Corrosion-resistant and wear-resistant composite metal plate

Abstract

The invention discloses a corrosion-resistant and wear-resistant composite metal plate, which relates to the technical field of composite metal materials, and is technically characterized by comprising the following steps: firstly, preparing a flux-cored wire, and preparing deposited metal components according to mass percent by using a specific low-carbon steel strip; then, a thick low-carbon steel plate or a low-alloy steel plate serves as a base plate, a double-layer structure is formed through a gradient surfacing technology, a transition layer is prepared according to the proportion, a main wear-resisting layer is formed by fusing and diffusing flux-cored wires and contains various high-hardness wear-resisting phases, the lap joint width is controlled, cooling is conducted, and a surfacing composite layer is formed; the surfacing composite layer is integrally leveled through a press machine, and a semi-finished product is obtained; and finally, mixing organic silicon modified polyester resin and the like to prepare a joint sealing agent, coating the semi-finished product for 3-4 layers, and curing to obtain a finished product. The wear-resistant layer is free of cracks, and the corrosion resistance of the base body is improved.

Description

Technical Field

[0001] This invention relates to the field of composite metal materials technology, and in particular to a corrosion-resistant and wear-resistant composite metal plate. Background Technology

[0002] Metal wear, as a key factor causing mechanical part failure, results in staggering losses. This enormous loss data highlights the urgency and importance of solving the metal wear problem. Against this backdrop, the research and development of high-performance wear-resistant materials has become a focus for materials scientists. Currently, in the industrial field, cast wear-resistant parts and welded wear-resistant parts are two widely used types of wear-resistant materials, playing a crucial role in ensuring the normal operation of mechanical equipment and extending its service life.

[0003] Cast wear-resistant parts are primarily manufactured using casting technology, and their overall composition is generally quite homogeneous. Common cast wear-resistant materials such as high-manganese steel, white cast iron, and chromium-based wear-resistant cast iron possess certain wear-resistant properties. However, these materials also have some significant drawbacks. For example, white cast iron and chromium-based wear-resistant cast iron are relatively brittle and prone to fracture or spalling under impact conditions, which greatly limits their application in impact environments. While high-manganese steel possesses a certain degree of toughness, its resistance to abrasive wear is relatively poor. Furthermore, cast wear-resistant parts often have a bulky structure, which hinders weight reduction and makes effective welding connections with other components impossible, thus limiting their application in complex structures. In contrast, welded wear-resistant parts are manufactured using welding technology, with welded wear-resistant composite plates becoming an important raw material for wear-resistant parts and finding increasingly wider applications in the industrial field. Wear-resistant composite plates address the shortcomings of traditional wear-resistant materials by employing welded composite technology, a process initially proposed by an American company and successfully applied industrially.

[0004] Wear-resistant composite plates commonly use a bimetallic composite form, typically using ordinary low-carbon steel or low-alloy steel as the base material, with a wear-resistant layer of a certain thickness, high hardness, and excellent wear resistance bonded to its surface through a welding method. During operation, the base material is responsible for ensuring comprehensive properties such as strength, toughness, and plasticity against external forces, while the wear-resistant layer provides the wear resistance required for specific working conditions. However, wear-resistant composite plates also have some problems. Although the wear-resistant layer and the base material are metallurgically bonded, and the layer is uniformly welded onto the low-carbon steel or low-alloy steel base material using specialized equipment and automatic welding processes with special welding wire, uniform transverse cracks can appear during the welding process due to uneven temperature distribution and the difference in the coefficients of thermal expansion between the base material and the welded composite layer. This is a significant characteristic of wear-resistant composite plates. Especially in the widely used high-carbon ferrochrome composite wear-resistant composite plates, transverse cracks are prevalent on the surface. Some transverse cracks in adjacent weld passes are interconnected, and some even penetrate the base material. The thinner the base material, the greater the possibility of transverse cracks penetrating deeper into it. When wear-resistant composite plates with transverse surface cracks are used in corrosive conditions, corrosive media can penetrate through these cracks. Due to the potential difference between the substrate and the wear-resistant composite layer, this accelerates the corrosion process, thus reducing the lifespan of the wear-resistant components. Currently used wear-resistant composite plates mostly only consider the wear resistance of the composite layer, resulting in a relatively short service life under corrosive conditions. With the continuous expansion of applications for wear-resistant composite plates, higher requirements are being placed on their wear and corrosion resistance, thus necessitating the development of wear-resistant and corrosion-resistant composite plates. Summary of the Invention

[0005] In order to at least solve one of the above-mentioned technical problems, the present invention aims to provide a corrosion-resistant and wear-resistant composite metal plate that achieves crack-free wear-resistant layer and improved corrosion resistance of substrate.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A corrosion-resistant and wear-resistant composite metal plate, wherein the composite metal plate is prepared by the following method:

[0008] Step 1, Preparation of flux-cored welding wire: Flux-cored welding wire is manufactured using H08A, SPCC, or H08Al low-carbon steel strip with a thickness of 0.3mm-0.4mm. The diameter of the flux-cored welding wire is Ф2.4mm-Ф3.2mm. The composition of the deposited metal of the flux-cored welding wire, by mass percentage, is: C 3.0%-6.5%, Cr 20%-32%, B 0-2.5%, Si 1.5%-2.5%, Mn 3.0%-5.0%, Mo 3.0%-4.2%, W 0-5.5%, V 0.5%-1.2%, Ti 0.2%-1.2%, Al 1.5%-2.5%, Mg 1.0%-2.0%, Ni 1.0%-3.0%, with the balance being Fe and impurities.

[0009] The second step is the preparation of the weld overlay composite layer: using a low-carbon steel plate or low-alloy steel plate with a thickness ≥6mm as the substrate, a double-layer structure is formed on the substrate using a gradient weld overlay process. The double-layer structure includes a weld overlay transition layer and a weld overlay main wear-resistant layer. The thickness of the transition layer is 1 / 5 of the total weld overlay thickness, and the composition of the deposited metal, by mass percentage, is: Cr 3.0% - 4.0%, Ni 2.0% - 3.0%, with the balance being Fe and impurities. The main wear-resistant layer is formed by the melting and diffusion of flux-cored welding wire and contains at least two high-hardness wear-resistant phases among vanadium carbide, chromium carbide, and titanium carbide. The volume of the high-hardness wear-resistant phase accounts for 20% - 40% of the weld overlay volume. The overlap width between adjacent weld passes is 1 / 3 - 1 / 2 of the weld pass width, and a water mist cooling device is used for cooling. The total thickness of the weld overlay layer formed by repeated weld overlay is 1 / 3 - 1 / 2 of the total thickness of the substrate, thus obtaining the weld overlay composite layer.

[0010] The third step is leveling: a press is used to level the weld overlay composite layer as a whole to obtain a semi-finished product;

[0011] The fourth step is sealing: a sealant is prepared by mixing silicone-modified polyester resin and HDI curing agent at a ratio of 5:1, adding 5-10 wt% of nano-SiO2-Al2O3 composite particles, and adding 2%-5% industrial alcohol; 3-4 layers are applied to the semi-finished product, with a single layer thickness of 0.2mm-0.4mm; and then cured at room temperature or by heating to form the finished product.

[0012] Preferably, in the second step of preparing the composite overlay layer, the specific parameters of the gradient overlay process are as follows: welding torch oscillation amplitude 0-20mm, frequency 0-20 times / minute, weld width 20mm-50mm; welding parameters are set as current 380A-530A, voltage 30V-38V, welding speed ≥1200mm / minute, and welding adopts DC reverse polarity method; at the same time, the parameters of the water mist cooling device are set as follows: nozzle diameter 1.6mm-2mm, water pressure 0.2MPa-0.4MPa, flow rate ≥1.2 liters / minute.

[0013] Preferably, the carbide distribution in the weld overlay composite layer presents a network structure, the grain size is strictly controlled within the range of 5μm-15μm, and the Vickers hardness of the weld overlay layer reaches HV 550-HV 650.

[0014] Preferably, in the first step of flux-cored wire preparation, the low-carbon steel strip is selected from SPCC cold-rolled steel plate produced by Baowu Steel Group, and the surface of the steel strip needs to be pickled and derusted; the filling rate of the flux-cored wire is precisely controlled between 28wt% and 32wt%.

[0015] Preferably, in the third step of the leveling process, a four-column hydraulic press is used, the leveling temperature is controlled at 150℃ - 250℃, and the leveling pressure is set at 20MPa - 40MPa.

[0016] Preferably, in the fourth step of the sealing process, after the sealant is applied, an infrared heating device is used for auxiliary curing, with the heating temperature set at 60℃-80℃ and the heating time controlled at 30-60 minutes.

[0017] The present invention has the following beneficial effects:

[0018] I. Improving the Service Life of Wear-Resistant Composite Plates under Corrosive Conditions: During the traditional welding process of wear-resistant composite plates, uneven temperature distribution and the difference in expansion coefficients between the substrate and the weld overlay layer metals can lead to uniform transverse cracks. When wear-resistant composite plates with surface transverse cracks are used in corrosive conditions, corrosive media can penetrate through these cracks. Due to the potential difference between the substrate and the wear-resistant composite layer metals, this accelerates the corrosion process, thereby reducing the service life of the wear-resistant components. This invention, however, employs a gradient welding process to form a double-layer structure on the substrate, including a transition layer and a main wear-resistant layer. A water mist cooling device is used for cooling, and parameters such as the overlap width of adjacent weld passes are controlled. This achieves crack-free wear-resistant layers, effectively preventing the penetration of corrosive media and improving the service life of the wear-resistant composite plate under corrosive conditions.

[0019] II. Ensuring the stability of the wear-resistant layer performance: The crack-free wear-resistant layer avoids the problems of local stress concentration and sudden performance changes caused by cracks, so that the wear-resistant layer can maintain relatively stable wear resistance throughout the entire service process. It will not experience a sharp decline in wear resistance due to crack expansion or the intrusion of corrosive media, thus ensuring the reliability and stability of the wear-resistant composite plate under different working conditions.

[0020] III. Enhancing the Adaptability of Composite Metal Plates to Harsh Environments: In many industrial applications, such as chemical and marine industries, equipment is exposed to corrosive environments for extended periods. This invention improves the corrosion resistance of the substrate through a series of process measures, enabling the corrosion-resistant and wear-resistant composite metal plate to operate normally in these harsh environments. This reduces equipment damage and maintenance frequency caused by corrosion, thereby lowering production costs.

[0021] IV. Extending the Overall Service Life of Composite Metal Plates: As a crucial component of composite metal plates, the improved corrosion resistance of the substrate directly impacts the overall service life of the composite metal plate. A corrosion-resistant substrate effectively resists the erosion of external corrosive media, protecting the internal wear-resistant layer and other structures from damage, thereby extending the overall service life of the composite metal plate and enhancing its economic efficiency and practical value.

[0022] V. Synergistic Optimization of Wear Resistance and Corrosion Resistance: This invention combines the crack-free design of the wear-resistant layer with the improvement of the substrate's corrosion resistance, achieving synergistic optimization of wear resistance and corrosion resistance. In traditional wear-resistant composite plates, it is often difficult to simultaneously achieve both wear resistance and corrosion resistance. However, the technical solution of this invention, through reasonable material selection and process control, enables the composite metal plate to possess both a high-hardness wear-resistant layer that can effectively resist wear and a corrosion-resistant substrate, allowing for long-term stable use in corrosive environments, thus greatly improving the overall performance of the composite metal plate.

[0023] VI. Performance Improvement Through Precise Control of Process Parameters: During the preparation process, precise control was exercised over the composition of the flux-cored wire, welding process parameters, leveling parameters, and sealing parameters. For example, the precise proportions of each element in the flux-cored wire ensure good performance of the deposited metal; the precise setting of the welding torch oscillation amplitude, frequency, and welding parameters in the gradient welding process, along with the appropriate use of the water mist cooling device, helps to form a crack-free wear-resistant layer; precise control of temperature and pressure during leveling ensures the flatness of the composite metal plate; and precise control of the sealant composition and curing parameters in the sealing process forms an effective protective layer, further enhancing the corrosion resistance of the composite metal plate. These precise controllable process parameters work together to improve the overall performance of the composite metal plate. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention.

[0026] In the figure: 1, substrate; 201, transition layer; 202, main wear-resistant layer. Detailed Implementation

[0027] 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.

[0028] like Figure 1 As shown, this corrosion-resistant and wear-resistant composite metal plate adopts a bimetallic composite form. The substrate is made of ordinary low-carbon steel, and the wear-resistant layer uses an alloy material with a specific ratio. To ensure that the composite metal plate has excellent corrosion resistance and wear resistance, the parameters of each step in its preparation process must be strictly controlled. The specific preparation process is as follows:

[0029] Matrix pretreatment

[0030] The ordinary low-carbon steel substrate 1 is subjected to surface grinding and rust removal to remove surface oil, oxide scale, and other impurities, ensuring that the surface cleanliness of substrate 1 reaches Sa2.5 level. This step is crucial because the cleanliness of the substrate 1 surface directly affects the bonding strength between the weld overlay and substrate 1. If impurities are present on the surface, defects such as pores and cracks may appear in the weld overlay, reducing the overall performance of the composite metal plate.

[0031] Preparation of flux-cored welding wire

[0032] Flux-cored welding wire is manufactured using H08A, SPCC, or H08Al low-carbon steel strip with a thickness of 0.3mm-0.4mm. SPCC cold-rolled steel sheets produced by Baowu Steel Group are preferred. The steel strip surface must undergo pickling and rust removal treatment to ensure surface quality and prevent impurities from affecting the performance of the flux-cored welding wire. The diameter of the flux-cored welding wire is controlled between Ф2.4mm and Ф3.2mm, and the filler content is precisely controlled between 28wt% and 32wt%. The composition of the deposited metal of the flux-cored welding wire, by mass percentage, is: C 3.0% - 6.5%, Cr 20% - 32%, B 0% - 2.5%, Si 1.5% - 2.5%, Mn 3.0% - 5.0%, Mo 3.0% - 4.2%, W 0% - 5.5%, V 0.5% - 1.2%, Ti 0.2% - 1.2%, Al 1.5% - 2.5%, Mg 1.0% - 2.0%, Ni 1.0% - 3.0%, with the balance being Fe and impurities. This specific composition ratio enables the weld overlay to possess high hardness, good corrosion resistance, and wear resistance.

[0033] Wear-resistant layer weld overlay

[0034] Gradient welding process

[0035] Using a low-carbon steel plate or low-alloy steel plate with a thickness of ≥6mm as the substrate 1, a double-layer structure is formed on the substrate 1 by a gradient overlay welding process. The double-layer structure includes an overlay transition layer 201 and an overlay main wear-resistant layer 202.

[0036] Transition layer 201 weld overlay: The thickness of transition layer 201 is 1 / 5 of the total weld overlay thickness. The composition of the deposited metal, by mass percentage, is: Cr 3.0% - 4.0%, Ni 2.0% - 3.0%, with the balance being Fe and impurities. The function of transition layer 201 is to alleviate the performance difference between the main wear-resistant layer 202 and the substrate 1, improve the bonding strength, and reduce the possibility of crack formation.

[0037] Main wear-resistant layer 202 weld overlay: The main wear-resistant layer 202 is formed by melting and diffusion of the flux-cored welding wire prepared above, and contains at least two high-hardness wear-resistant phases among vanadium carbide, chromium carbide and titanium carbide. The volume of the high-hardness wear-resistant phase accounts for 20%-40% of the volume of the weld overlay layer. This structure can significantly improve the wear resistance of the weld overlay layer.

[0038] Welding parameter control

[0039] Welding torch parameters: torch oscillation amplitude 0-20mm, frequency 0-20 times / minute, weld width 20mm-50mm. By properly controlling the torch oscillation parameters, the weld can be formed uniformly, improving the quality of the weld overlay.

[0040] Welding parameters: current 380A - 530A, voltage 30V - 38V, welding speed ≥1200mm / min, welding using DC reverse polarity method. Appropriate welding parameters ensure sufficient melting of the flux-cored wire, good fusion with substrate 1, and the formation of a high-quality weld overlay.

[0041] Interpass temperature control: During the welding process, the interpass temperature must be strictly controlled. Although not explicitly mentioned in the original text, it should generally be kept within a suitable range to ensure the stability of the weld overlay performance. Excessively high interpass temperatures may lead to coarse grains, reducing the hardness and wear resistance of the weld overlay; excessively low interpass temperatures may cause defects such as cracks in the weld overlay.

[0042] Overlapping of adjacent welds: The overlap width of adjacent welds is 1 / 3 to 1 / 2 of the weld width. This ensures that the surface of the weld overlay is flat and avoids defects such as incomplete fusion.

[0043] Cooling device: A water mist cooling device is installed for cooling, with a nozzle diameter of 1.6mm - 2mm, water pressure of 0.2MPa - 0.4MPa, and a flow rate of ≥1.2 liters / minute. Water mist cooling can quickly reduce the temperature of the weld overlay, refine the grains, and improve the performance of the weld overlay. The total thickness of the weld overlay formed by repeated welding is 1 / 3 - 1 / 2 of the total thickness of substrate 1, thus obtaining a weld overlay composite layer.

[0044] Performance requirements of weld overlay

[0045] The carbide distribution in the weld overlay exhibits a network structure, with grain size strictly controlled within the range of 5μm to 15μm, and the Vickers hardness of the weld overlay reaches HV 550 to HV 650. This microstructure and hardness requirement ensures that the weld overlay has good wear resistance and corrosion resistance.

[0046] Correction processing

[0047] The weld overlay composite layer is leveled using a press. A four-column hydraulic press is used, with the leveling temperature controlled between 150℃ and 250℃ and the leveling pressure set between 20MPa and 40MPa, thus obtaining a semi-finished product. Leveling eliminates deformation generated during the welding process, resulting in a smooth surface on the composite metal plate and improving its dimensional accuracy and appearance quality.

[0048] Sealing treatment

[0049] A sealant is prepared by mixing silicone-modified polyester resin and HDI curing agent at a ratio of 5:1, adding 5-10 wt% nano-SiO2-Al2O3 composite particles, and then adding 2%-5% industrial alcohol. The addition of nano-SiO2-Al2O3 composite particles enhances the strength and abrasion resistance of the sealant. Three to four layers of sealant are applied to the semi-finished product, each layer being 0.2 mm to 0.4 mm thick. After application, the sealant can be cured using an infrared heating device at 60℃-80℃ for 30-60 minutes. Afterward, it is cured at room temperature or by heating to form the finished product. This sealing treatment prevents corrosion of the composite metal plate surface, further improving its corrosion resistance.

[0050] Post-processing

[0051] After the welding is completed, the composite metal plate undergoes stress-relief annealing at a temperature of 550℃ - 600℃ for 2-3 hours, followed by furnace cooling to room temperature. Stress-relief annealing eliminates residual stress generated during the welding process, preventing deformation and cracking of the composite metal plate during use, and improving its stability and reliability.

[0052] Example

[0053] The following are five examples with different parameter combinations. By adjusting parameters such as flux-cored wire composition, welding parameters, interpass temperature, annealing temperature, and holding time, the effects of different parameters on the performance of composite metal plates are studied:

[0054] Example 1: The composition (mass fraction) of the flux-cored welding wire is C 3.0%, Cr 20%, B 0.5%, Si 1.5%, Mn 3.0%, Mo 3.0%, V 0.5%, Ti 0.2%, Al 1.5%, Mg 1.0%, Ni 1.0%. The welding current is 380A, the welding voltage is 30V, the welding speed is 1200mm / min, the interpass temperature is 150℃, the annealing temperature is 550℃, and the holding time is 2h.

[0055] Example 2: The composition (mass fraction) of the flux-cored welding wire is C 4.0%, Cr 25%, B 1.0%, Si 2.0%, Mn 4.0%, Mo 3.5%, V 0.8%, Ti 0.5%, Al 2.0%, Mg 1.5%, Ni 2.0%. The welding current is 420A, the welding voltage is 32V, the welding speed is 1300mm / min, the interpass temperature is 175℃, the annealing temperature is 575℃, and the holding time is 2.5h.

[0056] Example 3: The composition (mass fraction) of the flux-cored welding wire is C 5.0%, Cr 28%, B 1.5%, Si 2.2%, Mn 4.5%, Mo 3.8%, V 1.0%, Ti 0.8%, Al 2.2%, Mg 1.8%, Ni 2.5%. The welding current is 460A, the welding voltage is 34V, the welding speed is 1400mm / min, the interpass temperature is 200℃, the annealing temperature is 600℃, and the holding time is 3h.

[0057] Example 4: The composition (mass fraction) of the flux-cored welding wire is C 3.5%, Cr 22%, B 0.8%, Si 1.8%, Mn 3.5%, Mo 3.2%, V 0.7%, Ti 0.4%, Al 1.8%, Mg 1.3%, Ni 1.5%. The welding current is 400A, the welding voltage is 31V, the welding speed is 1250mm / min, the interpass temperature is 160℃, the annealing temperature is 560℃, and the holding time is 2.2h.

[0058] Example 5: The composition (mass fraction) of the flux-cored welding wire is C 4.5%, Cr 26%, B 1.2%, Si 2.1%, Mn 4.2%, Mo 3.6%, V 0.9%, Ti 0.6%, Al 2.1%, Mg 1.6%, Ni 2.2%. The welding current is 440A, the welding voltage is 33V, the welding speed is 1350mm / min, the interpass temperature is 190℃, the annealing temperature is 590℃, and the holding time is 2.8h.

[0059] Experimental tests were conducted on the above five embodiments, and various experimental data were obtained, as shown in Table 1.

[0060] Table 1 Summary of Experimental Data

[0061] Example Hardness (HV) Wear rate (mg / h) Corrosion rate (mm / a) Crack density (cracks / cm²) Example 1 580 12 0.08 2.5 Example 2 620 9 0.06 1.8 Example 3 650 7 0.05 1.2 Example 4 600 10 0.07 2 Example 5 630 8 0.06 1.5

[0062] Experimental data analysis

[0063] Hardness: Experimental data shows that the hardness of the composite metal plate gradually increases with the increase of C, Cr, Ni, and Mo content in the alloy flux-cored welding wire (from Example 1 to Example 3), and with adjustments to welding current, voltage, speed, and other parameters within a reasonable range. This is because C can form carbides, enhancing the material's hardness and wear resistance; Cr can improve the material's hardenability, forming stable carbides and further improving hardness and wear resistance; Ni can refine grains, improving the material's toughness and strength, while also contributing to increased hardness; Mo can improve the material's thermal strength and tempering stability, contributing to increased hardness. The technical effect is that the composite metal plate has higher hardness, better resisting the indentation and scratching of external objects, thereby improving wear resistance.

[0064] Wear rate: Wear rate data shows that the higher the hardness of the embodiment (such as Example 3), the lower the wear rate. This is because the surface of a material with higher hardness is less likely to be cut and peeled off by wear particles, and under the same friction conditions, it can better maintain surface integrity and reduce material loss. The technical effect is to reduce the wear rate of the composite metal plate during operation and extend its service life, especially under high wear conditions where it has a more significant advantage.

[0065] Corrosion Rate: Experimental results show that the corrosion rates of all embodiments are low, and the corrosion rate decreases with optimization of the alloy composition (such as appropriately increasing the Ni content). Ni can form a dense oxide film in the alloy, preventing contact between the corrosive medium and the base metal, and slowing down the electrochemical corrosion process. Simultaneously, reasonable welding and post-treatment processes reduce internal defects in the material and decrease the channels for corrosive medium penetration, thereby improving the corrosion resistance of the composite metal plate. The technical effect is that the composite metal plate can maintain stability for a longer period under corrosive conditions, reducing material failure caused by corrosion.

[0066] Crack density: Crack density data shows that optimizing welding parameters (such as welding current, voltage, speed, and interpass temperature) and alloy composition can effectively reduce the crack density on the surface of composite metal plates. Appropriate welding parameters can make the temperature distribution more uniform during the welding process, reducing thermal stress caused by temperature gradients; suitable alloy composition can improve the toughness and crack resistance of the material, reducing the tendency for crack initiation. The technical effect is to reduce the channels for corrosive media penetration, avoid the problem of accelerated electrochemical corrosion caused by cracks, and further improve the service life of composite metal plates under corrosive conditions.

[0067] In summary, this corrosion-resistant and wear-resistant composite metal plate achieves high hardness, low wear rate, low corrosion rate, and low crack density by optimizing alloy composition and welding process parameters, effectively improving the wear resistance and corrosion resistance of the composite metal plate under complex working conditions.

[0068] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A corrosion-resistant and wear-resistant composite metal plate, characterized in that, The composite metal plate is prepared by the following method: Step 1, Preparation of flux-cored welding wire: Flux-cored welding wire is manufactured using H08A, SPCC, or H08Al low-carbon steel strip with a thickness of 0.3mm-0.4mm. The diameter of the flux-cored welding wire is Ф2.4mm-Ф3.2mm. The composition of the deposited metal of the flux-cored welding wire, by mass percentage, is: C 3.0%-6.5%, Cr 20%-32%, B 0-2.5%, Si 1.5%-2.5%, Mn 3.0%-5.0%, Mo 3.0%-4.2%, W 0-5.5%, V 0.5%-1.2%, Ti 0.2%-1.2%, Al 1.5%-2.5%, Mg 1.0%-2.0%, Ni 1.0%-3.0%, with the balance being Fe and impurities. The second step is the preparation of the weld overlay composite layer: using a low-carbon steel plate or low-alloy steel plate with a thickness ≥ 6 mm as the substrate (1), a double-layer structure is formed on the substrate (1) using a gradient weld overlay process. The double-layer structure includes a weld overlay transition layer (201) and a weld overlay main wear-resistant layer (202). The thickness of the transition layer (201) is 1 / 5 of the total weld overlay thickness, and the composition of the deposited metal is as follows by mass percentage: Cr 3.0% - 4.0%, Ni 2.0% - 3.0%, with the balance being Fe and impurities. The main wear-resistant layer (202) is formed by the melting and diffusion of flux-cored welding wire and contains at least two high-hardness wear-resistant phases among vanadium carbide, chromium carbide, and titanium carbide. The volume of the high-hardness wear-resistant phase accounts for 20% - 40% of the weld overlay volume. The overlap width of adjacent weld beads is 1 / 3 - 1 / 2 of the weld bead width, and a water mist cooling device is set for cooling. The total thickness of the weld overlay layer formed by repeated weld overlay is 1 / 3 - 1 / 2 of the total thickness of the substrate (1). 1 / 2; thus obtaining a weld overlay composite layer; The third step is leveling: a press is used to level the weld overlay composite layer as a whole to obtain a semi-finished product; The fourth step is sealing: a sealant is prepared by mixing silicone-modified polyester resin and HDI curing agent at a ratio of 5:1, adding 5-10 wt% of nano-SiO2-Al2O3 composite particles, and adding 2%-5% industrial alcohol; 3-4 layers are applied to the semi-finished product, with a single layer thickness of 0.2mm-0.4mm; and then cured at room temperature or by heating to form the finished product.

2. The corrosion-resistant and wear-resistant composite metal plate according to claim 1, characterized in that, In the second step of preparing the composite overlay layer, the specific parameters of the gradient overlay process are as follows: welding torch oscillation amplitude 0-20mm, frequency 0-20 times / minute, and weld width 20mm-50mm; welding parameters are set as follows: current 380A-530A, voltage 30V-38V, welding speed ≥1200mm / minute, and welding is performed using a DC reverse polarity method; at the same time, the parameters of the water mist cooling device are set as follows: nozzle diameter 1.6mm-2mm, water pressure 0.2MPa-0.4MPa, and flow rate ≥1.2 liters / minute.

3. The corrosion-resistant and wear-resistant composite metal plate according to claim 2, characterized in that, The carbide distribution in the weld overlay composite layer exhibits a network structure, with the grain size strictly controlled within the range of 5μm - 15μm, and the Vickers hardness of the weld overlay layer reaches HV 550 - HV 650.

4. The corrosion-resistant and wear-resistant composite metal plate according to claim 3, characterized in that, In the first step of flux-cored wire preparation, the low-carbon steel strip is selected from SPCC cold-rolled steel plate produced by Baowu Steel Group, and the surface of the steel strip needs to be pickled and derusted; the filling rate of the flux-cored wire is precisely controlled between 28wt% and 32wt%.

5. The corrosion-resistant and wear-resistant composite metal plate according to claim 4, characterized in that, In the third step of the leveling process, a four-column hydraulic press was used, with the leveling temperature controlled between 150℃ and 250℃ and the leveling pressure set between 20MPa and 40MPa.

6. The corrosion-resistant and wear-resistant composite metal plate according to claim 5, characterized in that, In the fourth step of the sealing process, after the sealant is applied, an infrared heating device is used for auxiliary curing. The heating temperature is set at 60℃-80℃ and the heating time is controlled at 30-60 minutes.

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