Carbon steel-high chromium cast iron composite high wear-resistant plate and preparation method thereof

Abstract

The application belongs to the technical field of metal layered composite materials, and particularly relates to a carbon steel-high chromium cast iron composite high wear-resistant plate and a preparation method thereof. The preparation method comprises the following steps: S1, blank preparation and surface pretreatment; S2, pre-preparation of a micro-pit array: laser etching of a millimeter-level pit array on the high chromium cast iron clad plate; S3, application of an intermediate layer and a protective layer: uniform spraying of nickel powder on the surface of the high chromium cast iron clad plate, and then brushing of a borax aqueous solution paste, and low-temperature drying; S4, blank assembly: alignment and stacking, and close contact of the composite surfaces; S5, pre-rolling heat preservation and asynchronous rolling; and S6, subsequent heat treatment. Through the unique interface structure design, the introduction of the intermediate layer and the protective layer, and the combination of the asynchronous rolling composite process, the effective unification of high-strength metallurgical bonding and the integrity of the high chromium cast iron is realized, and the developed carbon steel-high chromium cast iron composite high wear-resistant plate has high toughness, high wear resistance and excellent interface bonding strength.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal laminated composite materials, and particularly relates to a carbon steel-high chromium cast iron composite high-wear-resistant plate and a preparation method thereof. BACKGROUND

[0002] High chromium cast iron has excellent wear resistance due to the presence of a large amount of high-hardness carbides in its microstructure, and is widely used in harsh working conditions such as mining, cement, and power. However, its inherent high brittleness and poor toughness limit its application under impact load conditions. To solve this problem, high chromium cast iron is often combined with carbon steel with good toughness in industry to prepare a bimetallic composite material, in order to simultaneously exert the synergistic advantages of wear resistance of the former and impact resistance of the latter.

[0003] Current existing metal composite technologies in this field mainly include the following: (1) explosive welding, for example, patent 104999728B proposes to combine high chromium cast iron plate and low carbon steel plate by explosive welding, although this method can achieve high-strength metallurgical bonding, but the process is violent, with high noise pollution, high safety requirements, and it is not easy to control the flatness of large-area plate, and the high chromium cast iron layer is easy to produce micro-cracks due to high-energy impact; (2) casting composite, for example, patent CN118668045B proposes to combine by preforming holes on the carbon steel substrate and pouring high chromium cast iron, although this method can achieve regular distribution, but the process flow is long, and casting defects are easy to occur at the hole, and the hard and brittle high chromium cast iron still faces the risk of cracking during deformation during subsequent hot rolling; (3) intermediate layer diffusion bonding, for example, patent CN110744266A proposes to use copper or copper alloy as an intermediate layer, and to combine at high temperature (1000-1200℃) with long time holding and pressure, but this method has high energy consumption, and the introduction of a third component may form a low-melting-point phase or affect the wear resistance and corrosion resistance of the overall material; (4) multi-layer rolling composite, for example, patent CN108480917B proposes to combine by double-layer composite rolling of high chromium cast iron plate and low carbon steel plate, but this method is relatively complex, requiring an intermediate separation layer and vacuum sealing, with many steps, and has high requirements for the size matching of the billet, and the production efficiency needs to be improved.

[0004] Therefore, it is of great industrial application value to develop a composite plate preparation method that is simple in process, high in interfacial bonding strength, can effectively protect the microstructure of high chromium cast iron from damage, and realizes excellent comprehensive performance. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a carbon steel-high chromium cast iron composite high wear-resistant plate and a preparation method thereof, aiming to overcome the shortcomings of the prior art, and by combining a unique interface structure design, the introduction of an intermediate layer and a protective layer, and an asynchronous rolling composite process, effectively unifying high-strength metallurgical bonding and the integrity of high chromium cast iron, and developing a carbon steel-high chromium cast iron composite high wear-resistant plate and a preparation method thereof, which have high toughness, high wear resistance and excellent interface bonding strength.

[0006] Specifically, the present application provides a preparation method of a carbon steel-high chromium cast iron composite high wear-resistant plate, which comprises the following steps:

[0007] S1, blank preparation and surface pretreatment: selecting a low carbon steel plate as a substrate and a high chromium cast iron plate as a cladding plate, and performing mechanical activation treatment and surface chemical cleaning on the surfaces to be combined of the substrate and the cladding plate.

[0008] Preferably, the chemical composition of the low carbon steel is as follows in terms of mass percentage: C: 0.15-0.25%, Si≤0.35%, Mn: 0.40-0.80%, P≤0.025%, S≤0.025%, and the balance is Fe and unavoidable impurities. The chemical composition of the high chromium cast iron is as follows in terms of mass percentage: C: 2.8-3.5%, Cr: 23-28%, Mn: 0.6-1.2%, Si: 0.4-0.9%, Mo: 1.5-2.5%, Ni: 0.5-1.5%, Cu≤1.0%, P≤0.05%, S≤0.04%, and the balance is Fe.

[0009] Preferably, the mechanical activation treatment is first to use a belt sander to polish and remove the surface rust layer, and then use angular corundum sand or quartz sand for sandblasting treatment at a pressure of 0.5-0.8 MPa until the surface presents a uniform silver-gray metallic luster without any rust or oxidation color, and the roughness of the high chromium cast iron treatment surface is controlled to be 6.5-12.5 μm, and the roughness of the low carbon steel treatment surface is controlled to be 3.2-6.3 μm.

[0010] The sandblasting treatment can effectively remove the stubborn oxide scale and work-hardened layer, so that a nanocrystalline / microcrystalline layer with high activity is formed on the surface, and the controllable roughness can realize the mechanical interlocking effect. Since the hardness of the high chromium cast iron is relatively high, a larger roughness is adopted, and the rougher the roughness is, the stronger the interlocking effect is, but it is necessary to avoid hiding impurities in the deep valley. For the low carbon steel, since it is relatively soft, a too large roughness is easy to be flattened at the top during rolling, and the effect is not good.

[0011] Preferably, the surface chemical cleaning is pickling with 10%~15% HCl solution for low carbon steel to remove the iron oxide film, pickling with 10%~20% HCl-HNO3 mixed acid solution for high chromium cast iron to remove the more stable chromium oxide film, and ultrasonic cleaning with alkaline degreasing solution before and after pickling to thoroughly remove oil, and drying immediately after cleaning with hot air.

[0012] S2, pre-preparation of micro-pit array: on the surface of the high chromium cast iron clad plate to be compounded after pretreatment, a regular array of millimeter-level pits is prepared by laser etching processing.

[0013] Preferably, the pits are hemispherical pits with a diameter of 1.0~2.0 mm and a depth of 0.5~1.0 mm, and the center-to-center distance of the array pits is 2~4 mm.

[0014] The pre-prepared regular pit array can create a "rivet" or "anchoring" effect, providing stronger and more controllable mechanical interlocking ability than random roughness. The high chromium cast iron pre-prepared micro-pit array with higher hardness remains undeformed during rolling, while the soft low carbon steel will undergo significant plastic flow under high temperature and high pressure and be squeezed into and fill the pits. After cooling, the low carbon steel is mechanically "locked" in the skeleton of the high chromium cast iron. Conversely, if the pits are pre-prepared on the soft low carbon steel, the pits will be flattened and deformed during rolling, losing their original geometry, and the interlocking effect will be greatly reduced.

[0015] If the pit size is too small, it will be filled and flow under the action of large deformation and high temperature diffusion during hot rolling, and the interlocking effect will be greatly weakened. The millimeter-level pits have sufficient macro size, and even after large plastic deformation, they can still retain obvious three-dimensional interlocking structure, with significant and stable effect.

[0016] S3, applying intermediate layer and protective layer: the high chromium cast iron clad plate is preheated to 150~200°C to remove moisture, the array pit surface is placed upward, and a low-pressure flame spraying device is used to uniformly spray nickel powder on the surface, followed by immediately brushing a layer of uniform borax aqueous solution paste on the nickel powder layer to form a continuous thin film, and low-temperature drying.

[0017] Preferably, the nickel powder is spherical or near-spherical pure nickel powder with a purity of ≥99.8%, a particle size of 300~500 mesh, and a coating thickness of 50~100 μm.

[0018] The sprayed nickel powder interlayer can effectively prevent the rapid diffusion of C, Cr and other elements to form carbides during subsequent heat preservation and rolling, significantly improving the interfacial bonding strength and toughness. The particle size of the sprayed nickel powder should be controlled within a reasonable range, too fine is easy to oxidize, too coarse is not easy to form a continuous layer, too thin coating thickness does not play a barrier role, and too thick coating thickness will increase the cost and may introduce new defects.

[0019] The melting point of borax is about 740°C. When heated, borax will melt into a glassy liquid film, which will densely cover the metal surface and effectively isolate oxygen. Under high rolling pressure, this glassy film will be crushed and discharged from the interface, without remaining in the interface to form inclusions. Borax also has a certain cleaning effect, which can further dissolve trace amounts of surface oxides and promote metallurgical bonding. The borax coating is brushed to form a high-temperature oxidation-resistant coating. This more economical "self-consumption coating protection method" replaces the high-cost and complex protection processes such as sealing welding around the composite plate during assembly, vacuum pumping or argon filling, etc.

[0020] S4, Assembly: Align and stack the high-chromium cast iron clad plate with a micro-pit array and the carbon steel base plate, ensuring that the surfaces to be compounded are in close contact.

[0021] S5, Pre-rolling heat preservation and asynchronous rolling: The assembled plate blank is sent to the heating furnace, heated to a specific target temperature in two stages, and then the heated plate blank is quickly transferred to the asynchronous rolling mill for asynchronous rolling.

[0022] Preferably, the two-stage heating is first slowly heated to 600°C at a rate of 3-5°C / min, and then rapidly heated to a specific target temperature at a rate of 5-10°C / min. The specific target temperature is 1050-1150°C, and the holding time is 30-90 min.

[0023] The slow heating in the first stage can prevent high-chromium cast iron from cracking due to thermal stress. Then rapidly heating to a target temperature of 1050-1150°C, at which the low-carbon steel is in the austenite region with excellent plasticity, while the high-chromium cast iron also has certain thermal plasticity, and the pure nickel interlayer can also be completely softened. The nickel powder interlayer and the matrix undergo preliminary sintering and diffusion, forming a pre-bonding that plays an ideal "bonding" and "buffering" role. The holding time is to ensure that the core of the blank is hot, and a holding time that is too long will lead to excessive diffusion of the interface and coarse grains.

[0024] Preferably, the ratio of the linear speeds of the upper and lower rolls in the asynchronous rolling is 1.1:1-1.4:1, the first pass deformation is 35%-45%, the cumulative total deformation is ≥ 60%, the rolling speed is 0.5-2 m / s, and the rolling pass is 2-3 times.

[0025] The asynchronous rolling mill utilizes the strong shear deformation generated by the speed difference between the upper and lower rollers to make the clean nickel powder / metal interface fully contact under high pressure at the moment when the borax protective layer is extruded, and can break the possible residual oxide film, greatly activates the interface, and promotes the flow and combination of metals. The ratio of the linear speed of the upper and lower rollers is a core parameter. If the speed ratio is too small, the shear effect is not obvious. If the linear speed is too large, the plate strip is prone to warping and deviation. The first pass deformation is crucial and must be large enough to break through the critical bonding strength to ensure that the mild steel fills the pits fully. The cumulative total large deformation is the physical basis for ensuring high bonding rate. The use of low-speed rolling is beneficial to the accumulation of deformation heat effect and the full deformation. The furnace can be temporarily returned for heat preservation between passes, but quick operation is required to prevent excessive temperature drop.

[0026] S6, subsequent heat treatment: immediately after rolling, the clad plate is sent to the slow cooling pit and cooled to room temperature with the furnace, and then stress relief annealing is performed.

[0027] Preferably, the temperature of the stress relief annealing is 550-650°C, the holding time is 2-4 hours, and the furnace cooling is performed.

[0028] Preferably, after the stress relief annealing of step S6, diffusion annealing can also be performed. The temperature of the diffusion annealing is 850-950°C, the time is 30-90 minutes, and the air cooling is performed to room temperature.

[0029] Controlling the cooling speed after rolling can avoid interface cracking caused by excessive thermal stress due to the difference in thermal expansion coefficients of high-chromium cast iron and low-carbon steel. Stress relief annealing can eliminate rolling stress, optimize interface structure, and balance the performance of the two materials.

[0030] Whether diffusion annealing is needed must be determined by interface metallographic and micro-area composition analysis. If the interface nickel layer is still thick and the bonding strength has not reached the peak value, diffusion annealing can be performed. The temperature of the diffusion annealing is lower than the rolling temperature, which can avoid excessive grain growth. The time must be accurately controlled to form a thin and continuous (Fe, Ni) solid solution diffusion layer. Long-time annealing is strictly avoided to cause nickel depletion and generate continuous (Cr, Fe)7C3 brittle compounds.

[0031] Compared with the prior art, the beneficial effects of the present application are:

[0032] (1) Unique interface strengthening design: according to the characteristics of low-carbon steel and high-chromium cast iron, different roughness sand blasting treatment is designed, and a micro-pit array is pre-prepared on the surface of the high-chromium cast iron clad plate. During rolling, the base metal flows into the micro-pits and the micro-profile of the clad plate surface, forming a strong three-dimensional mechanical interlocking effect, which significantly improves the interface bonding strength and solves the problem of insufficient bonding force that may exist in pure reliance on metallurgical bonding.

[0033] (2) High chromium cast iron high carbon high chromium, direct and steel composite easily generate brittle carbon chromium compounds, nickel and iron mutual solubility, nickel powder middle layer can effectively block carbon diffusion, through the spraying method and thickness control can effectively avoid the generation of brittle phase, improve the interface bonding toughness; borax protective layer instead of complex sealing vacuum process, while ensuring even improving the interface bonding quality, significantly reducing the process complexity and cost.

[0034] (3) Asynchronous rolling produces strong shear deformation, which is a "catalyst" for strong interface activation, extruding the borax protective layer instantly, making the clean nickel powder / metal interface fully contact under high pressure, which can break the possible residual oxide film, greatly activating the interface and promoting metal flow and bonding.

[0035] (4) Process simplification and performance optimization: eliminates four weeks of sealing, vacuum packaging and other high-cost, complex procedures, simple process flow, low energy consumption, easy to realize industrialized continuous production, subsequent heat treatment effectively eliminates processing stress, optimizes the comprehensive mechanical properties of the composite plate. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0037] Figure 1 The present application is a preparation method flowchart.

[0038] Figure 2 The present application is a preparation method flowchart. DETAILED DESCRIPTION

[0039] The following examples are used to illustrate the present application, but not to limit the scope of the present application. Modifications or replacements of the method, steps or conditions of the present application without departing from the spirit and essence of the present application all belong to the scope of the present application. If not specifically indicated, the technical means used in the examples is the conventional means familiar to those skilled in the art.

[0040] Example 1

[0041] (1) Preparation of blank and surface pretreatment:

[0042] Q235B low carbon steel is selected as the base plate, with a size of 400 mm x 200 mm x 10 mm, and KmTBCr26 high chromium cast iron plate is selected as the clad plate, with a size of 400 mm x 200 mm x 6 mm; the chemical composition of the low carbon steel meets the following mass percentages: C: 0.15~0.25%, Si≤0.35%, Mn: 0.40~0.80%, P≤0.025%, S≤0.025%, the balance being Fe and unavoidable impurities, and the high chromium cast iron meets the following mass percentages: C: 2.8~3.5%, Cr: 23~28%, Mn: 0.6~1.2%, Si: 0.4~0.9%, Mo: 1.5~2.5%, Ni: 0.5~1.5%, Cu≤1.0%, P≤0.05%, S≤0.04%, the balance being Fe.

[0043] First, use a belt sander to polish and remove the surface layer of rust, then use angular corundum sand for sandblasting treatment, with a sandblasting pressure of 0.5 MPa, until the surface presents a uniform silver-gray metallic luster without any rust or oxidation color, and the roughness of the high chromium cast iron treatment surface is controlled to be 6.5 μm, and the roughness of the low carbon steel treatment surface is controlled to be 3.2 μm.

[0044] The low carbon steel is pickled with 10% HCl solution to remove the iron oxide film, and the high chromium cast iron is pickled with 15% HCl-HNO3 mixed acid solution to remove the chromium oxide film, and both before and after pickling are ultrasonically cleaned with alkaline degreasing solution to thoroughly remove oil, and immediately dried with hot air after cleaning.

[0045] (2) Preparing a micro-pit array:

[0046] On the surface of the high chromium cast iron clad plate to be compounded after pretreatment, a regular array of millimeter-level pits is prepared by laser etching, the pits are hemispherical pits with a diameter of 1.0 mm and a depth of 0.5 mm, and the center-to-center distance of the arrayed pits is 2 mm.

[0047] (3) Applying an intermediate layer and a protective layer:

[0048] The high chromium cast iron clad plate is preheated to 170°C to remove moisture, with the arrayed pit surface facing up, a low-pressure flame spraying device is used to uniformly spray nickel powder on the surface, the nickel powder is spherical or near-spherical pure nickel powder with a purity of ≥99.8% and a particle size of 300 mesh, the coating thickness is 50 μm, and then a layer of uniform borax aqueous solution paste is immediately brushed on the nickel powder layer to form a continuous thin film, and low-temperature drying is performed.

[0049] (4) Assembling: align and stack the high chromium cast iron clad plate with the micro-pit array and the carbon steel base plate, ensuring that the surfaces to be compounded are in close contact.

[0050] (5) Pre-rolling heat preservation and asynchronous rolling:

[0051] The assembled slab is fed into a heating furnace, where it is first slowly heated to 600°C at a rate of 3°C / min, and then rapidly heated to the target temperature of 1050°C at a rate of 5°C, with a holding time of 30 min. After that, the heated slab is quickly transferred to an asynchronous rolling mill for asynchronous rolling. The ratio of the linear speeds of the upper and lower rolls in the asynchronous rolling mill is 1.1:1, the deformation in the first pass is 35%, the rolling speed is 0.5 m / s, the rolling passes are 3, and the cumulative total deformation is 60%.

[0052] (6) Subsequent heat treatment:

[0053] Immediately after rolling, the composite plate is sent to a slow cooling pit and cooled to room temperature in the furnace. Then, stress-relief annealing is carried out at a temperature of 550°C for 4 hours, followed by furnace cooling.

[0054] Example 2

[0055] The difference from Example 1 is that:

[0056] (1) Blank preparation and surface pretreatment:

[0057] The sandblasting pressure is 0.6 MPa, and the surface roughness of the high-chromium cast iron surface is controlled at 9.5 μm, while the surface roughness of the low-carbon steel surface is controlled at 4.8 μm.

[0058] (2) Prefabricated micro-pit array:

[0059] The hemispherical pits have a diameter of 1.5 mm and a depth of 0.7 mm, and the center-to-center spacing of the array of pits is 3 mm.

[0060] (3) Apply intermediate and protective layers:

[0061] The nickel powder has a particle size of 400 mesh and a coating thickness of 75 μm.

[0062] (5) Pre-rolling heat preservation and asynchronous rolling:

[0063] First, the temperature is slowly increased to 600°C at a rate of 4°C / min, and then rapidly increased to the target temperature of 1100°C at a rate of 7°C, with a holding time of 60min. The ratio of the linear speeds of the upper and lower rolls in the asynchronous rolling process is 1.25:1, the deformation amount in the first pass is 40%, the rolling speed is 1.2m / s, the rolling passes are 3, and the cumulative total deformation amount is 70%.

[0064] (6) Subsequent heat treatment:

[0065] The stress-relief annealing temperature is 600°C, held for 3 hours, and then cooled in the furnace.

[0066] Example 3

[0067] The difference from Example 1 is that:

[0068] (1) Blank preparation and surface pretreatment:

[0069] The sandblasting pressure is 0.8 MPa, and the surface roughness of the high-chromium cast iron surface is controlled at 12.5 μm, while the surface roughness of the low-carbon steel surface is controlled at 6.3 μm.

[0070] (2) Prefabricated micro-pit array:

[0071] The hemispherical pits have a diameter of 2.0 mm and a depth of 1.0 mm, and the center-to-center spacing of the array of pits is 4 mm.

[0072] (3) Apply intermediate and protective layers:

[0073] The nickel powder has a particle size of 500 mesh and a coating thickness of 100 μm.

[0074] (5) Pre-rolling heat preservation and asynchronous rolling:

[0075] First, the temperature is slowly increased to 600°C at a rate of 5°C / min, and then rapidly increased to the target temperature of 1150°C at a rate of 10°C, with a holding time of 90min. The ratio of the linear speeds of the upper and lower rolls in asynchronous rolling is 1.4:1, the deformation amount of the first pass is 45%, the rolling speed is 2m / s, the rolling passes are 3, and the cumulative total deformation amount is 80%.

[0076] (6) Subsequent heat treatment:

[0077] The stress-relief annealing temperature is 650°C, held for 2 hours, and then cooled in the furnace.

[0078] Comparative Example 1

[0079] The difference from Example 2 is that:

[0080] (1) Blank preparation and surface pretreatment:

[0081] The surface roughness of both the high-chromium cast iron and low-carbon steel treated surfaces was controlled to 6 μm.

[0082] (2) No prefabricated micro-pit array is used for high-chromium cast iron:

[0083] (5) Before rolling, the two-stage heating is not used. Instead, the temperature is raised to 1100℃ in one go at a heating rate of 8℃ / min. Asynchronous rolling is not used. Ordinary rolling is used instead. Other rolling control parameters are the same.

[0084] Comparative Example 2

[0085] The difference from Example 2 is that:

[0086] (1) Blank preparation and surface pretreatment:

[0087] The surface roughness of both the high-chromium cast iron and low-carbon steel treated surfaces was controlled to 6 μm.

[0088] (3) No intermediate or protective layer is applied.

[0089] (5) Before rolling, the two-stage heating is not used. Instead, the temperature is raised to 1100℃ in one go at a heating rate of 8℃ / min. Asynchronous rolling is not used. Ordinary rolling is used instead. Other rolling control parameters are the same.

[0090] Comparative Example 3

[0091] The difference from Example 2 is that:

[0092] (1) Blank preparation and surface pretreatment:

[0093] The surface roughness of both the high-chromium cast iron and low-carbon steel treated surfaces was controlled to 6 μm.

[0094] (2) No prefabricated micro-pit array is used for high-chromium cast iron;

[0095] (3) No intermediate or protective layer is applied;

[0096] (5) Before rolling, the two-stage heating is not used. Instead, the temperature is raised to 1100℃ in one go at a heating rate of 8℃ / min. Asynchronous rolling is not used. Ordinary rolling is used instead. Other rolling control parameters are the same.

[0097] The material samples prepared in the examples and comparative examples were subjected to interfacial shear strength tests, high-chromium cast iron layer strength tests, relative wear resistance tests, and interfacial microstructure observations. The results are shown in Table 1.

[0098] Table 1 Performance and interface observations of the examples and comparative examples

[0099]

[0100] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a carbon steel-high chromium cast iron composite high wear-resistant plate, characterized in that, The preparation method includes the following steps: S1. Blank preparation and surface pretreatment: Low-carbon steel plate is selected as the substrate and high-chromium cast iron plate is selected as the cover plate. The surfaces of the substrate and cover plate to be composite are subjected to mechanical activation treatment and surface chemical cleaning. The mechanical activation treatment is to first use a belt sander to grind away the obvious rust layer on the surface, and then use angular corundum sand or quartz sand for sandblasting treatment. The sandblasting pressure is 0.5~0.8MPa until the surface presents a uniform silver-gray metallic luster without any rust or oxidation color. The roughness of the high-chromium cast iron surface is controlled at 6.5~12.5μm, and the roughness of the low-carbon steel surface is controlled at 3.2~6.3μm. S2. Prefabricated micro-pit array: On the pretreated high-chromium cast iron cladding plate to be composited, a regularly arranged millimeter-scale pit array is prepared by laser etching. The pits are hemispherical pits with a diameter of 1.0~2.0 mm and a depth of 0.5~1.0 mm. The center-to-center spacing of the array pits is 2~4 mm. S3. Apply intermediate and protective layers: Preheat the high-chromium cast iron cladding plate to 150~200°C to remove moisture, place it with the pitted surface facing up, and use a low-pressure flame spraying device to uniformly spray nickel powder on the surface. The nickel powder is spherical or near-spherical pure nickel powder with a purity of ≥99.8% and a particle size of 300~500 mesh. The coating thickness is 50~100μm. Immediately afterwards, brush a uniform borax aqueous solution paste onto the nickel powder layer to form a continuous film and dry it at low temperature. S4. Assembly: Align and stack the high-chromium cast iron cladding plate with micro-pit array and the carbon steel substrate to ensure close contact between the surfaces to be laminated. S5. Pre-rolling heat preservation and asynchronous rolling: The assembled slab is fed into a heating furnace and heated to a specific target temperature in two stages and held for a period of time. The two-stage heating is as follows: first, the temperature is slowly raised to 600°C at a rate of 3~5°C / min, and then rapidly raised to the specific target temperature at a rate of 5~10°C / min. The specific target temperature is 1050~1150°C, and the holding time is 30~90min. After that, the heated slab is quickly transferred to an asynchronous rolling mill for asynchronous rolling. The ratio of the linear speeds of the upper and lower rolls in the asynchronous rolling is 1.1:1~1.4:1, the deformation of the first pass is 35%~45%, the cumulative total deformation is ≥ 60%, the rolling speed is 0.5~2m / s, and the number of rolling passes is 2~3. S6. Subsequent heat treatment: Immediately after rolling, the composite plate is sent to a slow cooling pit and cooled to room temperature in the furnace, and then stress-relief annealing is performed.

2. The method for preparing the carbon steel-high chromium cast iron composite high wear-resistant plate according to claim 1, characterized in that, The chemical composition of the low-carbon steel in step S1, by mass percentage, is: C: 0.15~0.25%, Si≤0.35%, Mn: 0.40~0.80%, P≤0.025%, S≤0.025%, with the balance being Fe and unavoidable impurities; the chemical composition of the high-chromium cast iron, by mass percentage, is: C: 2.8~3.5%, Cr: 23~28%, Mn: 0.6~1.2%, Si: 0.4~0.9%, Mo: 1.5~2.5%, Ni: 0.5~1.5%, Cu≤1.0%, P≤0.05%, S≤0.04%, with the balance being Fe.

3. The method for preparing the carbon steel-high chromium cast iron composite high wear-resistant plate according to claim 1, characterized in that, In step S1, the surface chemical cleaning involves pickling low-carbon steel with a 10%~15% HCl solution to remove the iron oxide film, and pickling high-chromium cast iron with a 10%~20% HCl-HNO3 mixed acid solution to remove the more stable chromium oxide film. Before and after pickling, ultrasonic cleaning is performed with alkaline degreasing solution to thoroughly remove oil. After cleaning, the surface is immediately dried with hot air.

4. The method for preparing the carbon steel-high chromium cast iron composite high wear-resistant plate according to claim 1, characterized in that, In step S6, the stress-relief annealing temperature is 550~650°C, held for 2~4 hours, and then cooled in the furnace.

5. A carbon steel-high chromium cast iron composite high wear-resistant plate, characterized in that, The composite high wear-resistant plate is prepared by the preparation method according to any one of claims 1 to 4.

Images