni, and B elements is too high, which is not conducive to hot rolling processing and may cause copper embrittlement.

[0110] In Comparative Example 7, the Re:S ratio is too high, which is beyond the scope of the present invention, resulting in a decrease in yield strength and tensile strength. This is because excess rare earth elements can easily cause drastic fluctuations in the properties of the steel and an unstable production process, thereby affecting the final performance of the weathering steel; in Comparative Example 8, the Re:S ratio is too low, which will lead to a decrease in yield strength and tensile strength. This is because rare earth elements cannot effectively eliminate the hazards of inclusions such as MnS.

[0111] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A high aluminum rare earth weathering steel for bridge dampers, characterized in that: The invention comprises the following elements in terms of mass percentage: Al: 2.0-4.0%, Si: 0.30-2.0%, Mn: 0.6-0.8%, Ti: 0.02-0.15%, V: 0.05-0.20%, Cu: 0.18-0.30%, Ni: 0.15-0.25%, B: 0.12-0.20%, C: 0.06-0.09%, P: 0.018-0.40%, S: 0.003-0.008%, RE: 0.0075-0.080%, and the remainder is Fe and unavoidable impurities; wherein RE is a rare earth element; the mass percentage ratio of the Al, Ti and V elements is: Al: (Ti+V) = 10-20; the mass percentage ratio of the Al, Cu, Ni and B elements is: Al: (Cu+Ni+B) = 3~6; the mass percentage ratio of the RE and S elements is: RE: S = 2.5~10.

2. The high aluminum rare earth weathering steel for bridge damper according to claim 1, characterized in that: The mass percentage ratio of the Al, Ti and V elements is: Al: (Ti+V) = 10.

3. The high aluminum rare earth weathering steel for bridge damper according to claim 1 or 2, characterized in that: The mass percentage ratio of the Al, Cu, Ni and B elements is: Al: (Cu+Ni+B) = 5.

4. The high aluminum rare earth weathering steel for bridge damper according to claim 1 is characterized in that: RE is one or more of Ce, La, and Y.

5. The high aluminum rare earth weathering steel for bridge damper according to claim 4, characterized in that: RE is La; the mass percentage ratio of La and S elements is: La : S = 5.

6. A method for preparing high aluminum rare earth weathering steel for bridge damper according to any one of claims 1 to 5, characterized in that: The steps include: S1: Raw material pretreatment: remove dust and impurities from the surface of the raw materials of each element, cut the raw materials and grind them; S2: High temperature smelting: weigh the raw materials of each element in proportion and place them in a smelting blast furnace for heating and melting, stirring continuously until there is no slag on the surface of the molten metal and the raw materials are completely mixed to obtain a molten steel mixture; S3: Casting and rolling: Casting and rolling the obtained molten steel mixture to form steel and cooling it, followed by quenching heat treatment; S4: Cutting and grinding: Cut the heat-treated steel and grind the surface to remove burrs; S5: Final surface treatment: Several carbide balls are rolled on the surface of the steel material, causing uniform plastic deformation on the surface of the steel material, thereby refining the grains on the surface of the steel material to form a gradient structure. The steel material surface is then hot-dip coated with a metal layer, coated with a passivation liquid, and painted to obtain the high-aluminum rare earth weathering steel for the bridge damper.

7. The preparation method according to claim 6, characterized in that: The heating melting temperature in S2 is 1600~1900℃.

8. The preparation method according to claim 6, characterized in that: During the rolling process in S3, the starting rolling temperature is 1100~1200 ℃, the final rolling temperature is 800~900 ℃; the cooling time is 5~8h; the quenching heat treatment temperature is 750~800 ℃, and the time is 10 s~5 min.

9. The preparation method according to claim 6, characterized in that: The number of cemented carbide balls in S5 is 5 to 10, and the diameter is 15 to 25 mm; the moving direction of the cemented carbide balls on the surface of the steel plate can be freely adjusted, and uniform plastic deformation on the surface of the steel plate is counted as one surface gradient treatment, and the number of treatments is 20 to 50 times; the downward pressure of the cemented carbide balls during a single treatment on the surface of the steel plate remains unchanged, and as the number of treatments increases, the downward pressure increases uniformly from 15 mm to 45 mm; during a single treatment, all the cemented carbide balls move in the same direction on the surface of the steel plate, and the moving speed is 200 to 450 mm / s.

10. The preparation method according to claim 6 or 9, characterized in that: S5: Apply lubricating oil evenly on the steel surface before final surface treatment.

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