High-strength rim structural steel and preparation method thereof

Abstract

The invention provides high-strength rim structural steel and a preparation method thereof. The high-strength rim structural steel comprises, by weight, 0.06 wt%-0.10 wt% of C, 1.10 wt%-1.70 wt% of Mn, 0.15 wt%-0.35 wt% of Si, 0.01 wt%-0.03 wt% of Nb, 0.20 wt%-0.40 wt% of Cr, smaller than or equal to 0.005 wt% of S, smaller than or equal to 0.020 wt% of P, 0.02 wt%-0.06 wt% of Als, smaller than or equal to 0.005 wt% of N and the balance Fe and trace elements. According to the chemical components of the high-strength rim structural steel, on the basis of medium-manganese and low-silicon components, the carbon content is low, the content of Nb and Cr elements is low, particularly, the content of Nb is very small, other metal elements such as Ti elements do not reach the detection limit, the cleanliness of the steel is high, the fatigue performance is excellent, and the service life of the steel is prolonged. The high-strength rim structural steel can bear cyclic loading for more than or equal to 1 million times in a fatigue performance test.

Description

Technical Field

[0001] The present application belongs to the technical field of high-strength steel, and specifically relates to a high-strength wheel rim structural steel and a preparation method thereof. Background Art

[0002] Wheels are important driving safety parts for automobiles. Commercial vehicles mainly use steel wheels, with an annual demand of more than 35 million pieces, requiring more than 1 million tons of steel. Wheels are composed of spokes and rims. The processing techniques of the two parts are completely different. Spokes are mainly made by spinning or stamping, while rims are mainly made by flash welding and roller technology, and finally welded together.

[0003] Lightweighting is a development trend in the automotive industry, and the main problem with high-strength rims is that the rolling process is not neat, resulting in cracking after flash welding; in addition, cracking occurs during the rolling and expansion process due to poor plasticity; and fatigue performance does not meet requirements due to impure materials. Summary of the invention

[0004] The present application provides a high-strength wheel rim structural steel and a preparation method thereof, which can obtain high-strength wheel rim structural steel with high cleanliness and excellent fatigue performance.

[0005] In a first aspect, the present application provides a high-strength wheel rim structural steel, comprising the following components in weight percentage: C is 0.06wt% to 0.10wt%, Mn is 1.10wt% to 1.70wt%, Si is 0.15wt% to 0.35wt%, Nb is 0.01wt% to 0.03wt%, Cr is 0.20wt% to 0.40wt%, S≤0.005wt%, P≤0.020wt%, Als is 0.02wt% to 0.06wt%, N≤0.005wt%, and the rest are Fe and trace elements.

[0006] In a feasible implementation manner of the first aspect of the present application, the average grain size of the high-strength rim structural steel is ≤5 μm.

[0007] In a feasible implementation manner of the first aspect of the present application, the microstructure of the high-strength rim structural steel includes ferrite, pearlite and bainite; in the microstructure, the volume fraction of ferrite is 90% to 95%, the volume fraction of pearlite is 0.5% to 2.0%, and the volume fraction of bainite is 5.0% to 8.0%.

[0008] In a feasible implementation manner of the first aspect of the present application, the high-strength rim structural steel has Class B inclusions <1.0 level, Class D inclusions ≤1.0 level, and Class Ds inclusions <1.0 level.

[0009] Among them, type B inclusions refer to oxide inclusions; type D inclusions refer to spherical oxide inclusions with a diameter less than 3μm; type Ds inclusions refer to single-particle round spherical inclusions with a diameter greater than or equal to 13μm.

[0010] In a feasible implementation manner of the first aspect of the present application, the high-strength rim structural steel can withstand cyclic loading times of ≥ 1 million times in fatigue performance testing.

[0011] In a feasible implementation manner of the first aspect of the present application, the high-strength rim structural steel has a yield strength of ≥460MPa, a tensile strength of 590MPa-760MPa, an elongation after fracture of ≥20%, and a low-temperature impact toughness of -20°C of ≥47J.

[0012] The second aspect of the present application provides a method for preparing the high-strength rim structural steel according to the first aspect of the present application, comprising:

[0013] Obtaining a continuous casting billet having the above-mentioned weight percentage of the components in the high-strength wheel rim structural steel of the first aspect of the present application;

[0014] The continuous casting billet is heated, the heating temperature is controlled to be 1180°C to 1250°C, the heating time is 150min to 240min, and the uniform heating time is ≥30min, so as to obtain the billet out of the furnace;

[0015] The billet is rolled, coiled, cooled and flattened to obtain high-strength wheel rim structural steel.

[0016] In a feasible implementation manner of the second aspect of the present application, rolling includes rough rolling and finish rolling, the rough rolling includes 5 passes of rolling, and the outlet thickness is less than or equal to 50 mm; the inlet temperature of the finish rolling is 950°C to 1050°C, and the finish rolling outlet temperature is controlled at 810°C to 860°C.

[0017] In a feasible implementation manner of the second aspect of the present application, the coiling temperature is 500°C to 525°C.

[0018] In a feasible implementation manner of the second aspect of the present application, cooling includes a laminar cooling mode, and the cooling rate is ≤25°C / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is an electron microscope image of the microstructure of the high-strength wheel rim structural steel of Example 1;

[0020] Figure 2 is an inclusion diagram of the high-strength rim structural steel of Example 1;

[0021] Figure 3 is an electron microscope image of the microstructure of the high-strength wheel rim structural steel of Example 2;

[0022] Figure 4This is an inclusion diagram of the high-strength rim structural steel of Example 2. DETAILED DESCRIPTION

[0023] In order to make the invention purpose, technical scheme and beneficial technical effect of the present application clearer, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the embodiments described in this specification are only for explaining the present application, not for limiting the present application.

[0024] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unambiguous range; and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, although not explicitly stated, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unambiguous range.

[0025] In the description herein, when a composition is described as containing, comprising or including specific components, or when a process is described as containing, comprising or including specific process steps, it is expected that the composition of the present application also consists essentially of or consists of the components, and the process of the present application also consists essentially of or consists of the process steps.

[0026] The use of the terms "including," "comprising," "containing," and "having" should generally be interpreted as open ended and non-limiting unless expressly stated otherwise.

[0027] In the description of this article, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number itself, and the “multiple” in “one or more” means more than two.

[0028] The above-mentioned summary of the invention of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0029] The present application provides a high-strength wheel rim structural steel and a preparation method thereof, which improves the strength, plasticity and fatigue performance of the material, meets the wheel rim processing and performance requirements, and achieves lightweight.

[0030] In an embodiment of the first aspect of the present application, a high-strength wheel rim structural steel is provided, comprising the following components in weight percentage: C is 0.06wt% to 0.10wt%, Mn is 1.10wt% to 1.70wt%, Si is 0.15wt% to 0.35wt%, Nb is 0.01wt% to 0.03wt%, Cr is 0.20wt% to 0.40wt%, S≤0.005wt%, P≤0.020wt%, Als is 0.02wt% to 0.06wt%, N≤0.005wt%, and the rest are Fe and trace elements.

[0031] The chemical composition of the high-strength wheel rim structural steel of the present application, based on the medium manganese and low silicon components, not only has a low carbon content, but also has low contents of Nb and Cr, especially very little Nb, and other metal elements including Ti do not reach the detection limit. The steel has high cleanliness and excellent fatigue performance. The high-strength wheel rim structural steel can withstand ≥ 1 million cyclic loading times in fatigue performance tests.

[0032] At the same time, the high-strength rim structural steel of the present application has the properties of low stress and high plasticity based on excellent fatigue performance, with a yield strength ≥460MPa, a tensile strength of 590-760MPa, an elongation after fracture ≥20%, and a low-temperature impact toughness of -20°C ≥47J.

[0033] In some embodiments, the average grain size of the high-strength rim structural steel is ≤5 μm.

[0034] In some embodiments, the microstructure of the high-strength rim structural steel includes ferrite, pearlite and bainite; in the microstructure, the volume fraction of ferrite is 90% to 95%, the volume fraction of pearlite is 0.5% to 2.0%, and the volume fraction of bainite is 5.0% to 8.0%.

[0035] The internal microstructure of the high-strength steel of the present application is mainly ferrite-based, with a small amount of pearlite and bainite, and fine grains. Ferrite has good toughness, can effectively absorb and disperse impact energy, and prevent the rim structural steel from breaking when subjected to external force impact. In addition, the fine grain structure also helps to improve the toughness of the rim structural steel, so that the rim structural steel can remain stable in a complex stress environment and improve the fatigue resistance of the material. A small amount of pearlite and bainite can improve the strength of the rim structural steel, so that the rim structural steel of the present application has both good fatigue resistance and strength.

[0036] In some embodiments, the high-strength rim structural steel has a B-type inclusion of less than level 1.0, a D-type inclusion of ≤ level 1.0, and a Ds-type inclusion of less than level 1.0.

[0037] Among them, type B inclusions refer to oxide inclusions; type D inclusions refer to spherical oxide inclusions with a diameter less than 3μm; type Ds inclusions refer to single-particle round spherical inclusions with a diameter greater than or equal to 13μm.

[0038] The high-strength wheel rim structural steel of the present application has few inclusions, can improve the purity, strength and fatigue performance of the steel, and improve the safety and reliability of the wheel, which is conducive to lightweight design.

[0039] In some embodiments, the high-strength rim structural steel can withstand cyclic loading times of ≥ 1 million times in a fatigue performance test.

[0040] In some embodiments, the high-strength rim structural steel has a yield strength of ≥460 MPa, a tensile strength of 590 MPa to 760 MPa, an elongation after fracture of ≥20%, and a low-temperature impact toughness of -20°C of ≥47 J.

[0041] In an embodiment of the second aspect of the present application, there is provided a method for preparing the high-strength rim structural steel described above in the first aspect of the present application, comprising:

[0042] Obtaining a continuous casting billet having the above-mentioned weight percentage of the components in the high-strength wheel rim structural steel of the first aspect of the present application;

[0043] The continuous casting billet is heated, the heating temperature is controlled to be 1180°C to 1250°C, the heating time is 150min to 240min, and the uniform heating time is ≥30min, so as to obtain the billet out of the furnace;

[0044] The billet is rolled, coiled, cooled and flattened to obtain high-strength wheel rim structural steel.

[0045] In the preparation method of the high-strength rim structural steel of the present application, on the basis that the continuous casting billet has the above-mentioned weight percentage of the components in the high-strength rim structural steel, the heating process, including the heating temperature, the heating time, etc., is controlled to allow the micro-alloying elements to be completely dissolved and form carbonitrides, thereby hindering the growth of the original austenite grains, refining the grains, and obtaining a high-strength rim structural steel with excellent fatigue performance and good strength.

[0046] In addition, if the time in the furnace is too long, it will increase the difficulty of cleaning the iron oxide scale and affect the surface quality of the rim.

[0047] In some embodiments, the rolling includes rough rolling and finish rolling, the rough rolling includes 5 rolling passes, and the outlet thickness is less than or equal to 50 mm.

[0048] In some embodiments, the inlet temperature of the finishing rolling is 950°C to 1050°C, and may be 960°C to 1000°C; the outlet temperature of the finishing rolling is controlled at 810°C to 860°C, and may be 820°C to 840°C.

[0049] The inlet temperature of the finishing rolling is controlled within the above range, and the thickness of the surface oxide scale of the thick specification product is controlled by low temperature rapid rolling, thereby improving the surface quality of the steel and reducing the roughness. In addition, the steel of the present application can have a good microstructure, refined grains, and good mechanical properties.

[0050] The outlet temperature of finishing rolling is controlled within the above range. When rolling in the ferrite region, with the increase of large reduction, the grain boundary or deformation band of deformed austenite is the nucleation site of ferrite, thereby achieving the effect of grain refinement, and the gradual precipitation of micro-alloy elements can also improve the strength.

[0051] In some embodiments, the coiling temperature is 500°C to 525°C.

[0052] In some embodiments, the cumulative reduction rate in the rolling zone is 20% to 23%.

[0053] Controlling the coiling temperature within the above range allows the micro-alloying elements to be fully precipitated during cooling, thereby improving the strength and plasticity of the product.

[0054] In addition, slow cooling after coiling can physically release some internal stress, and adding a flattening process before leaving the factory can ensure that the internal stress is fully released, which is more suitable for the reliability of the rim rolling process and flash welding.

[0055] In some embodiments, cooling comprises a laminar cooling mode, and the cooling rate is ≤ 25°C / s.

[0056] In some embodiments, the flattening process is performed after cooling to room temperature, and the elongation is controlled to be 1.0% to 1.5%.

[0057] Example

[0058] The following examples more specifically describe the disclosure of the present application, which are intended for illustrative purposes only, as it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the disclosure of the present application. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0059] Example 1

[0060] The 600MPa high-strength wheel rim structural steel of this embodiment includes the following components in percentage by mass: C is 0.0843wt%, Mn is 1.4379wt%, Si is 0.263wt%, Nb is 0.0237wt%, Cr is 0.2842wt%, Als is 0.0337wt%, S is 0.0024wt%, P is 0.0122wt%, N is 0.0032wt%, and the rest are Fe and trace elements.

[0061] The preparation method of the 600MPa high-strength wheel rim structural steel in this embodiment includes:

[0062] Obtain a continuous casting billet, the continuous casting billet comprising the following components in percentage by weight: 0.0843wt% of C, 1.4379wt% of Mn, 0.263wt% of Si, 0.0237wt% of Nb, 0.2842wt% of Cr, 0.0337wt% of Als, 0.0024wt% of S, 0.0122wt% of P, 0.0032wt% of N, and the rest being Fe and trace elements;

[0063] The continuous casting billet is heated to 1225°C in a heating furnace, the soaking time is 32 minutes, and the cumulative time in the furnace is 193 minutes;

[0064] After the continuous casting billet is discharged from the heating furnace, it is roughly descaled by high-pressure water, and then it is rough rolled for 5 round trips. The rough rolling outlet is 46mm, and then it enters the fine descaling;

[0065] Entering the 7-stand finishing rolling, the finished steel coil with a thickness of 5.5 mm is rolled out; the starting rolling temperature is 987°C, the cumulative reduction rate of the ferrite rolling zone is 22%, the finishing rolling outlet temperature is 836°C, and the coiling temperature is 524°C;

[0066] The cooling adopts layer cooling and front-end centralized cooling mode with a cooling speed of 18℃ / s. It cannot be cooled by ultra-fast cooling. After coiling, it is air-cooled on the transport chain and then put into the insulation pit for slow cooling to room temperature with the furnace. After cooling to room temperature, the flattening process is carried out with the elongation controlled at 1.2% and high tension rolling to obtain higher flatness requirements.

[0067] The 600MPa high-strength wheel rim structural steel of this embodiment, after transverse testing of mechanical properties, has a yield strength of 541MPa, a tensile strength of 604MPa, and an elongation after fracture of 28%.

[0068] The microstructure of the 600 MPa high-strength wheel rim structural steel of this embodiment is mainly ferrite with a small amount of pearlite and bainite. The volume fraction of ferrite is 91%, the volume fraction of pearlite is 2%, the volume fraction of bainite is 7%, and the average grain size is 3.8 μm.

[0069] The inclusion grade of the 600MPa high-strength rim structural steel in this embodiment is: Class D 0.5.

[0070] The high-strength rim structural steel of this embodiment can withstand 1.24 million cycles of loading in the fatigue performance test.

[0071] Example 2

[0072] The 600MPa high-strength wheel rim structural steel of this embodiment includes the following components in percentage by mass: C is 0.0752wt%, Mn is 1.5104wt%, Si is 0.2542wt%, Nb is 0.0287wt%, Cr is 0.2678wt%, Als is 0.0349wt%, S is 0.0032wt%, P is 0.0114wt%, N is 0.0035wt%, and the rest are Fe and trace elements.

[0073] The preparation method of the 600MPa high-strength wheel rim structural steel in this embodiment includes:

[0074] Obtain a continuous casting billet, the continuous casting billet comprising the following components in percentage by weight: 0.0752wt% of C, 1.5104wt% of Mn, 0.2542wt% of Si, 0.0287wt% of Nb, 0.2678wt% of Cr, 0.0349wt% of Als, 0.0032wt% of S, 0.0114wt% of P, 0.0035wt% of N, and the rest being Fe and trace elements;

[0075] The continuous casting billet is heated to 1224°C in a heating furnace, the soaking time is 34 minutes, and the cumulative time in the furnace is 220 minutes;

[0076] After the continuous casting billet is discharged from the heating furnace, it is roughly descaled by high-pressure water, and then it is rolled back and forth for 5 times, with the rough rolling outlet being 42mm, and then it enters the fine descaling;

[0077] Entering the 7-stand finishing rolling, the finished steel coil with a thickness of 4.0 mm is rolled out; the starting rolling temperature is 987°C, the cumulative reduction rate of the ferrite rolling zone is 21%, the finishing rolling outlet temperature is 835°C, and the coiling temperature is 514°C;

[0078] The cooling adopts layer cooling and front-end centralized cooling mode with a cooling speed of 16℃ / s. It cannot be cooled by ultra-fast cooling. After coiling, it is air-cooled on the transport chain and then put into the insulation pit for slow cooling to room temperature with the furnace. After cooling to room temperature, the flattening process is carried out with the elongation controlled at 1.4% and high tension rolling to obtain higher flatness requirements.

[0079] The 600MPa high-strength wheel rim structural steel of this embodiment, after transverse testing of mechanical properties, has a yield strength of 533MPa, a tensile strength of 636MPa, and an elongation after fracture of 25%.

[0080] The microstructure of the 600 MPa high-strength wheel rim structural steel of this embodiment is mainly ferrite with a small amount of pearlite and bainite. The volume fraction of ferrite is 93%, the volume fraction of pearlite is 2%, the volume fraction of bainite is 6%, and the average grain size is 3.2 μm.

[0081] The inclusion levels of the 600MPa high-strength rim structural steel in this embodiment are: Class B 0.5, Class D 0.5.

[0082] The high-strength rim structural steel of this embodiment can withstand 1.2 million cycles of loading in the fatigue performance test.

[0083] Example 3

[0084] Compared with Example 1, the difference is that the process of the continuous casting billet passing through the heating furnace during the preparation process is different. The heating temperature of the heating furnace in this embodiment is 1350° C., and the time in the furnace is 150 minutes.

[0085] The 600MPa high-strength wheel rim structural steel of this embodiment, after transverse testing of mechanical properties, has a yield strength of 522MPa, a tensile strength of 615MPa, and an elongation after fracture of 26%.

[0086] The microstructure of the 600MPa high-strength wheel rim structural steel of this embodiment is mainly ferrite with a small amount of pearlite and bainite. The volume fraction of ferrite is 93%, the volume fraction of pearlite is 1.0%, the volume fraction of bainite is 6%, and the average grain size is 4.2nm.

[0087] The inclusion levels of the 600 MPa high-strength rim structural steel in this embodiment are: Class B, Class 1.0, and Class D, Class 0.5.

[0088] The high-strength rim structural steel of this embodiment can withstand 1.08 million cycles of loading in the fatigue performance test.

[0089] Example 4

[0090] Compared with Example 1, the difference is that the finishing rolling process in the preparation process is different. The inlet temperature of the finishing rolling in this embodiment is 1015°C, and the outlet temperature of the finishing rolling is 865°C.

[0091] The 600MPa high-strength wheel rim structural steel of this embodiment, after transverse testing of mechanical properties, has a yield strength of 539MPa, a tensile strength of 627MPa, and an elongation after fracture of 26.5%.

[0092] The microstructure of the 600 MPa high-strength wheel rim structural steel of this embodiment is mainly ferrite with a small amount of pearlite and bainite. The volume fraction of ferrite is 93%, the volume fraction of pearlite is 1%, the volume fraction of bainite is 6%, and the average grain size is 3.8 μm.

[0093] The inclusion levels of the 600MPa high-strength rim structural steel in this embodiment are: Class B 0.5, Class D 0.5.

[0094] The high-strength rim structural steel of this embodiment can withstand 1.02 million cycles of loading in the fatigue performance test.

[0095] Example 5

[0096] Compared with Example 1, the difference is that the coiling and cooling steps in the preparation process are different. The coiling temperature of this embodiment is 540°C and the cooling rate is 20°C / s.

[0097] The 600MPa high-strength wheel rim structural steel of this embodiment, after transverse testing of mechanical properties, has a yield strength of 535MPa, a tensile strength of 638MPa, and an elongation after fracture of 29%.

[0098] The microstructure of the 600MPa high-strength wheel rim structural steel of this embodiment is mainly ferrite with a small amount of pearlite and bainite. The volume fraction of ferrite is 94%, the volume fraction of pearlite is 1%, the volume fraction of bainite is 5%, and the average grain size is 3.6μm.

[0099] The inclusion grade of the 600MPa high-strength rim structural steel in this embodiment is Class B 0.5 and Class D 0.5.

[0100] The high-strength rim structural steel of this embodiment can withstand 1 million cycles of loading in the fatigue performance test.

[0101] Comparative Example 1

[0102] Compared with Example 1, the difference is that the components of the rim structural steel are different, its cleanliness is lower, the mass content of Nb is high, and there is also Ti element. The rim structural steel of this comparative example includes the following components in mass percentage: C is 0.0685wt%, Mn is 1.1451wt%, Si is 0.2465wt%, Nb is 0.032wt%, Cr is 0.03wt%, Ti is 0.0252wt%, Als is 0.0335wt%, S is 0.0045wt%, P is 0.0156wt%, N is 0.0057%, and the rest is Fe and trace elements.

[0103] After the transverse mechanical property test, the rim structural steel of this comparative example has a yield strength of 580 MPa, a tensile strength of 675 MPa, and an elongation after fracture of 22%.

[0104] The microstructure of the rim structural steel of this comparative example is as follows: the volume fraction of ferrite is 86%, the volume fraction of pearlite is 5%, the volume fraction of bainite is 9%, and the average grain size is 5.6 μm.

[0105] The inclusion grades of the rim structural steel of this comparative example are: Class B grade 1.0, Class D grade 0.5, and Class Ds grade 1.5.

[0106] The rim structural steel of this comparative example can withstand 800,000 cycles of loading in the fatigue performance test.

[0107] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A high-strength rim structural steel, characterized in that: The invention comprises the following components in weight percentage: C is 0.06wt%-0.10wt%, Mn is 1.10wt%-1.70wt%, Si is 0.15wt%-0.35wt%, Nb is 0.01wt%-0.03wt%, Cr is 0.20wt%-0.40wt%, S≤0.005wt%, P≤0.020wt%, Als is 0.02wt%-0.06wt%, N≤0.005wt%, and the rest are Fe and trace elements.

2. The high-strength rim structural steel according to claim 1, characterized in that: The average grain size of the high-strength rim structural steel is ≤5 μm.

3. The high-strength rim structural steel according to claim 1, characterized in that: The microstructure of the high-strength rim structural steel includes ferrite, pearlite and a small amount of bainite; in the microstructure, the volume fraction of the ferrite is 90% to 95%, the volume fraction of the pearlite is 0.2% to 2.0%, and the volume fraction of the bainite is 5.0% to 8.0%.

4. The high-strength rim structural steel according to claim 1, characterized in that: The high-strength rim structural steel has Class B inclusions <1.0 level, Class D inclusions ≤1.0 level, and Class Ds inclusions <1.0 level.

5. The high-strength rim structural steel according to claim 1, characterized in that: The high-strength rim structural steel can withstand cyclic loading times of ≥ 1 million times in fatigue performance testing.

6. The high-strength rim structural steel according to claim 1, characterized in that: The high-strength wheel rim structural steel has a yield strength of ≥460MPa, a tensile strength of 590MPa-760MPa, an elongation after fracture of ≥20%, and a low-temperature impact toughness of -20°C of ≥47J.

7. A method for preparing the high-strength rim structural steel according to any one of claims 1 to 6, characterized in that: include: Obtaining a continuous casting slab comprising the components in the weight percentage of claim 1; The continuous casting billet is heated, the heating temperature is controlled to be 1180° C. to 1250° C., the heating time is 150 min to 240 min, and the uniform heating time is ≥ 30 min, so as to obtain a billet out of the furnace; The furnace-out billet is rolled, coiled, cooled and flattened to obtain high-strength wheel rim structural steel.

8. The method for preparing high-strength rim structural steel according to claim 7, characterized in that: The rolling includes rough rolling and finish rolling, the rough rolling includes 5 rolling passes, and the outlet thickness is less than or equal to 50 mm; the inlet temperature of the finish rolling is 950° C. to 1050° C., and the outlet temperature of the finish rolling is controlled at 810° C. to 860° C.

9. The method for preparing high-strength rim structural steel according to claim 7, characterized in that: The coiling temperature is 500-525°C.

10. The method for preparing high-strength rim structural steel according to any one of claims 7 to 9, characterized in that: The cooling includes a laminar cooling mode, and the cooling speed is ≤25°C / s.

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