Wear-resistant bimetal plate and preparation method thereof

Abstract

The invention discloses a wear-resistant bimetal plate and a preparation method thereof, and relates to the technical field of bimetal plates, the wear-resistant bimetal plate comprises a base layer and a wear-resistant layer arranged on one side of the outer surface of the base layer, a micro-channel cooling network is distributed on the inner surface of the wear-resistant layer, and micro-channels form a continuous groove array on the inner surface of the wear-resistant layer. And the grooves longitudinally extend on the wear-resistant layer to form three-dimensional communicated branch-shaped channels. Through the micro-channel cooling network of the wear-resistant layer, the efficient heat dissipation function is achieved, the problems that in the long-term friction process of a traditional wear-resistant plate, due to heat accumulation, wear resistance is reduced, and materials are prone to embrittlement are solved, and the service life of the plate is prolonged while high wear resistance is kept.

Description

Technical Field

[0001] This invention relates to the field of bimetallic sheet technology, specifically to a wear-resistant bimetallic sheet and its preparation method. Background Technology

[0002] Industrial equipment components are constantly subjected to high-stress wear, impact loads, and corrosive environments. Traditional single-metal materials (such as carbon steel and high-manganese steel) cannot simultaneously meet the requirements of high hardness, impact resistance, and corrosion resistance. While non-metallic materials such as ceramics are wear-resistant, they are brittle and difficult to apply directly to structural components. The preparation of bimetallic sheets may lead to softening of the wear-resistant layer or coarsening of the base grains, and cemented carbide particles are prone to burn-off and poor dispersibility under high heat input.

[0003] Patent CN108179417B discloses a method for manufacturing a large-size bimetallic wear-resistant and corrosion-resistant composite plate. The patent achieves the following: removing pits from the surface of the metal substrate of the workpiece; pre-deforming the workpiece; laser cladding the pre-deformed protruding surface of the metal substrate; placing the metal substrate flat on the worktable; filling a cooling circulating water tank with "serpentine" baffles with water to 3 / 4 of the thickness of the metal substrate; maintaining cooling water circulation; and setting multiple serpentine baffles on the water tank to increase water flow and improve the efficiency and quality of cladding.

[0004] The aforementioned patent effectively solves the problems of surface cracks, flatness, and production efficiency in the production of large-size composite panels by combining laser cladding technology with a cooling circulating water tank with "serpentine" baffles. However, it does not address the issue that the narrow range of cladding layer thickness limits its long-term stability under high impact and wear environments.

[0005] Therefore, this application proposes a wear-resistant bimetallic sheet and its preparation method that enables carbon elements in the wear-resistant layer to exist in the form of carbides, combined with rare earth elements to form a high-density hard skeleton, achieving both lightweight and high wear resistance. Summary of the Invention

[0006] The purpose of this invention is to provide a wear-resistant bimetallic sheet and its preparation method, so as to solve the technical problems mentioned in the background art, such as softening of the wear-resistant layer or coarsening of the base grain, easy burning of cemented carbide particles and poor dispersibility under high heat input.

[0007] To achieve the above objectives, the present invention provides the following technical solution: including a base layer and a wear-resistant layer disposed on one side of the outer surface of the base layer, wherein a microchannel cooling network is distributed on the inner surface of the wear-resistant layer, the microchannels form a continuous groove array on the inner surface of the wear-resistant layer, and the grooves extend longitudinally in the wear-resistant layer to form a three-dimensional interconnected dendritic channel; The alloy composition of the wear-resistant layer includes 0.2%-1.0% carbon, 0.5%-3.0% silicon, 1.0%-5.0% manganese, 5.0%-20.0% chromium, 0.5%-5.0% molybdenum, 0.1%-3.0% nickel, 0.1%-3.0% tungsten, 0.05%-1.0% niobium, 0.05%-1.0% titanium, and 0.001%-0.1% boron, with the balance being iron.

[0008] Preferably, the base layer is low-carbon steel, low-alloy steel, stainless steel, aluminum alloy, and copper alloy. When the base layer is low-carbon steel, the carbon content is 0.05%-0.25% by mass, the manganese content is 0.3%-0.6%, the silicon content is 0.1%-0.3%, and the balance is iron. When the base layer is low-alloy steel, it contains low-carbon steel and 0.1%-1.0% chromium, 0.1%-0.5% molybdenum, and 0.05%-0.2% vanadium by mass. The wear-resistant layer also contains 0.1%-2.0% rare earth elements by mass percentage, namely cerium, lanthanum and yttrium. The addition of rare earth elements refines the grains in the metallographic structure of the wear-resistant layer. The thickness of the wear-resistant layer ranges from 0.5mm to 10mm.

[0009] Preferably, a transition layer is formed at the interface between the wear-resistant layer and the base layer. The thickness of the transition layer is 0.05mm-0.5mm. The elemental composition of the transition layer is between that of the wear-resistant layer and the base layer. The elemental distribution of the transition layer is gradient, with the elemental content of the base layer increasing by 5-15 at% from the base layer side to the wear-resistant layer side, and the elemental content of the wear-resistant layer increasing by 10-25 at%. The elements of the wear-resistant layer and the base layer diffuse into each other to form the transition layer.

[0010] Preferably, the surface of the wear-resistant bimetallic sheet is provided with a protective coating, the thickness of which is 0.1mm-0.2mm, and the material of the protective coating is a ceramic coating, an organic coating, or a metal oxide coating; When the protective coating is a ceramic coating, the main components are alumina, zirconium oxide, and silicon carbide. The ceramic coating is applied to the surface of the wear-resistant bimetallic sheet through plasma spraying, physical vapor deposition, and chemical vapor deposition. When the protective coating is an organic coating, the main components are epoxy resin, polyurethane, and fluorocarbon resin. The organic coating is applied to the surface of the wear-resistant bimetallic sheet by spraying or brushing. When the protective coating is a metal oxide coating, the main components are chromium oxide, nickel oxide, and titanium oxide. The metal oxide coating is applied to the surface of the wear-resistant bimetallic sheet by hot-dip galvanizing or electroplating.

[0011] Preferably, the wear-resistant bimetallic sheet has a reinforcing structure inside its base layer. The reinforcing structure is a fiber reinforcement, a particle reinforcement, or a mesh reinforcement. When the reinforcing structure is a fiber reinforcement, the fiber material is carbon fiber, boron fiber, or glass fiber. The fibers are uniformly dispersed and oriented in the base layer, and the volume fraction of the fibers is 5%-20%. When the reinforcing structure is a particulate reinforcement, the particulate material is tungsten carbide, titanium carbide, and alumina particles, the average particle size is 0.01μm-1μm, and the volume fraction of the particles in the base layer is 3%-15%. When the reinforcing structure is a mesh reinforcement, the mesh structure is made of woven metal wire mesh and sintered metal powder mesh. The mesh structure is evenly distributed in the base layer, and the mesh size is 0.01mm–0.1mm.

[0012] Preferably, the edge of the wear-resistant bimetallic sheet is provided with a connecting structure, which includes a welding bevel, a riveting hole, and a bolt connection hole. When the connection structure is a welded bevel, the bevel type is V-groove, U-groove, or X-groove, and the bevel angle is 30°-90°. When the connection structure is a riveting hole, the diameter of the riveting hole is 3mm-10mm, and the center distance between adjacent riveting holes is 10mm-50mm.

[0013] Preferably, the surface of the wear-resistant layer is provided with micro-texture, which is groove, ridge, and grid-like texture; The depth of the microtexture is 0.01mm-0.1mm, the width is 0.05mm-0.5mm, and the arrangement direction of the microtexture structure is at an angle of 30°-90° with the wear direction of the board.

[0014] Preferably, the volume fraction of primary carbides in the wear-resistant layer is ≥40%, the carbon element in the wear-resistant layer exists in the form of chromium carbide and molybdenum carbide carbides, the carbides are uniformly dispersed in the wear-resistant layer, and the average particle size of the carbides ranges from 0.1μm to 10μm.

[0015] Preferably, the preparation method includes the following steps: S1. Add low-carbon steel raw materials with C 0.05%-0.25%, Si 0.1%-0.3%, Mn 0.3%-0.6% to an electric arc furnace, with the balance being Fe. Control the power of the electric arc furnace at 1500-1600℃ to melt the raw materials. Argon gas is introduced for protection during the melting process. After melting is completed, the molten steel is poured into a mold and cooled to room temperature to obtain the base casting billet. The base casting billet is heated to 1100-1200℃, held for 2-3 hours and then hot rolled. The rolling passes are 5-8 times and the total reduction rate is 60%-80%, resulting in a base plate with a thickness of 3-10mm. S2. Add 0.8%-1.2% C, 15%-20% Cr, 1.0%-2.0% Mo, 0.5%-1.5% Ni, 0.8%-1.2% Si, and 1.5%-2.5% Mn to a medium-frequency induction furnace, with the balance being Fe. Melt at 1550-1650℃, adding ferrosilicon for deoxidation during the process. After deoxidation, let stand for 15-20 minutes. S3. Grind the surface of the base plate to remove the oxide scale and clean it with anhydrous ethanol; place the base plate in a heating furnace and preheat it to 400-600℃, and hold it for 30-60 minutes; pour the molten wear-resistant alloy layer onto the upper surface of the base plate, control the casting temperature at 1450-1550℃ and the casting speed at 5-10 kg / min, to form a wear-resistant cladding layer with a thickness of 2-5 mm. When the wear-resistant layer is semi-solidified, press the inner surface with a die with dendritic protrusions to form a three-dimensional interconnected groove array with a depth of 0.1-0.5 mm and a width of 0.2-1.0 mm. Allow it to cool naturally to room temperature to obtain the composite billet. S4. Heat the composite billet to 1000-1100℃, hold for 1-2 hours, hot roll 3-5 times, with a total reduction rate ≤30%, to obtain a composite plate with a thickness of 2-8mm. S5. Place the composite board into a box furnace, heat it to 900-1000℃, hold it for 1-2 hours, then oil cool it to room temperature for quenching. After quenching, put the composite board back into the furnace, heat it to 200-300℃, hold it for 2-3 hours, then air cool it to room temperature for tempering. S6. Grind the surface of the heat-treated composite sheet to remove the oxide scale, then level it with a leveling machine, and finally cut it to obtain the finished wear-resistant bimetallic sheet.

[0016] Preferably, the preparation method further includes the following steps: S31. Bimetallic composite molding adopts explosive welding. The base plate and the wear-resistant layer plate are placed parallel to each other with a distance of 5-15mm between them. Explosives are placed on the side of the wear-resistant layer plate away from the base plate. The detonation velocity of the explosives is controlled at 2000-3000m / s. The impact force generated by the detonation of the explosives causes the wear-resistant layer plate and the base plate to collide at high speed, forming a metallurgical bond at the contact surface to obtain a composite billet.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves efficient heat dissipation through a microchannel cooling network in the wear-resistant layer, solving the problem of decreased wear resistance and material embrittlement caused by heat accumulation during long-term friction of traditional wear-resistant plates, thus extending the service life of the plates while maintaining high wear resistance. 2. This invention forms a transition layer at the interface between the base layer and the wear-resistant layer, achieving a firm bond between the base layer and the wear-resistant layer, solving the problem of easy peeling between the layers of bimetallic sheets, and improving the overall structural stability of the sheet. 3. This invention strengthens the mechanical properties of the base layer by setting fiber reinforcements inside the base layer, solving the problem that insufficient base layer strength affects the overall load-bearing capacity of the board and improving the overall structural strength of the bimetallic board; 4. This invention achieves bimetallic composite forming by melting the wear-resistant layer alloy in a medium-frequency induction furnace, which solves the problem of low bonding strength in traditional preparation methods and ensures the metallurgical bonding quality of the plate. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the preparation process of the present invention; Figure 2 This is a schematic diagram of the enhanced structure of the present invention; Figure 3 This is a schematic diagram of the composite structure of the present invention; Figure 4 This is a schematic diagram of the surface microtexture of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 The present invention provides an embodiment of a wear-resistant bimetallic sheet, the preparation method of which includes the following steps: S1. Add low-carbon steel raw materials with C 0.05%-0.25%, Si 0.1%-0.3%, Mn 0.3%-0.6% to an electric arc furnace, with the balance being Fe. Control the power of the electric arc furnace at 1500-1600℃ to melt the raw materials. Argon gas is introduced for protection during the melting process. After melting is completed, the molten steel is poured into a mold and cooled to room temperature to obtain the base casting billet. The base casting billet is heated to 1100-1200℃, held for 2-3 hours and then hot rolled. The rolling passes are 5-8 times and the total reduction rate is 60%-80%, resulting in a base plate with a thickness of 3-10mm. S2. Add 0.8%-1.2% C, 15%-20% Cr, 1.0%-2.0% Mo, 0.5%-1.5% Ni, 0.8%-1.2% Si, and 1.5%-2.5% Mn to a medium-frequency induction furnace, with the balance being Fe. Melt at 1550-1650℃, adding ferrosilicon for deoxidation during the process. After deoxidation, let stand for 15-20 minutes. S3. Grind the surface of the base plate to remove the oxide scale and clean it with anhydrous ethanol; place the base plate in a heating furnace and preheat it to 400-600℃, and hold it for 30-60 minutes; pour the molten wear-resistant alloy layer onto the upper surface of the base plate, control the casting temperature at 1450-1550℃ and the casting speed at 5-10 kg / min, to form a wear-resistant cladding layer with a thickness of 2-5 mm. When the wear-resistant layer is semi-solidified, press the inner surface with a die with dendritic protrusions to form a three-dimensional interconnected groove array with a depth of 0.1-0.5 mm and a width of 0.2-1.0 mm. Allow it to cool naturally to room temperature to obtain the composite billet. S4. Heat the composite billet to 1000-1100℃, hold for 1-2 hours, hot roll 3-5 times, with a total reduction rate ≤30%, to obtain a composite plate with a thickness of 2-8mm. S5. Place the composite board into a box furnace, heat it to 900-1000℃, hold it for 1-2 hours, then oil cool it to room temperature for quenching. After quenching, put the composite board back into the furnace, heat it to 200-300℃, hold it for 2-3 hours, then air cool it to room temperature for tempering. S6. Grind the surface of the heat-treated composite sheet to remove the oxide scale, then level it with a leveling machine, and finally cut it to obtain the finished wear-resistant bimetallic sheet.

[0021] The preparation method further includes the following steps: S31. Bimetallic composite forming adopts explosive welding. The base plate and the wear-resistant layer plate are placed parallel to each other with a distance of 5-15mm between them. Explosives are placed on the side of the wear-resistant layer plate away from the base plate. The detonation velocity of the explosives is controlled at 2000-3000m / s. The impact force generated by the detonation of the explosives causes the wear-resistant layer plate and the base plate to collide at high speed, forming a metallurgical bond at the contact surface to obtain a composite billet. Furthermore, Q235 low-carbon steel is selected as the base material, with dimensions of 150×100×10mm. The composition of Q235 low-carbon steel is 0.20% carbon content, 0.21% silicon content, 0.51% manganese content, less than 0.035% phosphorus content, less than 0.045% sulfur content, and the remainder being iron and unavoidable impurities. The wear-resistant layer uses high-chromium cast iron powder with a particle size range controlled between 50-100μm. The composition of high-chromium cast iron powder is 20% chromium content, 2.43% carbon content, 6% molybdenum content, 6% vanadium content, 1.5% silicon content, and the remainder being iron and unavoidable impurities. First, the surface of the Q235 low-carbon steel substrate is sandblasted using brown corundum abrasive with a particle size of 1-2 mm. The sandblasting pressure is controlled at 0.4-0.6 MPa, and the sandblasting time is 5-10 minutes, so that the surface roughness of the substrate reaches Ra=3.2μm. After sandblasting, the substrate surface is cleaned with anhydrous ethanol to remove residual sand particles, oil stains, and other impurities. Then, the substrate is placed in a well-ventilated place to air dry naturally. High-chromium cast iron powder was evenly spread onto a surface-treated substrate using a vibrating screen powder spreading device. The powder spreading thickness was controlled at 5 mm, and the vibration frequency was set to 50-60 Hz. After spreading, the powder was compacted using a compaction tool at a pressure of 5-10 MPa for 3-5 minutes. The compacted substrate was then placed in a high-temperature sintering furnace and sintered under an argon protective atmosphere. The argon flow rate was controlled at 5-10 L / min to prevent material oxidation. The furnace temperature was increased to 1250°C at a heating rate of 8°C / min for approximately 156 minutes. Once the temperature reached 1250°C, it was maintained for 30 minutes to allow the wear-resistant layer powder to fully melt and react metallurgically with the base substrate. After the holding period, the substrate was cooled to room temperature with the furnace to obtain a preliminary wear-resistant bimetallic sheet.

[0022] According to the shear test method of GB / T6396-2008, the interfacial bonding strength was tested. Shear specimens with a joint surface size of 10×10×1mm were prepared. Five specimens were selected for each test group. The test was conducted using a universal testing machine with a shear rate of 1mm / min. The test results showed that the average interfacial bonding strength of the wear-resistant bimetallic sheet reached 615MPa.

[0023] According to ASTM E384 standard, the microhardness gradient of the board was tested using a Vickers hardness tester. In the base layer area, five test points were selected at 2 mm intervals, and the average value was taken as the base layer hardness, with a test result of 180 HV. In the interface area, the test was conducted by scanning from the base layer towards the wear layer at a step distance of 50 μm, and the hardness at the interface was found to be 320 HV. In the wear layer area, five test points were also selected at 2 mm intervals, and the wear layer hardness was measured to be 450 HV.

[0024] The abrasion resistance of the plates was tested according to the dry sand rubber wheel abrasion test method of ASTM G65 standard. The test conditions were: load 130N, rubber wheel speed 200r / min, quartz sand particle size 60 mesh, sand flow rate controlled at 300g / min, and total stroke 1400m. After the test, the samples before and after abrasion were weighed using an electronic balance with an accuracy of 0.1mg, and the abrasion amount was calculated to be 0.08g.

[0025] See also Figure 1 , Figure 3 and Figure 4This invention provides an embodiment of a wear-resistant bimetallic sheet, wherein the alloy composition of the wear-resistant layer comprises 0.2%-1.0% carbon, 0.5%-3.0% silicon, 1.0%-5.0% manganese, 5.0%-20.0% chromium, 0.5%-5.0% molybdenum, 0.1%-3.0% nickel, 0.1%-3.0% tungsten, 0.05%-1.0% niobium, 0.05%-1.0% titanium, and 0.001%-0.1% boron, with the balance being iron. The carbon element in the wear-resistant layer exists in the form of chromium carbide and molybdenum carbide carbides, which are uniformly dispersed in the wear-resistant layer, with an average particle size range of 0.1μm-10μm. The wear-resistant layer also contains 0.1%-2.0% rare earth elements by mass, namely cerium, lanthanum, and yttrium. The addition of rare earth elements refines the grain size in the metallographic structure of the wear-resistant layer. A transition layer is formed at the interface between the wear-resistant layer and the base layer. The thickness of the transition layer is 0.05mm-0.5mm. The elemental composition of the transition layer is between that of the wear-resistant layer and the base layer. The elemental distribution of the transition layer is gradient, with the elemental content of the base layer increasing by 5-15 at% and the elemental content of the wear-resistant layer increasing by 10-25 at% from the base layer side to the wear-resistant layer side. The elements of the wear-resistant layer and the base layer diffuse into each other to form the transition layer. Furthermore, Q235 steel is selected as the base material and smelted in a medium-frequency induction furnace. The Q235 steel raw material is added into the furnace, and the smelting temperature is controlled at 1580-1600℃ to fully melt the raw material. During the smelting process, an appropriate amount of deoxidizer is added for deoxidation treatment. The amount of deoxidizer added is 0.1%-0.2% of the mass of the molten steel. After the composition of the molten steel is uniform, the casting temperature is controlled at 1560℃ for casting. The wear-resistant layer uses high-chromium cast iron molten metal. The high-chromium cast iron raw material is added to another medium-frequency induction furnace, and the melting temperature is controlled at 1450-1470℃. During the melting process, deoxidizer is added to deoxidize the metal, and the amount of deoxidizer added is 0.15%-0.25% of the mass of the molten metal. After the composition of the molten metal is uniform, the pouring temperature is adjusted to 1420℃. The composition of the high-chromium cast iron molten metal is tested and found to be 24% chromium, 4.0% carbon, 2.5% molybdenum, 1.0% silicon, and the remainder is iron and unavoidable impurities. Sand casting is used. Before pouring, the mold is preheated to 300℃ for 2-3 hours to reduce the quenching effect of the mold on the molten metal and prevent defects in the casting. After preheating, a high-temperature resistant coating with a thickness of 0.1-0.2mm is evenly sprayed onto the inner surface of the mold to improve the surface quality of the casting. Electromagnetic coils are set around the mold, and a horizontal magnetic field is applied through a controllable power supply, with the magnetic field strength controlled at 0.4T. The role of the magnetic field is to stir the molten metal during the pouring process, suppress excessive mixing between the base layer and the wear-resistant layer, promote the uniform distribution of elements, and improve the interfacial bonding quality. First, molten high-chromium cast iron is slowly poured into a preheated mold at a rate of 5-8 kg / min. After pouring, wait 150 seconds to allow the molten high-chromium cast iron to initially solidify and gain sufficient strength within the mold. Then, immediately pour molten Q235 steel into the mold at the same rate, covering the molten high-chromium cast iron. Maintain a constant horizontal magnetic field throughout the pouring process. After the casting cools to room temperature, remove it and use a saw to remove excess material such as flash and burrs from the edges. Then, heat treat the plate using an oil quenching process of 840℃ for 30 minutes followed by tempering at 500℃ for 2 hours. During the oil quenching process, the plate is quickly immersed in quenching oil at 80-100℃, and the cooling rate of the quenching oil ensures that the plate achieves a good quenched structure.

[0026] According to ISO17636 standard, X-ray flaw detectors were used to inspect the interface of the sheet metal. During the flaw detection process, the X-ray tube voltage was set to 200-250kV, the tube current was 5-10mA, and the exposure time was 10-15s. The entire interface area was scanned. The test results showed that there were no defects such as pores or slag inclusions on the sheet metal interface, and the pass rate reached 100%.

[0027] Three-body wear testing was conducted according to the JB / T7705-1995 standard. The testing device was a rubber wheel three-body wear testing machine. The test conditions were: load 100N, rubber wheel speed 150r / min, quartz sand particle size 80 mesh, sand flow rate 250g / min, and test time 2 hours. High manganese steel was used as a comparison material. The test results showed that the relative wear resistance of the wear-resistant bimetallic plate was 3.2 times that of high manganese steel.

[0028] See also Figure 1 , Figure 2 and Figure 4 One embodiment of the present invention provides: a wear-resistant bimetallic sheet, wherein the volume fraction of primary carbides in the wear-resistant layer is ≥40%; It includes a base layer and a wear-resistant layer disposed on one side of the outer surface of the base layer. The inner surface of the wear-resistant layer is distributed with a microchannel cooling network. The microchannels form a continuous groove array on the inner surface of the wear-resistant layer. The grooves extend longitudinally in the wear-resistant layer to form a three-dimensionally connected dendritic channel. The base layer is made of low-carbon steel, low-alloy steel, stainless steel, aluminum alloy, or copper alloy. When the base layer is low-carbon steel, the carbon content is 0.05%-0.25% by mass, the manganese content is 0.3%-0.6%, the silicon content is 0.1%-0.3%, and the balance is iron. When the base layer is low-alloy steel, it contains low-carbon steel and 0.1%-1.0% chromium, 0.1%-0.5% molybdenum, and 0.05%-0.2% vanadium by mass. The thickness of the wear-resistant layer ranges from 0.5mm to 10mm. Furthermore, 20 steel was selected as the base substrate, with dimensions of 200×150×12mm. Its composition was 0.20% carbon, 0.20% silicon, and 0.50% manganese, with the remainder being iron and unavoidable impurities. Before welding, the substrate surface was pretreated by sanding it until a metallic luster was exposed, removing oxide scale and oil, and then cleaning the surface with acetone. The outer sheath of the flux-cored wire was made of H08A steel strip with a thickness of 0.8-1.0mm. The flux core contained 45% high-carbon ferrochrome powder, 12% metallic chromium powder, 10% graphite powder, 8% ferromolybdenum powder, and 2% aluminum-magnesium alloy powder, with the remainder being additives and unavoidable impurities. The welding process employed carbon dioxide gas shielded welding, with a welding current set to 380A. The welding voltage is 30V, the welding speed is controlled at 25cm / min, and the CO2 gas flow rate is maintained at 15-20L / min during the welding process to prevent oxidation of the weld metal. The interpass temperature is controlled at ≤150℃ and monitored in real time by an infrared thermometer. Three layers are welded, and the thickness of each layer is adjusted by controlling the welding current, voltage and welding speed. According to actual measurements, the thickness of each layer is about 1.3-1.5mm, and the total thickness after three layers is about 4mm. After the welding is completed, the plate is placed in a box-type resistance furnace and heated to 960℃ at a heating rate of 5℃ / min. After holding at this temperature for 1 hour, it is taken out and air-cooled for quenching. The quenched plate is then placed back into the furnace and heated to 450℃ at a heating rate of 3℃ / min. After holding at this temperature for 3 hours, it is air-cooled for tempering.

[0029] High-temperature wear resistance testing was conducted using a high-temperature pin-disc wear testing machine. The test temperature was set at 800℃, and the grinding balls were made of Al2O3 material with a diameter of 6mm. The pin samples were made of weld overlay material with dimensions of Ø6×20mm. During the wear test, the contact pressure between the pin sample and the grinding disc was 10N, the grinding disc rotation speed was 200r / min, and the test time was 1 hour. By measuring the mass loss of the pin sample before and after wear, the wear rate was calculated to be 4.2×10⁻⁻⁻⁶. 6 mm³ / N・m.

[0030] See also Figure 1 , Figure 3 and Figure 4 The present invention provides an embodiment of a wear-resistant bimetallic sheet, wherein the edge of the wear-resistant bimetallic sheet is provided with a connecting structure, the connecting structure being a welding bevel, a riveting hole, and a bolt connection hole; when the connecting structure is a welding bevel, the bevel type is a V-shaped bevel, a U-shaped bevel, or an X-shaped bevel, and the bevel angle is 30°-90°; when the connecting structure is a riveting hole, the diameter of the riveting hole is 3mm-10mm, and the center distance between adjacent riveting holes is 10mm-50mm; The wear-resistant layer surface is provided with micro-textures, which are grooves, ridges and grid-like textures; The depth of the microtexture is 0.01mm-0.1mm, the width is 0.05mm-0.5mm, and the arrangement direction of the microtexture structure is at an angle of 30°-90° to the wear direction of the board. Furthermore, Q345 low-alloy steel was selected as the base material, with a carbon content of 0.18%, a chromium content of 0.8%, a molybdenum content of 0.3%, and the remainder being iron and unavoidable impurities. Before lamination, the surface of the base plate was pretreated by first sanding off the oxide scale and oil stains, and then cleaning with acetone. The wear-resistant layer was made of high-chromium cast iron plate with a thickness of 3mm, with a chromium content of 22%, a carbon content of 3.8%, a vanadium content of 1.5%, and the remainder being iron and unavoidable impurities. The surfaces to be laminated, including the base plate and the wear-resistant layer, are milled or planed to remove the work-hardened layer, achieving a surface roughness of Ra=1.6-3.2μm. Then, the plates are cleaned using an ultrasonic cleaner in an aqueous solution containing surfactants to thoroughly remove surface impurities such as microparticles and oil. After cleaning, the plates are placed in a vacuum drying oven and dried at 80-100℃ for 1-2 hours. The treated base plate and wear-resistant layer are placed parallel to each other, with the distance between them controlled at 0.5-1.0mm using positioning pins. During welding, the argon flow rate is controlled at 8-12L / min, the welding current at 80-100A, and the welding speed at 3-5mm / s. The edge-sealed composite plate blank is then placed in a heating furnace and heated to 1100-1200℃ at a heating rate of 10℃ / min, and held at that temperature for 1-2 hours to ensure uniform heating. The billet is then quickly transferred to a hot rolling mill for hot rolling. The hot rolling process is divided into 5 passes, with the total reduction rate controlled at 60%-70%. The reduction rate of the first pass is set at 15%-20%, and it gradually decreases in subsequent passes. The temperature is controlled at 80-100℃ during the hot rolling process, and cooling is achieved through circulating cooling water.

[0031] The corrosion and wear test of the plate was carried out using 3.5% NaCl + quartz sand slurry. The test device was a corrosion and wear tester. The test conditions were: corrosion liquid flow rate 1 m / s, quartz sand particle size 80 mesh, and test time 2 hours. After the test, the samples before and after wear were weighed using an electronic balance with an accuracy of 0.1 mg. The weight loss rate was calculated to be 0.15 mg / h, indicating that the plate has good wear resistance under corrosive and wear conditions.

[0032] See also Figure 1 , Figure 2 and Figure 3This invention provides an embodiment of a wear-resistant bimetallic sheet, wherein the surface of the wear-resistant bimetallic sheet is provided with a protective coating, the thickness of which is 0.1mm-0.2mm, and the material of the protective coating is a ceramic coating, an organic coating, or a metal oxide coating. When the protective coating is a ceramic coating, the main components are alumina, zirconium oxide, and silicon carbide, and the ceramic coating is applied to the surface of the wear-resistant bimetallic sheet by plasma spraying, physical vapor deposition, or chemical vapor deposition. When the protective coating is an organic coating, the main components are epoxy resin, polyurethane, and fluorocarbon resin, and the organic coating is applied to the surface of the wear-resistant bimetallic sheet by spraying or brushing. When the protective coating is a metal oxide coating, the main components are chromium oxide, nickel oxide, and titanium oxide, and the metal oxide coating is applied to the surface of the wear-resistant bimetallic sheet by hot-dip galvanizing or electroplating. The wear-resistant bimetallic sheet has a reinforcing structure inside its base layer. This reinforcing structure can be fiber-reinforced, particle-reinforced, or mesh-reinforced. When the reinforcing structure is fiber-reinforced, the fiber material is carbon fiber, boron fiber, or glass fiber, and the fibers are uniformly dispersed or oriented in the base layer, with a fiber volume fraction of 5%-20%. When the reinforcing structure is particle-reinforced, the particle material is tungsten carbide, titanium carbide, or alumina particles, with an average particle size of 0.01μm-1μm and a particle volume fraction of 3%-15% in the base layer. When the reinforcing structure is mesh-reinforced, the mesh material is woven metal wire mesh or sintered metal powder mesh, and the mesh structure is uniformly distributed in the base layer, with a mesh size of 0.01mm–0.1mm. Furthermore, 304 stainless steel is selected as the base material, with a composition of 18% chromium, 8% nickel, 0.08% carbon, and the remainder being iron and unavoidable impurities. Before laser cladding, the surface of the base plate is sandblasted using white corundum abrasive with a particle size of 0.5-1.0 mm, at a pressure of 0.5-0.7 MPa for 3-5 minutes, to achieve a surface roughness of Ra=3.2-6.3 μm, thereby increasing the adhesion between the cladding layer and the base layer. After sandblasting, the surface is cleaned with anhydrous ethanol. The cladding material is high boron cast iron alloy powder, prepared by gas atomization. The composition of the alloy powder, by mass percentage, is: 2.0% boron, 15% chromium, 0.5% carbon, and the remainder being iron and unavoidable impurities. The particle size range of the alloy powder is controlled within 50-100 μm. The laser cladding process uses a high-power continuous fiber laser with a wavelength of 1070nm, a laser power set to 2000-2500W, a scanning speed of 5-8mm / s, and a spot diameter of 3-4mm. The powder feeding rate is controlled by a powder feeder at 8-12g / min. Argon is used as a protective gas during the cladding process, with a flow rate of 15-20L / min, to prevent oxidation of the cladding layer at high temperatures. Two layers are clad, and according to actual measurements, the thickness of each cladding layer is approximately 1.0-1.2mm, resulting in a total thickness of approximately 2.0-2.4mm after two layers. After cladding, the plate is placed in a heating furnace and heated to 1020℃ at a heating rate of 10℃ / min. After holding at this temperature for 15 minutes, it is quickly removed and placed in water for water quenching. Then, the plate is placed in a tempering furnace and heated to 250℃ at a heating rate of 5℃ / min. After holding at this temperature for 4 hours, it is air-cooled for tempering.

[0033] According to ISO 7438 standard, the bending performance of the sheet metal was tested using the three-point bending test method. A long strip of sheet metal measuring 10×10×50mm was prepared as the bending specimen with a span of 40mm. A universal testing machine was used with a loading rate of 0.5mm / min. The test showed that the wear-resistant bimetallic sheet metal did not crack when the deflection reached 15mm, indicating that it has good bending performance.

[0034] The erosion and wear properties of the plates were tested according to the gas-solid blasting test method of ASTM G76 standard. The test device was a gas-solid erosion and wear tester. The test conditions were: erosion medium was quartz sand with a particle size of 100 mesh, erosion angle of 30°, erosion velocity of 50 m / s, and erosion time of 1 hour. After the test, the samples before and after wear were weighed using an electronic balance with an accuracy of 0.1 mg. The weight loss rate was calculated to be 1.2 mg / g.

[0035] Control group: Q235 low carbon steel with the same base material, high manganese steel with traditional wear resistance, and 304 stainless steel with corrosion resistance reference material were selected. The dimensions were the same as the test sample. A single high chromium cast iron plate without base composite was used, and the final product was an ordinary welded composite plate without heat treatment and interface optimization.

[0036] Performance comparison analysis: In the control group, the interfacial bonding strength of ordinary welded composite plates is usually 300-450 MPa, while the strength of the wear-resistant bimetallic plate obtained by this invention is increased by 36.7%-70.8%; Example 1: The wear-resistant layer hardness of 450 HV is 50%-125% higher than that of 200-300 HV high manganese steel, and the interface gradient transition of 320 HV avoids the interface stress concentration caused by abrupt hardness transition; the dry sand wear amount of 0.08g is 60%-73.3% lower than that of 0.2-0.3g high manganese steel. Example 2: The relative wear resistance of the three-body wear test is 3.2 times that of high manganese steel; Example 3: High-temperature wear rate 4.2 × 10⁻ 6 mm³ / N・m is 8-10×10⁻ compared to ordinary high-chromium cast iron. 6 The reduction of mm³ / N・m by 47.5%-58% indicates that the grain refinement effect of rare earth elements has suppressed high-temperature softening. Example 4: The corrosion wear weight loss rate of 0.15 mg / h is only 1 / 3 to 1 / 2 of that of 304 stainless steel under the same conditions; Example 5: Bending performance with a deflection of 15mm without cracking is superior to that of single high-chromium cast iron, which typically fractures when the deflection is greater than 5mm. Working principle: The base layer is made of materials with good toughness, such as low-carbon steel and low-alloy steel, and is smelted in an electric arc furnace or medium-frequency induction furnace. The low-carbon steel is controlled to contain 0.05%-0.25% C and 0.1%-0.3% Si, etc., and the smelting temperature is 1500-1650℃. After casting, hot rolling and other processes, a base plate with good plasticity and toughness is made. The wear-resistant layer is made of wear-resistant alloys such as high-chromium cast iron, with a composition of 5.0%-20.0% Cr and 0.2%-1.0% C, etc., and is smelted. By adding ferrosilicon for deoxidation and controlling the particle size, it is ensured that it contains uniformly dispersed carbides. The surface of the base plate is ground, sandblasted and cleaned to remove oxide scale and impurities and increase surface roughness.

[0037] Then, the wear-resistant layer material is combined with the base plate. If casting cladding is used, the preheated base plate is placed in the mold, and the wear-resistant layer alloy liquid is poured onto the surface of the base plate at 1450-1550℃ and 5-10kg / min to form a cladding layer. If explosive welding is used, the base plate and the wear-resistant layer plate are placed parallel to each other, and the impact force generated by the explosion of the explosive causes the two to collide at high speed to form a metallurgical bond. During the bonding process, by controlling the temperature, pressure and protective gas, the diffusion of interface elements is promoted to form a transition layer with a thickness of 0.05-0.5mm, and the elements in the transition layer are distributed in a gradient.

[0038] Finally, the composite billet is hot-rolled to adjust its thickness, and then quenched and tempered. During quenching, it is heated to 900-1000℃ and then oil-cooled to refine the microstructure. During tempering, it is heated to 200-500℃ to eliminate internal stress. After that, the surface of the sheet is polished, leveled, and cut. Some sheets will also have protective coatings, connecting structures, and micro-textures added, ultimately resulting in a bimetallic sheet product that combines the toughness of the base layer with the wear resistance of the wear-resistant layer.

[0039] 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 or 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A wear-resistant bimetallic sheet, characterized in that: It includes a base layer and a wear-resistant layer disposed on one side of the outer surface of the base layer. The inner surface of the wear-resistant layer is distributed with a microchannel cooling network. The microchannels form a continuous groove array on the inner surface of the wear-resistant layer. The grooves extend longitudinally in the wear-resistant layer to form a three-dimensionally connected dendritic channel. The alloy composition of the wear-resistant layer includes 0.2%-1.0% carbon, 0.5%-3.0% silicon, 1.0%-5.0% manganese, 5.0%-20.0% chromium, 0.5%-5.0% molybdenum, 0.1%-3.0% nickel, 0.1%-3.0% tungsten, 0.05%-1.0% niobium, 0.05%-1.0% titanium, and 0.001%-0.1% boron, with the balance being iron.

2. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The base layer is made of low-carbon steel, low-alloy steel, stainless steel, aluminum alloy, and copper alloy. When the base layer is low-carbon steel, the carbon content is 0.05%-0.25% by mass, the manganese content is 0.3%-0.6%, the silicon content is 0.1%-0.3%, and the balance is iron. When the base layer is low-alloy steel, it contains low-carbon steel and 0.1%-1.0% chromium, 0.1%-0.5% molybdenum, and 0.05%-0.2% vanadium by mass. The wear-resistant layer also contains 0.1%-2.0% rare earth elements by mass percentage, namely cerium, lanthanum and yttrium. The addition of rare earth elements refines the grains in the metallographic structure of the wear-resistant layer. The thickness of the wear-resistant layer ranges from 0.5mm to 10mm.

3. The wear-resistant bimetallic sheet according to claim 1, characterized in that: A transition layer is formed at the interface between the wear-resistant layer and the base layer. The thickness of the transition layer is 0.05mm-0.5mm. The elemental composition of the transition layer is between that of the wear-resistant layer and the base layer. The elemental distribution of the transition layer is gradient, with the elemental content of the base layer increasing by 5-15 at% and the elemental content of the wear-resistant layer increasing by 10-25 at% from the base layer side to the wear-resistant layer side. The elements of the wear-resistant layer and the base layer diffuse into each other to form the transition layer.

4. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The surface of the wear-resistant bimetallic plate is provided with a protective coating, the thickness of which is 0.1mm-0.2mm, and the material of the protective coating is a ceramic coating, an organic coating, or a metal oxide coating. When the protective coating is a ceramic coating, the main components are alumina, zirconium oxide, and silicon carbide. The ceramic coating is applied to the surface of the wear-resistant bimetallic sheet through plasma spraying, physical vapor deposition, and chemical vapor deposition. When the protective coating is an organic coating, the main components are epoxy resin, polyurethane, and fluorocarbon resin. The organic coating is applied to the surface of the wear-resistant bimetallic sheet by spraying or brushing. When the protective coating is a metal oxide coating, the main components are chromium oxide, nickel oxide, and titanium oxide. The metal oxide coating is applied to the surface of the wear-resistant bimetallic sheet by hot-dip galvanizing or electroplating.

5. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The wear-resistant bimetallic sheet has a reinforcing structure inside its base layer. The reinforcing structure can be fiber reinforcement, particle reinforcement, or mesh reinforcement. When the reinforcing structure is fiber reinforcement, the fiber material is carbon fiber, boron fiber, or glass fiber. The fibers are uniformly dispersed and oriented in the base layer, and the volume fraction of the fibers is 5%-20%. When the reinforcing structure is a particulate reinforcement, the particulate material is tungsten carbide, titanium carbide, and alumina particles, the average particle size is 0.01μm-1μm, and the volume fraction of the particles in the base layer is 3%-15%. When the reinforcing structure is a mesh reinforcement, the mesh structure is made of woven metal wire mesh and sintered metal powder mesh. The mesh structure is evenly distributed in the base layer, and the mesh size is 0.01mm–0.1mm.

6. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The edge of the wear-resistant bimetallic plate is provided with a connecting structure, which includes a welding bevel, a riveting hole, and a bolt connection hole. When the connection structure is a welded bevel, the bevel type is V-groove, U-groove, or X-groove, and the bevel angle is 30°-90°. When the connection structure is a riveting hole, the diameter of the riveting hole is 3mm-10mm, and the center distance between adjacent riveting holes is 10mm-50mm.

7. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The wear-resistant layer surface is provided with micro-textures, which are grooves, ridges and grid-like textures; The depth of the microtexture is 0.01mm-0.1mm, the width is 0.05mm-0.5mm, and the arrangement direction of the microtexture structure is at an angle of 30°-90° with the wear direction of the board.

8. The wear-resistant bimetallic sheet according to claim 1, characterized in that: The volume fraction of primary carbides in the wear-resistant layer is ≥40%, and the carbon element in the wear-resistant layer exists in the form of chromium carbide and molybdenum carbide carbides. The carbides are uniformly dispersed in the wear-resistant layer, and the average particle size of the carbides ranges from 0.1μm to 10μm.

9. A method for preparing a wear-resistant bimetallic sheet, applicable to the wear-resistant bimetallic sheet according to any one of claims 1-8, characterized in that: The preparation method comprises the following steps: S1. Add low-carbon steel raw materials with C 0.05%-0.25%, Si 0.1%-0.3%, Mn 0.3%-0.6% to an electric arc furnace, with the balance being Fe. Control the power of the electric arc furnace at 1500-1600℃ to melt the raw materials. Argon gas is introduced for protection during the melting process. After melting is completed, the molten steel is poured into a mold and cooled to room temperature to obtain the base casting billet. The base casting billet is heated to 1100-1200℃, held for 2-3 hours and then hot rolled. The rolling passes are 5-8 times and the total reduction rate is 60%-80%, resulting in a base plate with a thickness of 3-10mm. S2. Add 0.8%-1.2% C, 15%-20% Cr, 1.0%-2.0% Mo, 0.5%-1.5% Ni, 0.8%-1.2% Si, and 1.5%-2.5% Mn to a medium-frequency induction furnace, with the balance being Fe. Melt at 1550-1650℃, adding ferrosilicon for deoxidation during the process. After deoxidation, let stand for 15-20 minutes. S3. Grind the surface of the base plate to remove the oxide scale and clean it with anhydrous ethanol; place the base plate in a heating furnace and preheat it to 400-600℃, and hold it for 30-60 minutes; pour the molten wear-resistant alloy layer onto the upper surface of the base plate, control the casting temperature at 1450-1550℃ and the casting speed at 5-10 kg / min, to form a wear-resistant cladding layer with a thickness of 2-5 mm. When the wear-resistant layer is semi-solidified, press the inner surface with a die with dendritic protrusions to form a three-dimensional interconnected groove array with a depth of 0.1-0.5 mm and a width of 0.2-1.0 mm. Allow it to cool naturally to room temperature to obtain the composite billet. S4. Heat the composite billet to 1000-1100℃, hold for 1-2 hours, hot roll 3-5 times, with a total reduction rate ≤30%, to obtain a composite plate with a thickness of 2-8mm. S5. Place the composite board into a box furnace, heat it to 900-1000℃, hold it for 1-2 hours, then oil cool it to room temperature for quenching. After quenching, put the composite board back into the furnace, heat it to 200-300℃, hold it for 2-3 hours, then air cool it to room temperature for tempering. S6. Grind the surface of the heat-treated composite sheet to remove the oxide scale, then level it with a leveling machine, and finally cut it to obtain the finished wear-resistant bimetallic sheet.

10. The method for preparing a wear-resistant bimetallic sheet according to claim 9, characterized in that: The preparation method further includes the following steps: S31. Bimetallic composite molding adopts explosive welding. The base plate and the wear-resistant layer plate are placed parallel to each other with a distance of 5-15mm between them. Explosives are placed on the side of the wear-resistant layer plate away from the base plate. The detonation velocity of the explosives is controlled at 2000-3000m / s. The impact force generated by the detonation of the explosives causes the wear-resistant layer plate and the base plate to collide at high speed, forming a metallurgical bond at the contact surface to obtain a composite billet.

Images