Production method of wire rod for high-carbon steel wire

Abstract

The invention discloses a production method of a wire rod for a high-carbon steel wire, which comprises the following steps: converter smelting, LF (ladle furnace) refining, small square billet continuous casting and wire rod rolling to form the wire rod with the diameter of 5.5 mm. The wire rod for the high-carbon steel wire comprises the following chemical components in percentage by mass: 0.68-0.72% of C, 0.10-0.25% of Si, 0.50-0.60% of Mn, 0.01-0.0.03% of V and the balance of Fe and inevitable impurities; low-vanadium microalloying design is adopted, the rolling cooling speed is strictly controlled, and rapid cooling (8-10 DEG C / s) is adopted before phase change at the temperature of 650 DEG C so as to reduce generation of network cementite; and at the later stage of phase transformation at the temperature of 650 DEG C, a slow cooling rate (0.80-1.2 DEG C / s) is adopted to inhibit the generation of martensite. The invention aims to realize stable tensile strength and stable drawing performance of the wire rod.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for producing a wire rod for high carbon steel wire. Background Art

[0002] High carbon steel wire rod is mainly used to manufacture prestressed concrete strands, bridge cables, high pressure oil pipes, springs and wire ropes. These applications have extremely high requirements on the performance of materials, so the development and application of high carbon steel wire rod is particularly important. With the rapid development of the construction and automotive industries, the demand for high strength and high durability steel is increasing, which will further promote the development of the high carbon steel wire rod market. At the same time, technological advances such as the development of new alloy elements and more efficient production technologies will also open up new possibilities for the application of high carbon steel wire rod.

[0003] However, the high carbon steel wire wire rod produced domestically has problems such as large fluctuation in tensile strength and unstable drawing performance. The present invention provides a high carbon steel wire wire rod with stable tensile strength and stable drawing performance. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method for producing a high-carbon steel wire wire rod, so as to produce a high-carbon steel wire wire rod with stable tensile strength and stable drawing performance.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for producing a wire rod for high carbon steel wire, comprising:

[0007] The sulfur content of molten iron is strictly controlled to be no more than 0.040%; deoxidizers and a series of alloying elements such as ferrosilicon and ferromanganese are added to the ladle to ensure the purification and alloying of molten steel;

[0008] During the steelmaking process, the carbon content, phosphorus and sulfur content at the end of smelting are precisely controlled to ensure that the remaining components are mainly iron; during the refining process, ferrosilicon powder is used for deep deoxidation, and aluminum-containing deoxidizers are prohibited to ensure that the oxygen content in the molten steel is controlled below 20ppm;

[0009] The binary basicity of the refined slag is controlled between 2.5 and 3.0, and the refining steelmaking temperature is controlled at 1530±10℃;

[0010] The continuous casting process adopts small square billet continuous casting technology. By controlling the superheat during continuous casting to ≤28℃ and the constant pulling speed to 2.0-2.2m / min, the center segregation is reduced and the internal quality of the ingot is improved. At the same time, protective pouring and electromagnetic stirring technology are used to improve the solidification structure of the ingot and reduce the formation of core martensite and network cementite.

[0011] In the rolling process, the rolling temperature is controlled at 1050-1150℃, and the spinning temperature is controlled at 870-930℃; the controlled cooling process adopts the Stelmor controlled cooling method, in which rapid cooling is adopted before the 650℃ phase change, and the cooling rate is 8-10℃ / s; slower cooling is adopted in the late 650℃ phase change, and the cooling rate is 0.80-1.2℃ / s;

[0012] The chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.68-0.72%, Si 0.10-0.25%, Mn 0.50-0.60%, V 0.01-0.0.03%, the remainder is Fe and unavoidable impurities, P in the impurities is ≤0.015%, and S in the impurities is ≤0.010%.

[0013] Furthermore, the constant pulling speed is 2.1 m / min.

[0014] Furthermore, the process parameters of the electromagnetic stirring technology were controlled as follows: the electromagnetic stirring current was 580 A and the frequency was 1.8 Hz.

[0015] Furthermore, the chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.69%, Si 0.15%, Mn 0.57%, V 0.02%, the remainder being Fe and unavoidable impurities, P in the impurities being 0.013%, and S in the impurities being 0.006%.

[0016] Furthermore, the chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.70%, Si 0.16%, Mn 0.58%, V 0.02%, the remainder being Fe and unavoidable impurities, P in the impurities being 0.010%, and S in the impurities being 0.005%.

[0017] Furthermore, the chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.70%, Si 0.15%, Mn 0.59%, V 0.02%, the remainder being Fe and unavoidable impurities, P in the impurities being 0.011%, and S in the impurities being 0.005%.

[0018] Furthermore, the tensile strength performance fluctuation range of the high carbon steel wire wire rod produced by the present invention satisfies ≤20MPa.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are:

[0020] The invention is characterized in that a low-vanadium microalloying design is adopted, the rolling cooling speed is strictly controlled, rapid cooling (8-10°C / s) is adopted before the 650°C phase transformation to reduce the formation of network cementite; a slower cooling rate (0.80-1.2°C / s) is adopted in the later stage of the 650°C phase transformation to inhibit the formation of martensite, thereby achieving stable tensile strength and stable drawing performance. BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION

[0021] In this example, the main preparation process of a wire rod for high carbon steel wire is: converter smelting-LF refining-small square billet continuous casting-wire rolling into Φ5.5mm wire rod.

[0022] Table 1 Finished product composition (wt%, balance iron)

[0023] C Si Mn P S V Example 1 0.69 0.15 0.57 0.013 0.006 0.02 Example 2 0.70 0.16 0.58 0.010 0.005 0.02 Example 3 0.70 0.15 0.59 0.011 0.005 0.02

[0024] Table 2 Rolling temperature control ℃

[0025]

[0026]

[0027] Table 3 Rolling cooling speed control ℃ / s

[0028] Before 650℃ After 650℃ Example 1 9.5 1.0 Example 2 9.6 1.1 Example 3 9.5 1.0

[0029] Table 4 Mechanical properties test

[0030]

[0031] It can be seen from Table 3 above that the performance fluctuation of the high carbon steel wire wire rod produced by the present invention is small, which meets the user requirements, is significantly better than the performance fluctuation range of domestic comparison manufacturers, and can better meet user requirements.

[0032] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for producing a wire rod for high carbon steel wire, characterized in that: include: The sulfur content of molten iron is strictly controlled to be no more than 0.040%; deoxidizers and a series of alloying elements such as ferrosilicon and ferromanganese are added to the ladle to ensure the purification and alloying of molten steel; During the steelmaking process, the carbon content, phosphorus and sulfur content at the end of smelting are precisely controlled to ensure that the remaining components are mainly iron; during the refining process, ferrosilicon powder is used for deep deoxidation, and aluminum-containing deoxidizers are prohibited to ensure that the oxygen content in the molten steel is controlled below 20ppm; The binary basicity of the refined slag is controlled between 2.5 and 3.0, and the refining steelmaking temperature is controlled at 1530±10℃; The continuous casting process adopts small square billet continuous casting technology. By controlling the superheat during continuous casting to ≤28℃ and the constant pulling speed to 2.0-2.2m / min, the center segregation is reduced and the internal quality of the ingot is improved. At the same time, protective pouring and electromagnetic stirring technology are used to improve the solidification structure of the ingot and reduce the formation of core martensite and network cementite. In the rolling process, the rolling temperature is controlled at 1050-1150℃, and the spinning temperature is controlled at 870-930℃; the controlled cooling process adopts the Stelmor controlled cooling method, in which rapid cooling is adopted before the 650℃ phase change, and the cooling rate is 8-10℃ / s; slower cooling is adopted in the late 650℃ phase change, and the cooling rate is 0.80-1.2℃ / s; The chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.68-0.72%, Si 0.10-0.25%, Mn 0.50-0.60%, V 0.01-0.0.03%, the remainder is Fe and unavoidable impurities, P in the impurities is ≤0.015%, and S in the impurities is ≤0.010%.

2. The method for producing a high carbon steel wire according to claim 1, characterized in that: The pulling speed using a constant pulling speed is 2.1 m / min.

3. The method for producing a high carbon steel wire according to claim 1, characterized in that: Process parameter control of electromagnetic stirring technology: electromagnetic stirring current is 580A, frequency is 1.8Hz.

4. The method for producing a wire rod for high carbon steel wire according to claim 1, characterized in that: The chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.69%, Si 0.15%, Mn 0.57%, V 0.02%, the remainder is Fe and unavoidable impurities, P in the impurities is 0.013%, and S in the impurities is 0.006%.

5. The method for producing a wire rod for high carbon steel wire according to claim 1, characterized in that: The chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.70%, Si 0.16%, Mn 0.58%, V 0.02%, the remainder is Fe and unavoidable impurities, P in the impurities is 0.010%, and S in the impurities is 0.005%.

6. The method for producing a wire rod for high carbon steel wire according to claim 1, characterized in that: The chemical composition of the high carbon steel wire rod is as follows in mass percentage: C 0.70%, Si 0.15%, Mn 0.59%, V 0.02%, the remainder is Fe and unavoidable impurities, P in the impurities is 0.011%, and S in the impurities is 0.005%.

7. The method for producing a high carbon steel wire according to claim 1, characterized in that: The tensile strength performance fluctuation range of the high carbon steel wire wire rod produced by the present invention satisfies ≤20MPa.

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