High-performance corrosion-resistant rack steel plate and manufacturing method thereof

Abstract

The invention relates to the technical field of corrosion-resistant rack steel plates, in particular to a high-performance corrosion-resistant rack steel plate and a manufacturing method thereof. The high-strength steel is composed of the following chemical components in percentage by weight: 0.1%-0.15% of C, 0.22%-0.45% of Si, 1.1%-1.7% of Mn, less than or equal to 0.02% of P, less than or equal to 0.01% of S, 0.03%-0.06% of Als, 3.8%-5.5% of Ni, 0.7%-1.2% of Cr, 0.5%-0.9% of Mo, 0.25%-0.55% of Cu, 0.05%-0.15% of Sn, 0.05%-0.09% of V, 0.008%-0.02% of Ti, 0.004%-0.011% of N and the balance of Fe and inevitable impurities. The large-thickness, high-performance and corrosion-resistant rack steel plate is produced by combining special processes of high cleanliness, alloying smelting, casting machine soft reduction, electroslag remelting, forging cogging, efficient rolling, two-time quenching and tempering. The maximum thickness of a steel plate finished product is 210 mm, the yield strength is larger than or equal to 690 MPa, the tensile strength is 800-940 MPa, the ductility is larger than or equal to 18%, the Charpy impact energy of a steel plate core part at the temperature of-40 DEG C is larger than or equal to 150 J, and the corrosion resistance in the marine environment is excellent.

Description

Technical Field

[0001] This invention relates to the field of corrosion-resistant rack steel plate technology, specifically to a high-performance corrosion-resistant rack steel plate and its manufacturing method. Background Technology

[0002] In recent years, with the rapid development of marine engineering, shipbuilding, and offshore wind power, the demand for high-performance corrosion-resistant rack steel plates has been increasing. As a key transmission component, rack steel plates are widely used in offshore platform lifting systems, large cranes, and deep-sea equipment. They are exposed to high salt spray, high humidity, and highly corrosive marine environments for extended periods, making them highly susceptible to corrosion fatigue, pitting, and stress corrosion cracking, which seriously affect their service life and safety.

[0003] Currently, traditional toothed steel plates mostly use ordinary alloy steel or surface coating treatments (such as galvanizing or spraying anti-corrosion coatings) to improve corrosion resistance. However, these methods have significant shortcomings: ordinary alloy steel is prone to electrochemical corrosion in marine environments, leading to a decline in mechanical properties; the surface protective layer is easily peeled off under long-term friction, impact, or seawater erosion, losing its protective function; some high-alloy corrosion-resistant steels (such as duplex stainless steel) are expensive and have complex welding processes, making large-scale application difficult.

[0004] Chinese patent application CN202310778326.6, entitled "Thick 800MPa Hydropower Steel with Excellent Core Toughness and its Manufacturing Method," proposes a 150mm thick hydropower steel plate. It employs a low-C, low-Mn alloy with Mg to deoxidize and purify the steel, improving its impact toughness by adding Mg to enhance cleanliness. However, the production process still uses conventional smelting, rolling, and heat treatment processes, without incorporating special processes such as casting press reduction, electroslag remelting, or forging, nor does it achieve the excellent low-temperature toughness of ultra-thick steel plates over 200mm by increasing the alloy composition. Chinese patent application CN202310903370.5, entitled "A Production Method for Thick Tempered High-Strength Steel Plate with Excellent Resistance to Lamellar Tear," proposes a steel plate with excellent resistance to lamellar tearing, using a low-C, low-Mn, and low-Ni alloy system. Although this solution can significantly improve the steel plate's resistance to lamellar tearing, its composition design and production process have certain limitations: conventional composition and processes are only suitable for producing steel plates with a thickness of less than 150mm. As the thickness increases, it is difficult to guarantee the core's strength and low-temperature toughness. The steel plate also has poor resistance to marine environmental corrosion, which limits its application in harsh environments such as marine engineering. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a high-performance corrosion-resistant rack steel plate and its manufacturing method. The steel plate has a maximum thickness of 210mm and excellent mechanical properties, processability, and environmental adaptability. Compared with conventional EH690 marine engineering steel plates, it is more corrosion-resistant in seawater environments and has a longer service life.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A high-performance corrosion-resistant rack steel plate is composed of the following chemical composition in weight percentages:

[0008] C: 0.1%~0.15%, Si: 0.22%~0.45%, Mn: 1.1%~1.7%, P≤0.02%, S≤0.01%, Als: 0.03%~0.06%, Ni: 3.8%~5.5%, Cr: 0.7%~1.2%, Mo: 0.5%~0.9%, Cu: 0.25%~0.55%, Sn: 0.05%~0.15%, V: 0.05%~0.09%, Ti: 0.008%~0.02%, N: 0.004%~0.011%, with the remainder being Fe and unavoidable impurities.

[0009] The rationale for the design of the components in this invention is as follows:

[0010] 1. Carbon (C) can dissolve in austenite to form a solid solution and combine with Fe to form carbides, which can improve the strength, hardness, and wear resistance of steel. As the C content increases, the yield strength and tensile strength of the steel plate improve. However, when the C content exceeds 0.15%, the low-temperature toughness decreases, and the steel plate's resistance to seawater corrosion and atmospheric corrosion reduces. Therefore, this invention precisely controls the C content to 0.1%~0.15%.

[0011] 2. Si can improve the strength of steel plates. Simultaneously, as a deoxidizer, Si can reduce the oxygen content. Si can form a dense and stable oxide film, improving corrosion resistance. When the Si content is below 0.45%, it can prevent the steel plate from losing its low-temperature toughness. Therefore, this invention precisely controls the Si content to be between 0.22% and 0.45%.

[0012] 3. Mn has a similar atomic radius to Fe and can dissolve extensively in the Fe matrix, increasing the strength of the steel plate. Mn can refine the grain structure of the steel plate, increase the number of grain boundaries, and improve the low-temperature impact toughness of the steel plate. However, when the Mn content is too high, the hardening effect of Mn will reduce the low-temperature toughness of the core of the thick plate. In this invention, the alloy strength is relatively high, which easily causes segregation in the core of the billet. However, with specific light reduction and electroslag remelting processes, the problem of uneven composition and structure in the core of the billet can be perfectly solved. This invention can appropriately increase the Mn content. Therefore, this invention precisely controls the Mn content to be 1.1%~1.7%.

[0013] 4. P and S elements have no benefit to the mechanical properties of steel plates, especially elongation. P should be controlled to ≤0.02% and S to ≤0.01%.

[0014] 5. The phosphates in Als can react with oxides on the steel surface to form phosphate oxides, thereby preventing further oxidation of the steel. This reaction can effectively reduce the oxidation rate of the steel, extend its service life, and the protective film formed reduces the contact between the steel and the external environment, delaying corrosion. Therefore, this invention precisely controls the Al content to be 0.03%~0.06%.

[0015] 6. Ni can significantly improve the toughness and corrosion resistance of steel plates. A large addition results in a lower ductile-brittle transition temperature. Furthermore, the addition of Ni, in conjunction with microalloying elements such as V, further enhances the strength, toughness, and corrosion fatigue resistance of the steel plate. Ni also possesses certain corrosion resistance, exhibiting good resistance to acidic marine environments. Combined with elements such as Cr and Mo, it can improve the hot strength and corrosion resistance of steel. Therefore, this invention precisely controls the Ni content to be 3.8%~5.5%.

[0016] 7. The corrosion resistance of Cr in steel is mainly due to its ability to form a dense passivation film. This film effectively prevents further oxidation of the metal surface, thus significantly improving the corrosion resistance of the steel. Combined with elements such as Ni and Sn, it can achieve excellent resistance to marine corrosion even at low Cr content. Cr can also effectively increase the strength of steel plates. Appropriate addition of Cr can improve the cooling control effect of steel plates and increase the core heat transfer rate of extra-thick steel plates. However, excessive Cr content will produce a large amount of Cr carbides, reducing the impact toughness of the steel plate, and a large amount of Cr will cause temper brittleness in the steel plate after quenching and tempering. Therefore, this invention precisely controls the Cr content to 0.7%~1.2%.

[0017] 8. Mo can promote the passivation of the FeCr matrix and enhance corrosion resistance in reducing media, especially significantly enhancing resistance to chloride ion corrosion and pitting corrosion, effectively preventing pitting corrosion caused by the presence of chloride ions. Mo can also combine with carbides to reduce Cr precipitation, thereby improving the corrosion resistance of the steel plate. The combination of elements such as Mo, Ni, and Cr is a targeted design of this invention for specific effects. Mo can also improve the hardenability of the steel plate, and at the same time, Mo can form fine carbides in the steel, which can effectively improve the strength of the steel plate. Based on the alloy system of this invention, Mo content below 0.9% will not significantly reduce low-temperature toughness. Therefore, this invention precisely controls the Mo content to 0.5%~0.9%.

[0018] 9. Cu, in synergy with elements such as Cr and P in steel, forms a dense oxide layer on the steel surface. This rust layer significantly enhances the steel's resistance to atmospheric corrosion. In marine environments, the addition of Cu can inhibit pitting and uniform corrosion in saline and humid environments, extending service life. Cu also helps resist biofouling. However, excessive Cu content can cause cracks in the steel billet during heating. Therefore, this invention precisely controls the Cu content to 0.25%~0.55%.

[0019] 10. Sn can synergistically interact with other elements in steel to form a dense oxide film. This oxide film can significantly hinder the transport of corrosive ions, thereby improving the corrosion resistance of the steel. In a chloride ion environment, Sn can accumulate in the rust layer to form SnO2. In the early stages of corrosion, it mainly accumulates in the retained austenite region and grain boundaries, gradually extending to the ferrite-bainite region, forming good corrosion resistance. Therefore, this invention precisely controls the Sn content to be 0.05%~0.15%.

[0020] 11. V is an important alloying element in the steel plate of this invention. V can refine the grain structure and improve the strength and toughness of the steel plate. V forms V(C,N) particles with C and N in the matrix, which can refine and strengthen the grains. Adding V to tempered steel plates can significantly improve the core strength and low-temperature toughness of the steel plate. Therefore, this invention precisely controls the V content to be 0.05%~0.09%.

[0021] 12. Ti can form TiCN with C and N, exhibiting extremely high stability at high temperatures, effectively preventing steel grain growth and thus refining the grain size. Therefore, this invention precisely controls the Ti content to be 0.008%~0.02%.

[0022] 13. Nitrogen (N) can combine with V and Ti to form fine, dispersed nitrogen oxide precipitates, which can effectively promote the nucleation and growth of ferrite within the grains and effectively control the growth of the original austenite grains. However, when the dissolved nitrogen content is too high, the hot plasticity and toughness of the steel decrease. Therefore, this invention precisely controls the nitrogen content to be 0.004%~0.011%.

[0023] The maximum thickness of the aforementioned high-performance corrosion-resistant rack steel plate is 210mm. Its yield strength is ≥690MPa, tensile strength is 800~940MPa, elongation is ≥18%, and the Charpy impact energy of the steel plate core at -40℃ is ≥150J. The Brinell hardness (HBW) is ≥250. The seawater corrosion resistance rate of the steel plate is less than 40% of that of conventional EH690 marine steel, and the marine atmospheric corrosion resistance rate is less than 50% of that of conventional EH690 marine steel.

[0024] The microstructure at half the thickness of the steel plate consists of lath bainite and retained austenite. The bainite lath spacing is 50~100nm; the retained austenite content is 3%~8%, the effective grain size is 5~25μm, and the mechanical properties are good.

[0025] The manufacturing method of the above-mentioned high-performance corrosion-resistant rack steel plate adopts a process of high-cleanliness and alloying smelting + light reduction on a casting machine + electroslag remelting + forging billet opening + high-efficiency rolling + double quenching + tempering, specifically including the following steps:

[0026] 1. Steel refining:

[0027] The molten steel is refined through a converter, LF furnace, RH or VD furnace to further reduce the content of P, S and non-metallic inclusions.

[0028] 2. Continuous casting:

[0029] The casting superheat is 10-20℃, and the light reduction in the casting machine is 4-6mm, effectively reducing shrinkage cavities and porosity in the billet core, and center segregation to C0.5. The main purpose of applying light reduction during continuous casting is to improve the quality and performance of the billet. By applying large deformation pressure at the end of solidification in the continuous casting machine and fully utilizing the temperature difference between the billet thickness and temperature, the reduction can be efficiently transferred to unevenly distributed areas in the billet core, thereby effectively solving problems such as segregation, porosity, and shrinkage cavities. This process can significantly improve the density and chemical composition consistency of the billet, ensuring that the final product meets higher quality standards.

[0030] 3. Electroslag remelting:

[0031] The slag melting time for electroslag remelting is 60–120 min, the crystallizer cooling rate is 0.5–1 °C / min, the feeding time is 6–8 h, and the slow cooling time after demolding of the electroslag ingot is ≥72 h. The electroslag remelting process demonstrates significant effectiveness in reducing alloy segregation, improving corrosion resistance, and enhancing the core mechanical properties of extra-thick steel plates. This process utilizes protective slag, argon protection, and deoxidizers to precisely control the alloy composition, effectively inhibiting the intrusion of harmful gases and reducing alloy oxidation, thereby optimizing the compositional uniformity within the alloy. The electroslag remelting process can reduce segregation generated during the melting process by adjusting the composition and morphology of the protective slag. Argon protection helps control oxygen content and prevents oxidation of the alloy surface; while the deoxidizer further inhibits the oxidation of harmful impurities and gases in the alloy. These combined measures not only effectively reduce the alloy potential difference and enhance its corrosion resistance but also significantly improve the mechanical properties of the core of extra-thick steel plates.

[0032] 4. Forging:

[0033] The forging heating temperature is 1230~1280℃. Forging involves three-directional compression during the initial forging stage, with at least three passes in each direction. The average single reduction is ≥30mm, and the deformation rate in the thickness direction is 40%~60%. By controlling temperature, optimizing forging reduction, and using slow cooling, the forging process can significantly improve the mechanical properties of steel plates. Reasonable temperature control avoids material phase transformations and reduces problems such as segregation and shrinkage cavities. Optimizing forging reduction can homogenize the grain structure, improving strength and toughness. Slow cooling reduces internal stress and refines the grains, further improving mechanical properties.

[0034] 5. Rolling:

[0035] The billet is loaded into the heating furnace at a temperature of 600-700℃ and held for 30-60 minutes. This is to ensure consistent thickness temperature during the low-temperature stage, preparing for a uniform microstructure in the high-temperature stage. The heating temperature is 1200-1250℃, and the holding time is 120-180 minutes. The initial rolling temperature is 1190-1240℃, with a single-pass reduction of ≥40mm, and the final rolling temperature is 1110-1220℃. Under the high pressure at high temperatures, the steel plate deforms more uniformly, reducing inhomogeneities in the microstructure and thus improving the material's density and consistency. High-temperature, high-reduction rolling effectively improves the tensile strength and yield strength of the material, and reduces local stress concentration through high-temperature treatment, enhancing the material's low-temperature toughness. With reasonable process parameter control, high-temperature, high-reduction rolling can complete large-scale batch production in a shorter time, improving production efficiency.

[0036] 6. Conditioning:

[0037] The primary quenching temperature is 850~920℃, and the holding time is 1.2~1.8 min / mm. The secondary quenching temperature is 830~880℃, and the holding time is 1.4~2.0 min / mm. The cooling rate of the quenched steel plate core is 0.4~0.8℃ / s. The tempering temperature is 570~670℃, and the holding time is 3~4.5 min / mm. The purpose of primary and secondary quenching is to refine the rolled microstructure, prepare the microstructure for tempering, further improve the grain size of the tempered microstructure, and enhance the low-temperature toughness of the steel plate core. Increasing the tempering temperature and holding time can refine and redistribute fine precipitates while ensuring the strength of the steel plate, maximizing the low-temperature toughness and corrosion resistance of the steel plate.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] 1. This invention employs a composition design that combines C, Mn, Ni, Cr, Mo, Cu with microalloying elements such as Sn, N, and V. The high strength of the alloys in this invention can easily lead to core segregation in the billet. However, by combining this with specific light reduction and electroslag remelting processes, the problem of uneven composition and microstructure in the billet core can be perfectly solved. The addition of Ni significantly improves the toughness and corrosion resistance of the steel plate. A large addition achieves a lower ductile-brittle transition temperature. Simultaneously, the addition of Ni, along with microalloying elements such as V, further enhances the strength, toughness, and corrosion fatigue resistance of the steel plate. Ni possesses certain corrosion resistance, exhibiting good resistance to acidic marine environments. Combined with Cr, Mo, Sn, and Cu, it improves the steel's thermal strength and corrosion resistance. The combination of Mo, Ni, and Cr is a targeted design of this invention to achieve specific effects, improving the hardenability of the steel plate. Mo can form fine carbides in the steel, effectively increasing its strength. It also inhibits pitting and uniform corrosion in saline and humid environments, extending service life. Cu also plays a role in resisting biofouling.

[0040] 2. This invention uses a casting superheat of 10-20°C and a light reduction of 4-6mm in the casting machine, effectively reducing shrinkage cavities and porosity in the billet core, and minimizing center segregation to C0.5. The main purpose of the light reduction is to improve the quality and performance of the cast billet. By applying large deformation pressure at the end of solidification in the continuous casting machine and fully utilizing the billet thickness and temperature difference, the reduction can be efficiently transferred to the core, thereby effectively solving problems such as segregation, porosity, and shrinkage cavities. This process can significantly improve the density and chemical composition consistency of the cast billet, ensuring that the final product meets higher quality standards.

[0041] 3. The slag-forming time for electroslag remelting in this invention is 60-120 min, the crystallizer cooling rate is 0.5-1℃ / min, the feeding time is 6-8 h, and the electroslag ingot demolding slow cooling is ≥72 h. The electroslag remelting process demonstrates significant effectiveness in reducing alloy segregation, improving corrosion resistance, and enhancing the core mechanical properties of extra-thick steel plates. This process utilizes protective slag, argon protection, and deoxidizers to precisely control the alloy composition, effectively inhibiting the intrusion of harmful gases and reducing alloy oxidation. This optimizes the compositional uniformity within the alloy, reduces segregation during melting, and prevents surface oxidation.

[0042] 4. The forging process of this invention significantly improves the mechanical properties of steel plates by controlling temperature, optimizing forging reduction, and slow cooling. Reasonable temperature control avoids material phase transformation and reduces problems such as segregation and shrinkage cavities; optimized forging reduction can homogenize the grain structure and improve strength and toughness; and slow cooling treatment reduces internal stress and refines grains, further improving mechanical properties.

[0043] 5. This invention effectively improves the tensile strength and yield strength of materials through a high-temperature, high-reduction rolling process, and reduces local stress concentration through high-temperature treatment, thereby enhancing the low-temperature toughness of the material. With reasonable control of process parameters, the high-temperature, high-reduction rolling process can complete large-scale batch production tasks in a short time, improving production efficiency.

[0044] 6. The purpose of the primary and secondary quenching in this invention is to refine the rolled microstructure, prepare the microstructure for tempering, further improve the grain size of the tempered microstructure, and enhance the low-temperature toughness of the steel plate core. Increasing the tempering temperature and tempering holding time can refine and redistribute fine precipitates while ensuring the strength of the steel plate, thereby maximizing the low-temperature toughness and corrosion resistance of the steel plate.

[0045] In summary, this invention employs a composition design combining C, Mn, Ni, Cr, Mo, Cu, and microalloying elements such as Sn, N, and V. It utilizes a unique process involving high-purity alloying smelting, light pressing in casting, electroslag remelting, forging, high-efficiency rolling, double quenching, and tempering to produce thick, high-performance, corrosion-resistant rack steel plates. The maximum thickness of the finished steel plate is 210 mm, with a yield strength ≥690 MPa, tensile strength 800~940 MPa, elongation ≥18%, Charpy impact energy at -40℃ ≥150 J, and Brinell hardness HBW ≥250. The steel plate's seawater corrosion resistance rate is less than 40% of that of conventional EH690 marine engineering steel, and its marine atmospheric corrosion resistance rate is less than 50% of that of conventional EH690 marine engineering steel. Attached Figure Description

[0046] Figure 1 This is a metallographic diagram of Embodiment 1 of the present invention. Detailed Implementation

[0047] This invention discloses a high-performance corrosion-resistant rack steel plate and its manufacturing method. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0048] The chemical composition of the embodiments of the present invention is shown in Table 1. The continuous casting, electroslag remelting and forging processes of the embodiments of the present invention are shown in Table 2. The rolling process of the embodiments of the present invention is shown in Table 3. The quenching and tempering process of the embodiments of the present invention is shown in Table 4. The mechanical properties of the steel plates of the embodiments of the present invention are shown in Table 5. The corrosion resistance of the embodiments of the present invention and the comparative examples are shown in Table 6.

[0049] Table 1 Chemical composition (wt%) of embodiments of the present invention

[0050]

[0051] Table 2. Continuous casting, electroslag remelting, and forging processes in embodiments of the present invention.

[0052]

[0053] Table 3 Rolling process of embodiments of the present invention

[0054]

[0055] Table 4. Conditioning process in the embodiments of the present invention

[0056]

[0057] Table 5 Mechanical properties of steel plates in embodiments of the present invention

[0058]

[0059] Table 6 Corrosion resistance of embodiments and comparative examples of the present invention

[0060]

[0061] The full immersion test reference standard is JBT7901, and the salt spray test reference standard is GBT10125. The comparison steel composition is 0.011C~0.2Si~1.20Mn~0.6Ni~0.4Cr~0.2Mo~0.04Nb~0.04V~0.01Ti.

[0062] like Figure 1 As shown, the metallographic structure of Example 1, at half the thickness of the steel plate, consists of lath bainite and retained austenite. The bainite lath spacing is 50~100nm; the retained austenite content is 3%~8%, the effective grain size is 5~25μm, and it exhibits good mechanical properties.

[0063] This invention employs a composition design combining C, Mn, Ni, Cr, Mo, Cu, and microalloying elements such as Sn, N, and V. It utilizes a unique process involving high-purity alloying smelting, light pressing in a casting machine, electroslag remelting, forging, high-efficiency rolling, double quenching, and tempering to produce thick, high-performance, corrosion-resistant rack steel plates. The maximum thickness of the finished steel plate is 210 mm, with a yield strength ≥690 MPa, tensile strength 800~940 MPa, elongation ≥18%, Charpy impact energy of the core at -40℃ ≥150 J, and Brinell hardness HBW ≥250. As shown in Table 6, the seawater corrosion resistance rate of the steel plate is less than 40% of that of conventional EH690 marine engineering steel, and the marine atmospheric corrosion resistance rate is less than 50% of that of conventional EH690 marine engineering steel.

[0064] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A high-performance corrosion-resistant rack steel plate, characterized in that, Composed of the following chemical components in weight percentage composition: C: 0.1%~0.15%, Si: 0.22%~0.45%, Mn: 1.1%~1.7%, P≤0.02%, S≤0.01%, Als: 0.03%~0.06%, Ni: 3.8%~5.5%, Cr: 0.7%~1.2%, Mo: 0.5%~0.9%, Cu: 0.25%~0.55%, Sn: 0.05%~0.15%, V: 0.05%~0.09%, Ti: 0.008%~0.02%, N: 0.004%~0.011%, with the remainder being Fe and unavoidable impurities.

2. The high-performance corrosion-resistant rack steel plate according to claim 1, characterized in that, Its yield strength is ≥690MPa, tensile strength is 800~940MPa, elongation is ≥18%, Charpy impact energy of steel plate core at -40℃ is ≥150J, and Brinell hardness HBW is ≥250.

3. The high-performance corrosion-resistant rack steel plate according to claim 1, characterized in that, The maximum thickness of the finished steel plate is 210 mm. The microstructure at 1 / 2 of the steel plate thickness is lath bainite + retained austenite. The bainite lath spacing is 50~100 nm, the retained austenite content is 3%~8%, and the effective grain size is 5~25 μm.

4. A method for manufacturing a high-performance corrosion-resistant rack steel plate as described in any one of claims 1 to 3, characterized in that, The manufacturing method specifically includes the following steps: 1) Steel refining; 2) Continuous casting: The light reduction of the casting machine is 4~6mm; 3) Electroslag remelting: The slag-forming time for electroslag remelting is 60~120 min, the cooling rate of the crystallizer is 0.5~1℃ / min, and the feeding time is 6~8 h; 4) Forging: The forging heating temperature is 1230~1280℃. The forging billet is compressed in three directions, and the number of compressions in each direction is not less than 3 times, with an average single compression amount ≥30mm. 5) Rolling: Heating temperature 1200~1250℃, hold temperature for 120~180min; The initial rolling temperature is 1190~1240℃, the single-pass reduction is ≥40mm, and the final rolling temperature is 1110~1220℃. 6) Conditioning: The quenching temperature for the first quenching is 850~920℃, and the holding time for the first quenching is 1.2-1.8 min / mm. The secondary quenching temperature is 830~880℃, the secondary quenching holding time is 1.4~2.0min / mm, and the core cooling rate of the quenched steel plate is 0.4~0.8℃ / s; The tempering temperature is 570~670℃, and the tempering holding time is 3~4.5min / mm.

5. The method for manufacturing the high-performance corrosion-resistant rack steel plate according to claim 4, characterized in that, In step 1), molten steel is refined through a converter, LF furnace, RH or VD furnace.

6. The method for manufacturing the high-performance corrosion-resistant rack steel plate according to claim 4, characterized in that, 2) During casting, the superheat temperature is 10~20℃.

7. The method for manufacturing the high-performance corrosion-resistant rack steel plate according to claim 4, characterized in that, 3) In the process, the electroslag ingot is demolded and slowly cooled for ≥72h.

8. The method for manufacturing the high-performance corrosion-resistant rack steel plate according to claim 4, characterized in that, 4) In this case, the deformation rate in the thickness direction is controlled to be 40%~60%.

9. The method for manufacturing the high-performance corrosion-resistant rack steel plate according to claim 4, characterized in that, 5) The billet is loaded into the heating furnace at a furnace temperature of 600~700℃ and held for 30~60 minutes.

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