800-mpa-grade quenched and tempered ultrahigh-strength hydrogen-resistant steel plate for pressure vessel, and preparation method therefor

Abstract

The present invention belongs to the field of the manufacturing of steel for vessels. Disclosed are an 800-MPa-grade quenched and tempered ultrahigh-strength hydrogen-resistant steel plate for a pressure vessel, and a preparation method therefor. The steel plate comprises the following chemical components in percentages by weight: C, Si, Mn, P, S, Ni, Cr, Mo, V, Ti, Als, B, and the balance of Fe and inevitable impurity elements. The preparation method therefor comprises: sequentially subjecting a steel billet to smelting and continuous casting procedures to produce a continuously cast billet containing target components; and sequentially subjecting the continuously cast billet to the procedures of heating, rolling, a heat treatment, inspection and warehousing. In the present invention, a new component design system of Ni-Cr-Mo is utilized to ensure good hydrogen brittleness resistance of the steel plate, and the 800-MPa-grade high-strength quenched and tempered super-thick plate (the thickness thereof being less than or equal to 80 mm) for a hydrogen-resistant pressure vessel is produced by means of a reasonable heat treatment process consisting of offline quenching and high-temperature tempering; therefore, a breakthrough is made to the bottleneck in the prior art, the requirements of a user for the high strength and high toughness of a quenched and tempered super-thick plate for a hydrogen-resistant pressure vessel are met, the service safety of the pressure vessel is improved, and a foundation is also laid for the development, production and application of new-generation hydrogen-resistant quenched and tempered high-strength steel for a pressure vessel.

Description

An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate and its preparation method Technical Field

[0001] The present invention belongs to the field of container steel manufacturing and relates to an 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate and a preparation method thereof. Background Art

[0002] Among the existing hydrogen storage technologies, high-pressure gaseous hydrogen storage technology is highly mature and low-cost, and is currently the most suitable technical solution for large-scale storage and transportation. This technical solution requires the construction of hundreds of cubic meters of high-pressure hydrogen storage tanks, hundreds of kilometers of high-pressure hydrogen pipelines, etc. For large-scale hydrogen storage and transportation needs, materials suitable for high-pressure hydrogen storage and transportation equipment are core technologies that must be broken through. The most critical technical features of this type of material are: high strength, weldability, good strength-toughness matching, and resistance to hydrogen corrosion and hydrogen embrittlement. At present, pressure vessel equipment is developing towards high parameters and large-scale. For safety reasons, the limit specifications and strength and toughness requirements of pressure vessel steel are also increasing. In terms of the physical level of steel plates, most domestically produced ultra-high-strength steel plates for pressure vessels not only lack data support for hydrogen resistance, but also have shortcomings such as narrow thickness specification range, poor surface quality, and low impact toughness. They cannot meet the current use requirements of large-scale, high-parameter hydrogen-resistant pressure vessels.

[0003] For example, the patent with publication number CN104532159A discloses "a quenched and tempered high-strength steel with a yield strength of 700 MPa and a production method thereof". Its chemical composition includes C, Si, Mn, Cr, Mo, Ni, Nb, Ti, V, B, Al, Ca, N, P, S and O, and the rest is Fe and inevitable impurities; the actual yield strength of the patented steel plate is 700-850 MPa, and the tensile strength is 750-900 MPa. Although the strength is relatively high, the elongation is only >14%, and the impact energy at -40°C is only >40J. The plastic toughness of the steel plate is relatively low.

[0004] For example, the patent with publication number CN109112421A discloses "a steel 07Cr2AlMoR for pressure vessels and its production method", whose chemical composition includes C, Mn, Cr, Mo, Alt, S, P and Si, and the rest is Fe and other inevitable impurities; although the production method disclosed in the patent has a wide range of steel plate thickness specifications, up to 80mm, the actual strength and toughness level of the steel plate is low, with a tensile strength of less than 500MPa, an impact toughness of less than 100J, and a quality grade of only D.

[0005] For example, patent publication number CN115261714A discloses "a steel for pressure vessels and its preparation method." Its chemical composition includes C, Si, Mn, P, S, Al, V, Nb, N, Cu, Sn, Sb, and Mg; the remainder is Fe and other unavoidable impurities. This patent only discloses the production method for relatively thin steel plates ≤55 mm thick. It does not mention production methods for thicker steel plates, making it unable to meet the performance requirements for ultra-thick plate applications. Furthermore, none of these patents mention the steel plates' hydrogen resistance.

[0006] Summary of the Invention

[0007] Purpose of the invention: The purpose of the present invention is to provide an 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate and a preparation method thereof.

[0008] Technical solution: The present invention provides an 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, wherein the chemical composition of the steel plate is as follows by weight: C: 0.07-0.13%, Si: 0.10-0.45%, Mn: 0.80-1.50%, P≤0.012%, S≤0.005%, Ni: 0.60-1.50%, Cr: 0.25-0.80%, Mo: 0.30-0.70%, V: 0.01-0.05%, Ti≤0.030%, Als: ≤0.05%, B: 0.0005-0.0030%, and the balance is Fe and unavoidable impurity elements;

[0009] The chemical composition of the steel plate is as follows by weight: C: 0.07%, Si: 0.12%, Mn: 0.93%, P: 0.011%, S: 0.005%, Ni: 0.61%, Cr: 0.27%, Mo: 0.32%, V: 0.015%, Ti: 0.017%, Als: 0.031%, B: 0.0007%, and the balance is Fe and unavoidable impurity elements;

[0010] The chemical composition of the steel plate is as follows by weight: C: 0.09%, Si: 0.23%, Mn: 0.99%, P: 0.010%, S: 0.004%, Ni: 0.88%, Cr: 0.47%, Mo: 0.47%, V: 0.022%, Ti: 0.019%, Als: 0.037%, B: 0.0014%, and the balance is Fe and unavoidable impurity elements;

[0011] The chemical composition of the steel plate is as follows by weight: C: 0.11%, Si: 0.29%, Mn: 1.18%, P: 0.009%, S: 0.003%, Ni: 0.99%, Cr: 0.78%, Mo: 0.56%, V: 0.039%, Ti: 0.021%, Als: 0.040%, B: 0.0026%, and the balance is Fe and unavoidable impurity elements;

[0012] The chemical composition of the steel plate is as follows by weight: C: 0.12%, Si: 0.36%, Mn: 1.33%, P: 0.010%, S: 0.003%, Ni: 1.17%, Cr: 0.65%, Mo: 0.60%, V: 0.045%, Ti: 0.023%, Als: 0.040%, B: 0.0028%, and the balance is Fe and unavoidable impurity elements;

[0013] The chemical composition of the steel plate is as follows by weight: C: 0.13%, Si: 0.43%, Mn: 1.45%, P: 0.011%, S: 0.004%, Ni: 1.46%, Cr: 0.63%, Mo: 0.67%, V: 0.047%, Ti: 0.029%, Als: 0.047%, B: 0.0027%, and the balance is Fe and unavoidable impurity elements;

[0014] A method for preparing 800MPa-grade quenched and tempered ultra-high-strength hydrogen-resistant pressure vessel steel plates comprises subjecting a steel billet having the same composition as the steel to smelting and continuous casting steps to produce a continuous cast billet having a target composition; the continuous cast billet then undergoes heating, rolling, heat treatment, inspection, and storage. The specific preparation steps are as follows:

[0015] (1): The smelting process includes molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1600-1650°C to ensure carbon pulling and no phosphorus regeneration in the later stage; LF refining adopts aluminum deoxidation, the total time is 40-45 minutes, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH refining; ferroboron is added after uniformity, and static stirring is performed after the wire feeding is completed, and the static stirring time is 25-30 minutes to ensure that the slag surface does not fluctuate and the molten steel is not exposed;

[0016] (2): The continuous casting process adopts slab soft reduction and electromagnetic stirring technology to reduce center segregation and looseness, and the solidification end is reduced by 5 to 7 mm. The continuous casting process adopts protective casting to prevent secondary oxidation of molten steel;

[0017] (3): The continuous casting billet heating process: the heating temperature is 1150-1280°C, and the total time coefficient in the furnace is 1.0-1.2 min / mm, to ensure that the original austenite structure is uniform inside the steel;

[0018] (4): The rolling process adopts a controlled rolling and controlled cooling process, which is a two-stage controlled rolling process, namely rolling in the austenite recrystallization zone and the austenite non-recrystallization zone, with a total reduction ratio of not less than 4 times: the starting temperature of the rough rolling is ≥1000℃, and a large reduction method is adopted in this stage; the starting temperature of the finishing rolling is 810-880℃, and in this stage, sufficient deformation is ensured so that the austenite grains are stretched and deformed along the rolling direction. At the same time, by adding micro-alloying elements such as Ti and V, carbonitride particles are precipitated by strain during the deformation process, which pins the austenite grains to prevent them from growing, thereby refining the structure after the phase transformation; the final rolling temperature is 800-850℃; after rolling, it is subjected to laminar cooling, the red-return temperature is 600-680℃, and then air-cooled to room temperature;

[0019] (5): The heat treatment process includes quenching and tempering processes, wherein the quenching temperature of the steel plate is 850-930°C, and the holding time coefficient is 1.3-1.8 min / mm. Subsequently, the tempering process is performed to eliminate the residual stress generated by quenching and homogenize the structure to obtain stable and excellent comprehensive performance. The tempering temperature of the steel plate is 610-670°C, and the holding time coefficient is 2.0-4.0 min / mm.

[0020] The ultra-high-strength hydrogen-resistant steel plate for pressure vessels disclosed herein has a thickness of 12 to 80 mm, a final microstructure of the steel plate mainly composed of bainite, and excellent physical properties: a hydrogen embrittlement index of the steel plate in a 25 MPa hydrogen environment is ≥0.75, internal flaw detection reaches NB / T 47013.3TI level, a tensile strength Rm of the steel plate is 800 to 900 MPa, an elongation A is ≥17%, and a KV2 at -40°C is ≥100 J.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following characteristics: 1. Through the calculation of material hydrogen resistance and chemical composition design based on the first principles, the good hydrogen resistance of the steel plate is guaranteed, and 12 to 80 mm thick steel plates are produced, covering a wide range of thickness specifications, with better strength, toughness and plasticity. The hydrogen embrittlement index of the steel plate in a 25MPa hydrogen environment is ≥0.75, the tensile strength Rm is 800 to 900MPa, the elongation A is ≥17%, and the KV2 at -40℃ is ≥100J; 2. Through the production process (smelting, continuous casting, rolling, heat treatment process, etc.) setting, the internal quality and performance stability of the steel plate are improved, and the steel plate has excellent comprehensive mechanical properties; 3. It breaks through the bottleneck of the existing technology and fills the technical gap of materials for large-scale high-pressure vessels in China. In the later stage, it will promote the formation of a series of specifications and preparation, storage, transportation and terminal application of pressure vessel equipment, materials, design, construction, application, safety evaluation, etc., and a complete and efficient industrial chain prototype, laying the foundation for the development, production and application of a new generation of tempered high-strength pressure vessel steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is an OM diagram of the microstructure of a steel plate for an ultra-high strength hydrogen-resistant pressure vessel according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Example 1:

[0025] 1. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment has a thickness of 12 mm. Its chemical composition and mass percentage are shown in Table 1.

[0026] 2. The method for preparing the quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment includes smelting, continuous casting, heating of the cast billet, rolling, and heat treatment. The specific process steps are as follows:

[0027] (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1610℃, the total time is 42min, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is carried out after the wire feeding is completed, and the static stirring time is 26min;

[0028] (2): In the continuous casting process, slab soft reduction and electromagnetic stirring technology are used to reduce center segregation and porosity, with a reduction of 6.1 mm at the end of solidification;

[0029] (3): Continuous casting slab heating process: heating temperature is 1150℃, total time coefficient in the furnace is 1.0min / mm;

[0030] (4): Rolling process: controlled rolling and controlled cooling process is adopted: the starting temperature of rough rolling is 1050℃; the starting temperature of finishing rolling is 815℃, and the final temperature of finishing rolling is 800℃; after rolling, it is subjected to laminar cooling, the return temperature is 680℃, and then air cooling to room temperature;

[0031] (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 850℃, the holding time coefficient is 1.6min / mm; the tempering temperature is 610℃, and the holding time coefficient is 4.0min / mm.

[0032] 3. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment meets the requirements of NB / T 47013.3TI-level ultrasonic flaw detection; the actual performance of the product is shown in Table 2.

[0033] Example 2:

[0034] 1. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment has a thickness of 20 mm. Its chemical composition and mass percentage are shown in Table 1.

[0035] 2. The method for preparing the quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment includes smelting, continuous casting, heating of the cast billet, rolling, and heat treatment processes. The specific process steps are as follows:

[0036] (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1645℃, the total time is 43min, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is carried out after the wire feeding is completed, and the static stirring time is 27min;

[0037] (2): In the continuous casting process, the slab is lightly pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 6.7 mm;

[0038] (3): Continuous casting slab heating process: heating temperature is 1185℃, total time coefficient in the furnace is 1.2min / mm;

[0039] (4): Rolling process: controlled rolling and controlled cooling process is adopted: the starting temperature of rough rolling is 1030℃; the starting temperature of finishing rolling is 865℃, and the final rolling temperature of finishing rolling is 820℃; after rolling, it is subjected to laminar cooling, the return temperature is 665℃, and then air cooling to room temperature;

[0040] (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 875℃, the holding time coefficient is 1.3min / mm; the tempering temperature is 670℃, and the holding time coefficient is 3.5min / mm.

[0041] 3. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment meets the requirements of NB / T 47013.3TI-level ultrasonic flaw detection; the actual performance of the product is shown in Table 2.

[0042] Example 3:

[0043] 1. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment has a thickness of 40 mm. Its chemical composition and mass percentage are shown in Table 1.

[0044] 2. The method for preparing the quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment includes smelting, continuous casting, heating of the cast billet, rolling, and heat treatment processes. The specific process steps are as follows:

[0045] (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1627℃, the total time is 41min, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is carried out after the wire feeding is completed, and the static stirring time is 26min;

[0046] (2): In the continuous casting process, the slab is lightly pressed down and electromagnetic stirring technology is used to reduce center segregation and porosity, and the pressure at the end of solidification is 5.2 mm;

[0047] (3): Continuous casting slab heating process: heating temperature is 1220℃, total time coefficient in the furnace is 1.0min / mm;

[0048] (4): Rolling process: controlled rolling and controlled cooling process is adopted: the starting temperature of rough rolling is 1045℃; the starting temperature of finishing rolling is 875℃, and the final temperature of finishing rolling is 840℃; after rolling, it is cooled by laminar flow, the return temperature is 680℃, and then air-cooled to room temperature;

[0049] (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 925℃, the holding time coefficient is 1.5min / mm; the tempering temperature is 650℃, and the holding time coefficient is 2.0min / mm.

[0050] 3. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment meets the requirements of NB / T 47013.3TI-level ultrasonic flaw detection; the actual performance of the product is shown in Table 2.

[0051] Example 4:

[0052] 1. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment has a thickness of 72 mm. Its chemical composition and mass percentage are shown in Table 1.

[0053] 2. The method for preparing the quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment includes smelting, continuous casting, heating of the cast billet, rolling, and heat treatment processes. The specific process steps are as follows:

[0054] (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1637℃, the total time is 44min, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after the wire feeding is completed, and the static stirring time is 29min;

[0055] (2): In the continuous casting process, the slab is lightly pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 5.8 mm;

[0056] (3): Continuous casting slab heating process: heating temperature is 1253℃, total time coefficient in the furnace is 1.2min / mm;

[0057] (4): Rolling process: controlled rolling and controlled cooling process is adopted: the starting temperature of rough rolling is 1050℃; the starting temperature of finishing rolling is 875℃, and the final temperature of finishing rolling is 830℃; after rolling, it is subjected to laminar cooling, the return temperature is 630℃, and then air cooling to room temperature;

[0058] (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 890℃, the holding time coefficient is 1.8min / mm; the tempering temperature is 630℃, and the holding time coefficient is 3.0min / mm.

[0059] 3. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment meets the requirements of NB / T 47013.3TI-level ultrasonic flaw detection; the actual performance of the product is shown in Table 2.

[0060] Example 5:

[0061] 1. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment has a thickness of 80 mm. Its chemical composition and mass percentage are shown in Table 1.

[0062] 2. The method for preparing the quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment includes smelting, continuous casting, heating of the cast billet, rolling, and heat treatment processes. The specific process steps are as follows:

[0063] (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1642℃, the total time is 45min, and the atmosphere in the ladle is controlled by micro-positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is carried out after the wire feeding is completed, and the static stirring time is 28min;

[0064] (2): In the continuous casting process, the slab is lightly pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the solidification end pressure is 6.3mm;

[0065] (3): Continuous casting slab heating process: heating temperature is 1275℃, total time coefficient in the furnace is 1.1min / mm;

[0066] (4): Rolling process: controlled rolling and controlled cooling process is adopted: the starting rolling temperature of rough rolling is 1040℃; the starting rolling temperature of finishing rolling is 880℃, and the final rolling temperature of finishing rolling is 850℃; after rolling, it is subjected to laminar cooling, the red-returning temperature is 630℃, and then air-cooled to room temperature;

[0067] (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 910℃, the holding time coefficient is 1.6min / mm; the tempering temperature is 645℃, and the holding time coefficient is 3.0min / mm.

[0068] 3. The quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate of this embodiment meets the requirements of NB / T 47013.3TI-level ultrasonic flaw detection; the actual performance of the product is shown in Table 2.

[0069] Table 1 Chemical composition mass percentage (wt.%)

[0070] Table 2 Actual performance

[0071] In order to improve the strength and toughness of domestically produced quenched and tempered high-strength steel plates for hydrogen-resistant pressure vessels, while focusing on improving the ultimate specifications of the steel plates, breaking through existing technical bottlenecks, and designing and developing a new generation of high-performance quenched and tempered high-strength steel plates for pressure vessels, the technology gap in materials for large-scale high-pressure vessels was filled. Reasonable chemical composition design and heat treatment process matching were the key technologies. Finally, the Ni-Cr-Mo series hydrogen-resistant component system and multi-element (micro) alloying technology were adopted. By utilizing precipitation strengthening, solid solution strengthening and fine grain strengthening effects, supplemented by appropriate rolling and heat treatment processes, the steel with excellent strength and toughness of ≤80mm thick for hydrogen-resistant pressure vessels was developed and produced. The aim was to realize the engineering demonstration application of the first 100-cubic-meter-level large-scale high-pressure hydrogen storage vessel in China. The actual level of the steel plate was ≥0.75 for the hydrogen embrittlement index in a 25MPa hydrogen environment, the internal flaw detection reached NB / T 47013.3TI level, the tensile strength Rm was 800~900MPa, the elongation A was ≥17%, and the KV2 at -40℃ was ≥100J.

[0072] The steel plate used in the present invention is mainly used in the construction of high-pressure hydrogen storage vessels. The new Ni-Cr-Mo composition design system is adopted to ensure its good resistance to hydrogen embrittlement. Through a reasonable offline quenching + high-temperature tempering heat treatment process, high-strength tempered extra-thick plates with a thickness of ≤80mm and 800MPa grade hydrogen-resistant pressure vessels are produced, breaking through the bottleneck of existing technologies, meeting the high strength and toughness requirements of tempered extra-thick plates for hydrogen-resistant pressure vessels, improving the service safety of pressure vessels, and also laying the foundation for the development, production and application of a new generation of hydrogen-resistant tempered high-strength pressure vessel steel.

[0073] The present invention discloses an 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate and a preparation method thereof. The steel plate has the comprehensive properties of high strength and toughness, high plasticity and excellent hydrogen embrittlement resistance. The produced steel plate is of great significance for the construction of large-scale high-pressure hydrogen storage vessels.

Claims

1. An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, characterized in that: The thickness of the steel plate is 12 mm, and the chemical composition of the steel plate is as follows by weight percentage: C: 0.07%, Si: 0.12%, Mn: 0.93%, P: 0.011%, S: 0.005%, Cr: 0.27%, Mo: 0.32%, Ni: 0.61%, V: 0.015%, Ti: 0.017%, Als: 0.031%, B: 0.0007%, and the balance is Fe and unavoidable impurity elements; The preparation method includes smelting, continuous casting, heating of ingot, rolling and heat treatment. The specific process is as follows: (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1610℃, the total time is 42min, and the atmosphere in the ladle is controlled by micro positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after wire feeding is completed, and the static stirring time is 26min; (2): In the continuous casting process, the slab is gently pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 6.1 mm; (3): Continuous casting billet heating process: heating temperature is 1150℃, total time coefficient in the furnace is 1.0min / mm; (4): Rolling process: controlled rolling and controlled cooling process: the starting temperature of rough rolling is 1050℃; the starting temperature of finishing rolling is 815℃, and the final temperature of finishing rolling is 800℃; after rolling, laminar cooling is performed, the red-returning temperature is 680℃, and then air cooling is performed to room temperature; (5): Heat treatment process: including quenching and tempering processes, in which the quenching temperature of the steel plate is 850℃, the holding time coefficient is 1.6min / mm; the tempering temperature is 610℃, and the holding time coefficient is 4.0min / mm; Its physical properties: R eL / R p0.2 :823Mpa; R m :851Mpa;A:17.5%; -40℃Akv / J: 109 132 109; the average value is:

117.

2. An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, characterized in that: The thickness of the steel plate is 20 mm, and the chemical composition of the steel plate is as follows by weight percentage: C: 0.09%, Si: 0.23%, Mn: 0.99%, P: 0.010%, S: 0.004%, Cr: 0.47%, Mo: 0.47%, Ni: 0.88%, V: 0.022%, Ti: 0.019%, Als: 0.037%, B: 0.0014%, and the balance is Fe and unavoidable impurity elements; The preparation method includes smelting, continuous casting, heating of ingot, rolling and heat treatment. The specific process is as follows: (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1645℃, the total time is 43min, and the atmosphere in the ladle is controlled by micro positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after wire feeding is completed, and the static stirring time is 27min; (2): In the continuous casting process, the slab is gently pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 6.7 mm; (3): Continuous casting billet heating process: heating temperature is 1185℃, total time coefficient in the furnace is 1.2min / mm; (4): Rolling process: controlled rolling and controlled cooling process: the starting temperature of rough rolling is 1030℃; the starting temperature of finishing rolling is 865℃, and the final rolling temperature of finishing rolling is 820℃; after rolling, laminar cooling is performed, the return temperature is 665℃, and then air cooling is performed to room temperature; (5): Heat treatment process: including quenching and tempering process, in which the steel plate quenching temperature is 875℃ and the insulation temperature is 200℃. Time coefficient 1.3min / mm; tempering temperature 670℃, holding time coefficient 3.5min / mm; Its physical properties: R eL / R p0.2 :796Mpa; R m :848Mpa; A:18.5%; -40℃Akv / J: 143 128 140; the average value is:

137.

3. An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, characterized in that: The thickness of the steel plate is 40 mm, and the chemical composition of the steel plate is as follows by weight percentage: C: 0.11%, Si: 0.29%, Mn: 1.18%, P: 0.009%, S: 0.003%, Cr: 0.78%, Mo: 0.56%, Ni: 0.99%, V: 0.039%, Ti: 0.021%, Als: 0.040%, B: 0.0026%, and the balance is Fe and unavoidable impurity elements; The preparation method includes smelting, continuous casting, billet heating, rolling, and heat treatment processes. The specific process is as follows: (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1627℃, the total time is 41min, and the atmosphere in the ladle is controlled by micro positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after wire feeding is completed, and the static stirring time is 26min; (2): In the continuous casting process, the slab is gently pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 5.2 mm; (3): Continuous casting billet heating process: heating temperature is 1220℃, total time coefficient in the furnace is 1.0min / mm; (4): Rolling process: controlled rolling and controlled cooling process: the starting temperature of rough rolling is 1045℃; the starting temperature of finishing rolling is 875℃, and the final temperature of finishing rolling is 840℃; after rolling, laminar cooling is performed, the red-returning temperature is 680℃, and then air cooling is performed to room temperature; (5): Heat treatment process: including quenching and tempering processes, where the quenching temperature of the steel plate is 925℃, the holding time coefficient is 1.5min / mm; the tempering temperature is 650℃, and the holding time coefficient is 2.0min / mm; Its physical properties: R eL / R p0.2 :791Mpa; R m :856Mpa; A:18.5%; -40℃Akv / J: 180 148 150; the average value is:

159.

4. An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, characterized in that: The thickness of the steel plate is 72 mm, and the chemical composition of the steel plate is as follows by weight percentage: C: 0.12%, Si: 0.36%, Mn: 1.33%, P: 0.010%, S: 0.003%, Cr: 0.65%, Mo: 0.60%, Ni: 1.17%, V: 0.045%, Ti: 0.023%, Als: 0.040%, B: 0.0028%, and the balance is Fe and unavoidable impurity elements; The preparation method includes smelting, continuous casting, billet heating, rolling, and heat treatment processes. The specific process is as follows: (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1637℃, the total time is 44min, and the atmosphere in the ladle is controlled by micro positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after wire feeding is completed, and the static stirring time is 29min; (2): In the continuous casting process, the slab is gently pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 5.8 mm; (3): Continuous casting billet heating process: heating temperature is 1253℃, total time coefficient in the furnace is 1.2min / mm; (4): Rolling process: controlled rolling and controlled cooling process: the starting temperature of rough rolling is 1050℃; Finish rolling start temperature The temperature is 875℃, the final rolling temperature is 830℃; after rolling, it is cooled by laminar flow, the red-returning temperature is 630℃, and then air-cooled to room temperature; (5): Heat treatment process: including quenching and tempering processes, where the quenching temperature of the steel plate is 890°C, the holding time coefficient is 1.8 min / mm; the tempering temperature is 630°C, and the holding time coefficient is 3.0 min / mm; Its physical properties: R eL / R p0.2 :786Mpa; R m :847Mpa;A:19%; -40℃Akv / J: 163 200 193; the average value is:

185.

5. An 800MPa grade quenched and tempered ultra-high strength hydrogen-resistant pressure vessel steel plate, characterized in that: The thickness of the steel plate is 80 mm, and the chemical composition of the steel plate is as follows by weight percentage: C: 0.13%, Si: 0.43%, Mn: 1.45%, P: 0.011%, S: 0.004%, Cr: 0.63%, Mo: 0.67%, Ni: 1.46%, V: 0.047%, Ti: 0.029%, Als: 0.047%, B: 0.0027%, and the balance is Fe and unavoidable impurity elements; The preparation method includes smelting, continuous casting, heating of ingot, rolling and heat treatment. The specific process is as follows: (1): Smelting process: including molten iron pretreatment, top and bottom double blowing converter, LF refining and RH refining, wherein the converter smelting end temperature is 1642℃, the total time is 45min, and the atmosphere in the ladle is controlled by micro positive pressure operation throughout the process; seamless pure calcium wire is fed after RH is finished; ferroboron is added after uniformity, and static stirring is performed after wire feeding is completed, and the static stirring time is 28min; (2): In the continuous casting process, the slab is gently pressed down and electromagnetic stirring technology is used to reduce center segregation and looseness, and the pressure at the end of solidification is 6.3mm; (3): Continuous casting billet heating process: heating temperature is 1275℃, total time coefficient in the furnace is 1.1min / mm; (4): Rolling process: controlled rolling and controlled cooling process: the starting temperature of rough rolling is 1040℃; the starting temperature of finishing rolling is 880℃, and the final temperature of finishing rolling is 850℃; after rolling, laminar cooling is performed, the red-returning temperature is 630℃, and then air cooling is performed to room temperature; (5): Heat treatment process: including quenching and tempering processes, where the quenching temperature of the steel plate is 910℃, the holding time coefficient is 1.6min / mm; the tempering temperature is 645℃, and the holding time coefficient is 3.0min / mm; Its physical properties: R eL / R p0.2 :793Mpa; R m :843Mpa; A:18.5%; -40℃Akv / J: 186 177 179; the average value is: 181.

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