High-performance Q345 composite board and preparation method thereof

Abstract

The invention discloses a high-performance Q345 composite board and a preparation method thereof.The high-performance Q345 composite board comprises a Q345R steel substrate and an embedded coating embedded in the surface of the Q345R steel substrate, the embedded coating comprises a spherical material and a Q345R steel substrate material, and the spherical material comprises, by weight, 98.91%-99.68% of a sharp crystal structure, 0.32%-0.86% of chromic oxide and 0-0.23% of nano zinc oxide. The Q345 composite board disclosed by the invention has good high-temperature strength, hydrogen embrittlement resistance and low-temperature toughness.

Description

Technical Field

[0001] This invention relates to a high-performance Q345 composite plate and its preparation method, belonging to the field of metal sheet preparation technology. Background Technology

[0002] Q345 steel plate is a low-alloy steel. Due to the addition of alloying elements such as manganese and vanadium, it possesses higher strength and low-temperature toughness, making it widely used in pressure vessels, ships, vehicles, and bridges in low-temperature environments. However, as industrial equipment develops towards extreme working conditions and lightweight designs, the performance limitations of traditional Q345 steel plate are becoming increasingly apparent. For example, when exposed to high-temperature environments exceeding 400°C for extended periods, the lattice vibrations of Q345 steel plate intensify, weakening the interatomic bonding forces and leading to material softening and creep, resulting in insufficient strength (such as decreased yield strength and tensile strength). Furthermore, in environments containing moist hydrogen sulfide, hydrogen atoms generated during the reaction penetrate to the grain boundaries, causing microcracks on the surface of Q345 steel containers. Additionally, fluctuations in heating and cooling rates during the rolling process result in uneven internal microstructure in Q345 steel plates, leading to dislocations, vacancies, and grain boundary defects, which can cause brittle fracture at low temperatures. These problems—insufficient high-temperature strength, hydrogen embrittlement sensitivity, and low-temperature toughness defects—significantly limit its application potential in extreme working conditions and lightweight applications. Summary of the Invention

[0003] In response to at least one problem existing in the prior art, the present invention provides a high-performance Q345 composite plate and its preparation method, which has good high-temperature strength, resistance to hydrogen embrittlement and low-temperature toughness.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a high-performance Q345 composite plate, comprising a Q345R steel substrate and an inlay layer embedded on the surface of the Q345R steel substrate, wherein the inlay layer comprises spherical material and Q345R steel substrate material, and the spherical material comprises the following raw materials and weight percentages: spinel structure 98.91~99.68%, chromium trioxide 0.32~0.86%, and nano zinc oxide 0~0.23%.

[0005] Preferably, the spherical material comprises the following raw materials and weight percentages: spinel structure 98.91~99.57%, chromium trioxide 0.32~0.86%, and nano zinc oxide 0.11~0.23%.

[0006] Preferably, the spherical material includes spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm.

[0007] Preferably, the coating layer includes a surface layer with a thickness of 1 to 1.5 mm and a transition layer with a thickness of 1.5 to 2 mm.

[0008] Preferably, in the surface layer, the spherical material is 45.8-52.6% of the Q345R steel substrate material, and the mass ratio of spherical material with a particle size of 0.25-1mm to spherical material with a particle size of 50-100μm is 3-4:1.

[0009] Preferably, in the transition layer, the spherical material accounts for 19.7~24.5% of the mass of the Q345R steel substrate material, and the mass ratio of spherical material with a particle size of 0.5~1mm to spherical material with a particle size of 50~100μm is 1.5~2:1.

[0010] Preferably, the spinel structure is magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm.

[0011] Preferably, the chromium trioxide particle size is 0.3~0.8μm.

[0012] Preferably, the nano-zinc oxide particles have a diameter of 20-50 nm.

[0013] Preferably, the spherical material preparation process is as follows: spinel structure, chromium trioxide and nano zinc oxide are mixed with an aqueous solution containing dispersant and binder, ball milled to form a uniformly dispersed slurry with a solid content of 60-65%, and then formed into spherical particles by wet spraying or fluidized bed spraying granulation process, and finally sintered under a protective atmosphere to obtain spherical material.

[0014] Preferably, the preparation process of the spherical material with a particle size of 0.5~1mm is as follows: spinel structure, chromium trioxide and nano zinc oxide are mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, ball milled to form a uniformly dispersed slurry with a solid content of 60~65%, and then formed into spherical particles with a particle size of 0.5~1mm by wet spray granulation process. Finally, under a protective gas atmosphere (such as nitrogen), it is sintered at 1580~1630℃ for 4~5h to obtain spherical material with a particle size of 0.5~1mm.

[0015] Preferably, the preparation process of the spherical material with a particle size of 50~100μm is as follows: spinel structure, chromium trioxide and nano zinc oxide are mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and ball-milled at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, the slurry is formed into spherical particles with a particle size of 50~100μm by fluidized bed spray granulation. Finally, the sintering is carried out at 1510~1560℃ for 2~3h under a protective gas atmosphere (such as nitrogen) to obtain spherical material with a particle size of 50~100μm.

[0016] This invention also provides a method for preparing a high-performance Q345 composite plate, comprising the following steps: (1) Pretreatment of Q345R steel substrate: The surface of Q345R steel substrate with a thickness of 10~20mm is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated. (2) Spherical material laying: The spherical material is laid flat on the pretreated surface, pre-pressed, and the gaps between the spherical materials are eliminated; (3) Hot pressing sintering: Under argon protection, the temperature is first raised to 780~810℃, then pressure is applied, then the temperature is raised to 1200~1250℃ and the pressure is raised to 55~60MPa in stages, then the temperature and pressure are maintained so that the spherical material is embedded in the surface of the Q345R steel substrate to form an inlay layer, then the temperature is lowered, and when the temperature drops to 800℃, the pressure is released, and when the temperature drops to 200℃, the mold is removed. (4) After demolding, heat treatment is performed to obtain high-performance Q345 composite board.

[0017] Preferably, the preheating conditions are: preheating to a temperature of 80~100℃.

[0018] Preferably, the spherical material laying includes transition layer laying and surface layer laying.

[0019] Preferably, the transition layer is laid by first spreading 50% of the weight of the spherical material of the transition layer on the pretreated surface of the Q345R steel substrate and lightly pressing it for 10-15 seconds under 8-10 MPa, and then spreading the remaining spherical material of the transition layer to fill in the gaps and lightly pressing it for 10-15 seconds under 8-10 MPa.

[0020] Preferably, the surface layer is laid by spreading the spherical material of the surface layer on the transition layer and applying a light pressure of 12-15 MPa for 20-25 seconds.

[0021] Preferably, the hot-pressing sintering conditions are as follows: first, the temperature is increased to 780-810°C at a rate of 5-10°C / min, then a pressure of 10-15 MPa is applied, followed by increasing the temperature to 910-960°C at a rate of 5-10°C / min and simultaneously increasing the pressure to 30-35 MPa, then increasing the temperature to 1200-1250°C at a rate of 5-10°C / min and simultaneously increasing the pressure to 55-60 MPa, and then holding the temperature and pressure for 90-120 min, so that the spherical material is embedded in the surface of the Q345R steel substrate to form an intercalation layer, then the temperature is decreased at a rate of 2-5°C / min, and when the temperature drops to 800°C, the pressure is released at a rate of 1-2 MPa / min, and when the temperature drops to 200°C, the material is demolded.

[0022] Preferably, the heat treatment conditions are: temperature 550~600℃, time 1~2h.

[0023] The beneficial effects of this invention are as follows: The high-performance Q345 composite plate of this invention, through the embedding of spherical materials of two particle sizes prepared from magnesium aluminum spinel and chromium trioxide, or chromium trioxide and nano zinc oxide, into a Q345R steel substrate, forms a "matrix-spinel particle" gradient structure, which can improve the high-temperature strength, hydrogen embrittlement resistance, and low-temperature toughness of the Q345 composite plate. In the spherical material of this invention, chromium trioxide and magnesium aluminum spinel work synergistically, resulting in a high degree of densification of the intercalation layer, reducing hydrogen embrittlement sensitivity, and improving high-temperature strength. At the same time, the interaction between nano zinc oxide and magnesium aluminum spinel can alleviate the Q345 steel substrate's high strength. The interfacial stress concentration of the Q345 composite plate reduces low-temperature toughness defects. In the spherical material of this invention, spherical materials with a particle size of 0.5~1mm form a continuous skeleton support, while spherical materials with a particle size of 50~100μm are dispersed for reinforcement. This synergistic effect further optimizes the fine grain strengthening effect, the dense structure of the interlayer, and the interfacial stress, thereby further improving the comprehensive performance of the Q345 composite plate. This invention also adopts an interlayer combining a transition layer and a surface layer. The transition layer and the surface layer form a composite gradient structure, which strengthens the fine grain structure, enhances the densification structure, and strengthens the synergistic effect of fine grain toughening and stress dispersion. Detailed Implementation

[0024] The following is a clear and complete description of the technical solutions in the implementation of this invention. The described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply.

[0025] Example 1 A high-performance Q345 composite board and its preparation method, comprising the following steps: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and they are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.32% and chromium trioxide 0.68% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 0.5~1mm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, and dispersed evenly under ball milling at 300 rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, spherical particles with a particle size of 0.5~1mm are formed by wet spray granulation process. Finally, the sintering is carried out at 1600℃ for 4.5h under nitrogen atmosphere to obtain spherical material with a particle size of 0.5~1mm. Step 1.2 Preparation of spherical material with a particle size of 50~100μm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, it is granulated by fluidized bed spraying to form spherical particles with a particle size of 50~100μm. Finally, it is sintered at 1550℃ for 2.5h under a nitrogen atmosphere to obtain spherical material with a particle size of 50~100μm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 90℃. Step 3, Transition Layer Laying: Mix spherical materials with a particle size of 0.5~1mm and spherical materials with a particle size of 50~100μm at a mass ratio of 1.5:1 to form a transition layer of spherical materials. Spread 50% of the weight of the transition layer of spherical materials evenly on the surface of the pretreated Q345R steel substrate and press lightly at 9MPa for 12s. Then fill in the remaining transition layer of spherical materials and spread evenly, and press lightly at 9MPa for 12s to form a transition layer with a thickness of 1.8mm. The spherical material of the transition layer accounts for 22.1% of the mass of the Q345R steel substrate material of the transition layer; Step 4, Surface layer laying: The mass ratio of spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm is 3:1 to form the spherical material of the surface layer. The spherical material of the surface layer is laid flat on the transition layer and lightly pressed at 13.5MPa for 22s to form a surface layer with a thickness of 1.2mm. Among them, the spherical material of the surface layer accounts for 47.8% of the Q345R steel substrate material of the surface layer; Step 5, Hot Press Sintering: Under argon protection, the temperature is first raised to 800℃ at a rate of 5~10℃ / min, then a pressure of 12MPa is applied. The temperature is then raised to 935℃ at a rate of 5~10℃ / min and the pressure is simultaneously increased to 33MPa. The temperature is then raised to 1225℃ at a rate of 5~10℃ / min and the pressure is simultaneously increased to 58MPa. The temperature and pressure are then maintained for 115min, so that the spherical material is embedded into the surface of the Q345R steel substrate to form an intercalation layer. Then the temperature is lowered at a rate of 2~5℃ / min. When the temperature drops to 800℃, the pressure is released at a rate of 1~2MPa / min. When the temperature drops to 200℃, the material is demolded. Step 6: After demolding, heat-treat at 580℃ for 1.5h to obtain high-performance Q345 composite board.

[0026] Example 2 A high-performance Q345 composite board and its preparation method, comprising the following steps: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and are weighed and mixed according to the following mass percentages: 99.55% magnesium aluminum spinel and 0.45% chromium trioxide to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 0.5~1mm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, spherical particles with a particle size of 0.5~1mm are formed by wet spray granulation process. Finally, the sintering is carried out at 1580℃ for 5h under nitrogen atmosphere to obtain spherical material with a particle size of 0.5~1mm. Step 1.2 Preparation of spherical material with a particle size of 50~100μm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, it is granulated by fluidized bed spraying to form spherical particles with a particle size of 50~100μm. Finally, it is sintered at 1510℃ for 3h under a nitrogen atmosphere to obtain spherical material with a particle size of 50~100μm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 80℃. Step 3, Transition Layer Laying: Mix spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm at a mass ratio of 1.8:1 to form a transition layer of spherical material. Spread 50% of the weight of the transition layer of spherical material evenly on the surface of the pretreated Q345R steel substrate and press lightly at 8MPa for 10s. Then fill in the remaining transition layer of spherical material and spread it evenly, and press lightly at 8MPa for 10s to form a transition layer with a thickness of 1.5mm. The spherical material of the transition layer accounts for 19.7% of the mass of the Q345R steel substrate material of the transition layer; Step 4, Surface layer laying: The mass ratio of spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm is 3.5:1 to form the spherical material of the surface layer. The spherical material of the surface layer is laid flat on the transition layer and lightly pressed at 12MPa for 20s to form a surface layer with a thickness of 1mm. Among them, the spherical material of the surface layer accounts for 45.8% of the Q345R steel substrate material of the surface layer; Step 5, Hot Press Sintering: Under argon protection, the temperature is first raised to 780°C at a rate of 5~10°C / min, then a pressure of 10MPa is applied. The temperature is then raised to 910°C at a rate of 5~10°C / min and the pressure is simultaneously increased to 30MPa. The temperature is then raised to 1250°C at a rate of 5~10°C / min and the pressure is simultaneously increased to 55MPa. The temperature and pressure are then maintained for 120 minutes, so that the spherical material is embedded into the surface of the Q345R steel substrate to form an intercalation layer. Then the temperature is lowered at a rate of 2~5°C / min. When the temperature drops to 800°C, the pressure is released at a rate of 1~2MPa / min. When the temperature drops to 200°C, the material is demolded. Step 6: After demolding, heat-treat at 550℃ for 2 hours to obtain high-performance Q345 composite board.

[0027] Example 3 A high-performance Q345 composite board and its preparation method, comprising the following steps: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.2% and chromium trioxide 0.8% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 0.5~1mm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, spherical particles with a particle size of 0.5~1mm are formed by wet spray granulation process. Finally, the sintering is carried out at 1630℃ for 4h under nitrogen atmosphere to obtain spherical material with a particle size of 0.5~1mm. Step 1.2 Preparation of spherical material with a particle size of 50~100μm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, it is granulated by fluidized bed spraying to form spherical particles with a particle size of 50~100μm. Finally, it is sintered at 1560℃ for 2h under a nitrogen atmosphere to obtain spherical material with a particle size of 50~100μm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 100℃. Step 3, Transition Layer Laying: Mix spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm at a mass ratio of 2:1 to form a transition layer of spherical material. Spread 50% of the weight of the transition layer of spherical material evenly on the surface of the pretreated Q345R steel substrate and press lightly at 10MPa for 15s. Then fill in the remaining transition layer of spherical material and spread it evenly. Press lightly at 10MPa for 15s to form a 2mm thick transition layer. The spherical material of the transition layer accounts for 24.5% of the mass of the Q345R steel substrate material of the transition layer; Step 4, Surface layer laying: The mass ratio of spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm is 4:1 to form the spherical material of the surface layer. The spherical material of the surface layer is laid flat on the transition layer and lightly pressed at 15MPa for 25s to form a surface layer with a thickness of 1.5mm. Among them, the spherical material of the surface layer accounts for 52.6% of the Q345R steel substrate material of the surface layer; Step 5, Hot Press Sintering: Under argon protection, the temperature is first raised to 810℃ at a rate of 5~10℃ / min, then a pressure of 15MPa is applied. The temperature is then raised to 960℃ at a rate of 5~10℃ / min and the pressure is simultaneously increased to 35MPa. The temperature is then raised to 1200℃ at a rate of 5~10℃ / min and the pressure is simultaneously increased to 60MPa. The temperature and pressure are then maintained for 90 minutes, so that the spherical material is embedded into the surface of the Q345R steel substrate to form an intercalation layer. Then the temperature is lowered at a rate of 2~5℃ / min. When the temperature drops to 800℃, the pressure is released at a rate of 1~2MPa / min. When the temperature drops to 200℃, the material is demolded. Step 6: After demolding, heat-treat at 600℃ for 1 hour to obtain high-performance Q345 composite board.

[0028] Example 4 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm, chromium trioxide with a particle size of 0.3~0.8μm, and nano zinc oxide with a particle size of 20~50nm are used as raw materials. They are weighed and mixed according to the following mass percentages: 99.57% magnesium aluminum spinel, 0.68% chromium trioxide, and 0.17% nano zinc oxide to form a mixture; the rest are exactly the same.

[0029] Example 5 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm, chromium trioxide with a particle size of 0.3~0.8μm, and nano zinc oxide with a particle size of 20~50nm are used as raw materials. They are weighed and mixed according to the following mass percentages: 98.91% magnesium aluminum spinel, 0.86% chromium trioxide, and 0.23% nano zinc oxide to form a mixture; the rest are exactly the same.

[0030] Example 6 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm, chromium trioxide with a particle size of 0.3~0.8μm, and nano zinc oxide with a particle size of 20~50nm are used as raw materials. They are weighed and mixed according to the following mass percentages: 99.57% magnesium aluminum spinel, 0.32% chromium trioxide, and 0.11% nano zinc oxide to form a mixture; the rest are exactly the same.

[0031] Example 7 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: The spherical material of the transition layer is a mixture of spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm in a mass ratio of 1.8:1; the spherical material of the transition layer accounts for 22.45% of the mass of the Q345R steel substrate material of the transition layer; The spherical material of the surface layer consists of spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm in a mass ratio of 4:1; the spherical material of the surface layer accounts for 45.8% of the Q345R steel substrate material of the surface layer; the rest are exactly the same.

[0032] Example 8 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and they are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.32% and chromium trioxide 0.68% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 0.5~1mm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, and dispersed evenly under ball milling at 300 rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, spherical particles with a particle size of 0.5~1mm are formed by wet spray granulation process. Finally, the sintering is carried out at 1600℃ for 4.5h under nitrogen atmosphere to obtain spherical material with a particle size of 0.5~1mm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 90℃. Step 3: Forming a surface layer by laying spherical material: Spread 50% of the weight of spherical material with a particle size of 0.5~1mm evenly on the pretreated surface of the Q345R steel substrate, and lightly press it at 9MPa for 12s to form a surface layer with a thickness of 1.8mm; wherein, the spherical material accounts for 22.1% of the mass of the Q345R steel substrate material in the surface layer. The subsequent hot pressing sintering and heat treatment processes are exactly the same.

[0033] Example 9 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and they are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.32% and chromium trioxide 0.68% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 0.5~1mm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.5% polyvinyl alcohol, and dispersed evenly under ball milling at 300 rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, spherical particles with a particle size of 0.5~1mm are formed by wet spray granulation process. Finally, the sintering is carried out at 1600℃ for 4.5h under nitrogen atmosphere to obtain spherical material with a particle size of 0.5~1mm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 90℃. Step 3: Spherical material is laid to form a surface layer: Spherical material with a particle size of 0.5~1mm is laid flat on the pretreated surface of Q345R steel substrate and lightly pressed at 13.5MPa for 22s to form a surface layer with a thickness of 1.2mm. Among them, the spherical material of the surface layer accounts for 47.8% of the Q345R steel substrate material of the surface layer; The subsequent hot pressing sintering and heat treatment processes are exactly the same.

[0034] Example 10 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and they are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.32% and chromium trioxide 0.68% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 50~100μm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, it is granulated by fluidized bed spraying to form spherical particles with a particle size of 50~100μm. Finally, it is sintered at 1550℃ for 2.5h under a nitrogen atmosphere to obtain spherical material with a particle size of 50~100μm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 90℃. Step 3: Forming a surface layer by laying spherical material: Spread 50% of the weight of spherical material with a particle size of 0.5~1mm evenly on the pretreated surface of the Q345R steel substrate, and lightly press it under 9MPa for 12s to form a surface layer with a thickness of 1.8mm; wherein, the spherical material accounts for 22.1% of the mass of the Q345R steel substrate material in the surface layer. The subsequent hot pressing sintering and heat treatment processes are exactly the same.

[0035] Example 11 A high-performance Q345 composite board and its preparation method differ from Example 1 in that: Step 1, Preparation of spherical material: Magnesium aluminum spinel with a purity greater than 99.9% and a particle size of 0.8~1.5μm and chromium trioxide with a particle size of 0.3~0.8μm are used as raw materials, and they are weighed and mixed according to the mass percentage of magnesium aluminum spinel 99.32% and chromium trioxide 0.68% to form a mixture. Step 1.1 Preparation of spherical material with a particle size of 50~100μm: The mixture is mixed with an aqueous solution containing 0.2% ammonium polyacrylate and 0.3% polyethylene glycol, and dispersed evenly under ball milling at 300rpm to form a uniformly dispersed slurry with a solid content of 60~65%. Then, it is granulated by fluidized bed spraying to form spherical particles with a particle size of 50~100μm. Finally, it is sintered at 1550℃ for 2.5h under a nitrogen atmosphere to obtain spherical material with a particle size of 50~100μm. Step 2, Q345R steel substrate pretreatment: The surface of the 15mm thick Q345R steel substrate is polished to remove the oxide layer and increase the surface roughness. Impurities are removed by cleaning. The pretreated Q345R steel substrate is placed in a mold and preheated to 90℃. Step 3: Spherical material is laid to form a surface layer: Spherical material with a particle size of 50~100μm is laid flat on the pretreated surface of Q345R steel substrate and lightly pressed at 13.5MPa for 22s to form a surface layer with a thickness of 1.2mm. Among them, the spherical material of the surface layer accounts for 47.8% of the Q345R steel substrate material of the surface layer; The subsequent hot pressing sintering and heat treatment processes are exactly the same.

[0036] The Q345R steel substrate used in Examples 1-11 above is a traditional Q345R steel plate.

[0037] The performance of the high-performance Q345 composite plates in Examples 1 to 11 above was tested. The high-temperature strength was analyzed at 500℃, and the hydrogen embrittlement sensitivity was analyzed at 600℃ and 5MPa hydrogen pressure. The low-temperature toughness was analyzed by impact (standard V-notch) at -196℃. The traditional Q345R steel substrate was used as a control group. The results are shown in Table 1.

[0038] Table 1

[0039] As shown in Table 1, embedding spherical materials of two particle sizes, prepared from magnesium aluminum spinel and chromium trioxide, or chromium trioxide and nano-zinc oxide, into the Q345R steel substrate to form a "matrix-spinel particle" gradient structure can improve the strength and hydrogen embrittlement resistance of the Q345 composite plate at 600℃ and enhance its toughness at -196℃. The synergistic effect of chromium trioxide and magnesium aluminum spinel not only increases the density of the coating layer and reduces hydrogen embrittlement sensitivity, but also reduces the wettability of the coating by slag at high temperatures, thus improving strength. Furthermore, the interaction between nano-zinc oxide and magnesium aluminum spinel further enhances the grain refinement effect, improving the strength of the coating layer. The fracture toughness, at low temperatures, can alleviate interfacial stress concentration in Q345 composite plates and reduce low-temperature toughness defects. Furthermore, the continuous skeletal support formed by spherical materials with a particle size of 0.5~1mm and the dispersed reinforcement by spherical materials with a particle size of 50~100μm, along with the composite gradient structure formed by the intercalation layer combining the transition layer and the surface layer, further optimizes the fine grain strengthening effect, the dense structure of the intercalation layer, and the interfacial stress of the Q345 composite plate. As a result, the high-temperature strength of the Q345 composite plate is improved, the hydrogen embrittlement sensitivity is reduced, and the low-temperature toughness defects are reduced, thus further enhancing the overall performance of the Q345 composite plate.

[0040] In summary, the 345 composite plate of the present invention has good high-temperature strength, resistance to hydrogen embrittlement, and low-temperature toughness.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit and essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high-performance Q345 composite board, characterized in that, The material includes a Q345R steel substrate and an inlay layer embedded on the surface of the Q345R steel substrate. The inlay layer includes spherical material and Q345R steel substrate material. The spherical material includes the following raw materials and weight percentages: spinel structure 98.91~99.68%, chromium trioxide 0.32~0.86%, and nano zinc oxide 0~0.23%.

2. The high-performance Q345 composite board according to claim 1, characterized in that, The spherical material comprises the following raw materials and weight percentages: spinel structure 98.91~99.57%, chromium trioxide 0.32~0.86%, and nano zinc oxide 0.11~0.23%.

3. A high-performance Q345 composite board according to claim 1 or 2, wherein the inlay layer comprises a surface layer with a thickness of 1~1.5mm and a transition layer with a thickness of 1.5~2mm.

4. The high-performance Q345 composite board according to claim 3, characterized in that, The spherical material includes spherical material with a particle size of 0.5~1mm and spherical material with a particle size of 50~100μm.

5. A high-performance Q345 composite board according to claim 4, characterized in that, In the surface layer, the spherical material accounts for 45.8~52.6% of the Q345R steel substrate material, and the mass ratio of spherical material with a particle size of 0.25~1mm to spherical material with a particle size of 50~100μm is 3~4:

1.

6. The high-performance Q345 composite board according to claim 4, characterized in that, In the transition layer, the spherical material accounts for 19.7~24.5% of the mass of the Q345R steel substrate material, and the mass ratio of spherical material with a particle size of 0.5~1mm to spherical material with a particle size of 50~100μm is 1.5~2:

1.

7. A high-performance Q345 composite board according to any one of claims 1, 2, or 4, characterized in that, The preparation process of the spherical material is as follows: spinel structure, chromium trioxide and nano zinc oxide are mixed with an aqueous solution containing dispersant and binder, ball milled to form a uniformly dispersed slurry with a solid content of 60-65%, and then formed into spherical particles by wet spraying or fluidized bed spraying granulation process, and finally sintered under a protective atmosphere to obtain spherical material.

8. A method for preparing a high-performance Q345 composite plate according to claim 1 or 2, characterized in that, Includes the following steps: (1) Pretreatment of Q345R steel substrate: The surface of Q345R steel substrate with a thickness of 10~20mm is polished and cleaned to remove impurities. The pretreated Q345R steel substrate is placed in a mold and preheated. (2) Spherical material laying: The above-mentioned spherical material is laid flat on the pretreated surface, and the pre-pressing temperature is 80~100℃; (3) Hot pressing sintering: Under argon protection, the temperature is first raised to 780-810℃ at a rate of 5-10℃ / min, then a pressure of 10-15MPa is applied, then the temperature is raised to 910-960℃ at a rate of 5-10℃ / min and the pressure is raised to 30-35MPa simultaneously, then the temperature is raised to 1200-1250℃ at a rate of 5-10℃ / min and the pressure is raised to 55-60MPa simultaneously, then the temperature and pressure are maintained for 90-120min, then the temperature is lowered at a rate of 2-5℃ / min, when the temperature drops to 800℃, the pressure is released at a rate of 1-2MPa / min, when the temperature drops to 200℃, the mold is removed; (4) After demolding, heat treatment: temperature 550~600℃, time 1~2h, to obtain high performance Q345 composite board.

9. The method for preparing a high-performance Q345 composite plate according to claim 8, characterized in that, Step (2) involves laying spherical material, which includes laying a transition layer and laying a surface layer.

10. The method for preparing a high-performance Q345 composite plate according to claim 8, characterized in that, The transition layer is laid by first laying 50% of the weight of the spherical material of the transition layer flat on the surface of the pretreated Q345R steel substrate, and then lightly pressing it for 10-15 seconds under 8-10 MPa. Then, the remaining spherical material of the transition layer is filled and laid flat, and lightly pressed for 10-15 seconds under 8-10 MPa. The surface layer is laid by spreading the spherical material of the surface layer on the transition layer and applying a light pressure of 12-15 MPa for 20-25 seconds.

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