Wear-resistant and corrosion-resistant composite steel plate and manufacturing method thereof

Abstract

The application provides a wear-resistant and corrosion-resistant composite steel plate and a manufacturing method thereof. The wear-resistant and corrosion-resistant composite steel plate comprises a base layer and a composite layer which is combined on the surface of the base layer. The composite layer comprises Fe and the following chemical elements in mass percentage: C: 0.33%-0.45%, Si: 0.2%-0.8%, Mn: 0.4%-1%, P: less than or equal to 0.030%, S: less than or equal to 0.010%, Cr: 11%-15%, Nb: 0.005%-0.05%, Al: 0.01%-0.07%, Cu: less than or equal to 0.3%, and Ni: less than or equal to 0.2%. The wear-resistant and corrosion-resistant composite steel plate has excellent wear resistance and good impact resistance.

Description

Technical Field

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

[0002] Wear-resistant steel plates are typically used in mechanical equipment in engineering, mining, cement production, ports, power, and metallurgy industries where working conditions are particularly harsh and high wear resistance is required. They are also typically required to have good corrosion resistance.

[0003] In the prior art, high-grade stainless steel is usually used to replace low-alloy high-strength wear-resistant steel plates for wear-resistant equipment in corrosive environments. However, high-grade stainless steel has a large amount of precious metals added, resulting in high material costs and poor wear resistance. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a wear-resistant and corrosion-resistant composite steel plate.

[0005] The present invention also provides a method for manufacturing a wear-resistant and corrosion-resistant composite steel plate.

[0006] According to a first aspect of the present invention, a wear-resistant and corrosion-resistant composite steel plate includes a base layer and a composite layer bonded to the surface of the base layer;

[0007] The composite layer comprises an Fe base and chemical elements dispersed in the Fe base in the following mass percentages: C: 0.33%–0.45%, Si: 0.2%–0.8%, Mn: 0.4%–1%, P≤0.030%, S≤0.010%, Cr: 11%–15%, Nb: 0.005%–0.05%, Al: 0.01%–0.07%, Cu≤0.3%, Ni≤0.2%.

[0008] Further, the base layer comprises an Fe base and chemical elements dispersed in the Fe base in the following mass percentages: C: 0.2%–0.35%, Si: 0.1%–0.6%, Mn: 0.6%–1.6%, P≤0.03%, S≤0.01%, Cr: 0.1%–1%, Nb: 0.005%–0.05%, Ti: 0.005%–0.05%, Al: 0.01%–0.06%, B: 0.001%–0.005%, Mo: 0.01%–0.50%, Ni: 0.01%–1%.

[0009] According to another embodiment of the present invention, a wear-resistant and corrosion-resistant composite steel plate includes a base layer and a composite layer bonded to the surface of the base layer;

[0010] The composite layer comprises, by mass percentage: C: 0.33%–0.45%, Si: 0.2%–0.8%, Mn: 0.4%–1%, P≤0.030%, S≤0.010%, Cr: 11%–15%, Nb: 0.005%–0.05%, Al: 0.01%–0.07%, Cu≤0.3%, Ni≤0.2%, with the balance being Fe and unavoidable impurities.

[0011] Further, by mass percentage, the composition of the base layer is as follows: C: 0.2%–0.35%, Si: 0.1%–0.6%, Mn: 0.6%–1.6%, P≤0.03%, S≤0.01%, Cr: 0.1%–1%, Nb: 0.005%–0.05%, Ti: 0.005%–0.05%, Al: 0.01%–0.06%, B: 0.001%–0.005%, Mo: 0.01%–0.50%, Ni: 0.01%–1%, with the balance being Fe and unavoidable impurities.

[0012] Furthermore, the composite layer includes a first composite layer located on one side surface of the base layer.

[0013] Furthermore, the composite layer also includes a second composite layer located on the other side surface of the base layer, wherein the components and / or thicknesses of the first composite layer and the second composite layer are independent of each other.

[0014] Furthermore, the first composite layer and the second composite layer are continuously cast billets with the same chemical composition and the same thickness specification.

[0015] Furthermore, the Brinell hardness of the base layer is above 450 HBW, and the Rockwell hardness of the composite layer is above 50 HRC.

[0016] Furthermore, the method for manufacturing a wear-resistant and corrosion-resistant composite steel plate according to a second aspect embodiment of the present invention includes the following steps:

[0017] S1, the components of the base layer and the composite layer in the composite steel plate are respectively proportioned, and then smelted and cast to obtain the base layer steel billet and the composite layer steel billet;

[0018] S2, the base steel billet and composite layer steel billet in step S1 are assembled and rolled in sequence to obtain precast steel plates with a rolling reduction rate of ≥50%;

[0019] S3, the precast steel plate from step S2 is subjected to online quenching to obtain the composite steel plate.

[0020] Furthermore, in step S2, before the blank is assembled, the rust and oxide layers on each of the surfaces to be contacted are removed by machining to a depth of 5mm to 10mm.

[0021] Further, step S2 includes:

[0022] S21, multiple bevels are formed on the four sides of each of the contact surfaces of the base steel billet and the composite layer steel billet by machining, and multiple right-angle holes are formed at each of the bevels by machining, and the multiple right-angle holes are connected to form a vacuum channel.

[0023] S22, the contact surface of the base steel billet described in step S21 is aligned with the release surface of the composite layer steel billet and stacked, and then a composite billet is formed by sealing welding.

[0024] S23, Vacuum treatment is performed on the composite blank in step S22;

[0025] S24, Seal the vacuum channel on the composite billet in step S23;

[0026] S25, place the composite blank from step S24 in a heating furnace and heat it to 1000-1250℃, and keep it at that temperature for 1-3 hours;

[0027] S26, the composite billet in step S25 is subjected to vacuum hot rolling. In the vacuum hot rolling step, the initial rolling temperature is 1000-1250℃ and the final rolling temperature is 850-950℃.

[0028] Further, in step S3, the precast steel plate obtained in step S2 is water-quenched to 100-300°C and then tempered at a tempering temperature of 150-350°C. Given a holding time of t minutes at the tempering temperature and a composite steel plate thickness of d millimeters, the holding time and the thickness of the composite steel plate satisfy the following relationship:

[0029] t = nd, where n is 2 to 4.

[0030] The above-described technical solution of the present invention has at least one of the following beneficial effects:

[0031] According to an embodiment of the present invention, a wear-resistant and corrosion-resistant composite steel plate includes a base layer and a composite layer bonded to the surface of the base layer. By designing the composition of the composite layer and combining it with an optimized manufacturing process, and by combining the manufacturing process of vacuum hot rolling and online quenching based on the chemical element composition of the present invention, a microstructure consisting of martensite, retained austenite, and dispersed precipitates can be formed, ultimately resulting in a composite steel plate with excellent corrosion resistance and wear resistance. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0033] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "connected" or "linked" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up," "down," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship also changes accordingly.

[0034] The wear-resistant and corrosion-resistant composite steel plate (hereinafter referred to as composite steel plate) of the present invention will be described in detail below.

[0035] According to an embodiment of the present invention, the composite steel plate includes a base layer and a composite layer bonded to the surface of the base layer. The composite layer includes an Fe base and chemical elements dispersed in the Fe base in the following mass percentages: C: 0.33%–0.45%, Si: 0.2%–0.8%, Mn: 0.4%–1%, P≤0.030%, S≤0.010%, Cr: 11%–15%, Nb: 0.005%–0.05%, Al: 0.01%–0.07%, Cu≤0.3%, Ni≤0.2%. In other words, through the design of the above chemical element composition, a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates, and a Rockwell hardness of 50 HRC or higher can be formed. By adjusting the mass percentages of Cr, Cu, and other beneficial elements such as Mn, Nb, and Ni in the composite layer, the wear resistance and corrosion resistance of the composite steel plate can be improved.

[0036] Furthermore, the base layer comprises an Fe base and chemical elements dispersed in the Fe base with the following mass percentages: C: 0.2%–0.35%, Si: 0.1%–0.6%, Mn: 0.6%–1.6%, P≤0.03%, S≤0.01%, Cr: 0.1%–1%, Nb: 0.005%–0.05%, Ti: 0.005%–0.05%, Al: 0.01%–0.06%, B: 0.001%–0.005%, Mo: 0.01%–0.50%, Ni: 0.01%–1%. In other words, through the design of the above chemical element composition, a base layer with a Brinell hardness of 450 HBW or higher can be obtained under the premise of low carbon and low alloy element addition. The amount of precious metals added to the base layer of this composite steel plate is small, which can save costs.

[0037] Furthermore, the composite steel plate includes a base layer and a composite layer bonded to the surface of the base layer. The composite layer, by mass percentage, comprises: C: 0.33%–0.45%, Si: 0.2%–0.8%, Mn: 0.4%–1%, P≤0.030%, S≤0.010%, Cr: 11%–15%, Nb: 0.005%–0.05%, Al: 0.01%–0.07%, Cu≤0.3%, Ni≤0.2%, with the balance being Fe and unavoidable impurities. In other words, the composite layer uses Fe as the main constituent element, and by adjusting the mass percentage of beneficial elements and controlling the content of unavoidable impurities, the wear and corrosion resistance of the composite steel plate is improved.

[0038] Furthermore, the composition of the base layer, by mass percentage, is as follows: C: 0.2%–0.35%, Si: 0.1%–0.6%, Mn: 0.6%–1.6%, P≤0.03%, S≤0.01%, Cr: 0.1%–1%, Nb: 0.005%–0.05%, Ti: 0.005%–0.05%, Al: 0.01%–0.06%, B: 0.001%–0.005%, Mo: 0.01%–0.50%, Ni: 0.01%–1%, with the balance being Fe and unavoidable impurities. In other words, the base layer uses Fe as the main component element. By adjusting the mass percentage of beneficial elements and controlling the content of unavoidable impurities, the amount of alloying elements added is reduced, thereby lowering costs, while ensuring the comprehensive mechanical properties of the base layer.

[0039] Specifically, the design principles of each chemical element in the base layer and composite layer of this invention are as follows:

[0040] Carbon (C): Carbon is the most basic and important element in wear-resistant steel. It promotes the formation of martensitic structure in steel through solid solution strengthening and precipitation strengthening, thereby increasing the steel's strength and hardness. If the C content in steel is too low, it cannot guarantee the formation of martensitic structure and the required mechanical and wear-resistant properties, while simultaneously increasing the steel's plasticity and toughness. If the C content in steel is too high, it will increase the tendency for segregation during continuous casting or ingot casting, leading to severe segregation in the steel plate, reducing its toughness, and causing the mechanical properties to fail to meet standards.

[0041] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of C in the composite layer is controlled at 0.33% to 0.45%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of C in the base layer is controlled at 0.2% to 0.35%.

[0042] Si: Appropriate Si is a beneficial deoxidizer in steel. It can form calcium aluminum silicate inclusions that are easy to float together with Ca and Al in steel, thereby improving the purity of steel. Furthermore, the solid solution strengthening effect of Si in ferrite and austenite can improve hardness and strength. However, excessive Si content will lead to a sharp decrease in the toughness of steel.

[0043] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of Si in the composite layer is controlled at 0.2% to 0.8%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Si in the base layer is controlled at 0.1% to 0.6%.

[0044] Mn: Mn can increase the hardenability of steel, reduce the transformation temperature and critical cooling rate of steel. However, when the Mn content is high, it tends to coarsen the grains and increase the steel's temper brittleness sensitivity. It can also easily lead to segregation and cracks in the billet, reducing the performance of the steel plate.

[0045] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of Mn in the composite layer is controlled at 0.4% to 1%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Mn in the base layer is controlled at 0.6% to 1.6%.

[0046] Cr: Cr can improve the hardenability of steel, as well as its strength and hardness. During tempering, Cr can prevent or slow down the precipitation and aggregation of carbides, thus improving the tempering stability of steel. Cr can also significantly improve corrosion resistance. However, excessive Cr content can impair the low-temperature toughness, impact load fracture characteristics, and bending cold workability of steel plates, especially their weldability.

[0047] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of Cr in the composite layer is controlled at 11% to 15%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Cr in the base layer is controlled at 0.1% to 1%.

[0048] Ti: Ti is one of the strong carbide-forming elements, forming fine TiC particles with C. The small TiC particles are distributed at the grain boundaries, achieving the effect of refining the grains. The relatively hard TiC particles improve the wear resistance of steel.

[0049] Therefore, in this invention, for obtaining a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Ti in the base layer is controlled between 0.005% and 0.05%.

[0050] Al: Al can combine with nitrogen in steel to form fine, insoluble AlN particles, refining the steel grain structure. Al can refine the steel grain structure, fix nitrogen and oxygen in the steel, reduce the steel's sensitivity to notches, reduce or eliminate aging phenomena in the steel, and improve the steel's toughness.

[0051] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of Al in the composite layer is controlled between 0.01% and 0.07%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Al in the base layer is controlled between 0.01% and 0.06%.

[0052] P and S: P is an impurity introduced into steel from pig iron. P can completely dissolve in ferrite, reducing the plasticity and toughness of steel. S is an impurity introduced into steel from pig iron and fuel. Sulfides formed during steel production reduce the mechanical properties of steel, and hot-working fibrous structures are formed during rolling. Therefore, in wear-resistant steel, both P and S are harmful elements, and their content must be strictly controlled.

[0053] Therefore, in this invention, the mass percentage of P in the base layer and composite layer is controlled to be ≤0.030%, and the mass percentage of S is controlled to be ≤0.010%.

[0054] Mo: Mo can refine grains and improve strength and toughness. Mo is an element that reduces temper brittleness and can improve tempering stability.

[0055] Therefore, in this invention, for obtaining a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Mo in the base layer is controlled between 0.01% and 0.50%.

[0056] Ni: Ni has the effect of significantly reducing the brittle transition temperature, but if the content is too high, it will make it difficult to remove the oxide scale on the surface of the steel plate, and the cost will increase significantly.

[0057] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates and a Rockwell hardness of 50 HRC or higher, the mass percentage of Ni in the composite layer is ≤0.2%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Ni in the base layer is controlled between 0.01% and 1%.

[0058] Nb: Nb can improve the strength and toughness of steel through grain refinement.

[0059] Therefore, in this invention, for a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates, and a Rockwell hardness of 50 HRC or higher, the mass percentage of Nb in the composite layer is controlled between 0.005% and 0.05%; for a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of Nb in the base layer is controlled between 0.005% and 0.05%.

[0060] Cu: In steel, Cu mainly exists in solid solution and as a single-phase precipitate. Solid solution Cu plays a role in solid solution strengthening. Since the solid solubility of Cu in ferrite decreases rapidly with decreasing temperature, at lower temperatures, supersaturated solid solution Cu precipitates as a single element, playing a role in precipitation strengthening. At the same time, adding Cu to steel can significantly improve its resistance to atmospheric corrosion, and the effect is particularly significant when it coexists with phosphorus.

[0061] Therefore, in this invention, for obtaining a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates, and a Rockwell hardness of 50 HRC or higher, the mass percentage of Cu in the composite layer is ≤0.3%.

[0062] B: The main function of B is to improve the hardenability of steel, so that the steel has high strength and hardness after quenching, and thus has good comprehensive properties after tempering. Excessive B content will lead to hot brittleness, affecting the weldability and hot working performance of steel.

[0063] Therefore, in this invention, for obtaining a base layer with a Brinell hardness of 450 HBW or higher, the mass percentage of B in the base layer is controlled between 0.001% and 0.005%.

[0064] This invention improves the wear and corrosion resistance of the composite steel plate by rationally designing the composition of the composite layer on the surface of the base layer, specifically by rationally designing the mass percentage of each chemical element. This results in a composite layer with a microstructure of martensite, retained austenite, and dispersed precipitates, and a Rockwell hardness of 50 HRC or higher. Furthermore, by rationally designing the mass percentage of each chemical element in the base layer, a base layer with a Brinell hardness of 450 HBW or higher is obtained, reducing the amount of alloying elements added to the composite steel plate, lowering production costs, and ensuring the wear resistance of the composite steel plate.

[0065] Furthermore, the composite layer includes a first composite layer located on one side surface of the base layer. That is, the first composite layer is laminated on one surface of the base layer, and this first composite layer can be used when exposed to corrosive working environments, thereby improving the overall wear and corrosion resistance of the composite steel plate.

[0066] Furthermore, the composite layer also includes a second composite layer located on the other side of the base layer, wherein the components and / or thicknesses of the first and second composite layers are independent of each other. That is, by laminating a second composite layer onto the other surface of the base layer, this second composite layer can also be used in corrosive working environments. This second composite layer can further improve the overall wear and corrosion resistance of the composite steel plate and expand its application range.

[0067] It should be noted that the phrase "the components and / or thicknesses of the first composite layer and the second composite layer are independent of each other" means that the components of the first composite layer and the second composite layer can be the same or different, and similarly, their thicknesses can be the same or different.

[0068] Furthermore, the first composite layer and the second composite layer are continuously cast billets with the same chemical composition and thickness specifications. That is to say, the first composite layer and the second composite layer have the same chemical composition and thickness specifications. This allows the first composite layer and the second composite layer to be laminated onto the upper and lower surfaces of the base layer respectively using the same manufacturing method and process parameters, which has the advantage of convenient processing and manufacturing.

[0069] It should be noted that there are no specific limitations on the thickness of the composite layer; it can be adjusted appropriately according to the usage environment.

[0070] Furthermore, there are no particular restrictions on whether the composite layer is formed on one side or on both sides (i.e., the first composite layer and the second composite layer). The design can be made according to the environment in which it is used. For example, when the composite steel plate is used to prepare parts for conveying corrosive, high-speed flowing gases / liquids, the composite layer can be formed on one side. When the composite steel plate is used for parts of processing machines in a corrosive atmosphere, the composite layer can be formed on both sides.

[0071] This invention also provides a method for manufacturing a wear-resistant and corrosion-resistant composite steel plate, comprising the following steps: S1, proportioning the components of the base layer and composite layer in the composite steel plate, and smelting and casting to obtain a base layer steel billet and a composite layer steel billet; S2, sequentially assembling and rolling the base layer steel billet and the composite layer steel billet from step S1 to obtain a precast steel plate, wherein the reduction rate after rolling is ≥50%; S3, subjecting the precast steel plate from step S2 to online quenching treatment to obtain the composite steel plate. In other words, based on the compositional design of the composite layer and base layer of the composite steel plate, and under the premise of low carbon and low alloy content, the effect of microstructure refinement and strengthening can be further improved by controlling the reduction rate during the rolling process.

[0072] Furthermore, in step S2, before assembling the billets, the rust and oxide layers on each surface to be contacted are removed by machining to a depth of 5mm to 10mm. In other words, before assembling the billets, the rust and oxide layers on their surfaces are removed by machining to prevent impurities from being mixed into the composite billet and affecting the performance of the composite steel plate.

[0073] Further, step S2 includes: S21, forming multiple bevels on the four sides of each contact surface of the base steel billet and the composite layer steel billet by machining, and then forming multiple right-angle holes at each bevel by machining, with the multiple right-angle holes connected to form a vacuum channel; S22, stacking the contact surfaces of the base steel billet in step S21 with the contact surfaces of the composite layer steel billet, and then forming a composite billet by sealing welding; S23, performing vacuum treatment on the composite billet in step S22; S24, sealing the vacuum channel on the composite billet in step S23; S25, placing the composite billet in step S24 in a heating furnace and heating it to 1000-1250℃, holding it at that temperature for 1-3 hours; S26, performing vacuum hot rolling on the composite billet in step S25, wherein the initial rolling temperature is 1000-1250℃ and the final rolling temperature is 850-950℃.

[0074] In other words, firstly, the composite billet is rolled using a vacuum hot rolling method. This method facilitates complete metallurgical bonding between the base steel billet and the composite layer steel billet, resulting in strong bonding and excellent comprehensive mechanical properties. Furthermore, controlling the process parameters of vacuum hot rolling further enhances the comprehensive mechanical properties of the composite steel plate. Specifically, controlling the heating temperature between 1000 and 1250°C allows carbon and alloying elements to fully diffuse at the composite interface, achieving metallurgical bonding and promoting the homogenization of carbon and alloying elements. A staged controlled rolling method with an initial rolling temperature of 1000–1250°C and a final rolling temperature of 850–950°C fully utilizes the recrystallization and non-recrystallization effects, achieving grain refinement and improving the strength and toughness of the steel. Finally, high-reduction rolling with a reduction rate ≥50% further enhances the controlled rolling effect, achieving a grain refinement and strengthening effect.

[0075] Further, in step S3, the precast steel plate obtained in step S2 is water-quenched to 100–300°C and then tempered at 150–350°C. With a holding time of t minutes and a composite steel plate thickness of d millimeters, the holding time and the thickness of the composite steel plate satisfy the following relationship: t = nd, where n is 2–4. In other words, by using online quenching to heat-treat the vacuum-hot-rolled composite steel plate, under the premise of low carbon and low alloy content, and by optimizing the water quenching midpoint temperature in the online quenching process, the microstructure refinement and strengthening effects can be further improved, resulting in a composite steel plate with excellent comprehensive mechanical properties.

[0076] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to examples.

[0077] Examples 1-5 and Comparative Example 1

[0078] The composite steel plates of Examples 1-5 of the present invention are obtained by the following steps:

[0079] (1) Calculate the allowance of the composite layer billet according to the components and component content of the composite layer shown in Table 1. Calculate the allowance of the base layer billet according to the components and component content of the base layer shown in Table 2. When calculating, the content of unavoidable impurities in the billet should be taken into account. Then, smelting and casting are carried out to obtain the base layer steel billet and the composite layer steel billet respectively.

[0080] (2) Remove the rust and oxide layers from the surfaces of the base steel billet and the composite layer steel billet by machining, with a machining depth of 8mm.

[0081] The surface of the composite steel billet to be contacted is attached to the surface of the base steel billet to be contacted, and then a composite billet is formed by sealing welding.

[0082] Precast steel plates were obtained by vacuum hot rolling of composite billets according to the parameters shown in Table 3.

[0083] (3) The rolled composite steel plate was subjected to online quenching treatment according to the parameters shown in Table 3.

[0084] The steel plate of Comparative Example 1 was manufactured according to the composition and composition content shown in Table 1 and the manufacturing method shown in Table 3. The difference is that Comparative Example 1 is a single-layer steel billet.

[0085] Table 1 lists the components of the composite layer in the composite steel plates of Examples 1-5 and the steel plate of Comparative Example 1.

[0086] Table 1. Composition (wt.%) of the composite layer in the composite steel plates of Examples 1-5 and the steel plate of Comparative Example 1.

[0087]

[0088]

[0089] Table 2 lists the components of the base layer in the composite steel plates of Examples 1-5.

[0090] Table 2. Components (wt.%) of the base layer in the composite steel plates of Examples 1-5

[0091]

[0092] Table 3 lists the main process parameters for hot rolling and online quenching of composite steel plates in Examples 1-5, as well as the main process parameters for the manufacturing method of Comparative Example 1.

[0093] Table 3 shows the main process parameters for hot rolling and online quenching of composite steel plates in Examples 1-3, and the main process parameters for the manufacturing method in Comparative Example 1.

[0094]

[0095] Samples were taken from the composite steel plates of Examples 1-5 and the steel plate of Comparative Example 1, and then hardness tests were performed on the base layer and composite layer of the composite steel plates of Examples 1-5 and the surface of the steel plate of Comparative Example 1.

[0096] The test results for Examples 1-5 and Comparative Example 1 are shown in Table 3.

[0097] Table 4 lists the base layer and composite layer of the composite steel plates in Examples 1-5, as well as the hardness test results of Comparative Example 1.

[0098] Table 4 shows the hardness test results of the base layer and composite layer of the composite steel plates in Examples 1-5, and Comparative Example 1.

[0099]

[0100] As shown in Table 4, the Rockwell hardness of the composite layer located on the base surface in Examples 1-5 of the present invention is above 50 HRC. Through composition design and optimized manufacturing process, composite steel plates with good comprehensive mechanical properties and good wear and corrosion resistance can be obtained.

[0101] In comparison, as shown in Tables 1-4, although the chemical element mass percentage of Comparative Example 1 is within the range of chemical element composition of the composite layer of the composite steel plate of the present invention, the vacuum hot rolling reduction rate, cooling temperature, and tempering temperature of its manufacturing method were not carried out in accordance with the manufacturing method provided by the present invention. This is not conducive to further refining and strengthening the microstructure through the manufacturing process, resulting in the comprehensive mechanical properties of Comparative Example 1 being lower than those of Examples 1-5.

[0102] The composite steel plate of this invention, through compositional design and optimized manufacturing process of the base layer, achieves excellent comprehensive mechanical properties and improves the wear resistance of the composite steel plate under the premise of low carbon and low alloying element addition; and by designing the composition of the composite layer and optimizing the manufacturing process, adding beneficial alloying elements such as Cr and Cu, the corrosion resistance of the composite steel plate is improved.

[0103] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A wear-resistant and corrosion-resistant composite steel plate, characterized in that, Includes a base layer and a composite layer bonded to the surface of the base layer; The composite layer comprises, by mass percentage: C: 0.33%~0.45%, Si: 0.2%~0.8%, Mn: 0.4%~1%, P≤0.030%, S≤0.010%, Cr: 11%~15%, Nb: 0.005%~0.05%, Al: 0.01%~0.07%, Cu≤0.3%, Ni≤0.2%, with the balance being Fe and unavoidable impurities; The composition of the base layer, by mass percentage, is as follows: C: 0.2%–0.35%, Si: 0.1%–0.6%, Mn: 0.6%–1.6%, P≤0.03%, S≤0.01%, Cr: 0.1%–1%, Nb: 0.005%–0.05%, Ti: 0.005%–0.05%, Al: 0.01%–0.06%, B: 0.001%–0.005%, Mo: 0.01%–0.50%, Ni: 0.01%–1%, with the balance being Fe and unavoidable impurities; The base layer has a Brinell hardness of 450 HBW or higher, the microstructure of the composite layer consists of martensite, retained austenite, and dispersed precipitates, and the Rockwell hardness of the composite layer is 50 HRC or higher.

2. The wear-resistant and corrosion-resistant composite steel plate according to claim 1, characterized in that, The composite layer includes a first composite layer located on one side surface of the base layer.

3. The wear-resistant and corrosion-resistant composite steel plate according to claim 2, characterized in that, The composite layer further includes a second composite layer located on the other side surface of the base layer, wherein the components and / or thicknesses of the first composite layer and the second composite layer are independent of each other.

4. The wear-resistant and corrosion-resistant composite steel plate according to claim 3, characterized in that, The first composite layer and the second composite layer are continuously cast billets with the same chemical composition and the same thickness specification.

5. A method for manufacturing a wear-resistant and corrosion-resistant composite steel plate, said method being used to manufacture the wear-resistant and corrosion-resistant composite steel plate according to any one of claims 1-4, characterized in that, Includes the following steps: S1, the components of the base layer and the composite layer in the composite steel plate are respectively proportioned, and then smelted and cast to obtain the base layer steel billet and the composite layer steel billet; S2, the base steel billet and composite layer steel billet in step S1 are assembled and rolled in sequence to obtain precast steel plates with a rolling reduction rate of ≥50%; S3, the precast steel plate from step S2 is subjected to online quenching to obtain the composite steel plate.

6. The manufacturing method according to claim 5, characterized in that, In step S2, before the blanks are assembled, the rust and oxide layers on each surface to be contacted are removed by machining to a depth of 5mm to 10mm.

7. The manufacturing method according to claim 5, characterized in that, Step S2 includes: S21, multiple bevels are formed on the four sides of each contact surface of the base steel billet and the composite layer steel billet by machining, and multiple right-angle holes are formed at each bevel by machining, and the multiple right-angle holes are connected to form a vacuum channel. S22, the contact surface of the base steel billet described in step S21 is aligned with the release surface of the composite layer steel billet and stacked, and then a composite billet is formed by sealing welding. S23, Vacuum treatment is performed on the composite blank in step S22; S24, Seal the vacuum channel on the composite billet in step S23; S25, place the composite blank from step S24 in a heating furnace and heat it to 1000~1250℃, and keep it at that temperature for 1~3 hours; S26, the composite billet in step S25 is subjected to vacuum hot rolling. In the vacuum hot rolling step, the initial rolling temperature is 1000~1250℃ and the final rolling temperature is 850~950℃.

8. The manufacturing method according to claim 7, characterized in that, In step S3, the precast steel plate obtained in step S2 is water-quenched to 100~300℃ and then tempered at a tempering temperature of 150~350℃. Given a holding time of t minutes at the tempering temperature and a composite steel plate thickness of d millimeters, the holding time and the thickness of the composite steel plate satisfy the following relationship: t=nd, where n is 2~4.

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