High-temperature oxidation-resistant high-speed steel wear-resistant coating composite material and preparation method thereof

Abstract

The application discloses a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material and a preparation method thereof. The preparation method comprises the following steps: after one-stage ball milling of metal raw materials and a forming agent, ceramic additives are added for two-stage ball milling, and then spray granulation and sintering are sequentially performed to obtain coating raw material powder; the coating raw material powder is cladded on the surface of a pretreated base material, and then aging tempering treatment is performed, and the high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material is obtained. The material is based on the synergistic effect among components, and through the addition of oxidation-resistant elements, a dense oxide film is formed on the surface of the material, ion diffusion and migration are hindered, the oxidation resistance of the coating is greatly improved, the ceramic additives can inhibit grain growth and play a fine-grain strengthening role, and on the other hand, the ceramic additives can be used as hard phase particles to enhance the wear resistance of the whole coating. The preparation method adopts a three-step process, the production process is short, automation and industrialization are easy to realize, the thickness of the obtained coating is controllable, and the method has the advantages of high yield and fault tolerance.

Description

Technical Field

[0001] This invention relates to a wear-resistant coating composite material, specifically to a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material and its preparation method, belonging to the field of metal surface treatment technology. Background Technology

[0002] Wear is one of the main failure modes of modern industrial parts. International tribology research generally considers that approximately 80% of damaged parts are caused by various forms of wear, demonstrating the enormous economic losses caused by wear. Wear at high temperatures is particularly severe, being a complex process involving multiple factors such as oxide layer growth and peeling, matrix tempering and softening, changes in microstructure, and transformation of wear mechanisms. It has a significant negative impact on critical sectors such as military, aerospace, steel, and automotive. Improving the high-temperature wear resistance of industrial parts focuses on enhancing the material's oxidation resistance and mitigating high-temperature softening. Applying a certain thickness of anti-oxidation and wear-resistant coating to the workpiece surface using laser cladding or plasma cladding techniques can effectively reduce wear and significantly extend workpiece life.

[0003] Patent CN114574852 provides a high-temperature gradient coating composed of a base layer, a transition layer, and a wear-resistant layer, which has high hardness, good hot hardness, good toughness, and excellent high-temperature wear resistance. Although it has excellent wear resistance, its high-temperature oxidation resistance is poor, making it unsuitable for working conditions with high requirements for oxidation resistance. Moreover, it requires the preparation of multiple layers of coating, which is complicated, has a long process, and low efficiency. Summary of the Invention

[0004] To address the problems existing in the prior art, the first objective of this invention is to provide a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material. This composite material is based on the synergistic effect between its components, utilizing in-situ generated micro-nano intermetallic compounds for strong hardening. By adding antioxidant elements such as Cr, Al, and Si, a dense oxide film is formed on the material surface, hindering ion diffusion and migration, and significantly improving the coating's oxidation resistance. The additional ceramic additives can significantly inhibit grain growth, playing a role in grain refinement and strengthening, and can also act as hard phase particles, further enhancing the overall wear resistance of the coating.

[0005] The second objective of this invention is to provide a method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material. This method adopts a "three-step" process, which has a short production process, is easy to automate and industrialize, and the thickness of the resulting coating is controllable. It has the advantages of high yield and fault tolerance, and only one layer of coating is needed to achieve both oxidation resistance and high wear resistance.

[0006] To achieve the above-mentioned technical objectives, this invention provides a method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material. The method involves first-stage ball milling of metallic raw materials, including Co, Cr, W, Mo, Ni, and aluminum-chromium alloys, with a forming agent, followed by second-stage ball milling with ceramic additives. The mixture is then sequentially spray-granulated and sintered to obtain coating raw material powder. This powder is then fused onto the surface of a pretreated substrate and subjected to aging and tempering treatment to obtain the final product. The ceramic additives include aluminum nitride, titanium nitride, and silicon nitride.

[0007] The preparation method provided by this invention improves the surface activation energy of raw materials by homogenizing them through multi-stage ball milling. It obtains alloy powder with good sphericity, good flowability, and certain strength through spray granulation and subsequent sintering, which is easy to clad. The intermetallic compounds generated in situ through aging treatment endow the coating with excellent high-temperature hardness and wear resistance. In addition, solid solution strengthening and external micron-particle second phase composite strengthening further enhance the oxidation resistance of the material while ensuring its excellent high-temperature mechanical properties.

[0008] As a preferred technical solution, the composite material comprises the following components by mass percentage: Co 10-20%, Cr 8-12%, W 5-9%, Mo 4-8%, Ni 4-8%, Si 1-3%, aluminum-chromium alloy 4-8%, aluminum nitride 1-2%, titanium nitride 1-2%, silicon nitride 0.5-1%, with the balance being Fe.

[0009] As a preferred embodiment, the composite material also includes unavoidable impurities, with a total impurity content of ≤0.1%.

[0010] As a preferred technical solution, the pure element powder in the raw material is a commercially available high-purity powder with a purity of not less than 99.95%.

[0011] As a preferred technical solution, the aluminum-chromium alloy powder contains 50-70% Al by mass. Using aluminum-chromium alloy powder as the Al source can effectively reduce aluminum oxidation during ball milling and avoid potential safety hazards caused by highly active powders during ball milling.

[0012] As a preferred technical solution, the molding agent is at least one of paraffin, PEG and PVB.

[0013] As a preferred technical solution, the amount of the molding agent added accounts for 2 to 4% of the raw material mass percentage.

[0014] As a preferred technical solution, both the single-stage ball mill and the two-stage ball mill are wet ball mills, and the ball milling media are at least one of ethanol, propanol and petroleum ether.

[0015] As a preferred technical solution, both the one-stage ball milling and the two-stage ball milling are carried out under a protective atmosphere.

[0016] As a preferred technical solution, the conditions for the one-stage ball mill are: a ball-to-material ratio of 4 to 8:1, a ball milling speed of 200 to 250 r / min, and a time of 24 to 36 h.

[0017] As a preferred technical solution, the conditions for the two-stage ball milling are: a ball-to-material ratio of 4 to 8:1, a ball milling speed of 200 to 250 r / min, and a time of 36 to 48 h.

[0018] As a preferred technical solution, the spray granulation method is pressure spray drying granulation or centrifugal spray drying granulation, with the following conditions: slurry solid ratio of 45-55%, inlet temperature of 190-210℃, outlet temperature of 80-95℃, and granulation particle size of 50-200μm.

[0019] As a preferred technical solution, the sintering is one of vacuum sintering, hydrogen sintering, and nitrogen sintering.

[0020] As a preferred technical solution, the sintering conditions are: temperature of 850-900℃, holding time of 1-3h, and cooling to room temperature with the furnace.

[0021] As a preferred technical solution, the substrate is low alloy steel; the pretreatment process of the substrate is as follows: grinding to remove rust and oxide film from the surface of the substrate, cleaning and drying.

[0022] As a preferred technical solution, the cladding method is laser cladding or plasma synchronous powder feeding cladding.

[0023] As a preferred technical solution, the laser cladding process is as follows: the substrate is preheated at 100-200°C for 20-40 minutes, the laser power is 1000-2000W, the scanning speed is 400-800mm / min, and the overlap rate is 40-60%.

[0024] As a preferred technical solution, the plasma synchronous powder feeding and cladding process is as follows: the substrate is preheated at 100-200℃ for 20-40 minutes, the main arc current is 180-220A, and the scanning speed is 50-100mm / min; the conditions for the aging tempering treatment are: temperature 550-650℃, time 1-2 hours.

[0025] The present invention also provides a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material, obtained by any of the preparation methods described above, comprising an Fe matrix and an in-situ generated intermetallic compound.

[0026] As a preferred technical solution, the intermetallic compound includes A7B6 type, AB2 type and AB3 type intermetallic compounds.

[0027] The coating composite material provided by this invention utilizes the synergistic effect of multiple composite strengthening methods, including in-situ generation of micro-nano intermetallic compounds, solid solution strengthening, fine grain strengthening generated by the addition of a second phase, and dispersion strengthening, to generate intermetallic compounds of types A7B6, AB2, and AB3. These intermetallic compounds can strongly hinder grain boundary movement and dislocation motion, thereby endowing the material with excellent high-temperature mechanical properties and oxidation resistance.

[0028] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0029] 1) The coating composite material provided by this invention is based on the synergistic effect between its components. By adding antioxidant elements such as Cr, Al, and Si, a dense oxide film is formed on the material surface, hindering ion diffusion and migration, and significantly improving the coating's antioxidant performance. The nitride ceramic additives can significantly inhibit grain growth, playing a role in grain refinement and strengthening, and can also act as hard phase particles, further enhancing the overall wear resistance of the coating. In other words, by introducing these three types of nitride micron-sized particles and controlling them in conjunction with intermetallic compounds, synergy can be achieved, thereby further improving the coating performance.

[0030] 2) The preparation method provided by the present invention improves the surface activation energy of the raw materials by multi-stage ball milling under the premise of homogenization. The alloy powder with good sphericity, good fluidity and certain strength is obtained by spray granulation and subsequent sintering. The intermetallic compounds generated in situ by aging treatment endow the coating with excellent high-temperature hardness and wear resistance. In addition, solid solution strengthening and external micron-particle second phase composite strengthening further enhance its oxidation resistance while ensuring the material has excellent high-temperature mechanical properties.

[0031] 3) In the technical solution provided by the present invention, various intermetallic compounds such as (Fe,Co)7(Mo,W)6, Fe2Ti, Ni3Al and Ni3Ti are generated in situ during the aging and tempering process. Compared with carbides, these intermetallic compounds have better anti-aggregation ability and thermal stability. Moreover, they have a coherent / semi-coherent orientation relationship with the iron matrix in the microstructure, which hinders grain boundary movement and dislocation movement, and endows the coating with high hardness, excellent hot hardness and red hardness. It is not easy to soften during long-term high-temperature application, and can ensure excellent high-temperature wear resistance. Attached Figure Description

[0032] Figure 1 The image shows the microstructure of the coating prepared in Example 1;

[0033] Figure 2The image shows the surface morphology of the coating obtained in Example 1 after a tribological test at 800°C.

[0034] Figure 3 SEM images of the surface morphology of H13 hot work die steel after a friction and wear test at 800℃;

[0035] Figure 4 The image shows a cross-sectional SEM image of the coating prepared in Example 1 after oxidation at 800°C for 100 hours. Detailed Implementation

[0036] To better explain and facilitate understanding of the present invention, the technical solutions and effects of the present invention will be described in detail below through the following embodiments.

[0037] Example 1

[0038] Raw materials were prepared according to the designed formula. The following percentages are by mass: 18% Co powder, 10% Cr powder, 8% W powder, 7% Mo powder, 6% Ni powder, 3% Si powder, 7% aluminum-chromium alloy powder, 2% aluminum nitride powder, 1.7% titanium nitride powder, 0.8% silicon nitride powder, with the remainder being Fe and unavoidable impurities. First, the pure elemental powders, aluminum-chromium alloy powder, and 4% paraffin wax were placed in a ball mill and wet-milled for 30 hours. Then, the weighed aluminum nitride, titanium nitride, and silicon nitride powders were added and ball-milled for another 40 hours. Argon gas was introduced for protection during each ball milling process. The ball milling medium was anhydrous ethanol, the ball-to-material ratio was 5:1, and the ball milling speed was 230 r / min. The ball-milled slurry was spray-granulated according to industry-standard methods to obtain powders of 80–150 μm. After vacuum sintering at a maximum temperature of 880℃ for 2 hours, a pre-alloyed powder with good sphericity and excellent flowability was obtained.

[0039] Using 45 steel as the substrate, the substrate was first ground with a grinding wheel to remove surface rust and oxide film, then sanded smooth with sandpaper, and finally cleaned with anhydrous ethanol and dried. Before cladding, the substrate was preheated in a 150℃ vacuum oven for 30 minutes. The coating was prepared using laser cladding technology under high-purity argon protection. The main process parameters were: spot diameter 3mm, laser power 1500W, scanning speed 600mm / min, and overlap rate 50%. Finally, the coating was tempered in a vacuum tempering furnace at 600℃ for 1 hour.

[0040] Example 2

[0041] Raw materials were prepared according to the designed formula. The following percentages are by mass: 14% Co powder, 9% Cr powder, 6% W powder, 5% Mo powder, 6% Ni powder, 2% Si powder, 6% aluminum-chromium alloy powder, 1.5% aluminum nitride powder, 1.4% titanium nitride powder, 0.7% silicon nitride powder, with the remainder being Fe and unavoidable impurities. First, the pure elemental powders, aluminum-chromium alloy powder, and 4% paraffin wax were placed in a ball mill and wet-milled for 30 hours. Then, the weighed aluminum nitride, titanium nitride, and silicon nitride powders were added and ball-milled for another 40 hours. Argon gas was introduced for protection during each ball milling process. The ball milling medium was anhydrous ethanol, the ball-to-material ratio was 5:1, and the ball milling speed was 230 r / min. The ball-milled slurry was spray-granulated according to industry-standard methods to obtain powders of 80–150 μm. After vacuum sintering at a maximum temperature of 860℃ for 2 hours, a pre-alloyed powder with good sphericity and excellent flowability was obtained.

[0042] Using 45 steel as the substrate, the substrate was first ground with a grinding wheel to remove surface rust and oxide film, then sanded smooth, and finally cleaned with anhydrous ethanol and dried. Before cladding, the substrate was preheated in a 150℃ vacuum oven for 30 minutes. The coating was prepared using laser cladding technology under high-purity argon protection. The main process parameters were: spot diameter 3mm, laser power 1400W, scanning speed 600mm / min, and overlap rate 50%. Finally, the coating was tempered in a vacuum tempering furnace at 600℃ for 1 hour.

[0043] Example 3

[0044] Raw materials were prepared according to the designed formula. The following percentages are by mass: 10% Co powder, 8% Cr powder, 5% W powder, 4% Mo powder, 4% Ni powder, 1% Si powder, 4% aluminum-chromium alloy powder, 1% aluminum nitride powder, 1% titanium nitride powder, 0.5% silicon nitride powder, with the remainder being Fe and unavoidable impurities. First, the pure elemental powders, aluminum-chromium alloy powder, and 4% paraffin wax were placed in a ball mill and wet-milled for 32 hours. Then, the weighed aluminum nitride, titanium nitride, and silicon nitride powders were added and ball-milled for another 40 hours. Argon gas was introduced for protection during each ball milling process. The ball milling medium was anhydrous ethanol, the ball-to-material ratio was 5:1, and the ball milling speed was 230 r / min. The ball-milled slurry was spray-granulated according to industry-standard methods to obtain powders of 80–150 μm. After vacuum sintering at a maximum temperature of 850℃ for 2 hours, a pre-alloyed powder with good sphericity and excellent flowability was obtained.

[0045] Using 45 steel as the substrate, the substrate was first ground with a grinding wheel to remove surface rust and oxide film, then sanded smooth with sandpaper, and finally cleaned with anhydrous ethanol and dried. Before cladding, the substrate was preheated in a 150℃ vacuum oven for 30 minutes. The coating was prepared using laser cladding technology under high-purity argon protection. The main process parameters were: spot diameter 3mm, laser power 1200W, scanning speed 500mm / min, and overlap rate 50%. Finally, the coating was tempered in a vacuum tempering furnace at 590℃ for 1 hour.

[0046] Example 4

[0047] Raw materials were prepared according to the designed formula. The following percentages are by mass: 17% Co powder, 11% Cr powder, 7% W powder, 7% Mo powder, 8% Ni powder, 2% Si powder, 8% aluminum-chromium alloy powder, 1.6% aluminum nitride powder, 1.2% titanium nitride powder, 0.6% silicon nitride powder, with the remainder being Fe and unavoidable impurities. First, the pure elemental powders, aluminum-chromium alloy powder, and 4% paraffin wax were placed in a ball mill and wet-milled for 30 hours. Then, the weighed aluminum nitride, titanium nitride, and silicon nitride powders were added and ball-milled for another 40 hours. Argon gas was introduced for protection during each ball milling process. The ball milling medium was anhydrous ethanol, the ball-to-material ratio was 5:1, and the ball milling speed was 230 r / min. The ball-milled slurry was spray-granulated according to industry-standard methods to obtain powders of 80–150 μm. After vacuum sintering at a maximum temperature of 870℃ for 2 hours, a pre-alloyed powder with good sphericity and excellent flowability was obtained.

[0048] Using 45 steel as the substrate, the substrate was first ground with a grinding wheel to remove surface rust and oxide film, then sanded smooth with sandpaper, and finally cleaned with anhydrous ethanol and dried. Before cladding, the substrate was preheated in a 150℃ vacuum oven for 30 minutes. The coating was prepared using plasma cladding technology under high-purity argon protection. The main process parameters were: main arc current of 200A, scanning speed of 70mm / min, and overlap rate of 50%. Finally, the coating was tempered in a vacuum tempering furnace at 600℃ for 1 hour.

[0049] Comparative Example 1

[0050] Compared with Example 1, the only difference is that no nitride powder is added. That is, the raw material formula is: 18% Co powder, 10% Cr powder, 8% W powder, 7% Mo powder, 6% Ni powder, 3% Si powder, 7% aluminum chromium alloy powder, and the remainder is Fe and unavoidable impurities.

[0051] Comparative Example 2

[0052] Compared with Example 1, the only difference is that the raw material formula is: 18% Co powder, 8% W powder, 7% Mo powder, 2% aluminum nitride powder, 1.7% titanium nitride powder, 0.8% silicon nitride powder, and the remainder is Fe and unavoidable impurities.

[0053] Comparative Example 3

[0054] Compared with Example 1, the only difference is that the raw material formula is: 8% Co powder, 10% Cr powder, 4% W powder, 3% Mo powder, 6% Ni powder, 3% Si powder, 7% aluminum chromium alloy powder, 2% aluminum nitride powder, 1.7% titanium nitride powder, 0.8% silicon nitride powder, and the remainder is Fe and unavoidable impurities.

[0055] Comparative Example 4

[0056] Compared with Example 1, the only difference is that the laser power is 900W and the scanning speed is 350mm / min.

[0057] Comparative Example 5

[0058] Compared with Example 1, the only difference is that the laser power is 2100W and the scanning speed is 900mm / min.

[0059] Comparative Example 6

[0060] Compared with Example 4, the only difference is that the main arc current is 230A and the scanning speed is 50-110mm / min.

[0061] The coating samples obtained in the above examples and comparative examples were subjected to microhardness, oxidation weight gain, and high-temperature tribological wear tests under the same conditions. The microhardness of the coating sample cross-section at room temperature was measured using a Buehler ER510 microhardness tester with a load of 200g and a loading time of 15s. The average value of 10 measurements was taken as the coating hardness value. The high-temperature wear performance of the coating was tested using an HT-1000 high-temperature tribological wear testing machine. The grinding balls were 5mm diameter silicon nitride balls, the load was 25N, the frequency was 8Hz, the friction time was 30min, and the experimental temperature was 800℃. The oxidation resistance of the samples at 800℃ was tested using the cyclic oxidation weight gain method, with weight gain as the indicator. The relevant results are shown in Table 1.

[0062] Table 1. Results of hardness, oxidation weight gain, and wear rate for the examples and comparative examples.

[0063]

[0064] Comparing the results of the examples and comparative examples, it can be seen that compared with the 45 steel substrate, the wear rate of Examples 1-4 is significantly reduced, while also exhibiting excellent oxidation resistance. This indicates that the coating strengthened by the multiple strengthening mechanisms of the present invention possesses excellent high-temperature wear resistance and high-temperature oxidation resistance. Comparative Examples 1-3 show that when Cr, Si, Al, and Ni elements are lacking, or nitride powder is not added, or the content of elements such as Co, W, and Mo is reduced, a significant decrease in oxidation resistance or weakened wear resistance occurs. In other words, optimal performance can only be obtained when the formulation composition and process parameters are within the design range of the present invention.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method of making a high temperature oxidation resistant high speed steel wear resistant coating composite material, characterized by: The raw material comprises a metal raw material and ceramic additives; the metal raw material is subjected to one-stage ball milling with a forming agent, and then the ceramic additives are added for two-stage ball milling, and then the coating raw material powder is obtained through spray granulation and sintering in sequence; the coating raw material powder is cladded on the surface of a pretreated base material, and then the coating is obtained through aging and tempering treatment. The raw material comprises the following components in percentage by mass: Co 10-20%, Cr 8-12%, W 5-9%, Mo 4-8%, Ni 4-8%, Si 1-3%, aluminum-chromium alloy 4-8%, aluminum nitride 1-2%, titanium nitride 1-2%, silicon nitride 0.5-1%, and the rest is Fe and unavoidable impurities.

2. The preparation method of high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The forming agent is at least one of paraffin, PEG and PVB; and the adding amount of the forming agent is 2-4% of the raw material in percentage by mass.

3. The preparation method of high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The one-stage ball milling and the two-stage ball milling are uniform wet ball milling, and the ball milling medium is at least one of ethanol, propanol and petroleum ether; the one-stage ball milling is carried out under the following conditions: ball-to-material ratio 4-8:1, ball milling speed 200-250 r / min, and time 24-36 h; and the two-stage ball milling is carried out under the following conditions: ball-to-material ratio 4-8:1, ball milling speed 200-250 r / min, and time 36-48 h.

4. The method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The spray granulation is carried out by pressure or centrifugal spray drying granulation under the following conditions: slurry solid ratio 45-55%, inlet temperature 190-210 DEG C, outlet temperature 80-95 DEG C, and granulation particle size 50-200 μm.

5. The method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The sintering is one of vacuum sintering, hydrogen sintering and nitrogen sintering; and the sintering is carried out under the following conditions: temperature 850-900 DEG C, holding time 1-3 h, and cooling to room temperature in the furnace.

6. The method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The base material is low-alloy steel; and the pretreatment process of the base material comprises the following steps: polishing to remove rust and oxide film on the surface of the base material, cleaning and drying.

7. The method for preparing a high-temperature oxidation-resistant high-speed steel wear-resistant coating composite material according to claim 1, characterized in that: The cladding is carried out by laser cladding or plasma synchronous powder feeding cladding; the laser cladding is carried out by the following process: preheating the base material at 100-200 DEG C for 20-40 min, laser power 1000-2000 W, scanning speed 400-800 mm / min, and overlap rate 40-60%; the plasma synchronous powder feeding cladding is carried out by the following process: preheating the base material at 100-200 DEG C for 20-40 min, main arc current 180-220 A, and scanning speed 50-100 mm / min; and the aging and tempering treatment is carried out under the following conditions: temperature 550-650 DEG C, and time 1-2 h.

8. A high temperature oxidation resistant high speed steel wear resistant coating composite material characterized by: The coating is obtained by the preparation method of any one of claims 1-7, and comprises a Fe base and in-situ generated intermetallic compounds.

9. The high temperature oxidation resistant high speed steel wear resistant coated composite material of claim 8, wherein: The intermetallic compounds comprise A7B6-type, AB2-type and AB3-type intermetallic compounds.

Images