Metal strip winding segment, mandrel, winding device, process line, metal strip winding method, and high-tensile steel sheet manufacturing method

Abstract

To provide a segment for winding a metal strip, a mandrel, a winding device, a process line, a method for winding the metal strip, a method for manufacturing a high-tensile steel sheet, capable of suppressing occurrence of slip between the segment and a sleeve during winding the metal strip, and suppressing winding failure of the metal strip, rewinding work, and a decrease in product yield.SOLUTION: There is provided a segment for winding a metal strip which is provided around a mandrel shaft rotating when winding the metal strip and in which a sleeve in contact with metal strip is attached outside, wherein an arithmetic average roughness Ra of a surface in contact with the sleeve is 3.2 μ m or more and 12.5 μ m or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal strip winding segment for winding a metal strip such as a high-tensile steel sheet into a coil, a mandrel, a winding device, a process line, a metal strip winding method, and a method for manufacturing a high-tensile steel sheet. [Background technology]

[0002] In recent years, there has been an increasing demand for high-tensile steel sheets as automobile frames in order to reduce the weight of automobile bodies and improve collision safety. In the manufacture of metal strips such as high-tensile steel sheets, heat treatment is carried out in continuous annealing equipment to obtain the mechanical properties of the products. The metal strips after the heat treatment are then wound on a reel in a winding device to form a coil.

[0003] The winding device has a mandrel shaft that rotates for winding, steel segments provided around the mandrel shaft, and sleeves attached to the outside of the segments.

[0004] High-tensile steel sheets with a tensile strength of 1180 MPa or more are prone to inner diameter collapse after being formed into a coil if the tension applied during coiling after heat treatment is insufficient. As a method for preventing inner diameter collapse, a method for increasing the tension applied to the metal strip during coiling has been proposed (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-267746 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method described in Patent Document 1 (increasing the tension of the metal strip during winding) sometimes causes slippage between the segment and the sleeve, resulting in winding defects. These winding defects then lead to problems such as the need for rewinding work and a decrease in product yield.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide a metal strip winding segment, a mandrel, a winding device, a process line, a metal strip winding method, and a method for manufacturing high-tensile steel plate, which are capable of suppressing the occurrence of slippage between the segment and the sleeve when winding the metal strip, and suppressing poor winding of the metal strip, the need for rewinding, and a decrease in product yield. [Means for solving the problem]

[0008] The gist and configuration of the present invention to solve the above problems are as follows. [1] A metal strip winding segment that is provided around a mandrel shaft that rotates when winding a metal strip, and has a sleeve attached to the outside that contacts the metal strip, wherein the arithmetic mean roughness Ra of the contact surface with the sleeve is 3.2 μm or more and 12.5 μm or less. [2] A mandrel comprising the metal strip winding segment according to [1] and the mandrel shaft. [3] A winding device having the mandrel described in [2]. [4] A process line having the winding device described in [3]. [5] A method for winding a metal strip, comprising winding the metal strip using the winding device described in [3]. [6] A method for manufacturing a high-tensile steel plate by winding a high-tensile steel plate using the metal strip winding method described in [5]. [Effects of the Invention]

[0009] According to the present invention, the occurrence of slippage between the segment and the sleeve during winding of the metal strip is suppressed, and it is possible to suppress poor winding of the metal strip, rewinding work, and a decrease in product yield. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a perspective schematic view showing an example of a winding device. [Figure 2] FIG. 2 is a schematic side view showing an example of a mandrel and a sleeve. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described below through embodiments of the present invention. Here, the configuration of a winding device 10 according to one embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 shows a schematic perspective view of the winding device 10.

[0012] As shown in FIG. 1, a winding device 10 is provided in a process line for heat treatment in a continuous annealing facility. The winding device 10 has a mandrel 3, pinch rolls 4, and a tension adjusting device 7. The metal strip S is transported in the sheet passing direction (arrow A in the figure) as the mandrel 3 rotates. The metal strip S is wound around the mandrel 3 to form a coil. During transport in the sheet passing direction A, the metal strip S changes its direction of transport toward the mandrel 3 where it is wound, via pinch rolls 4 provided midway.

[0013] During transport of the metal strip S, the tension (t) of the metal sheet S increases or decreases by increasing or decreasing the rotation speed of the mandrel 3 (mandrel shaft 1). In other words, the tension of the metal strip S can be increased by increasing the rotation speed of the mandrel 3 (mandrel shaft 1). For this reason, the tension adjusting device 7 transmits a control signal for controlling the rotation speed to the mandrel 3 (mandrel shaft 1) and adjusts the tension of the metal strip S during winding.

[0014] Next, the configuration of the mandrel 3 will be described with reference to Figure 2. As shown in Figure 2, the mandrel 3 has a mandrel shaft 1 and segments 2. The segments 2 are arranged around the mandrel shaft 1. The mandrel shaft 1 rotates upon receiving a rotational driving force from a rotational driving source (not shown) such as a motor. The segments 2 are divided into multiple segments and can be expanded or contracted. The segments 2 expand to relatively fix the sleeve 5 when winding the metal strip S, and can be contracted when pulling out the sleeve 5 after winding the metal strip S. The segments 2 correspond to the metal strip winding segments in the present invention.

[0015] The sleeve 5 is attached to the outside of the segment 2. The sleeve 5 is made of an elastic material such as rubber. There are several types of sleeve 5 with different thicknesses. Therefore, by replacing the sleeve 5, the inner diameter of the coil of the metal strip S after winding can be changed.

[0016] When the metal strip S is wound, the segments 2 and sleeve 5 rotate simultaneously with the rotation of the mandrel shaft 1, and the metal strip S is wound around the sleeve 5 to form a coil. The contact surface of the segments 2 that comes into contact with the sleeve 5 is processed by shot blasting (shot peening) or electric discharge machining to have an arithmetic mean roughness Ra of 3.2 μm or more. This increases the friction between the segments 2 and the sleeve 5, thereby suppressing slippage between the segments 2 and the sleeve 5. An arithmetic mean roughness Ra of 4.0 μm or more is preferable. While a higher arithmetic mean roughness Ra can suppress slippage, a value large enough to prevent interference when unwinding the sleeve 5 from the segments 2 after winding the metal strip S is preferable. For example, an arithmetic mean roughness Ra of 12.5 μm or less allows for smooth unwinding of the sleeve 5 from the segments 2. An arithmetic mean roughness Ra of 10.0 μm or less is more preferable.

[0017] With the above-described configuration, the winding device 10 may be used to carry out a method for winding a metal strip S, in which the metal strip S is wound. Furthermore, in carrying out the method for winding a metal strip S using the winding device 10, a high-tensile steel plate may be used as the metal strip S. Then, the method for winding a metal strip S may be used to carry out a method for manufacturing a high-tensile steel plate by winding the high-tensile steel plate. [Example]

[0018] Next, Table 1 shows the results of winding a metal strip S having a thickness of 1.8 to 2.3 mm and a tensile strength TS of 1180 MPa or more using the winding device 10 shown in FIG. 1. In Table 1, Examples 1 to 6 of the present invention show results obtained when the arithmetic mean roughness Ra of the segment 2 was set to 3.2 μm or more and 12.5 μm or less, while Comparative Examples 1 to 6 show results obtained when the arithmetic mean roughness Ra of the segment 2 was set to 0.8 μm, 2.0 μm, and 13.0 μm, respectively. During winding of the metal strip S, the tension (t) was calculated based on the torque of the motor rotating the mandrel shaft 1 and the outer diameter of the coil. The tension (t) was adjusted (controlled) by controlling the magnetic flux of the motor rotating the mandrel shaft 1 so as to correspond to the conveying speed (line speed) of the metal sheet S and the coil diameter.

[0019] [Table 1]

[0020] As shown in Table 1, in Comparative Examples 1 to 4, when the winding tension was set to 4.3 to 6.0 t and the arithmetic mean roughness Ra of segment 2 was set to 0.8 μm or 2.0 μm, slippage occurred. In Comparative Examples 5 and 6, when the winding tension was set to 4.3 to 6.0 t and the arithmetic mean roughness Ra of segment 2 was set to 13.0 μm, slippage was avoided, but problems occurred when pulling out sleeve 5 from segment 2.

[0021] On the other hand, as can be seen from the results of Inventive Examples 1 to 6, when the winding tension was set to 4.3 to 6.0t and the arithmetic mean roughness Ra of segment 2 was set to 3.2 μm, 5.0 μm, or 12.5 μm, slippage was avoided and problems when pulling out the sleeve 5 from segment 2 were also avoided. In other words, it was confirmed that when winding the metal strip S, the tension of the metal strip S was set to a value exceeding 4.0(t) and the arithmetic mean roughness Ra of segment 2 was set to 3.2 μm or more and 12.5 μm or less, so that slippage was suppressed. [Explanation of symbols]

[0022] 1 mandrel shaft 2 segments 3 mandrels 4 Pinch Roll 5 Sleeve 7 Tension adjustment device 10 Winding device A Threading direction

Claims

1. A segment for winding high-tensile steel plates, the segment being provided around a mandrel shaft that rotates when winding high-tensile steel plates having a tensile strength of 1180 MPa or more, and having a rubber sleeve attached to the outside that comes into contact with the high-tensile steel plates, The segment for winding high-tensile steel sheet has an arithmetic mean roughness Ra of the contact surface with the rubber sleeve of 3.2 μm or more and 12.5 μm or less.

2. A mandrel comprising the high-tensile steel sheet winding segment according to claim 1 and the mandrel shaft.

3. A winding device comprising the mandrel of claim 2.

4. A process line comprising the winding device of claim 3.

5. A method for winding a high-tensile steel plate, comprising winding the high-tensile steel plate using the winding device according to claim 3.

6. A method for producing a high-tensile steel plate, comprising winding a high-tensile steel plate by the method for winding a high-tensile steel plate according to claim 5.

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