A steel strand and its preparation process

Abstract

The present invention relates to the technical field of steel strands, and provides a steel strand and a preparation process thereof. The steel strand is composed of the following components by mass percentage: C 0.88% - 0.95%, Si 0.35% - 0.55%, Mn 0.7% - 0.8%, Cr 0.33% - 0.46%, Al 0.015% - 0.055%, V 0.05% - 0.07%, Ni 0.13% - 0.19%, Gd 0.03% - 0.05%, P ≤ 0.012%, S ≤ 0.008%, and the balance is Fe and inevitable impurities, and Ni / Gd ≥ 3.8. Through the above technical solution, the problems of low strength and poor corrosion resistance of the steel strand in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of steel strands, and specifically, to a steel strand and a preparation process thereof. Background Art

[0002] A steel strand is a steel product composed of multiple steel wires twisted together, and is widely used in fields such as bridges, buildings, and ships. These application fields have relatively high requirements for the corrosion resistance and strength of materials. After the steel strand is subjected to the action of corrosive media such as moisture, chemical gases, dust, and salts in the atmosphere, corrosion occurs, which will cause the overall tensile strength of the steel strand to decrease. In severe cases, the phenomenon of broken strands of the steel strand may occur. At present, the anti-corrosion measures for steel strands mainly focus on adjusting the components of the steel wires and applying a corrosion-resistant coating on the surface of the steel strand, but there are disadvantages such as insufficient strength of the steel strand itself and easy peeling of the coating. Ultimately, the strength and corrosion resistance of the steel strand are not alleviated. Therefore, it is necessary to obtain a steel strand with high strength and excellent corrosion resistance, improve the strength of the steel strand, reduce the intrusion of corrosive media, and extend the service life of the steel strand. Summary of the Invention

[0003] The present invention provides a steel strand and a preparation process thereof, which solve the problems of low strength and poor corrosion resistance of the steel strand in the related art.

[0004] The technical solution of the present invention is as follows:

[0005] The present invention provides a steel strand, which is composed of the following components by mass percentage: C 0.88% - 0.95%, Si 0.35% - 0.55%, Mn 0.7% - 0.8%, Cr 0.33% - 0.46%, Al 0.015% - 0.055%, V 0.05% - 0.07%, Ni 0.13% - 0.19%, Gd 0.03% - 0.05%, P≤0.012%, S≤0.008%, and the balance is Fe and unavoidable impurities, and Ni / Gd≥3.8.

[0006] As a further technical solution, the surface of the steel strand further includes a Ni-Mo-Ti-La chemical coating.

[0007] In the present invention, a Ni-Mo-Ti-La chemical coating is provided on the surface of the steel strand with nickel salt, molybdenum salt, titanium salt, and lanthanum salt as raw materials in a mass ratio of 10:5 - 10:8:2, further improving the corrosion resistance of the steel strand.

[0008] As a further technical solution, the Ni-Mo-Ti-La electroless plating layer comprises raw materials in the following parts by weight: 20-30 parts of metal salt, 15-20 parts of sodium hypophosphite, 30-45 parts of sodium tartrate, and 3-5 parts of polyethylene glycol; the metal salt is nickel salt, molybdenum salt, titanium salt and lanthanum salt.

[0009] As a further technical solution, the mass ratio of the nickel salt, molybdenum salt, titanium salt and lanthanum salt is 10:5-10:8:2.

[0010] As a further technical solution, the mass ratio of the nickel salt, molybdenum salt, titanium salt and lanthanum salt is 10:6-8:8:2.

[0011] In the present invention, when the mass ratio of the nickel salt, molybdenum salt, titanium salt and lanthanum salt in the raw materials of the Ni-Mo-Ti-La electroless plating layer is limited to 10:6-8:8:2, the corrosion resistance of the steel strand is further improved.

[0012] As a further technical solution, the nickel salt includes one or more of nickel hypophosphite, nickel nitrate and nickel sulfate; the molybdenum salt includes one or more of molybdenum nitrate, molybdenum acetate and molybdenum sulfate; the titanium salt includes one or more of titanium oxalate, titanium tetrachloride and titanium trichloride; the lanthanum salt includes one or more of lanthanum carbonate, lanthanum chloride and lanthanum nitrate.

[0013] The present invention also provides a preparation process of the steel strand, comprising the following steps:

[0014] S1. Weigh the raw materials according to the components of the steel strand, carry out melting, refining and slag removal treatment, and then cast and mold to obtain a metal blank.

[0015] S2. Roll, draw and heat-treat the metal blank to obtain steel wires.

[0016] S3. Mix the raw materials of the Ni-Mo-Ti-La electroless plating layer and water to obtain an electroless plating solution.

[0017] S4. Place the steel wires in the electroless plating solution for electroless plating to obtain electroless plated steel wires.

[0018] S5. Twist and carry out stabilization treatment on the electroless plated steel wires to obtain steel strands.

[0019] As a further technical solution, in step S3, the volume ratio of the total mass of the raw materials of the electroless plating layer to water is 68-100 g / L.

[0020] As a further technical solution, in step S4, the temperature of the electroless plating is 85-95 °C and the time is 2-3 h.

[0021] As a further technical solution, in step S5, the temperature of the stabilization treatment is 380~410°C, and the linear velocity is 42~46 m / min.

[0022] The working principle and beneficial effects of the present invention are as follows:

[0023] In the present invention, by adjusting the content of Ni in the components of the steel strand to 0.13%~0.19% and the content of Gd to 0.03%~0.05%, and when the ratio of Ni to Gd is greater than or equal to 3.8, the strength and corrosion resistance of the steel strand are significantly improved. Specific embodiments

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0025] Embodiment 1

[0026] The steel strand is composed of the following components by mass percentage: C 0.88%, Si 0.35%, Mn 0.7%, Cr 0.33%, Al 0.015%, V 0.05%, Ni 0.13%, Gd 0.033%, P 0.01%, S 0.005%, and the balance is Fe and inevitable impurities;

[0027] The preparation process of the steel strand includes the following steps:

[0028] S1. Weigh the raw materials according to the components of the steel strand, melt them, and after refining and slag removal treatment, cast them into shape to obtain a metal blank;

[0029] S2. Roll, draw, and heat-treat the metal blank to obtain steel wires;

[0030] S3. Twist the steel wires and perform stabilization treatment at 380°C and a linear velocity of 42 m / min to obtain a steel strand; among them, when twisting, 1 steel wire is used as the center wire and 15 steel wires are used as the side wires. After winding on the shaft respectively, strand twisting is carried out, the strand pitch is 200 mm, and the strand angle is 10 degrees.

[0031] Embodiment 2

[0032] The steel strand is composed of the following components by mass percentage: C 0.95%, Si 0.55%, Mn 0.8%, Cr 0.46%, Al 0.055%, V 0.07%, Ni 0.19%, Gd 0.0487%, P 0.008%, S 0.006%, and the balance is Fe and inevitable impurities;

[0033] The preparation process of the steel strand includes the following steps:

[0034] S1. Weigh the raw materials according to the components of the steel strand, carry out melting, refining, and slag removal treatments, and then cast and form to obtain a metal blank;

[0035] S2. Roll, draw, and heat-treat the metal blank to obtain steel wires;

[0036] S3. Twist the steel wires, and carry out stabilization treatment at 395°C and a linear speed of 43 m / min to obtain the steel strand; among them, when twisting, 1 steel wire is used as the center wire and 15 steel wires are used as the side wires. After respectively winding onto shafts, strand twisting is carried out, the strand pitch is 200 mm, and the strand angle is 10 degrees.

[0037] Example 3

[0038] The steel strand is composed of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Ni 0.1835%, Gd 0.047%, P 0.009%, S 0.005%, and the balance is Fe and inevitable impurities;

[0039] The preparation process of the steel strand includes the following steps:

[0040] S1. Weigh the raw materials according to the components of the steel strand, carry out melting, refining, and slag removal treatments, and then cast and form to obtain a metal blank;

[0041] S2. Roll, draw, and heat-treat the metal blank to obtain steel wires;

[0042] S3. Twist the steel wires, and carry out stabilization treatment at 410°C and a linear speed of 46 m / min to obtain the steel strand; among them, when twisting, 1 steel wire is used as the center wire and 15 steel wires are used as the side wires. After respectively winding onto shafts, strand twisting is carried out, the strand pitch is 200 mm, and the strand angle is 10 degrees.

[0043] Example 4

[0044] The difference between this embodiment and Embodiment 3 is only that the steel strand is composed of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Ni 0.19%, Gd 0.05%, P 0.009%, S 0.005%, and the balance is Fe and unavoidable impurities.

[0045] Embodiment 5

[0046] The difference between this embodiment and Embodiment 3 is only that the steel strand is composed of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Ni 0.18%, Gd 0.03%, P 0.009%, S 0.005%, and the balance is Fe and unavoidable impurities.

[0047] Embodiment 6

[0048] The difference between this embodiment and Embodiment 3 is only that the surface of the steel strand further includes a Ni-Mo-Ti-La chemical plating layer;

[0049] The raw materials of the Ni-Mo-Ti-La chemical plating layer include: metal salts, sodium hypophosphite, sodium tartrate, and polyethylene glycol.

[0050] The preparation process of the steel strand includes the following steps:

[0051] S1. Weigh the raw materials according to the components of the steel strand, conduct melting, refining, and slag removal treatments, and then cast and form to obtain a metal blank;

[0052] S2. Roll, draw, and heat-treat the metal blank to obtain steel wires;

[0053] S3. Mix the raw materials of the Ni-Mo-Ti-La chemical plating layer and water to obtain a chemical plating solution with the composition of 20 g / L of metal salts, 15 g / L of sodium hypophosphite, 30 g / L of sodium tartrate, and 3 g / L of polyethylene glycol, where the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate, and lanthanum carbonate with a mass ratio of 11:5:8:2;

[0054] S4. Place the steel wires in the chemical plating solution and conduct chemical plating at 85 °C for 3 h to obtain chemically plated steel wires;

[0055] S5. Twist and conduct stabilization treatment on the chemically plated steel wires to obtain a steel strand.

[0056] Embodiment 7

[0057] The difference between this embodiment and Embodiment 6 is only that the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate, and lanthanum carbonate with a mass ratio of 10:5:8:3.

[0058] Example 8

[0059] The difference between this example and Example 6 is only that the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate and lanthanum carbonate with a mass ratio of 10:5:8:2.

[0060] Example 9

[0061] The difference between this example and Example 6 is only that the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate and lanthanum carbonate with a mass ratio of 5:5:4:1.

[0062] Example 10

[0063] The difference between this example and Example 6 is only that the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate and lanthanum carbonate with a mass ratio of 5:3:4:1.

[0064] Example 11

[0065] The difference between this example and Example 6 is only that the metal salts are nickel nitrate, molybdenum nitrate, titanium oxalate and lanthanum carbonate with a mass ratio of 5:4:4:1.

[0066] Example 12

[0067] The difference between this example and Example 11 is only the preparation process of the steel strand, including the following steps:

[0068] S1. Weigh the raw materials according to the components of the steel strand, carry out melting, refining and slag removal treatment, and then cast and form to obtain a metal blank.

[0069] S2. Roll, draw and heat-treat the metal blank to obtain steel wires.

[0070] S3. Mix the raw materials of the Ni-Mo-Ti-La chemical coating and water to obtain a chemical plating solution with a composition of 30 g / L of metal salt, 20 g / L of sodium hypophosphite, 45 g / L of sodium tartrate and 5 g / L of polyethylene glycol.

[0071] S4. Place the steel wires in the chemical plating solution and carry out chemical plating at 95°C for 2 h to obtain chemically plated steel wires.

[0072] S5. Twist the steel wires and carry out stabilization treatment at 410°C with a linear velocity of 46 m / min to obtain the steel strand.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Example 3 is only that the steel strand consists of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Ni 0.15%, Gd 0.05%, P 0.009%, S 0.005%, and the balance is Fe and unavoidable impurities.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Example 3 is only that the steel strand consists of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Gd 0.047%, P 0.009%, S 0.005%, and the balance is Fe and unavoidable impurities.

[0077] Comparative Example 3

[0078] The difference between this comparative example and Example 3 is only that the steel strand consists of the following components by mass percentage: C 0.91%, Si 0.43%, Mn 0.76%, Cr 0.39%, Al 0.048%, V 0.06%, Ni 0.1835%, P 0.009%, S 0.005%, and the balance is Fe and unavoidable impurities.

[0079] In accordance with the standard GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", the tensile strength tests were respectively carried out on the steel strand specimens prepared in Examples 1 to 12 and Comparative Examples 1 to 3, which were recorded as the initial tensile strength. Then, in accordance with the standard GB / T 10125-2021 "Artificial atmosphere corrosion tests - Salt spray tests", the neutral salt spray tests were carried out on the steel strand specimens respectively, and then the tensile strength tests were carried out again, which were recorded as the tensile strength after corrosion, and the change rate of tensile strength was calculated (the result was reserved to two decimal places). The change rate of tensile strength = [(initial tensile strength - tensile strength after corrosion) / initial tensile strength]×100%, as shown in the following table.

[0080]

[0081] Compared with Comparative Examples 1 to 3, the steel strands prepared in Examples 1 to 12 have higher tensile strength and smaller change rate of tensile strength after corrosion, indicating that by adjusting the content of Ni in the components of the steel strand to 0.13% - 0.19% and the content of Gd to 0.03% - 0.05%, and when the ratio of Ni to Gd is greater than or equal to 3.8, the strength and corrosion resistance of the steel strand are significantly improved.

[0082] Compared with Examples 5 to 7, the change rate of the tensile strength of the steel strands prepared in Examples 8 to 12 after corrosion is smaller, indicating that a Ni-Mo-Ti-La chemical coating is provided on the surface of the steel strands with nickel salt, molybdenum salt, titanium salt and lanthanum salt in a mass ratio of 10:5 to 10:8:2 as raw materials, further improving the corrosion resistance of the steel strands.

[0083] Compared with Examples 8 to 9, the change rate of the tensile strength of the steel strands prepared in Examples 10 to 12 after corrosion is smaller, indicating that when the mass ratio of nickel salt, molybdenum salt, titanium salt and lanthanum salt in the Ni-Mo-Ti-La chemical coating raw materials is limited to 10:6 to 8:8:2, the corrosion resistance of the steel strands is further improved.

[0084] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A steel strand, characterized in that: The steel strand is composed of the following components in mass percentage: C 0.88%~0.95%, Si0.35%~0.55%, Mn 0.7%~0.8%, Cr 0.33%~0.46%, Al 0.015%~0.055%, V 0.05%~0.07%, Ni0.13%~0.19%, Gd 0.03%~0.05%, P≤0.012%, S≤0.008%, the balance is Fe and unavoidable impurities, and Ni / Gd≥3.8; The surface of the steel strand also includes a Ni-Mo-Ti-La chemical plating layer; The Ni-Mo-Ti-La chemical plating layer comprises the following raw materials in parts by weight: 20-30 parts of metal salt, 15-20 parts of sodium hypophosphite, 30-45 parts of sodium tartrate, and 3-5 parts of polyethylene glycol; the metal salt is nickel salt, molybdenum salt, titanium salt, and lanthanum salt; The mass ratio of the nickel salt, molybdenum salt, titanium salt and lanthanum salt is 10:5-10:8:

2.

2. A steel strand according to claim 1, characterized in that: The mass ratio of the nickel salt, molybdenum salt, titanium salt and lanthanum salt is 10:6-8:8:

2.

3. The steel strand according to claim 1, characterized in that: The nickel salt includes one or more of nickel hypophosphite, nickel nitrate, and nickel sulfate; the molybdenum salt includes one or more of molybdenum nitrate, molybdenum acetate, and molybdenum sulfate; the titanium salt includes one or more of titanium oxalate, titanium tetrachloride, and titanium trichloride; the lanthanum salt includes one or more of lanthanum carbonate, lanthanum chloride, and lanthanum nitrate.

4. A process for preparing a steel strand according to any one of claims 2 to 3, characterized in that: The following steps are involved: S1. Weigh the raw materials according to the components of the steel strand, perform smelting, refining, and slag removal, and then cast them into a metal billet; S2, rolling, drawing and heat treating the metal blank to obtain steel wire; S3, mixing the raw materials of the Ni-Mo-Ti-La chemical plating layer with water to obtain a chemical plating solution; S4, placing the steel wire in a chemical plating solution for chemical plating to obtain a chemically plated steel wire; S5. Twisting the chemically plated steel wire and subjecting it to stabilization treatment to obtain a steel strand.

5. A process for preparing a steel strand according to claim 4, characterized in that: In step S3, the volume ratio of the total mass of the raw materials for the chemical plating layer to water is 68-100 g / L.

6. A process for preparing a steel strand according to claim 4, characterized in that: In step S4, the temperature of the chemical plating is 85-95° C. and the time is 2-3 hours.

7. The process for preparing a steel strand according to claim 4, characterized in that: In step S5, the temperature of the stabilization treatment is 380-410° C., and the line speed is 42-46 m / min.

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