Alloyed hot-dip galvanized steel sheet having excellent stamping lubrication processing performance, and manufacturing method therefor

Abstract

Disclosed is an alloyed hot-dip galvanized steel sheet having excellent stamping lubrication processing performance, comprising a substrate, the surface of the substrate being provided with an alloyed hot-dip galvanized layer; the surface of the alloyed hot-dip galvanized layer is covered with a composite nano-structure treatment layer; the composite nano-structure treatment layer comprises nano-particles and a nano-film, the nano-particles at least being in a plate-like form and randomly distributed on the surface of the alloyed hot-dip galvanized layer. Also disclosed is a manufacturing method for the alloyed hot-dip galvanized steel sheet, comprising the steps: performing hot-dip galvanizing, alloying heat treatment and leveling on a substrate, so as to form an alloyed hot-dip galvanized layer on the surface of the substrate; and performing surface treatment on the alloyed hot-dip galvanized layer using a water-based treatment agent, to obtain a composite nano-structure treatment layer.

Description

Alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication properties and its manufacturing method Technical Field

[0001] This invention relates to a steel plate and a method for manufacturing the same, and more particularly to a galvanized steel plate and a method for manufacturing the same. Background Technology

[0002] Alloyed hot-dip galvanized steel sheets are widely used in the automotive manufacturing industry, primarily for manufacturing body structures and components. However, during the stamping process, stamping wear and a high coefficient of friction significantly impact manufacturing efficiency.

[0003] In existing technologies, the coefficient of friction of the zinc-iron alloy coating in alloyed hot-dip galvanized steel sheets can be altered by adjusting the composition of the coating. Furthermore, a lubrication layer can be constructed on the surface of the alloyed hot-dip galvanized steel sheet to reduce the coefficient of friction and the amount of zinc powder wear, thereby improving stamping performance. For example:

[0004] Chinese patent document with publication number CN102575330A and publication date July 11, 2012, entitled "Alloyed hot-dip galvanized steel sheet and manufacturing method thereof", discloses a scheme that optimizes forming performance by forming a composite oxide layer containing amorphous compounds of Mn, Zn and P on the surface of the alloyed hot-dip galvanized layer using a coating machine.

[0005] Chinese patent document CN108018512A, published on May 11, 2018, entitled "An Alloyed Hot-Dip Galvanized Steel Sheet with Excellent Processability and its Manufacturing Method," discloses a method to improve the processability of a hot-dip galvanized steel sheet by imparting a solid lubricating film composed of phosphate, sulfate, Zn oxide, and Fe oxide to the surface of the alloyed hot-dip galvanized layer. The common feature of this type of technology is the use of the excellent high-temperature friction properties of the phosphate surface treatment layer to optimize surface forming performance. However, the chemical treatment of phosphorus-containing surfaces presents problems such as an environmentally unfriendly manufacturing process and high costs for wastewater treatment. Summary of the Invention

[0006] One of the objectives of this invention is to provide an alloyed hot-dip galvanized steel sheet with excellent stamping lubrication performance. This steel sheet has good surface lubrication properties, which can reduce the coefficient of friction during the stamping process, thereby optimizing the stamping performance.

[0007] To achieve the above objectives, the present invention provides an alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication processing performance, comprising a substrate having an alloyed hot-dip galvanized layer on its surface.

[0008] The surface of the alloyed hot-dip zinc-plated layer is covered with a composite nanostructure treatment layer; the composite nanostructure treatment layer includes nanoparticles and nanofilms.

[0009] The nanoparticles are randomly distributed on the surface of the alloyed hot-dip galvanized layer, at least in a sheet-like form.

[0010] The alloyed hot-dip galvanized steel sheet of the present invention, which has excellent stamping and lubrication processing performance, includes a substrate and an alloyed hot-dip galvanized layer located on the surface of the substrate.

[0011] In this invention, nanoparticles are distributed on the surface of the alloyed hot-dip galvanized layer. In some embodiments, the nanoparticles are randomly distributed on the surface of the alloyed hot-dip galvanized layer.

[0012] In this invention, at least a portion of the nanoparticles are in the form of sheets.

[0013] In this invention, nanoparticles are randomly distributed on the coating surface in the form of sheets or spheres. The sheet-like nanoparticles reduce the direct contact between the mold and the coating surface during the molding process, transforming the micro-friction adhesion area into a boundary lubrication state, thereby reducing the coefficient of friction and improving lubrication performance.

[0014] In this invention, the nanofilm structure can, on the one hand, improve the surface hardness of the alloyed hot-dip galvanized layer and increase its resistance to wear; on the other hand, the nanofilm structure can also absorb and disperse some of the heat generated by friction at the friction interface, reduce local temperature rise, and thus reduce friction damage.

[0015] In some embodiments, the chemical composition of the substrate is as follows by mass percentage: C: ≤0.12%, Si: ≤0.25%, Mn: ≤0.8%, P: ≤0.045%, S: ≤0.045%, Ti: ≤0.3%, with the balance being Fe and unavoidable impurities.

[0016] In some embodiments, the chemical composition of the substrate by mass percentage satisfies at least one of the following: C: 0.01% to 0.12%; Si: 0.05% to 0.25%; Mn: 0.05% to 0.8%; P: 0.005% to 0.045%; S: 0.005% to 0.045%; Ti: 0.01% to 0.3%.

[0017] In this invention, the alloyed hot-dip galvanized layer comprises a Zn-Fe alloy phase.

[0018] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the mass percentage content of Fe element in the Zn-Fe alloy phase of the alloyed hot-dip galvanized layer is 9%-11.5%.

[0019] In this invention, when the mass percentage of Fe in the Zn-Fe alloy phase of the alloyed hot-dip galvanized layer is too low, a phase with low hardness is easily formed in the coating, increasing the friction coefficient of the coating surface, and the optimization of high-temperature friction performance during steel plate stamping is not significant. When the mass percentage of Fe in the Zn-Fe alloy phase of the alloyed hot-dip galvanized layer is too high, a phase with excessively high hardness and high brittleness is easily formed in the coating, resulting in insufficient resistance to friction and wear during steel plate stamping and easy zinc powder peeling. In some embodiments, the mass percentage of Fe in the Zn-Fe alloy phase of the alloyed hot-dip galvanized layer can be further controlled to 10%-11%.

[0020] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the alloyed hot-dip galvanized layer also contains Al element and at least one of Bi, Cd, Co, Ni, and Sn elements.

[0021] Preferably, in the alloyed hot-dip galvanized steel sheet of the present invention, the alloyed hot-dip galvanized layer further contains Al element and at least one of Bi, Co, Ni, and Sn elements.

[0022] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the mass percentage content of Al element in the alloyed hot-dip galvanized layer is 0.03%-0.2%.

[0023] In this invention, when the Al content in the alloyed hot-dip galvanized layer is too low, the alloyed hot-dip galvanized layer is prone to unevenness, directly affecting the surface friction uniformity during the stamping process; when the Al content in the alloyed hot-dip galvanized layer is too high, the surface brittleness of the alloyed hot-dip galvanized layer increases, leading to zinc powder peeling during the stamping process. In some embodiments, the Al content in the alloyed hot-dip galvanized layer can be further controlled to 0.08%-0.15%.

[0024] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the total mass percentage of Bi, Cd, Co, Ni, and Sn elements in the alloyed hot-dip galvanized layer does not exceed 0.1% (i.e., ≤0.1%).

[0025] Preferably, in the alloyed hot-dip galvanized steel sheet of the present invention, the total mass percentage of Bi, Co, Ni, and Sn elements in the alloyed hot-dip galvanized layer does not exceed 0.1% (i.e., ≤0.1%).

[0026] In this invention, the Bi, Cd, Co, Ni, and Sn elements in the alloyed hot-dip galvanized layer can be combined with manufacturing process requirements to further optimize the coating hardness and uniformity.

[0027] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the surface of the alloyed hot-dip galvanized layer has zinc-iron alloy crystalline regions and randomly distributed platform regions, and the area ratio of zinc-iron alloy crystalline regions per unit area of ​​the surface is 15%-85%.

[0028] In this invention, the composite nanostructure treatment layer covering the surface of randomly distributed platform areas can provide sufficient boundary lubrication for the platform areas during the high-pressure forming process of body parts through its excellent solid friction lubrication properties, effectively reducing the formation of frictional adhesion zones and thus improving the surface friction coefficient. In this invention, the nanoscale particles of the composite nanostructure treatment layer on the surface of the zinc-iron alloy crystalline region are distributed between the microscopically rough crystals. When the stamping die for forming the body part moves relative to the sheet metal, wear and breakage of the surface zinc-iron alloy crystals occur. At this time, the nanoscale particles in this region can fully play a lubricating bearing role, thereby reducing further wear and damage to the coating surface and achieving optimized surface friction and wear performance.

[0029] In this invention, the platform area is formed in the manufacturing method of alloyed hot-dip galvanized steel sheet by treating the surface of the alloyed hot-dip galvanized steel sheet with a leveling roller in the leveling step.

[0030] In this invention, when the area ratio of the zinc-iron alloy crystalline region is less than 15%, the surface roughness of the zinc-iron alloy coating decreases and the oil storage capacity is insufficient, resulting in a significant decrease in the surface oil film lubrication performance; when the area ratio of the zinc-iron alloy crystalline region is greater than 85%, the surface roughness of the zinc-iron alloy coating is too high and it is difficult to achieve stable control, which in turn affects the coating appearance quality.

[0031] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the equivalent sphere radius of the nanoparticles is 40-400 nm.

[0032] It should also be noted that in this invention, nanoparticles refer to a three-dimensional structure. Different particle shapes all represent a three-dimensional structure, and sheet-like structures also have a certain thickness. Therefore, the concept of equivalent sphere radius is used to describe the size of sheet-like nanoparticles.

[0033] In this invention, when the equivalent sphere radius of the nanoparticles is too low, a good isolation layer cannot be formed at the interface between the mold and the steel plate during deformation, resulting in insufficient boundary lubrication and reduced surface lubrication performance. When the equivalent sphere radius of the nanoparticles is too high, the surface lubrication particles may generate additional friction between the friction surfaces, leading to increased friction and further reducing the lubrication effect. In some embodiments, the equivalent sphere radius of the nanoparticles can be further controlled to 100-300 nm.

[0034] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the sheet-like nanoparticles contain a metal-based compound, which includes metal and non-metal elements, wherein the metal in the metal-based compound is selected from at least one of Ca, Cu, K, Al, Na, Fe, Zn, and Mg.

[0035] The Zn and Fe elements in the aforementioned metals mainly come from the steel plate. The Ca, Cu, K, Al, Na, and Mg elements in the aforementioned metals come from the water-based treatment agent.

[0036] In this invention, the non-metallic elements constituting the above-mentioned metal-based compounds are selected from at least one of Si, O, C, N, and H, and they mainly combine with the metal elements through coordination bonds via silicon-oxygen bonds, carboxyl groups, and amino groups to form the nanoparticle structure. In this invention, the silicon-oxygen bonds, carboxyl groups, and amino groups are provided by a second substance in the water-based treatment agent.

[0037] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the proportion of flaky nanoparticles to all nanoparticles per unit area of ​​the surface is 50%-90%.

[0038] In this invention, when the proportion of sheet-like nanoparticles to all nanoparticles is too low, the lubrication layer is not fully formed. At the same time, too many spherical particles can easily cause inter-particle jamming and wear, which in turn leads to a decrease in friction performance. When the proportion of sheet-like nanoparticles to all nanoparticles is too high, the spherical nanoparticles do not fill the micro-depression areas on the surface during deformation, resulting in a reduction in lubrication effect, especially a significant decrease in high-temperature friction lubrication effect.

[0039] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the nanofilm comprises metallic and non-metallic elements; the metallic element is selected from at least one of La, Zn, Mn, Ce, Fe, W, and Mo; and the non-metallic element is selected from at least one of S, O, C, B, and H.

[0040] In this invention, La, Mn, Ce, W, and Mo are mainly derived from water-based treatment agents, while Zn and Fe are mainly derived from steel plates.

[0041] In the alloyed hot-dip galvanized steel sheet of the present invention, the non-metallic elements combine with the metallic elements through at least one group selected from boron-oxygen bonds, carboxyl groups, and thiol groups to jointly form the nanofilm. In some embodiments, in the alloyed hot-dip galvanized steel sheet of the present invention, the non-metallic elements combine with the metallic elements through boron-oxygen bonds, carboxyl groups, and thiol groups to jointly form the nanofilm.

[0042] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the non-metallic elements combine with the metallic elements through boron-oxygen bonds, carboxyl groups, and thiol groups to jointly form the nanofilm.

[0043] In this invention, the boron-oxygen bond, carboxyl group, and mercapto group are provided by a second substance in the water-based treatment agent.

[0044] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the metal element accounts for 25%-80% of the mass percentage of the nanofilm.

[0045] In this invention, when the mass percentage of the metal element in the nanofilm is too low, the surface wear performance optimization is not significant, and the effect of significantly optimizing surface wear performance cannot be achieved; when the mass percentage of the metal element in the nanofilm is too high, its structure is not stable enough, and it cannot form an effective bonding force on the surface of the alloyed hot-dip galvanized layer, which easily leads to peeling and thus deterioration of wear performance. In some embodiments, the mass percentage of the metal element in the nanofilm can be further controlled to 30%-60%.

[0046] Furthermore, in the alloyed hot-dip galvanized steel sheet of the present invention, the nanoparticles account for 40%-80% of the mass percentage in the composite nanostructure treatment layer.

[0047] In this invention, when the mass percentage of nanoparticles in the composite nanostructure treatment layer is too low, the improvement in surface lubrication performance of the alloyed hot-dip galvanized layer is not significant; when the mass percentage of nanoparticles in the composite nanostructure treatment layer is too high, the surface lubrication performance is significant, but the improvement in friction and wear performance is not significant. In some embodiments, the mass percentage of nanoparticles in the composite nanostructure treatment layer can be further controlled to 60%-80%.

[0048] Another objective of this invention is to provide a method for manufacturing alloyed hot-dip galvanized steel sheet. This method involves hot-dip galvanizing, alloying heat treatment, and leveling of a substrate, followed by surface treatment, thereby conveniently and economically obtaining an alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication processing performance.

[0049] To achieve the above objectives, the present invention provides a method for manufacturing alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication properties, comprising the following steps:

[0050] The substrate is subjected to hot-dip galvanizing, alloying heat treatment and flattening to form the alloyed hot-dip zinc plating layer on the substrate surface;

[0051] The alloyed hot-dip galvanized layer is surface-treated with a water-based treatment agent to obtain the composite nanostructure treatment layer.

[0052] Furthermore, in the manufacturing method of the present invention, the water-based treatment agent includes a first substance providing a metallic element and a second substance providing a non-metallic element; wherein the mass ratio of the first substance and the second substance is 1:1.5 to 1:15.

[0053] Furthermore, in the manufacturing method described in this invention, the mass content of the first substance in the water-based treatment agent can be 0.5%-2.5%, and the mass content of the second substance in the water-based treatment agent can be 1%-15%.

[0054] Furthermore, in the manufacturing method described in this invention, the first substance is selected from at least one of the following: lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, cerium chloride, cerium sulfate, cerium nitrate, sodium tungstate, ammonium tungstate, potassium tungstate, sodium molybdate, ammonium molybdate, potassium molybdate, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum acetate, sodium aluminate, sodium fluorotitanate, potassium fluorotitanate, manganese nitrate, copper nitrate, barium nitrate, copper sulfate, calcium nitrate, calcium acetate, calcium sulfate, magnesium sulfate, magnesium citrate, and magnesium lactate.

[0055] Furthermore, in the manufacturing method described in this invention, the second substance is selected from at least one of the following: boric acid, sodium borate, ammonium borate, 3,4,5-trihydroxybenzoic acid, ethylenediaminetetraacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, tannic acid, cysteine, mercaptoacetic acid, mercaptoethanol, mercaptoethanol, polyethyleneimine, glycine, aspartic acid, ammonia, ethanolamine, propanolamine, isopropanolamine, ethylsilanol, and propylenesilanol.

[0056] In some embodiments, in the manufacturing method described in this invention, the chemical composition of the zinc bath used for hot-dip galvanizing is as follows (mass percentage): Al: 0.03-0.2%; Bi: 0-0.04%; Co: 0-0.03%; Ni: 0-0.02%; Sn: 0-0.03%; with the balance being Zn and unavoidable impurities.

[0057] Furthermore, in the manufacturing method described in this invention, the temperature of the alloying heat treatment is 500-570°C.

[0058] Furthermore, in the manufacturing method described in this invention, the water-based treatment agent is coated onto the alloyed hot-dip galvanized layer by roller coating, spraying or immersion coating for surface treatment, and then dried into a film by blowing or drying.

[0059] The alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication processing performance and its manufacturing method described in this invention have the following characteristics and beneficial effects:

[0060] The alloyed hot-dip galvanized steel sheet with excellent stamping lubrication processing performance described in this invention has good surface lubrication properties, which can reduce the friction coefficient during the stamping process and thus optimize the stamping performance.

[0061] The alloyed hot-dip galvanized steel sheet with excellent stamping lubrication and processing performance described in this invention reduces the amount of zinc powder wear during the stamping process and improves the stamping lubrication and processing performance.

[0062] The alloyed hot-dip galvanized steel sheet of the present invention has excellent stamping and lubrication performance and is environmentally friendly and phosphorus-free, avoiding the negative environmental impact of phosphorus-containing surface chemical treatment, and has high environmental protection performance.

[0063] The manufacturing process of the alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication properties described in this invention is convenient and economical, reducing production costs. Attached Figure Description

[0064] Figure 1 shows the microstructure of the composite nanostructure treatment layer on the surface of the alloyed hot-dip galvanized steel sheet of Example 3 of the present invention.

[0065] Figure 2 shows the microstructure at point A in Figure 1 magnified.

[0066] Figure 3 shows the microstructure at point B in Figure 1 magnified.

[0067] Figure 4 shows a schematic diagram of the mold for the flat plate friction testing machine. Detailed Implementation

[0068] The following will further explain and illustrate the alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication processing performance and its manufacturing method according to specific embodiments of the present invention. However, this explanation and illustration do not constitute an undue limitation on the technical solution of the present invention.

[0069] Examples 1-7 and Comparative Example 1

[0070] The alloyed hot-dip galvanized steel sheets of Examples 1-7 of this invention were all prepared by the following method:

[0071] (1) Obtaining the substrate: The substrate used in Examples 1-7 and Comparative Example 1 of this invention is DC53 (Baosteel) with a thickness of 0.7 μm.

[0072] Table 1 lists the chemical composition ratios of the substrates used in Examples 1-7 and Comparative Example 1 of this invention.

[0073] Table 1. (The balance is Fe and other unavoidable impurities)

[0074] (2) The substrate is subjected to hot-dip galvanizing, alloying heat treatment and flattening to form an alloyed hot-dip zinc plating layer on the substrate surface.

[0075] Cold-rolled strip steel is hot-dip galvanized by immersing it in molten zinc in a hot-dip galvanizing pot, with a coating thickness of 45 g / m. 2 Then, the steel plate is heated to 500-570℃ in a vertical heat treatment furnace for alloying heat treatment, and then held for 2-8 seconds to allow the steel plate substrate to react and diffuse with liquid zinc, transforming into Fe-Zn intermetallic compounds, thereby forming an alloyed hot-dip galvanized layer on the substrate surface; then, a leveling process is performed using leveling rollers.

[0076] Table 2-1 lists the chemical composition of the zinc liquid in Examples 1-7 and Comparative Example 1 of the present invention.

[0077] Table 2-1. (wt%, balance Zn and unavoidable impurities)

[0078] Table 2-2 lists the chemical composition content and process parameters of the alloyed hot-dip galvanized layer of the alloyed hot-dip galvanized steel sheets of Examples 1-7 and Comparative Example 1 of the present invention.

[0079] Table 2-2.

[0080] Note: (1) In Table 2, the mass percentage of Fe in the Zn-Fe alloy phase was determined by X-ray fluorescence spectroscopy; (2) In Table 2, the mass percentage of Al, Bi, Co, Ni, and Sn in the alloyed hot-dip galvanized layer was determined by inductively coupled plasma optical emission spectroscopy / mass spectrometry (ICP-OES / MS); (3) The "area percentage of the zinc-iron alloy crystallization region" in Table 2 was obtained by randomly selecting 1 cm from the photograph. 2 The region is determined by identifying the platform region through image processing programs and calculating its area proportion.

[0081] (3) A water-based treatment agent is used to treat the surface of the alloyed hot-dip galvanized layer to obtain a composite nanostructure treatment layer.

[0082] Water-based treatment agents consist of a first substance that provides metallic elements and a second substance that provides non-metallic elements.

[0083] The first substance providing the metallic element is selected from at least one of the following: lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, cerium chloride, cerium sulfate, cerium nitrate, sodium tungstate, ammonium tungstate, potassium tungstate, sodium molybdate, ammonium molybdate, potassium molybdate, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum acetate, sodium aluminate, sodium fluorotitanate, potassium fluorotitanate, manganese nitrate, copper nitrate, barium nitrate, copper sulfate, calcium nitrate, calcium acetate, calcium sulfate, magnesium sulfate, magnesium citrate, and magnesium lactate.

[0084] The second substance providing the nonmetallic element is selected from at least one of the following: boric acid, sodium borate, ammonium borate, 3,4,5-trihydroxybenzoic acid, ethylenediaminetetraacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, tannic acid, cysteine, mercaptoacetic acid, mercaptoethanol, mercaptoethanol, polyethyleneimine, glycine, aspartic acid, ammonia, ethanolamine, propanolamine, isopropanolamine, ethylsilanol, and propylenesilanol.

[0085] The water-based treatment agent consists of a first substance, a second substance, and water.

[0086] Water-based treatment agents are applied by roller coating, spraying, or immersion, and then dried into a film by blowing or drying to prepare coiled steel.

[0087] Comparative Example 1 used the same substrate as the embodiment of the present invention and performed steps (1) and (2), but did not perform step (3).

[0088] Table 3 lists the composition and coating process of the water-based treatment agent for alloyed hot-dip galvanized steel sheets of Examples 1-7 and Comparative Example 1 of the present invention. The values ​​in parentheses after the components are the mass percentages of the components in the water-based treatment agent.

[0089] Table 3.

[0090] Table 4 lists the characteristics of the composite nanostructure treatment layer of the alloyed hot-dip galvanized steel sheets of Examples 1-7 and Comparative Example 1 of the present invention.

[0091] Table 4.

[0092] Note: (1) The equivalent sphere radius of the nanoparticles was observed and measured using a high-resolution scanning electron microscope; (2) The metal species of the metal-based compounds were detected using energy dispersive spectroscopy (EDS); (3) The proportion of sheet-like nanoparticles to all nanoparticles was expressed using the ratio of the number of nanoparticles per unit area (e.g., 1 mm²). 2 (3) The percentage of particles is evaluated; (4) The percentage of metal elements in the mass of the nanofilm is detected by micro-area elemental quantitative scanning; (5) The percentage of nanoparticles in the composite nanostructure treatment layer is determined by transmission electron microscopy (TEM), X-ray diffraction (XRD), and atomic absorption spectrometry (AAS) to clarify the composition and volume percentage of nanoparticles and film, and then the mass percentage is calculated by combining the composition density and volume percentage.

[0093] The alloyed hot-dip galvanized steel sheets of Examples 1-7 and Comparative Example 1 were processed to a size of 400*25.4mm, and the edge burrs were effectively removed.

[0094] Figure 1 shows the microstructure of the composite nanostructure treatment layer on the surface of the alloyed hot-dip galvanized steel sheet of Example 3 of the present invention.

[0095] Figure 2 shows the microstructure at point A in Figure 1 magnified.

[0096] Figure 3 shows the microstructure at point B in Figure 1 magnified.

[0097] As shown in Figures 1 and 2, the composite nanostructure treatment layer effectively covers the zinc-iron alloy crystallization region A.

[0098] As shown in Figures 1 and 3, the composite nanostructure treatment layer also forms an effective coverage in the randomly distributed platform region B.

[0099] In this invention, zinc-iron alloy crystallization region A is a zinc-iron alloy crystal structure, and platform region B is a physical structure formed by flattening the crystal structure after it has been leveled.

[0100] To verify the implementation effect of the embodiments of the present invention, the friction performance of alloyed hot-dip galvanized steel sheets of Examples 1-7 and Comparative Example 1 was tested using a flat plate friction testing machine as shown in Figure 4. The friction performance of the steel sheets was evaluated at room temperature (25℃) and high temperature (65℃), respectively. The pressure load was controlled at 2500N and the test distance was controlled at 100mm. The performance test results are recorded in Table 5.

[0101] The coefficient of friction of a flat plate can effectively simulate the surface forming performance of materials during automotive stamping, and is mainly evaluated through the coefficient of friction. The lower the initial coefficient of friction, the better the surface lubrication; the average coefficient of friction from the 2nd to the 10th time can be used to characterize the surface wear performance, and the lower the average coefficient of friction, the better the wear resistance.

[0102] Table 5 lists the performance test results of Examples 1-7 and Comparative Example 1 of the present invention.

[0103] Table 5.

[0104] As can be seen from Table 5 above, Examples 1-7 all exhibited good performance in the frictional performance evaluation at both room temperature and 65°C, with their flat plate friction coefficients all below 0.12, indicating a significant optimization of their surface stamping lubrication performance. Furthermore, Examples 1, 3, and 4 demonstrate that the effective composite nanostructures imparted to the surface through typical coating treatments such as spraying, dipping, and roller coating all achieved excellent surface frictional performance. The preparation of composite nanostructures can have broader process adaptability.

[0105] In contrast, in Comparative Example 1, without the composite nanostructure treatment layer, the surface friction coefficient was consistently above 0.3. This clearly demonstrates the influence of the composite nanostructure treatment layer in this invention on the lubrication performance of surface stamping.

[0106] It should be noted that the embodiments listed above are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and similar changes or modifications made thereto are those that can be directly derived or easily conceived by those skilled in the art from the content disclosed in the present invention, and should all fall within the protection scope of the present invention.

Claims

1. An alloyed hot-dip galvanized steel sheet with excellent stamping and lubrication processing performance, comprising a substrate, the surface of which has an alloyed hot-dip galvanized layer; characterized in that: The surface of the alloyed hot-dip zinc-plated layer is covered with a composite nanostructure treatment layer; the composite nanostructure treatment layer includes nanoparticles and nanofilms. The nanoparticles are randomly distributed on the surface of the alloyed hot-dip galvanized layer, at least in a sheet-like form.

2. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The alloyed hot-dip galvanized layer includes a Zn-Fe alloy phase, and the mass percentage of Fe element in the Zn-Fe alloy phase of the alloyed hot-dip galvanized layer is 9%-11.5%.

3. The alloyed hot-dip galvanized steel sheet as described in claim 2, characterized in that, The alloyed hot-dip galvanized layer further contains Al and at least one of Bi, Co, Ni, and Sn elements; preferably, the mass percentage of Al in the alloyed hot-dip galvanized layer is 0.03%-0.2%; preferably, the total mass percentage of Bi, Co, Ni, and Sn elements in the alloyed hot-dip galvanized layer does not exceed 0.1%.

4. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The surface of the alloyed hot-dip galvanized layer has zinc-iron alloy crystalline regions and randomly distributed platform regions. Within a unit area of ​​the surface, the area of ​​the zinc-iron alloy crystalline regions accounts for 15%-85%.

5. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The equivalent sphere radius of the nanoparticles is 40-400 nm.

6. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The sheet-like nanoparticles contain a metal-based compound, wherein the metal in the metal-based compound is selected from at least one of Ca, Cu, K, Al, Na, Fe, Zn, and Mg.

7. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, Within a unit area of ​​the surface, sheet-like nanoparticles account for 50%-90% of all nanoparticles.

8. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The nanofilm comprises metallic and non-metallic elements; the metallic element is selected from at least one of La, Zn, Mn, Ce, Fe, W, and Mo; and the non-metallic element is selected from at least one of S, O, C, B, and H.

9. The alloyed hot-dip galvanized steel sheet as described in claim 8, characterized in that, The non-metallic element combines with the metallic element through at least one group selected from boron-oxygen bonds, carboxyl groups, and thiol groups to form the nanofilm.

10. The alloyed hot-dip galvanized steel sheet as described in claim 8, characterized in that, The metal element accounts for 25%-80% of the mass percentage of the nanofilm.

11. The alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, The nanoparticles account for 40%-80% of the mass percentage in the composite nanostructure treatment layer.

12. The method for manufacturing alloyed hot-dip galvanized steel sheet as described in claim 1, characterized in that, Including the following steps: The substrate is subjected to hot-dip galvanizing, alloying heat treatment and flattening to form the alloyed hot-dip zinc plating layer on the substrate surface; The alloyed hot-dip galvanized layer is surface-treated with a water-based treatment agent to obtain the composite nanostructure treatment layer.

13. The manufacturing method as described in claim 12, characterized in that, The water-based treatment agent comprises a first substance providing a metallic element and a second substance providing a non-metallic element; wherein the mass ratio of the first substance and the second substance is 1:1.5 to 1:15; preferably, the first substance is selected from: lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, cerium chloride, cerium sulfate, cerium nitrate, sodium tungstate, ammonium tungstate, potassium tungstate, sodium molybdate, ammonium molybdate, potassium molybdate, aluminum sulfate, aluminum chloride, aluminum nitrate, aluminum acetate, sodium aluminate, sodium fluorotitanate, potassium fluorotitanate, manganese nitrate, copper nitrate, barium nitrate. The second substance is selected from at least one of copper sulfate, calcium nitrate, calcium acetate, calcium sulfate, magnesium sulfate, magnesium citrate, and magnesium lactate; preferably, the second substance is selected from at least one of boric acid, sodium borate, ammonium borate, 3,4,5-trihydroxybenzoic acid, ethylenediaminetetraacetic acid, citric acid, oxalic acid, salicylic acid, tartaric acid, tannic acid, cysteine, mercaptoacetic acid, mercaptoethanol, mercaptoethanol, polyethyleneimine, glycine, aspartic acid, ammonia, ethanolamine, propanolamine, isopropanolamine, ethylsilanol, and propylenesilanol.

14. The manufacturing method as described in claim 12, characterized in that, The alloying heat treatment temperature is 500-570℃.

15. The manufacturing method as described in claim 12, characterized in that, The water-based treatment agent is applied to the alloyed hot-dip galvanized layer by roller coating, spraying or immersion coating for surface treatment, and then dried to form a film by blowing or drying.

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