Rust-proof saw blade and saw blade rust-proof treatment method

Abstract

According to the rust-proof saw blade and the saw blade rust-proof treatment method provided by the invention, the matrix structure of the frame saw blade is uniform, the internal stress is low and the chemical stability is high through adding Cu and Ni elements and heat treatment optimization; a composite anti-rust system which is compact in structure and high in binding force is constructed on the surface of the frame saw blade, and a frame saw blade base body treated through the method has excellent mechanical performance and also has long-acting anti-rust capacity.

Description

Technical Field

[0001] This invention relates to the field of high-performance metal material manufacturing, specifically to a rust-proof substrate for frame saw blades and a rust-proof treatment method thereof. Background Technology

[0002] Frame saw blades, as important metal cutting tools, are widely used in machining, construction decoration, and woodworking. However, traditional frame saw blades are prone to corrosion during use, especially in humid environments or when exposed to corrosive media. Alloy steel, a commonly used saw blade material, possesses good strength and toughness, but its rust resistance is relatively insufficient. Existing technologies typically employ surface coating with rust-preventive oil to improve rust resistance, but these methods suffer from problems such as short-lived rust prevention and easy wear and peeling. Therefore, there is an urgent need for a substrate rust-preventive treatment method for frame saw blades that can significantly improve rust resistance while maintaining the excellent mechanical properties of the substrate. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rust-proof saw blade and a rust-proof treatment method for the saw blade, which can significantly improve the rust-proof performance of frame saw blades.

[0004] A method for rust prevention treatment of saw blades includes the following steps: (1) Smelting of the base material of the frame saw blade: The raw materials are proportioned by mass fraction as follows: C is 0.75%; Cr is 1.10%; Si is 0.25%; Mn is 0.50%; Cu is 0.40%; Ni is 0.15%; P is 0.01%-0.03%; S is 0.01%-0.03%; and the balance is Fe. The raw materials are smelted in a vacuum induction furnace, cast into Φ150mm round billets, and then hot rolled into 1.2mm thick strip steel.

[0005] (2) Quenching and tempering treatment The smelted frame saw blade matrix was placed in a heating furnace and heated to 700-800℃ at a heating rate of 80-90℃ / hour, and held for 60 minutes to ensure complete and uniform austenitization. It was then cooled using a 200-250℃ salt bath. The quenched matrix was then subjected to segmented tempering. In the first stage (stress-relief tempering), the matrix was heated to 300-350℃ at a heating rate of 50℃ / hour and held for 1 hour to decompose the unstable martensite and initially release the quenching stress. In the second stage (high-temperature tempering), the matrix was further heated to 550-600℃ at a heating rate of 70℃ / hour, the final tempering temperature, and held for 5-6 hours to fully transform the microstructure into uniform and stable tempered sorbite. The frame saw blade was then uniformly cooled to room temperature.

[0006] (3) Surface pretreatment After quenching and tempering, immerse the frame saw blade substrate in an alkaline degreasing solution for 5-8 minutes; then rinse with deionized water for 20 minutes to prevent alkali residue; then sandblast with 80-100 mesh alumina sand; and finally soak in hydrochloric acid solution for 30-60 seconds.

[0007] (4) Chemical passivation treatment The passivation solution comprises the following components by mass percentage: nitric acid (HNO3) 8–12 wt%, chromic anhydride (CrO3) 2–4 wt%, sodium silicate (Na2SiO3) 0.5–1 wt%, sodium fluoride (NaF) 0.05–0.10 wt%, with the balance being deionized water. The pre-treated frame saw blade substrate is immersed in the passivation solution for 10–20 minutes, with the treatment temperature controlled at 50–60°C and the pH maintained within the range of 1.0–2.0. After treatment, the frame saw blade substrate is removed and thoroughly rinsed with deionized water to remove any residual passivation solution components. It is then dried under 60°C hot air for 10 minutes to ensure the stability of the film structure and prevent secondary oxidation.

[0008] (5) High-temperature diffusion anti-rust coating treatment The chemically passivated frame saw blade substrate is placed in a closed tube furnace and heated under a nitrogen protective atmosphere. The heating rate is controlled at 5-8℃ / min. When the furnace temperature rises to 520-550℃, it is held at that temperature. Then, it is cooled with the furnace to below 150℃ and removed from the furnace, and placed at 25-30℃.

[0009] (6) Surface sealing treatment The sealant is a fluorosilane-containing nanocomposite liquid, composed of the following components by mass percentage: fluorosilane (FAS-17 or KH-132) 3-5 wt%; nano-SiO2 sol 2-3 wt%; isopropanol 20-25 wt%; deionized water balance, with pH controlled at 4.0-5.5. The frame saw blade substrate, after high-temperature diffusion treatment, is immersed in the sealant liquid for 2-3 minutes to ensure the liquid fully wets the film surface and micropores. The frame saw blade substrate is then removed and dried and cured at 110-130℃ for 25-35 minutes to form a hydrophobic sealing layer. Drying and curing can be performed on a rack in a drying equipment such as an oven.

[0010] The alkaline degreasing solution described in step (3) above has the following composition by mass percentage: NaOH: 2-4 wt%; Na2CO3: 1-2 wt%; Na3PO4: 1-2 wt%; the remainder is deionized water.

[0011] In step (3) above, the frame saw blade substrate is immersed in an alkaline degreasing solution for 5-8 minutes at a temperature of 60-70℃.

[0012] The above step (3) involves soaking in a hydrochloric acid solution, wherein the mass fraction of the hydrochloric acid solution is 10-15 wt%.

[0013] The chemical passivation treatment described in step (4) above, wherein the passivation solution treatment temperature is 50-60℃.

[0014] The high-temperature diffusion anti-rust layer treatment in step (5) above, the heat preservation time is 1-2 hours.

[0015] In the high-temperature diffusion rust-preventive layer treatment described in step (5) above, the nitrogen protective atmosphere is a nitrogen atmosphere with a volume fraction ≥ 99.99%. The surface sealing treatment described in step (6) above uses nano-SiO2 sol with a particle size of 20-40 nm. 20-40 nm SiO2 particles can construct a nanoscale rough structure on the coating surface, maintaining the original appearance of the substrate and preventing it from becoming cloudy due to the addition of particles. If the size is too small, the resulting rough structure is not significant enough, and the effect of enhancing hydrophobicity is insufficient; if the size is too large, it leads to particle aggregation and sedimentation, resulting in an uneven coating.

[0016] The surface sealing treatment described in step (6) above, where the pH value is controlled at 4.0-5.5, uses acetic acid to adjust the pH value. Maintaining the pH value at 4.0-5.5 (weakly acidic range) is crucial in the entire process, affecting whether the fluorosilane can be effectively hydrolyzed and form a stable, dense hydrophobic coating. If the pH value is too high (alkaline), the hydrolysis rate will be too fast, causing a large number of fluorosilane molecules to rapidly transform into silanols in the solution. These molecules will quickly connect with each other, forming large clusters or even gel precipitation, thus losing their effectiveness and failing to form a uniform film on the substrate. If the pH value is too low (strongly acidic), although it also catalyzes hydrolysis, it may be too vigorous and may adversely affect the stability of the substrate metal or nano-SiO2 sol. Acetic acid is used to adjust the pH because it is a weak organic acid that partially ionizes in water, providing H+. + The presence of ions in this relatively mild acidic environment prevents fluorosilanes from hydrolyzing too quickly. Using strong acids (such as hydrochloric acid or sulfuric acid) will cause them to completely ionize, producing a large amount of H+. + The hydrolysis reaction is too violent and rapid. Acetic acid provides a buffer reaction environment, allowing fluorosilane molecules sufficient time to be uniformly adsorbed and arranged on the substrate and the surface of nano-SiO2 particles, thereby forming a high-quality film.

[0017] This invention first quenches the martensite to obtain high strength, and then tempers it to transform it into stable tempered troostite. The tempering process of this invention can effectively release these stresses, significantly reduce stress corrosion sensitivity, and result in a uniform matrix structure, low internal stress, high chemical stability, fewer defects, and better corrosion resistance.

[0018] This invention utilizes chemical passivation treatment on the substrate of a frame saw blade, which forms a dense oxide film rich in chromium and nickel on the surface of the substrate, thereby improving its rust resistance. The passivation solution is a composite acidic passivation solution, whose components, by mass percentage, include: nitric acid (HNO3), chromic anhydride (CrO3), sodium silicate (Na2SiO3), sodium fluoride (NaF), and the balance being deionized water. During the chemical passivation treatment, the pre-treated frame saw blade substrate is immersed in the passivation solution, with the treatment temperature controlled at 50–60°C, the treatment time at 10–20 minutes, and the pH value of the system maintained within the range of 1.0–2.0. Under these conditions, a redox reaction occurs on the surface of the saw blade substrate, causing metal ions to interact with the components in the passivation solution. The reaction mechanism is as follows: Fe 2+ +Cr 6+ →Fe 3+ +Cr 3+ During the reaction, Cr 3+ and SiO3 in solution 2- Synergistic deposition forms a Cr-Si composite oxide film on the substrate surface, exhibiting excellent density and adhesion. After treatment, the frame saw blade substrate is removed and thoroughly rinsed with deionized water to remove residual passivation solution components; subsequently, it is dried under 60°C hot air for 10 minutes to ensure film structure stability and prevent secondary oxidation.

[0019] In this invention, the high-temperature diffusion rust-preventive layer treatment utilizes thermal diffusion to cause elements such as Cu and Ni in the substrate to migrate and accumulate on the surface, thereby forming a Cu-Ni alloyed diffusion layer under the passivation film to further enhance the material's corrosion resistance and film bonding strength. Specifically, the chemically passivated frame saw blade blank is placed in a closed tube furnace and heated under a high-purity nitrogen atmosphere (volume fraction ≥99.99%). The heating rate is controlled at 5℃ / min, and when the furnace temperature reaches 520–550℃, it is maintained at a constant temperature for 1–2 hours to promote element diffusion. Within this temperature range, Cu and a small amount of Ni elements accumulate in the surface region under thermal drive and interdiffused with the matrix ferrite to form a Cu-Mi solid solution layer, creating a Cu-Mi alloyed rust-preventive diffusion layer with good adhesion. This layer has a dense structure and forms a continuous transition structure with the passivation film.

[0020] Its reaction can be represented as: Cu + Ni → Cu-Ni (alloy layer) After the treatment is completed, the workpiece is cooled to below 150°C in the furnace and then removed to prevent surface oxidation. Through this high-temperature diffusion treatment step, a composite gradient structure of "Cu-Ni alloy layer / Cr-Si passivation film / base steel" is formed on the surface of the frame saw blade, which significantly improves the resistance to salt spray corrosion and wear resistance, and provides a stable interface basis for subsequent sealing treatment.

[0021] Compared with the prior art, the present invention has the following advantages: (1) The present invention optimizes the matrix structure by heat treatment to make it uniform, with low internal stress and high chemical stability. Then, through multiple synergistic treatments such as surface pretreatment, chemical passivation, high temperature diffusion and surface sealing, a composite anti-rust system with dense structure and strong bonding force is constructed on the surface of the frame saw blade.

[0022] (2) The combination of chemical passivation and high-temperature diffusion treatment significantly enhances the cohesion of the passivation layer and its bonding with the substrate, thereby improving the stability and durability of the anti-rust layer.

[0023] (3) The surface is sealed with a fluorinated silane nanocomposite sealant, forming a protective layer with excellent hydrophobicity, which can effectively block the intrusion of moisture and corrosive media, so that the frame saw blade substrate has long-term rust prevention capability. Detailed Implementation

[0024] Example 1: Rust-proof steel frame saw blade base of the present invention.

[0025] Rust prevention methods include the following steps: (1) Smelting of the frame saw blade matrix: The mass fraction of the raw materials is as follows: C is 0.75%; Cr is 1.10%; Si is 0.25%; Mn is 0.50%; Cu is 0.40%; Ni is 0.15%; P is 0.03%; S is 0.03%; and the balance is Fe. The raw materials are smelted in a vacuum induction furnace, cast into Φ150mm round billets, and then hot rolled into 1.2mm thick strip steel.

[0026] (2) Quenching and tempering treatment The frame saw blade substrate was placed in a heating furnace and heated to 800°C at a rate of 90°C / hour, and held for 60 minutes to ensure complete and uniform austenitization. It was then cooled using a 250°C salt bath. The quenched substrate was then subjected to segmented tempering. In the first stage (stress-relief tempering), the substrate was heated to 300°C at a rate of 50°C / hour and held for 1 hour to decompose the unstable martensite and initially release the quenching stress. In the second stage (high-temperature tempering), the substrate was further heated to 600°C at a rate of 70°C / hour, reaching the final tempering temperature, and held for 5 hours to fully transform the microstructure into uniform and stable tempered sorbite. Finally, the frame saw blade was uniformly cooled to room temperature at a cooling rate of 20°C / minute.

[0027] (3) Surface pretreatment: Immerse the quenched and tempered base material for frame saw blades in alkaline degreasing solution for 6 minutes; then rinse with deionized water for 20 minutes; then sandblast with 90 mesh alumina sand; then soak in 15% hydrochloric acid solution for 45 seconds.

[0028] (4) Chemical passivation treatment: Prepare a passivation solution with the following composition: 10wt% nitric acid, 3wt% chromic anhydride, 0.8wt% sodium silicate, 0.08wt% sodium fluoride, and the balance being deionized water. Immerse the pretreated frame saw blade substrate in the passivation solution, control the temperature at 60℃ for 15 minutes, and maintain the pH at 1.5. After treatment, rinse thoroughly with deionized water and dry with hot air at 60℃ for 10 minutes.

[0029] (5) High temperature diffusion anti-rust layer treatment: The passivated frame saw blade substrate is placed in a tube furnace with high-purity nitrogen gas, heated to 535°C at 6°C / min, kept at the temperature for a certain time, cooled to 120°C with the furnace and removed from the furnace, and placed to room temperature.

[0030] (6) Surface sealing treatment: Prepare a sealant with the following composition: 4wt% KH-132 fluorosilane, 2.5wt% nano-SiO2 sol, 22wt% isopropanol, and the balance is deionized water. Adjust the pH to 4.8 with acetic acid. Immerse the saw blade in the sealant for 2.5 minutes, remove it, and dry and cure it at 120℃ for 30 minutes to obtain a rust-proof saw blade.

[0031] The control sample A is a blank experiment, and is processed using step (1) of the present invention.

[0032] Compared with sample B, the present invention is processed using steps (1) and (2), but steps (3)-(6) are not performed.

[0033] Compared with sample C, after processing using step (1) of the present invention, surface treatment is performed using traditional anti-rust oil, that is, anti-rust oil is sprayed on the surface of the frame saw blade substrate.

[0034] The performance of the frame saw blade substrate of the above-mentioned Example 1 and control sample A, control sample B and control sample C was tested. The key performance comparison is shown in Table 1 below. The salt spray test was conducted in accordance with the GB / T10125-2012 standard.

[0035] Table 1

[0036] The mechanical properties of the control samples prepared according to Embodiment 1 of the present invention, namely the salt spray test, were tested. As shown in Table 1 above, the frame saw blade substrate treated with the anti-rust treatment method of Embodiment 1 of the present invention has a yield strength Rp0.2 of 740 MPa, a tensile strength of 930 MPa, and a surface Brinell hardness of 410. The control sample A has a yield strength Rp0.2 of 400 MPa, a tensile strength of 730 MPa, and a surface Brinell hardness of 220. The control sample B has a yield strength Rp0.2 of 720 MPa, a tensile strength of 910 MPa, and a surface Brinell hardness of 310. The control sample C has a yield strength Rp0.2 of 730 MPa, a tensile strength of 910 MPa, and a surface Brinell hardness of 320. The mechanical properties of the frame saw blade substrate treated with Embodiment 1 of the present invention are higher than those of the control sample A. The mechanical properties of the first embodiment of the present invention are comparable to those of control sample B and control sample C. Meanwhile, the salt spray test results of the frame saw blade substrate treated with the first embodiment of the present invention show that the time to white rust appearance is 550 hours, far superior to the 10 hours of control sample A, the 40 hours of control sample B, and the 72 hours of control sample C treated with traditional rust-preventive oil. This is mainly because the present invention optimizes the substrate structure through heat treatment to achieve uniformity, low internal stress, and high chemical stability, and then constructs a dense and strongly bonded composite rust-preventive system on the surface of the frame saw blade through multiple synergistic treatments: surface pretreatment → chemical passivation → high-temperature diffusion → surface sealing.

[0037] Example 2: The rust prevention treatment method in Example 2 of the present invention includes the following steps: (1) Smelting of the frame saw blade matrix: The mass fraction of the raw materials is as follows: C is 0.75%; Cr is 1.10%; Si is 0.25%; Mn is 0.50%; Cu is 0.40%; Ni is 0.15%; P is 0.01%; S is 0.01%; and the balance is Fe. The raw materials are smelted in a vacuum induction furnace, cast into Φ150mm round billets, and then hot rolled into 1.2mm thick strip steel.

[0038] (2) Quenching and tempering treatment The frame saw blade substrate was placed in a heating furnace and heated to 780°C at a rate of 90°C / hour, and held for 60 minutes to ensure complete and uniform austenitization. It was then cooled using a 250°C salt bath. The quenched substrate was then subjected to segmented tempering. In the first stage (stress-relief tempering), the substrate was heated to 350°C at a rate of 50°C / hour and held for 1 hour to decompose the unstable martensite and initially release the quenching stress. In the second stage (high-temperature tempering), the substrate was further heated to 550°C at a rate of 70°C / hour, the final tempering temperature, and held for 5 hours to fully transform the microstructure into uniform and stable tempered sorbite. Finally, the frame saw blade was uniformly cooled to room temperature at a cooling rate of 20°C / minute.

[0039] (3) Surface pretreatment: Immerse the quenched and tempered base material for frame saw blades in alkaline degreasing solution for 6 minutes; then rinse with deionized water for 20 minutes; then sandblast with 100 mesh alumina sand; then soak in 15% hydrochloric acid solution for 45 seconds.

[0040] (4) Chemical passivation treatment: Prepare a passivation solution with the following composition: 10wt% nitric acid, 3wt% chromic anhydride, 0.8wt% sodium silicate, 0.08wt% sodium fluoride, and the balance being deionized water. Immerse the pretreated frame saw blade substrate in the passivation solution at a controlled temperature of 55℃ for 15 minutes, maintaining the pH at 1.5. After treatment, rinse thoroughly with deionized water and dry with hot air at 60℃ for 10 minutes.

[0041] (5) High temperature diffusion anti-rust layer treatment: The passivated frame saw blade substrate is placed in a tube furnace with high-purity nitrogen gas, heated to 550°C at 6°C / min, kept at the temperature for a certain time, cooled to 120°C with the furnace and removed from the furnace, and placed at room temperature.

[0042] (6) Surface sealing treatment: Prepare a sealant with the following composition: 4wt% KH-132 fluorosilane, 2.5wt% nano-SiO2 sol, 22wt% isopropanol, and the balance is deionized water. Adjust the pH to 4.8 with acetic acid. Immerse the saw blade in the sealant for 2.5 minutes, remove it, and dry and cure it at 120℃ for 30 minutes to obtain a rust-proof saw blade.

[0043] The control sample D is used as a blank sample and is processed using step (1) of this invention.

[0044] Compare sample E with the steps (1) and (2) of the present invention, but do not perform the steps (3)-(6).

[0045] Compared with sample F, after processing using step (1) of the present invention, surface treatment is performed using traditional rust-preventive oil, that is, rust-preventive oil is sprayed on the surface of the frame saw blade substrate.

[0046] The performance of the frame saw blade substrate of the above-mentioned Example 2 and control samples C, D and E was tested. The key performance comparison is shown in Table 2 below. The salt spray test was conducted in accordance with the GB / T10125-2012 standard.

[0047] Table 2

[0048] The mechanical properties of the control sample D, control sample E, and control sample F prepared according to Example 2 of this invention, i.e., the salt spray test, were tested. Table 2 shows that the frame saw blade substrate treated with the rust-prevention method of Example 2 of this invention has a yield strength Rp0.2 of 1250 MPa, a tensile strength of 1400 MPa, and a surface Brinell hardness of 750. In contrast, control sample D has a yield strength Rp0.2 of 900 MPa, a tensile strength of 700 MPa, and a surface Brinell hardness of 400; control sample E has a yield strength Rp0.2 of 1200 MPa, a tensile strength of 1370 MPa, and a surface Brinell hardness of 740; and control sample F has a yield strength Rp0.2 of 1105 MPa, a tensile strength of 1405 MPa, and a surface Brinell hardness of 740. Therefore, the mechanical properties of the frame saw blade substrate of Example 2 of this invention are higher than those of control sample D. The mechanical properties of the present invention are comparable to those of control samples E and F. The main advantage lies in the superior mechanical properties resulting from the primary heat treatment. Furthermore, salt spray testing of the frame saw blade substrate in Example 2 of this invention showed that the time to white rust formation was 600 hours, significantly better than the 12 hours for control sample D, the 45 hours for control sample E, and the 83 hours for control sample F treated with traditional rust-preventive oil. This invention, through heat treatment optimization resulting in a uniform substrate structure, low internal stress, and high chemical stability, employs multiple synergistic treatments including surface pretreatment, chemical passivation, high-temperature diffusion, and surface sealing to construct a dense and strongly bonded composite rust-preventive system on the surface of the frame saw blade.

Claims

1. A method of rust-proofing a saw blade, characterized by: It comprises the following steps: (1) Frame saw blade base smelting: according to mass fraction: C is 0.75%; Cr is 1.10%, Si is 0.25%; Mn is 0.50%; Cu is 0.40%; Ni is 0.15%; P is 0.03%; S is 0.03%; the balance is Fe; vacuum induction melting furnace is adopted to smelt, and Φ150mm round billet is poured, and 1.2mm thick strip steel is formed through hot rolling; (2) Quenching and tempering treatment The frame saw blade base is placed in a heating furnace, the frame saw blade base is heated to 700-800 DEG C at a heating rate of 80-90 DEG C / hour, and is kept for 60 minutes, then is cooled by using 200-250 DEG C nitrate bath; then the quenched frame saw blade base is subjected to segmented tempering, in the first stage, is heated to 300-350 DEG C at a heating rate of 50 DEG C / hour, and is kept for 1 hour; then is continuously heated to 550-600 DEG C at a heating rate of 70 DEG C / hour, and is kept for 5-6 hours, then the frame saw blade base is cooled to room temperature; (3) Surface pretreatment The frame saw blade base after quenching and tempering treatment is immersed in alkaline degreasing solution for 5-8 minutes; then is washed with deionized water for 20 minutes; then is subjected to sand blasting treatment by using 80-100 mesh alumina sand; then is immersed in hydrochloric acid solution for 30-60 seconds; (4) Chemical passivation treatment A passivation solution is prepared, and the components thereof are as follows in terms of mass percentage: nitric acid: 8-12wt%, chromic anhydride: 2-4wt%, sodium silicate: 0.5-1wt%, sodium fluoride: 0.05-0.10wt%, and the balance is deionized water; the frame saw blade base after surface pretreatment is immersed in the passivation solution for treatment, the treatment time is 10-20 minutes, and pH is 1.0-2.0; after the treatment, the frame saw blade base is taken out and washed with deionized water; then is dried under the condition of 60 DEG C hot air for 10 minutes; (5) High-temperature diffusion treatment The frame saw blade base after chemical passivation treatment is placed in a sealed tube furnace, and is heated and treated under nitrogen protection atmosphere, is heated to 520-550 DEG C at a heating rate of 5-8 DEG C / min, and is kept for a period of time; then is cooled to 150 DEG C or below out of the furnace, and is placed in air to 25-30 DEG C; (6) Surface sealing treatment A sealing agent is prepared, and the components thereof are as follows in terms of mass percentage: fluorosilane: 3-5wt%; nano-SiO2 sol: 2-3wt%; isopropyl alcohol: 20-25wt%; and the balance is deionized water, and pH is 4.0-5.5; the frame saw blade base after high-temperature diffusion treatment is immersed in the sealing agent liquid for 2-3 minutes; then the frame saw blade base is taken out and is dried and solidified at 110-130 DEG C for 25-35 minutes. The alkaline degreasing solution in step (3) comprises the following components in terms of mass percentage: NaOH: 2-4wt%; Na2CO3: 1-2wt%; Na3PO4: 1-2wt%; and the balance is deionized water.

2. The saw blade rust prevention method according to claim 1, characterized by: The alkaline degreasing solution in step (3) has a temperature of 60-70 DEG C.

3. The saw blade rust prevention method according to claim 1, characterized by: The hydrochloric acid solution in step (3) has a mass fraction of 10-15wt%.

4. The saw blade rust prevention method according to claim 1, characterized by: ​ 5. The saw blade rust prevention method according to claim 1, characterized by: The step (4) is that the frame saw blade substrate after surface pre-treatment is immersed into a passivation liquid for treatment, and the temperature is 50-60℃.

6. The method of claim 1, wherein: The step (5) is high-temperature diffusion treatment, and the holding time is 1-2 hours.

7. The method of claim 1, wherein: The step (5) is nitrogen protection atmosphere, which is nitrogen atmosphere with a volume fraction of greater than or equal to 99.99%.

8. The saw blade rust prevention method according to claim 1, characterized by: The step (6) is that the nano-SiO2 sol has a particle size of 20-40 nm.

9. The saw blade rust prevention method according to claim 1, characterized by: The step (6) is that the pH is 4.0-5.5, and the pH value is adjusted by using acetic acid.

10. A saw blade rust-proofing treatment method according to any one of claims 1 to 9, the treated saw blade characterized by: The mass fraction of the saw blade substrate is that C is 0.75%; Cr is 1.10%, Si is 0.25%; Mn is 0.50%; Cu is 0.40%; Ni is 0.15%; P is 0.03%; S is 0.03%; and the balance is Fe.

Images