T-shaped steel resistant to seawater corrosion and preparation method thereof
By constructing a dense, hydrophobic multilayer coating structure on the surface of T-shaped steel, the corrosion problem of T-shaped steel in marine environments is solved, achieving high corrosion resistance and strong adhesion, and improving the mechanical properties and service life of T-shaped steel.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIXING JUFENG CALENDERING TECH CO LTD
- Filing Date
- 2026-03-19
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, T-shaped steel is susceptible to corrosion in marine environments. Traditional anti-corrosion methods such as hot-dip galvanizing and ordinary coatings have problems such as zinc layer dissolution, weak adhesion, and pore channels, which cannot effectively prevent seawater from entering and have insufficient mechanical properties, resulting in a shortened service life.
Hyperbranched siloxane copolymers were used as the coating matrix, combined with POSS@ZIF-8 and modified boron nitride nanoparticles, and a fluorine-doped diamond-like transition layer was formed by plasma-enhanced chemical vapor deposition to construct a dense, hydrophobic multilayer coating structure, thereby enhancing the protective and mechanical properties of the composite material.
It forms a dense, hydrophobic multilayer coating structure, effectively blocking the penetration of seawater, improving the coating's wear resistance, hardness and impact resistance, extending the service life of T-shaped steel, and ensuring the safety and stability of marine engineering.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of corrosion-resistant coating technology, specifically to a seawater-resistant T-shaped steel and its preparation method. Background Technology
[0002] T-shaped steel, as a profile with excellent cross-sectional mechanical properties, is widely used in marine engineering fields such as offshore platform construction, cross-sea bridge construction, and port and wharf reinforcement. However, the marine environment is characterized by high salinity and high humidity. Large amounts of chloride ions in seawater can penetrate the steel surface through osmosis and diffusion, damaging the metal passivation film and causing pitting corrosion and crevice corrosion. Simultaneously, the alternating wet and dry conditions in marine environments, the impact of waves, and the attachment of marine organisms further accelerate the corrosion and aging process of T-shaped steel, significantly shortening its service life. This not only increases the economic cost of later maintenance but also poses a serious threat to the safety and stability of marine engineering structures.
[0003] Currently, corrosion protection for T-shaped steel primarily employs traditional techniques such as hot-dip galvanizing and ordinary coatings. While hot-dip galvanizing can form a protective layer, the zinc layer is prone to dissolution and peeling under prolonged seawater immersion, and the coating exhibits microporous defects, making long-term protection difficult. Ordinary anti-corrosion coatings generally suffer from weak adhesion to the steel substrate and poor filler dispersion, easily forming pore channels within the coating and failing to effectively block the intrusion of seawater. Furthermore, conventional coatings lack sufficient mechanical properties, easily leading to coating damage and cracking under wave erosion, thus losing their protective effect. Therefore, developing a T-shaped steel manufacturing technology that combines high corrosion resistance, strong adhesion, and excellent mechanical properties has become a critical issue urgently needing to be addressed in the field of marine engineering materials. Summary of the Invention
[0004] The purpose of this invention is to provide a seawater corrosion-resistant T-shaped steel and its preparation method, so as to solve the problems raised in the prior art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a seawater corrosion resistant T-shaped steel includes the following steps: S1: Add phenyltriethoxysilane and dimethylhydrochlorosilane to a reaction vessel, react at 40-50℃ for 6-8 hours under a nitrogen atmosphere, and purify by vacuum distillation to obtain phenyldiethoxydimethyldisiloxane monomer. Furthermore, in the preparation process of the phenyldiethoxydimethyldisiloxane monomer, the mass ratio of phenyltriethoxysilane to dimethylhydrochlorosilane is (2-3):1; Phenyldiethoxydimethyldisiloxane monomer and tris(pentafluorophenyl)borane catalyst were added to toluene and reacted at 30-50℃ for 8-12 h. Alumina was added to neutralize the tris(pentafluorophenyl)borane catalyst, and the mixture was filtered and rotary evaporated to obtain hyperbranched siloxane copolymer. Furthermore, in the preparation process of the hyperbranched siloxane copolymer, the amount of tris(pentafluorophenyl)borane catalyst added is 0.05-0.1 wt% of the mass of the phenyldiethoxydimethyldisiloxane monomer; Furthermore, the addition rate of the phenyldiethoxydimethyldisiloxane monomer is 0.5-1.5 mL / min; Furthermore, the hyperbranched siloxane copolymer has a number-average molecular weight of 20-25 kDa and a branching degree of 0.45-0.55; S2: Add phenyltriethoxysilane to an aqueous methanol solution, add hydrochloric acid catalyst, and hydrolyze and condense at 30-40℃ for 8-12 hours. Filter and vacuum dry to obtain octaphenyl polyhedral oligomeric silsesquioxane. Add zinc nitrate hexahydrate and 2-methylimidazole to methanol, stir evenly, add octaphenyl polyhedral oligomeric silsesquioxane, stir at room temperature for 12-16 hours, centrifuge, wash the precipitate with methanol, and vacuum dry to obtain POSS@ZIF-8. Furthermore, in the preparation process of POSS@ZIF-8, the molar ratio of zinc nitrate hexahydrate to 2-methylimidazole is 1:(4-6); the amount of octaphenyl polyhedral oligomeric silsesquioxane added is 20-30 wt% of the mass of zinc nitrate hexahydrate. S3: Add boric acid and 1,4-butanediol to the reaction vessel, react at 100-120℃ for 4-6 h, dehydrate, and distill under reduced pressure to obtain borate ester reagent; Furthermore, in the preparation of the borate ester reagent, the molar ratio of boric acid to 1,4-butanediol is 1:(2-3); Hexagonal boron nitride nanoparticles were dispersed in toluene to obtain a suspension with a concentration of 5-10 wt%. The suspension was ultrasonically dispersed, and borate ester reagent was added. The mixture was reacted at 80-100℃ for 4-6 h under a nitrogen atmosphere. The mixture was filtered, washed with toluene, and vacuum dried to obtain borate ester modified boron nitride nanoparticles. Furthermore, in the preparation process of the borate ester modified boron nitride nanoparticles, the amount of borate ester reagent added is 10-15 wt% of the mass of the hexagonal boron nitride nanoparticles; S4: Add POSS@ZIF-8 and borate ester modified boron nitride nanoparticles to a mixer and mix evenly to obtain a composite filler; Furthermore, in the preparation process of the composite filler, the mass ratio of POSS@ZIF-8 to borate ester modified boron nitride nanoparticles is (1-2):1; S5: First, soak the T-shaped steel in a 10-15wt% sodium hydroxide solution at 50-60℃ for 30-40 minutes, then soak it in a 15-20wt% hydrochloric acid solution at room temperature for 20-30 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S6: Fluorine-doped diamond-like transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition on the surface of pretreated T-shaped steel. Furthermore, the parameters of the plasma-enhanced chemical vapor deposition method include: using methane, carbon tetrafluoride, and argon in a volume ratio of (3-5):(1-2):(10-15) as the reaction gas, silane as the doping auxiliary gas, and a vacuum degree of 1×10⁻⁶. -3 -5×10 -3 Pa, deposition temperature is room temperature, self-bias voltage is 405-479V, and deposition time is 30-60min; Furthermore, in the fluorine-doped diamond-like carbon transition layer T-shaped steel, the thickness of the fluorine-doped diamond-like carbon transition layer is 500-800 nm, and the fluorine content of the fluorine-doped diamond-like carbon transition layer is 6-8 wt%. Furthermore, the silane comprises 1-3% of the total gas volume; The composite filler was added to the hyperbranched siloxane copolymer and dispersed evenly to obtain a coating slurry. The coating slurry was then sprayed under high pressure onto the surface of the fluorine-doped diamond-like transition layer T-shaped steel and pre-cured under vacuum at 50-60℃ for 4-8 hours to obtain a pre-cured coated T-shaped steel. Furthermore, in the coating slurry, the mass ratio of composite filler to hyperbranched siloxane copolymer is (15-25):100; Furthermore, in the pre-cured coated T-shaped steel, the thickness of the pre-cured coating is 150-250 μm; POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain a hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, and in-situ crosslinked at 100-110℃ for 1.5-2.5h, and then cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. Furthermore, the concentration of the hydrophobic slurry is 8-12 wt%; Furthermore, in the seawater corrosion-resistant T-shaped steel, the thickness of the hydrophobic slurry coating is 30-50 μm.
[0006] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses hyperbranched siloxane copolymers as the coating matrix. Its low glass transition temperature ensures the flexibility of the coating, and its high decomposition temperature improves its high temperature resistance and anti-aging ability. A large number of terminal groups enhance the compatibility with the composite filler, forming a dense film structure that blocks the penetration of seawater media. 2. In the composite filler of this invention, the phenyl group of POSS in POSS@ZIF-8 forms a π-π stacking effect with the imidazole ring of ZIF-8, which improves the stability of the composite structure; the inorganic siloxane core of POSS enhances chemical inertness, the phenyl group imparts hydrophobicity, and the porous structure of ZIF-8 can adsorb small molecule corrosive media in seawater; the two work synergistically to reduce the surface energy of the coating, reduce seawater wetting, and simultaneously inhibit the Zn in ZIF-8 in salt water. 2+ Leakage; the boron groups of borate esters coordinate with surface defects of boron nitride, while their organic segments are compatible with the siloxane chains of hyperbranched siloxane copolymers, solving the problem of boron nitride agglomeration; the high mechanical strength and corrosion resistance of boron nitride itself, after modification, are uniformly dispersed in the coating, further improving the coating hardness, wear resistance and impact resistance, and avoiding coating damage caused by seawater erosion.
[0007] 3. This invention deposits a transition layer on the surface of T-shaped steel using plasma-enhanced chemical vapor deposition. Nitrogen doping enhances the sp(s) content of the diamond-like carbon transition layer. 2 / sp 3 Compared to the previous method, the surface contact angle is increased and the hydrophobicity is enhanced; at the same time, the fluorine-doped diamond-like transition layer forms a dense amorphous carbon film, which provides a basic corrosion inhibition rate for T-shaped steel and forms a strong bond with the pretreated steel surface, providing a smooth and highly adhesive substrate for the upper coating.
[0008] 4. This invention utilizes a bottom transition layer: high corrosion resistance to block the penetration of corrosive media, and hydrophobicity to reduce the contact between seawater and the substrate; a middle layer: hyperbranched copolymers form a continuous film matrix, POSS@ZIF-8 provides chemical stability and hydrophobic enhancement, and modified boron nitride enhances mechanical support, the three working together to construct an integrated "protection-reinforcement" structure; a top layer: hydrophobic slurry further enhances surface hydrophobicity, forming a "double hydrophobic + double protection" structure, reducing the retention and wetting of seawater on the coating surface. Detailed Implementation
[0009] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0010] In the following examples, the preparation method of hyperbranched siloxane copolymer includes the following steps: 200g of phenyltriethoxysilane and 100g of dimethylhydrochlorosilane are added to a reaction vessel, reacted at 40°C for 6h under a nitrogen atmosphere, and purified by vacuum distillation to obtain phenyldiethoxydimethyldisiloxane monomer. 100g of phenyldiethoxydimethyldisiloxane monomer and 0.05g of tris(pentafluorophenyl)borane catalyst were added to toluene and reacted at 40°C for 8 hours. Alumina was added to neutralize the tris(pentafluorophenyl)borane catalyst, and the mixture was filtered and rotary evaporated to obtain hyperbranched siloxane copolymer. The preparation method of POSS@ZIF-8 includes the following steps: adding phenyltriethoxysilane to an aqueous methanol solution, adding hydrochloric acid catalyst, hydrolyzing and condensing at 30°C for 8 hours, filtering, and vacuum drying to obtain octaphenyl polyhedral oligomeric silsesquioxane; adding 50g zinc nitrate hexahydrate and 64.8g 2-methylimidazole to methanol, stirring evenly, adding 10g octaphenyl polyhedral oligomeric silsesquioxane, stirring at room temperature for 12 hours, centrifuging, washing the precipitate with methanol, and vacuum drying to obtain POSS@ZIF-8; The preparation method of boron ester modified boron nitride nanoparticles includes the following steps: 6.2g boric acid and 14.8g 1,4-butanediol are added to a reaction vessel, reacted at 100℃ for 4h, dehydrated, and distilled under reduced pressure to obtain boron ester reagent; 20g of hexagonal boron nitride nanoparticles were dispersed in 380g of toluene to obtain a suspension with a concentration of 5wt%. The suspension was ultrasonically dispersed, and 2g of borate ester reagent was added. The mixture was reacted at 80℃ for 4h under a nitrogen atmosphere. The mixture was filtered, washed with toluene, and dried under vacuum to obtain borate ester modified boron nitride nanoparticles. Example 1: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: 15g of POSS@ZIF-8 and 10g of borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: First, soak the T-shaped steel in a 10wt% sodium hydroxide solution at 50℃ for 30 minutes, then soak it in a 15wt% hydrochloric acid solution at room temperature for 20 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S3: Fluorine-doped diamond-like carbon transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition (PECVD) on the surface of pretreated T-shaped steel. The PECVD parameters included: a mixture of methane, carbon tetrafluoride, and argon in a volume ratio of 4:1.5:12 as the reactant gas; silane as the doping auxiliary gas; and a vacuum degree of 3 × 10⁻⁶. -3 Pa, deposition temperature was room temperature, self-bias voltage was 450V, deposition time was 450min; transition layer thickness was 650nm; S4: Add 20g of composite filler to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain coating slurry; spray the coating slurry onto the surface of fluorine-doped diamond-like transition layer T-shaped steel under high pressure and pre-cur it under vacuum at 50℃ for 4h to obtain pre-cured coated T-shaped steel; the coating thickness is 200μm; S5: POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain a 10wt% hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, crosslinked in situ at 105℃ for 2 hours, and cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. The coating thickness was 40μm.
[0011] Example 2: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: 10g of POSS@ZIF-8 and 10g of borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: First, soak the T-shaped steel in a 10wt% sodium hydroxide solution at 50℃ for 30 minutes, then soak it in a 15wt% hydrochloric acid solution at room temperature for 20 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S3: A fluorine-doped diamond-like carbon transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition (PECVD) on the surface of pretreated T-shaped steel. The parameters of the PECVD included: methane, carbon tetrafluoride, and argon mixed in a volume ratio of 3:1:10 as the reaction gas, silane as the doping auxiliary gas, and a vacuum degree of 3×10⁻⁶. -3 Pa, deposition temperature was room temperature, self-bias voltage was 450V, deposition time was 450min; transition layer thickness was 650nm; S4: Add 15g of composite filler to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain coating slurry; spray the coating slurry onto the surface of fluorine-doped diamond-like transition layer T-shaped steel under high pressure and pre-cur it under vacuum at 50℃ for 4h to obtain pre-cured coated T-shaped steel; the coating thickness is 200μm; S5: POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain an 8wt% hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, in-situ crosslinked at 105℃ for 2 hours, and cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. The coating thickness was 40μm.
[0012] Example 3: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: 20g of POSS@ZIF-8 and 10g of borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: First, soak the T-shaped steel in a 10wt% sodium hydroxide solution at 50℃ for 30 minutes, then soak it in a 15wt% hydrochloric acid solution at room temperature for 20 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S3: A fluorine-doped diamond-like carbon transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition (PECVD) on the surface of pretreated T-shaped steel. The PECVD parameters included: a mixture of methane, carbon tetrafluoride, and argon in a volume ratio of 5:2:15 as the reaction gas; silane as the doping auxiliary gas; and a vacuum degree of 3 × 10⁻⁶. -3 Pa, deposition temperature was room temperature, self-bias voltage was 450V, deposition time was 450min; transition layer thickness was 650nm; S4: Add 25g of composite filler to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain coating slurry; spray the coating slurry onto the surface of fluorine-doped diamond-like transition layer T-shaped steel under high pressure and pre-cur it under vacuum at 50℃ for 4h to obtain pre-cured coated T-shaped steel; the coating thickness is 200μm; S5: POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain a 12wt% hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, crosslinked in situ at 105℃ for 2 hours, and cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. The coating thickness was 40μm.
[0013] Comparative Example 1: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: 15g of POSS@ZIF-8 and 10g of borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: First, soak the T-shaped steel in a 10wt% sodium hydroxide solution at 50℃ for 30 minutes, then soak it in a 15wt% hydrochloric acid solution at room temperature for 20 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S3: Add 20g of composite filler to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain coating slurry; spray the coating slurry onto the surface of pretreated T-shaped steel under high pressure and pre-cur it under vacuum at 50℃ for 4h to obtain pre-cured coated T-shaped steel; the coating thickness is 200μm; S4: POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain a 10wt% hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, crosslinked in situ at 105℃ for 2 hours, and cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. The coating thickness was 40μm.
[0014] Comparative Example 2: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: The surface of the T-shaped steel is first soaked in a 10wt% sodium hydroxide solution at 50°C for 30 min, then soaked in a 15wt% hydrochloric acid solution at room temperature for 20 min, and finally rinsed with deionized water until neutral, and dried to obtain a pretreated T-shaped steel. S2: Fluorine-doped diamond-like carbon transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition (PECVD) on the surface of pretreated T-shaped steel. The PECVD parameters included: a mixture of methane, carbon tetrafluoride, and argon in a volume ratio of 4:1.5:12 as the reactant gas; silane as the doping auxiliary gas; and a vacuum degree of 3 × 10⁻⁶. -3 Pa, deposition temperature was room temperature, self-bias voltage was 450V, deposition time was 450min; transition layer thickness was 650nm; S3: Add 20g of POSS@ZIF-8 to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain a coating slurry; spray the coating slurry onto the surface of the fluorine-doped diamond-like transition layer T-shaped steel under high pressure and pre-cur it under vacuum at 50℃ for 4h to obtain a pre-cured coated T-shaped steel; the coating thickness is 200μm; S4: POSS@ZIF-8 was ultrasonically dispersed in anhydrous ethanol to obtain a 10wt% hydrophobic slurry; the hydrophobic slurry was sprayed onto the surface of a pre-cured coated T-shaped steel, crosslinked in situ at 105℃ for 2 hours, and cooled to room temperature to obtain a T-shaped steel resistant to seawater corrosion. The coating thickness was 40μm.
[0015] Comparative Example 3: A method for preparing a seawater corrosion resistant T-shaped steel, comprising the following steps: S1: 15g of POSS@ZIF-8 and 10g of borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: First, soak the T-shaped steel in a 10wt% sodium hydroxide solution at 50℃ for 30 minutes, then soak it in a 15wt% hydrochloric acid solution at room temperature for 20 minutes, and finally rinse it with deionized water until neutral, and dry it to obtain the pretreated T-shaped steel. S3: Fluorine-doped diamond-like carbon transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition (PECVD) on the surface of pretreated T-shaped steel. The PECVD parameters included: a mixture of methane, carbon tetrafluoride, and argon in a volume ratio of 4:1.5:12 as the reactant gas; silane as the doping auxiliary gas; and a vacuum degree of 3 × 10⁻⁶. -3 Pa, deposition temperature was room temperature, self-bias voltage was 450V, deposition time was 450min; transition layer thickness was 650nm; S4: Add 20g of composite filler to 100g of hyperbranched siloxane copolymer and disperse evenly to obtain a coating slurry; spray the coating slurry under high pressure onto the surface of a fluorine-doped diamond-like carbon transition layer T-shaped steel, pre-cur under vacuum at 50℃ for 4h, cross-link in situ at 105℃ for 2h, and cool to room temperature to obtain a seawater corrosion-resistant T-shaped steel. The coating thickness is 40μm.
[0016] Performance testing: Seawater corrosion resistance: Simulated seawater immersion test: 3.5wt% NaCl solution, 25℃, immersion for 1000h, corrosion rate was tested; Surface hydrophobicity: Contact angle tester: deionized water, room temperature, 5μL droplet, 3 measurements and average value; Coating hardness performance: Microhardness tester: HV0.2 load, average value of 5 test points; Coating wear resistance: Reciprocating wear tester: load 5N, speed 100r / min, wear distance 100m, measure wear amount.
[0017] The performance test results are shown in Table 1 below.
[0018] Table 1. Test data of T-shaped steel resistant to seawater corrosion
[0019] Conclusion: The seawater corrosion-resistant T-shaped steel prepared by this invention can meet the stringent requirements for T-shaped steel in marine engineering.
[0020] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.
Claims
1. A method for preparing a seawater corrosion-resistant T-shaped steel, characterized in that: Includes the following steps: S1: POSS@ZIF-8 and borate-modified boron nitride nanoparticles are added to a mixer and mixed evenly to obtain a composite filler; S2: The T-shaped steel is subjected to degreasing, rust removal and oil removal pretreatment in sequence to obtain pretreated T-shaped steel; S3: Fluorine-doped diamond-like transition layer T-shaped steel was prepared by plasma-enhanced chemical vapor deposition on the surface of pretreated T-shaped steel. S4: The composite filler is added to the hyperbranched siloxane copolymer and dispersed evenly to obtain a coating slurry; the coating slurry is sprayed under high pressure onto the surface of the fluorine-doped diamond-like transition layer T-shaped steel and pre-cured under vacuum at 50-60℃ for 4-8 hours to obtain a pre-cured coated T-shaped steel. S5: Disperse POSS@ZIF-8 ultrasonically in anhydrous ethanol to obtain a hydrophobic slurry; spray the hydrophobic slurry onto the surface of a pre-cured coated T-shaped steel, crosslink in situ at 100-110℃ for 1.5-2.5h, and cool to room temperature to obtain a T-shaped steel resistant to seawater corrosion.
2. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: The preparation method of the hyperbranched siloxane copolymer includes the following steps: adding phenyldiethoxydimethyldisiloxane monomer and tris(pentafluorophenyl)borane catalyst to toluene, reacting at 30-50℃ for 8-12 h, adding alumina to neutralize the tris(pentafluorophenyl)borane catalyst, filtering, and rotary evaporating to obtain the hyperbranched siloxane copolymer; in the preparation process of the hyperbranched siloxane copolymer, the amount of tris(pentafluorophenyl)borane catalyst added is 0.05-0.1 wt% of the mass of phenyldiethoxydimethyldisiloxane monomer.
3. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 2, characterized in that: The method for preparing the phenyldiethoxydimethyldisiloxane monomer includes the following steps: adding phenyltriethoxysilane and dimethylhydrochlorosilane into a reaction vessel, reacting at 40-50°C for 6-8 hours under a nitrogen atmosphere, and purifying by vacuum distillation to obtain the phenyldiethoxydimethyldisiloxane monomer. In the preparation of phenyldiethoxydimethyldisiloxane monomer, the mass ratio of phenyltriethoxysilane to dimethylhydrochlorosilane is (2-3):
1.
4. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: The preparation method of POSS@ZIF-8 includes the following steps: adding phenyltriethoxysilane to an aqueous methanol solution, adding hydrochloric acid catalyst, hydrolyzing and condensing at 30-40℃ for 8-12 hours, filtering, and vacuum drying to obtain octaphenyl polyhedral oligomeric silsesquioxane; adding zinc nitrate hexahydrate and 2-methylimidazole to methanol, stirring evenly, adding octaphenyl polyhedral oligomeric silsesquioxane, stirring at room temperature for 12-16 hours, centrifuging, washing the precipitate with methanol, and vacuum drying to obtain POSS@ZIF-8; In the preparation of POSS@ZIF-8, the molar ratio of zinc nitrate hexahydrate to 2-methylimidazole is 1:(4-6); the amount of octaphenyl polyhedral oligomeric silsesquioxane added is 20-30 wt% of the mass of zinc nitrate hexahydrate.
5. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: The method for preparing the boron ester modified boron nitride nanoparticles includes the following steps: dispersing hexagonal boron nitride nanoparticles in toluene to obtain a suspension with a concentration of 5-10 wt%, ultrasonically dispersing, adding boron ester reagent, reacting at 80-100℃ for 4-6 h under a nitrogen atmosphere, filtering, washing the product with toluene, and vacuum drying to obtain boron ester modified boron nitride nanoparticles. In the preparation of boron ester modified boron nitride nanoparticles, the amount of boron ester reagent added is 10-15 wt% of the mass of hexagonal boron nitride nanoparticles.
6. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 5, characterized in that: The method for preparing the borate ester reagent includes the following steps: adding boric acid and 1,4-butanediol into a reaction vessel, reacting at 100-120℃ for 4-6 hours, dehydrating, and distilling under reduced pressure to obtain the borate ester reagent; In the preparation of borate ester reagents, the molar ratio of boric acid to 1,4-butanediol is 1:(2-3).
7. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: In the preparation of the composite filler, the mass ratio of POSS@ZIF-8 to borate ester modified boron nitride nanoparticles is (1-2):
1.
8. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: The parameters for the plasma-enhanced chemical vapor deposition method include: using a mixture of methane, carbon tetrafluoride, and argon in a volume ratio of (3-5):(1-2):(10-15) as the reaction gas, silane as the doping auxiliary gas, and a vacuum degree of 1×10⁻⁶. -3 -5×10 -3 Pa, deposition temperature is room temperature, self-bias voltage is 405-479V, deposition time is 30-60min; the silane accounts for 1-3% of the total gas volume.
9. The method for preparing a seawater corrosion-resistant T-shaped steel according to claim 1, characterized in that: In the coating slurry, the mass ratio of composite filler to hyperbranched siloxane copolymer is (15-25):
100.
10. The seawater-resistant T-shaped steel prepared by the method for preparing seawater-resistant T-shaped steel according to any one of claims 1-9.