Steel strand and method for manufacturing the same

Abstract

The application relates to the technical field of steel strands, and discloses a steel strand and a preparation method thereof. The steel strand is obtained by twisting steel wires; the steel wires are composed of the following components in percentage by weight: C 0.80%-0.86%, Si 0.36%-0.45%, Mn 0.7%-0.8%, Cr 0.33%-0.46%, V 0.05%-0.07%, Ni 0.15%-0.20%, Mo 0.05%-0.12%, W 0.04%-0.12%, P<=0.015%, S<=0.010%, the rest being Fe and inevitable impurities, and the weight content of Mn, Mo and W satisfies the relationship: Mn / (Mo+W)=3.25-8. The above technical scheme solves the problem of low tensile strength of the steel strand in the related art.

Description

Technical Field

[0001] This invention relates to the field of steel strand technology, specifically to a steel strand and its preparation method. Background Technology

[0002] Steel strand is a core load-bearing steel product made of multiple steel wires twisted together. With its compact structure and convenient construction, it is widely used in bridge engineering, mining, undersea tunnels, power engineering and other fields. It is one of the core basic components to ensure the stability and safety of various engineering structures.

[0003] With the rapid development of modern engineering towards large-scale, heavy-duty, and long-term applications, increasingly stringent requirements are being placed on the mechanical properties of steel strands, whether for bridge cables, prestressed building structures, mine anchoring, submarine engineering, or load-bearing components for cable laying. Among these requirements, tensile strength, as the most critical mechanical indicator of steel strands, directly determines the load-bearing capacity, deformation resistance, and service life of engineering structures, and is a key parameter for evaluating the quality of steel strand products.

[0004] Therefore, it is necessary to propose a steel strand with high tensile strength and its preparation method. Summary of the Invention

[0005] This invention proposes a steel strand and its preparation method, which solves the problem of low tensile strength of steel strand in related technologies.

[0006] The technical solution of the present invention is as follows: This invention proposes a steel strand, which is obtained by stranding steel wires. The steel wires, by weight percentage, consist of the following components: C 0.80%~0.86%, Si 0.36%~0.45%, Mn 0.7%~0.8%, Cr 0.33%~0.46%, V 0.05%~0.07%, Ni 0.15%~0.20%, Mo 0.05%~0.12%, W 0.04%~0.12%, P≤0.015%, S≤0.010%, with the remainder being Fe and unavoidable impurities. The weight content of Mn, Mo, and W satisfies the relationship: Mn / (Mo+W) = 3.25~8, preferably 5.

[0007] As a further technical solution, the weight content of Mo and W satisfies the relationship: Mo / W = 0.6~3, preferably 1.

[0008] The present invention also proposes a method for preparing steel strand, which includes the following steps: S1. After the steel wire is prepared according to its composition, it is melted and refined, and then cast into a billet. S2. The billet is rolled, drawn, and heat-treated to obtain steel wire; S3. Twist the steel wires together to obtain a semi-finished product; S4. The semi-finished product is immersed in polyurethane emulsion and then cured to obtain steel strand.

[0009] As a further technical solution, in step S4, the polyurethane emulsion includes the following raw materials in parts by weight: 100 parts of waterborne polyurethane emulsion, 8-12 parts of filler, 8-10 parts of waterborne polyurethane curing agent, and 0.5-1 parts of additives.

[0010] As a further technical solution, the filler is silane-modified mica powder, which is composed of γ-aminopropyltriethoxysilane-modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane-modified mica powder in a mass ratio of 1:1~2.

[0011] In this invention, after the polyurethane emulsion cures, a polyurethane layer is formed, which acts as a physical barrier and improves the corrosion resistance of the steel strand. The raw materials of the polyurethane emulsion also contain silane-modified mica powder. After silane modification, the dispersibility of mica powder in the polyurethane emulsion is improved. Furthermore, the silane-modified mica powder is composed of γ-aminopropyltriethoxysilane-modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane-modified mica powder in a mass ratio of 1:1~2. This improves the interfacial bonding between the modified mica powder and the water-based polyurethane emulsion, making the formed polyurethane layer denser and thus improving the overall corrosion resistance of the steel strand.

[0012] As a further technical solution, the filler is silane-modified mica powder, which is composed of γ-aminopropyltriethoxysilane-modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane-modified mica powder in a mass ratio of 1:1.5. As a further technical solution, the raw materials for the γ-aminopropyltriethoxysilane modified mica powder include γ-aminopropyltriethoxysilane and mica powder I in a mass ratio of 1:10; the raw materials for the N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder include N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and mica powder II in a mass ratio of 1:10.

[0013] As a further technical solution, the preparation method of the γ-aminopropyltriethoxysilane modified mica powder includes the following steps: adding γ-aminopropyltriethoxysilane to a solvent and mixing, then adding mica powder I and mixing, and finally filtering and drying to obtain γ-aminopropyltriethoxysilane modified mica powder.

[0014] As a further technical solution, the preparation method of the N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder includes the following steps: adding N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane to a solvent and mixing, then adding mica powder II and mixing, and finally filtering and drying to obtain N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder.

[0015] As a further technical solution, the additives include one or more of defoamers, dispersants, leveling agents, and stabilizers.

[0016] As a further technical solution, step S2 specifically involves: after the billet is rolled and drawn in 15 to 24 passes, it is heated to 850 to 900°C and held for 1 to 2 hours, then cooled to 300°C, and then heated to 700°C and held for 0.5 to 1 hour, and then cooled to room temperature to obtain steel wire.

[0017] The working principle and beneficial effects of this invention are as follows: In this invention, by limiting the composition of the steel wire and further defining the mass content relationship of Mn, Mo, and W, the tensile strength of the steel wire can be improved, thereby enhancing the tensile strength of the steel strand. When the mass content relationship of Mn, Mo, and W satisfies the formula: Mn / (Mo+W) = 3.25~8, the enhancing effect of Mn, Mo, and W components on tensile strength can be fully utilized. Through carbide strength, solid solution strength, and grain refinement, the tensile strength of the steel wire is synergistically improved, thereby enhancing the tensile strength of the steel strand. Detailed Implementation

[0018] 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.

[0019] In the following embodiments and comparative examples: Waterborne polyurethane emulsion: solid content 35%; average particle size of mica powder is 800 mesh.

[0020] Example 1 By weight percentage, the steel wire is composed of the following components: C 0.80%, Si 0.36%, Mn 0.7%, Cr 0.33%, V 0.05%, Ni 0.15%, Mo 0.05%, W 0.05%, P 0.015%, S 0.010%, with the remainder being Fe and unavoidable impurities; among which, the weight contents of Mn, Mo, and W satisfy the following relationships: Mn / (Mo+W) = 7, Mo / W = 1; The polyurethane emulsion comprises the following raw materials in parts by weight: 100 parts waterborne polyurethane emulsion, 8 parts filler, 8 parts waterborne polyurethane curing agent, and 0.5 parts leveling agent BYK349; the filler is mica powder; the polyurethane emulsion is prepared by mixing the above raw materials. A method for preparing steel strand includes the following steps: S1. After the steel wire is prepared according to the above composition, it is melted and refined, and then cast into a billet. S2. After the billet is rolled and drawn in 24 passes (total compression rate of 92%), it is heated to 850℃ and held for 2 hours, then cooled to 300℃, then heated to 700℃ and held for 0.5 hours, and then cooled to room temperature to obtain steel wire. S3. Twist the steel wires to obtain a semi-finished product; S4. The semi-finished product is immersed in polyurethane emulsion and then cured to obtain steel strand.

[0021] Example 2 By weight percentage, the steel wire is composed of the following components: C 0.82%, Si 0.40%, Mn 0.8%, Cr 0.46%, V 0.06%, Ni 0.18%, Mo 0.08%, W 0.08%, P 0.012%, S 0.008%, with the remainder being Fe and unavoidable impurities; among which, the weight contents of Mn, Mo, and W satisfy the following relationships: Mn / (Mo+W) = 5, Mo / W = 1; The polyurethane emulsion comprises the following raw materials in parts by weight: 100 parts waterborne polyurethane emulsion, 12 parts filler, 10 parts waterborne polyurethane curing agent, and 0.5 parts leveling agent BYK349; the filler is mica powder; the polyurethane emulsion is prepared by mixing the above raw materials. A method for preparing steel strand includes the following steps: S1. After the steel wire is prepared according to the above composition, it is melted and refined, and then cast into a billet. S2. After the billet is rolled and drawn in 24 passes (total compression rate of 92%), it is heated to 900℃ and held for 1 hour, then cooled to 300℃, and then heated to 700℃ and held for 1 hour, and then cooled to room temperature to obtain steel wire. S3. Twist the steel wires to obtain a semi-finished product; S4. The semi-finished product is immersed in polyurethane emulsion and then cured to obtain steel strand.

[0022] Example 3 By weight percentage, the steel wire is composed of the following components: C 0.86%, Si 0.45%, Mn 0.78%, Cr 0.46%, V 0.07%, Ni 0.20%, Mo 0.12%, W 0.12%, P 0.010%, S 0.005%, with the remainder being Fe and unavoidable impurities; among which, the weight contents of Mn, Mo, and W satisfy the following relationships: Mn / (Mo+W) = 3.25, Mo / W = 1; The polyurethane emulsion comprises the following raw materials in parts by weight: 100 parts waterborne polyurethane emulsion, 12 parts filler, 10 parts waterborne polyurethane curing agent, and 1 part leveling agent BYK349; the filler is mica powder; the polyurethane emulsion is prepared by mixing the above raw materials. A method for preparing steel strand includes the following steps: S1. After the steel wire is prepared according to the above composition, it is melted and refined, and then cast into a billet. S2. After the billet is rolled and drawn in 24 passes (total compression rate of 92%), it is heated to 900℃ and held for 1 hour, then cooled to 300℃, and then heated to 700℃ and held for 1 hour, and then cooled to room temperature to obtain steel wire. S3. Twist the steel wires to obtain a semi-finished product; S4. The semi-finished product is immersed in polyurethane emulsion and then cured to obtain steel strand.

[0023] Example 4 Compared with Example 2, the only difference in this example is that, by weight percentage, the steel wire is composed of the following components: C 0.82%, Si 0.40%, Mn 0.8%, Cr 0.46%, V 0.06%, Ni 0.18%, Mo 0.05%, W 0.05%, P 0.012%, S 0.008%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 8, Mo / W = 1.

[0024] Example 5 Compared with Example 2, the only difference in this example is that, by weight percentage, the steel wire is composed of the following components: C 0.82%, Si 0.40%, Mn 0.8%, Cr 0.46%, V 0.06%, Ni 0.18%, Mo 0.1%, W 0.1%, P 0.012%, S 0.008%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 4, Mo / W = 1.

[0025] Example 6 Compared with Example 2, the only difference in this example is that, by weight percentage, the steel wire is composed of the following components: C 0.82%, Si 0.40%, Mn 0.8%, Cr 0.46%, V 0.06%, Ni 0.18%, Mo 0.06%, W 0.1%, P 0.012%, S 0.008%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 5, Mo / W = 0.6.

[0026] Example 7 Compared with Example 2, the only difference in this example is that, by weight percentage, the steel wire is composed of the following components: C 0.82%, Si 0.40%, Mn 0.8%, Cr 0.46%, V 0.06%, Ni 0.18%, Mo 0.12%, W 0.04%, P 0.012%, S 0.008%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 5, Mo / W = 3.

[0027] Example 8 Compared with Example 7, the only difference in this example is that the filler is γ-aminopropyltriethoxysilane-modified mica powder. The preparation method of γ-aminopropyltriethoxysilane-modified mica powder is as follows: γ-aminopropyltriethoxysilane is added to water and mixed, then mica powder is added and mixed at 45°C for 1.5 h. After filtration and drying, γ-aminopropyltriethoxysilane-modified mica powder is obtained. The mass ratio of γ-aminopropyltriethoxysilane to mica powder is 1:10, and the mass-volume ratio of mica powder to water is 1 g: 8 mL.

[0028] Example 9 Compared with Example 7, the only difference in this example is that the filler is N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder. The preparation method of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder is as follows: N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane is added to water and mixed, then mica powder is added and mixed at 45°C for 1.5 h. After filtration and drying, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder is obtained. The mass ratio of γ-aminopropyltriethoxysilane to mica powder is 1:10, and the mass-volume ratio of mica powder to water is 1 g: 8 mL.

[0029] Example 10 Compared with Example 7, the only difference in this example is that the filler is composed of γ-aminopropyltriethoxysilane modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder in a mass ratio of 1:1. The preparation method of γ-aminopropyltriethoxysilane modified mica powder is as follows: γ-aminopropyltriethoxysilane is added to water and mixed, then mica powder is added and mixed at 45℃ for 1.5h. After filtration and drying, γ-aminopropyltriethoxysilane modified mica powder is obtained; wherein the mass ratio of γ-aminopropyltriethoxysilane to mica powder is 1:10, and the mass-volume ratio of mica powder to water is 1g:8mL. The preparation method of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder is as follows: N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane is added to water and mixed, then mica powder is added and mixed at 45℃ for 1.5h. After filtration and drying, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder is obtained; wherein the mass ratio of γ-aminopropyltriethoxysilane to mica powder is 1:10, and the mass-volume ratio of mica powder to water is 1g:8mL.

[0030] Example 11 Compared with Example 10, the only difference in this example is that the filler is composed of γ-aminopropyltriethoxysilane modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder in a mass ratio of 1:1.5.

[0031] Example 12 Compared with Example 10, the only difference in this example is that the filler is composed of γ-aminopropyltriethoxysilane modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder in a mass ratio of 1:2.

[0032] Comparative Example 1 Compared with Example 1, the only difference in this comparative example is that, by weight percentage, the steel wire is composed of the following components: C 0.80%, Si 0.36%, Mn 0.7%, Cr 0.33%, V 0.05%, Ni 0.15%, W 0.05%, P 0.015%, S 0.010%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 7, Mo / W = 1.

[0033] Comparative Example 2 Compared with Example 1, the only difference in this comparative example is that, by weight percentage, the steel wire is composed of the following components: C 0.80%, Si 0.36%, Mn 0.7%, Cr 0.33%, V 0.05%, Ni 0.15%, Mo 0.05%, P 0.015%, S 0.010%, with the remainder being Fe and unavoidable impurities; wherein, the weight content of Mn, Mo, and W satisfies the following relationship: Mn / (Mo+W) = 7, Mo / W = 1.

[0034] Comparative Example 3 Compared with Example 1, the only difference in this comparative example is that, by weight percentage, the steel wire is composed of the following components: C 0.80%, Si 0.36%, Mn 0.7%, Cr 0.33%, V 0.05%, Ni 0.15%, P 0.015%, S 0.010%, with the remainder being Fe and unavoidable impurities; wherein, the weight contents of Mn, Mo, and W satisfy the following relationships: Mn / (Mo+W) = 7, Mo / W = 1.

[0035] Experimental Example 1 The steel wires prepared in Examples 1-7 and Comparative Examples 1-3 were used to determine their tensile strength according to the method in GB / T 228.1-2021 "Metallic materials, tensile testing—Part 1: Test at room temperature," with a test speed of 0.008 s. -1 The measurement results are shown in Table 1.

[0036] Table 1. Tensile strength of steel wires in Examples 1-7 and Comparative Examples 1-3

[0037] As shown in Table 1, the tensile strength of Examples 1-7 is higher than that of Comparative Examples 1-3, indicating that the addition of Mn, Mo and W components in this invention can improve the tensile strength of the steel wire.

[0038] Experiment Example 2 The steel strands prepared in Examples 7-12 were subjected to salt spray resistance tests according to the test methods in GB / T 1771-2007. The time of appearance of bubbles, rust or detachment was recorded. The test results are shown in Table 2.

[0039] Table 2 Corrosion resistance of steel strands in Examples 7-12

[0040] As shown in Table 2, the salt spray resistance time of Examples 8-12 is higher than that of Example 7, indicating that the use of silane-modified mica powder can further improve the corrosion resistance of steel strands.

[0041] 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 type of steel strand, characterized in that, The steel strand is obtained by stranding steel wires; by weight percentage, the steel wires are composed of the following components: C 0.80%~0.86%, Si 0.36%~0.45%, Mn 0.7%~0.8%, Cr 0.33%~0.46%, V 0.05%~0.07%, Ni 0.15%~0.20%, Mo 0.05%~0.12%, W 0.04%~0.12%, P≤0.015%, S≤0.010%, with the remainder being Fe and unavoidable impurities, and the weight content of Mn, Mo, and W satisfies the relationship: Mn / (Mo+W) = 3.25~8.

2. The steel strand according to claim 1, characterized in that, The weight contents of Mo and W satisfy the following relationship: Mo / W = 0.6~3.

3. A method for preparing steel strand, characterized in that, The method for preparing the steel strand according to any one of claims 1 to 2 comprises the following steps: S1. After the steel wire is prepared according to its composition, it is melted and refined, and then cast into a billet. S2. The billet is rolled, drawn, and heat-treated to obtain steel wire; S3. Twist the steel wires together to obtain a semi-finished product; S4. The semi-finished product is immersed in polyurethane emulsion and then cured to obtain steel strand.

4. The method for preparing steel strand according to claim 3, characterized in that, In step S4, the polyurethane emulsion comprises the following raw materials in parts by weight: 100 parts of waterborne polyurethane emulsion, 8-12 parts of filler, 8-10 parts of waterborne polyurethane curing agent, and 0.5-1 parts of additives.

5. The method for preparing steel strand according to claim 4, characterized in that, The filler is silane-modified mica powder, which is composed of γ-aminopropyltriethoxysilane-modified mica powder and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane-modified mica powder in a mass ratio of 1:1~2.

6. The method for preparing steel strand according to claim 5, characterized in that, The raw materials for the γ-aminopropyltriethoxysilane-modified mica powder include γ-aminopropyltriethoxysilane and mica powder I in a mass ratio of 1:10; the raw materials for the N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane-modified mica powder include N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and mica powder II in a mass ratio of 1:

10.

7. The method for preparing steel strand according to claim 6, characterized in that, The preparation method of the γ-aminopropyltriethoxysilane modified mica powder includes the following steps: adding γ-aminopropyltriethoxysilane to a solvent and mixing, then adding mica powder I and mixing, and finally filtering and drying to obtain γ-aminopropyltriethoxysilane modified mica powder.

8. The method for preparing steel strand according to claim 6, characterized in that, The preparation method of the N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder includes the following steps: N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane is added to a solvent and mixed, then mica powder II is added and mixed, and finally filtered and dried to obtain N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane modified mica powder.

9. The method for preparing steel strand according to claim 4, characterized in that, The additives include one or more of the following: defoamers, dispersants, leveling agents, and stabilizers.

10. The method for preparing steel strand according to claim 3, characterized in that, Step S2 is as follows: After the billet is rolled and drawn 15 to 24 times, it is heated to 850 to 900°C and held for 1 to 2 hours, then cooled to 300°C, and then heated to 700°C and held for 0.5 to 1 hour, and then cooled to room temperature to obtain steel wire.

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