A high-strength steel strand

Abstract

This invention relates to the field of building materials technology, and proposes a high-strength steel strand comprising steel wire and a coating disposed on the surface of the steel wire. It is prepared by the following steps: immersing bare steel wire in a modified epoxy resin, curing, and stranding to obtain the high-strength steel strand. The modified epoxy resin includes stearic acid-modified silica, tetrabutyl titanate-modified epoxy resin, and a curing agent. This technical solution solves the problem of poor tensile strength of the epoxy resin coating in existing epoxy-coated steel strands.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a high-strength steel strand. Background Technology

[0002] Steel strand is a steel product made by twisting multiple steel wires together. Its manufacturing process includes single-wire manufacturing and multi-wire stranding. Single-wire manufacturing typically uses high-carbon steel wire rod, stainless steel wire rod, or medium-to-low-carbon steel wire rod as raw materials, employing cold drawing technology. Multi-wire stranding involves twisting multiple steel wires together using a stranding machine. As a common linear steel product, steel strand is widely used in bridges, construction, water conservancy, energy, and geotechnical engineering. However, existing steel strands often suffer from severe corrosion and short service life due to their low corrosion resistance when exposed to harsh natural environments for extended periods.

[0003] Based on the above problems, the existing technology uses epoxy resin spraying on the surface of steel strands to improve the corrosion resistance of steel strands. However, the tensile strength of the epoxy resin coating is poor, which can easily lead to damage of the coating layer, thereby affecting the corrosion resistance of the steel strands. Summary of the Invention

[0004] This invention proposes a high-strength steel strand that solves the problem of poor tensile strength of the epoxy resin coating in existing epoxy-coated steel strands.

[0005] The technical solution of the present invention is as follows:

[0006] A high-strength steel strand includes steel wire and a coating disposed on the surface of the steel wire, and is prepared by the following steps: immersing bare steel wire in modified epoxy resin, curing, and stranding to obtain high-strength steel strand, wherein the modified epoxy resin includes stearic acid modified silica, tetrabutyl titanate modified epoxy resin, and a curing agent.

[0007] As a further technical solution, the mass of stearic acid-modified silica in the modified epoxy resin is 2%-10% of the mass of tetrabutyl titanate-modified epoxy resin.

[0008] In this invention, the mass of stearic acid-modified silica in the modified epoxy resin is limited to 2%-10% of the mass of tetrabutyl titanate-modified epoxy resin, which improves the tensile strength and corrosion resistance of the modified epoxy resin coating, thereby improving the strength and corrosion resistance of the epoxy-coated steel strand.

[0009] As a further technical solution, the mass of stearic acid-modified silica in the modified epoxy resin is 5%-7% of the mass of tetrabutyl titanate-modified epoxy resin.

[0010] In this invention, the mass of stearic acid-modified silica in the modified epoxy resin is further limited to 5%-7% of the mass of tetrabutyl titanate-modified epoxy resin, which further improves the tensile strength and corrosion resistance of the modified epoxy resin coating, thereby further improving the strength and corrosion resistance of the epoxy-coated steel strand.

[0011] As a further technical solution, the mass of the curing agent in the modified epoxy resin is 8%-12% of the mass of the tetrabutyl titanate modified epoxy resin.

[0012] As a further technical solution, the curing agent is a latent curing agent.

[0013] As a further technical solution, the latent curing agent is dicyandiamide.

[0014] As a further technical solution, the latent curing agent is one or more of SH-900, SH-500, and SH-300.

[0015] As a further technical solution, the method for preparing stearic acid modified silica includes the following steps: dissolving stearic acid in ethanol, adding silica to react, and obtaining stearic acid modified silica.

[0016] As a further technical solution, the mass ratio of silicon dioxide to stearic acid is 1g:35-45mg, and the reaction temperature is 65-75℃.

[0017] As a further technical solution, the preparation method of the tetrabutyl titanate modified epoxy resin includes the following steps: dissolving epoxy resin in benzene, adding tetrabutyl titanate benzene solution, reacting, and distilling to obtain tetrabutyl titanate modified epoxy resin.

[0018] As a further technical solution, the reaction temperature is 40-45℃ and the reaction time is 35-55min.

[0019] As a further technical solution, the mass fraction of tetrabutyl titanate in the tetrabutyl titanate benzene solution is 25%-35%.

[0020] As a further technical solution, the thickness of the coating is 0.1-0.25 mm.

[0021] The working principle and beneficial effects of this invention are as follows:

[0022] 1. The present invention applies epoxy resin to the surface of steel strand, forming an epoxy resin protective layer on the surface of the steel strand, which isolates the steel strand from contact with the harsh environment and improves the corrosion resistance of the steel strand.

[0023] 2. This invention uses fatty acid-modified silica and tetrabutyl titanate-modified epoxy resin as the modified epoxy resin, which improves the tensile strength and corrosion resistance of the modified epoxy resin coating. The modified epoxy resin is applied to the surface of the steel strand to form a coating, further improving the strength and corrosion resistance of the epoxy-coated steel strand. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] In the following embodiments and comparative examples:

[0026] The silica is 1250-mesh precipitated silica;

[0027] The ethanol is anhydrous ethanol;

[0028] The epoxy resin type is: Epoxy Resin E44;

[0029] The bare steel wire is made of 82MnA.

[0030] Example 1

[0031] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0032] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0033] S3, 10g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0034] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0035] Example 2

[0036] S1, 4.5g stearic acid was dissolved in 2L ethanol, 100g silicon dioxide was added, the reaction was carried out at 75℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0037] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 35% tetrabutyl titanate benzene solution is added. The temperature is controlled at 45℃ and the reaction is carried out for 55min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0038] S3, 10g of stearic acid modified silica, and 120g of SH-300 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 20 minutes to obtain modified epoxy resin.

[0039] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 165℃ for 40 minutes to form a 0.25mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0040] Example 3

[0041] S1, 3.5g stearic acid was dissolved in 2L ethanol, 100g silicon dioxide was added, the reaction was carried out at 65℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0042] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 25% tetrabutyl titanate benzene solution is added. The temperature is controlled at 40℃ and the reaction is carried out for 35min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0043] S3, 10g of stearic acid modified silica, and 80g of SH-500 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 10 minutes to obtain modified epoxy resin.

[0044] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 145℃ for 20 minutes to form a 0.1mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0045] Example 4

[0046] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0047] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0048] S3, 20g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0049] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0050] Example 5

[0051] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0052] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0053] S3, 50g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0054] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0055] Example 6

[0056] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0057] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0058] S3, 60g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0059] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0060] Example 7

[0061] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0062] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0063] S3, 70g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0064] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0065] Example 8

[0066] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0067] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0068] S3, 100g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0069] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0070] Example 9

[0071] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0072] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0073] S3, 110g of stearic acid modified silica, and 100g of SH-900 were added to 1000g of tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0074] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0075] Comparative Example 1

[0076] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of silicon dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified silicon dioxide;

[0077] S2, 10g of stearic acid modified silica, and 100g of SH-900 are added to 1000g of epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0078] S3. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0079] Comparative Example 2

[0080] S1, 4g of stearic acid was dissolved in 2L of ethanol, 100g of titanium dioxide was added, the reaction was carried out at 70℃ for 60min, filtered, and dried to obtain stearic acid modified titanium dioxide.

[0081] S2. 1000g of epoxy resin is dissolved in 80g of benzene, and 150g of 30% tetrabutyl titanate benzene solution is added. The temperature is controlled at 43℃ and the reaction is carried out for 45min. The temperature is increased to 142℃ at a rate of 5℃ / min to control the solvent distillation rate. The solution is then distilled under reduced pressure until no solvent is distilled off to obtain tetrabutyl titanate modified epoxy resin.

[0082] S3, 10g stearic acid modified titanium dioxide, and 100g SH-900 were added to 1000g tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0083] S4. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0084] Comparative Example 3

[0085] S1. Dissolve 1000g of epoxy resin in 80g of benzene, add 150g of 30% (w / w) tetrabutyl titanate benzene solution, control the temperature at 43℃, react for 45min, raise the temperature to 142℃ at a rate of 5℃ / min to control the solvent distillation rate, and distill under reduced pressure until no solvent distillation occurs.

[0086] S2, 0.4% stearic acid, 10g silica, and 100g SH-900 were added to 1000g tetrabutyl titanate modified epoxy resin and stirred for 15 minutes to obtain modified epoxy resin.

[0087] S3. The modified epoxy resin is impregnated onto the surface of 7 bare steel wires, cured at 155℃ for 30 minutes to form a 0.15mm thick coating, and then stranded with a stranding machine to obtain high-strength steel strands.

[0088] Performance testing:

[0089] The modified epoxy resins obtained in Examples 1-9 and Comparative Examples 1-3 were transferred into polytetrafluoroethylene molds and cured using the methods described in each example and comparative example. Test strips with a thickness of 0.15 mm and rectangular dimensions of 25 mm × 150 mm were prepared. Tensile strength was tested using a tensile testing machine at a test speed of 10 mm / min. The modified epoxy resins obtained in Examples 1-9 and Comparative Examples 1-3 were coated with a 0.15 mm thick film on the surface of 82MnA steel sheets and cured using the methods described in each example and comparative example. A neutral salt spray test was conducted for 240 h according to the method in GB / T 10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test". The mass loss rate was recorded. The test results are recorded in Table 1.

[0090] Table 1 Tensile strength and corrosion resistance of high-strength steel strand

[0091]

[0092] Compared with Comparative Examples 1-3, the tensile strength of the modified epoxy resin samples prepared in Example 1 was higher than that of Comparative Examples 1-3, and the mass loss rate was lower than that of Comparative Examples 1-3. This indicates that the combination of stearic acid modified silica and tetrabutyl titanate modified epoxy resin improves the tensile strength and corrosion resistance of epoxy resin, thereby improving the strength and corrosion resistance of epoxy-coated steel strands.

[0093] Compared with Examples 1 and 9, the tensile strength of the steel strands prepared in Examples 4-8 is higher than that in Examples 1 and 9, and the mass loss rate is lower than that in Examples 1 and 9. This indicates that when the mass of stearic acid modified silica is 2%-10% of the mass of tetrabutyl titanate modified epoxy resin, the tensile strength and corrosion resistance of the modified epoxy resin coating are further improved, thereby further improving the strength and corrosion resistance of the epoxy-coated steel strands.

[0094] Compared with Examples 4 and 8, the tensile strength of the steel strands obtained in Examples 5-7 is higher than that in Examples 4 and 8, and the mass loss rate is lower than that in Examples 4 and 8. This indicates that when the mass of stearic acid modified silica is 5%-7% of the mass of tetrabutyl titanate modified epoxy resin, the tensile strength and corrosion resistance of the modified epoxy resin coating are further improved, thereby further improving the strength and corrosion resistance of the epoxy-coated steel strands.

[0095] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength steel strand, comprising steel wire and a coating disposed on the surface of the steel wire, prepared by the following steps: immersing bare steel wire in a modified epoxy resin, curing, and stranding to obtain the high-strength steel strand, characterized in that... The modified epoxy resin comprises stearic acid-modified silica, tetrabutyl titanate-modified epoxy resin, and a curing agent. The mass of stearic acid-modified silica in the modified epoxy resin is 2%-10% of the mass of tetrabutyl titanate-modified epoxy resin. The preparation method of the stearic acid-modified silica includes the following steps: dissolving stearic acid in ethanol, adding silica to react, and obtaining stearic acid-modified silica. In the preparation method of stearic acid-modified silica, the mass ratio of silica to stearic acid is 1g:35-45mg, and the reaction temperature is 65-75℃. The preparation method of the tetrabutyl titanate-modified epoxy resin includes the following steps: dissolving epoxy resin in benzene, adding tetrabutyl titanate-benzene solution, reacting, and distilling to obtain tetrabutyl titanate-modified epoxy resin. In the preparation method of tetrabutyl titanate-modified epoxy resin, the reaction temperature is 40-45℃, and the reaction time is 35-55min.

2. The high-strength steel strand according to claim 1, characterized in that, The mass of stearic acid-modified silica in the modified epoxy resin is 5%-7% of the mass of tetrabutyl titanate-modified epoxy resin.

3. The high-strength steel strand according to claim 1, characterized in that, The mass of the curing agent in the modified epoxy resin is 8%-12% of the mass of the tetrabutyl titanate modified epoxy resin.

4. The high-strength steel strand according to claim 1, characterized in that, The mass fraction of tetrabutyl titanate in the tetrabutyl titanate benzene solution is 25%-35%.

5. A high-strength steel strand according to claim 1, characterized in that, The thickness of the coating is 0.1-0.25 mm.

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