JP5353236B2 - Winding / extracting method and coiling apparatus for thick and high strength hot rolled steel sheet coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of winding/pulling out a thick high-strength hot-rolled steel sheet coil and a device for winding the coil by which the coil of the thick high-strength hot-rolled steel sheet after winding is pulled out of a coiler housing stably by suppressing the loosing of a coil due to springback and preventing the coil from instabilizing while conveying it to the banding device at the next stage. <P>SOLUTION: After winding the thick high-strength hot-rolled steel sheet into a coil 10 with a winding device and completing winding so as to situate the tail end of the steel sheet on the downside of the coil, the coil is pulled out by pulling out of the coiler housing 11 together with a coil truck 9 by extending a mandrel in the state that the mandrel 7 is inserted into the coil and without contracting the diameter of the mandrel 7 and transferred to the banding device 12. The mandrel of the winding device has a spline shaft 15, for example, is made extendable and contractable in the axial direction and the coil is transferred to the banding device by extending the mandrel in the axial direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to winding of a thick-walled high-strength hot-rolled steel sheet coil for stably producing a thick-walled high-strength hot-rolled steel sheet, in particular, a coil of a thick-walled high-strength hot-rolled steel sheet, which is a material such as a high-strength pipe The present invention relates to an extraction method and a winding device thereof.

  In recent years, the demand for large-diameter, thick-walled, high-strength pipe materials having an API standard of X70 to 100 is increasing mainly for the purpose of improving the transportation efficiency of resources such as crude oil and natural gas in pipelines. In order to efficiently transport these resources, high internal pressure is applied to the inside of the pipe, and characteristics such as high toughness and high strength are also considered for pipe materials in consideration of crustal deformation due to use in cold regions and earthquakes. It has become very important. The pipes used in these pipelines have a large diameter of about 15 to 25 mm and an outer diameter of about 20 inches or more. Conventionally, as a high-strength pipe, a short steel plate that is vertically long in the longitudinal direction An electric sewing tube is often used in which the side is formed into a circular shape, and then the butt portion is welded in the longitudinal direction to form a pipe. Usually, a thick steel plate is manufactured in a substantially rectangular shape by multi-pass rolling in a thick plate mill having one or two hot slabs, and the product length is about 30 m at the maximum. is there.

  On the other hand, in recent years, a thick steel plate is rolled on a hot rolling (hot strip mill) line for thin plate rolling and wound into a coil shape to form a hot-rolled steel plate coil, and then the coil is unwound to a predetermined length. In addition to forming a hot-rolled steel sheet into a longitudinal direction and then forming a hot-rolled steel sheet into a spiral shape at the same time, the spiral steel pipe manufactured into a pipe while welding the butted portion at the end of the plate width is increasing. The hot-rolled steel sheet coil can be manufactured up to about 45 tons. For example, if the thickness is 20 mm and the width is about 1900 mm, the hot-rolled steel sheet has a length of about 151 m, and is formed into a spiral steel pipe having a diameter of 28 inches. The pipe length is about 128m. In this way, by manufacturing the base material before pipe forming with a hot strip mill and making it a hot-rolled steel sheet coil, it is possible to manufacture a continuously long pipe as compared with the case of manufacturing from a thick steel sheet manufactured with a thick plate mill. Can be expected to improve productivity.

  By the way, the conventional winding method of a hot-rolled steel sheet and extraction from a winding device of a hot-rolled coil will be described with reference to FIGS. 3 and 6 showing the outline of the winding device and the winding equipment as follows. It is.

That is, a hot-rolled steel sheet (sometimes referred to as a hot strip or simply a strip) 1 that has passed through a finishing mill of a hot strip mill in a hot rolling line passes over a runout table roller 2 and travels by a pair of pinch rolls 3. The direction is guided downward, passes between the throat guides 4, and is guided by the winding device. The winding device includes a mandrel 7 and a plurality of wrapper rolls 5 and guide aprons 6 on the outer periphery of the mandrel 7, and the hot rolled steel sheet is wound around the outer periphery of the mandrel 7 by the wrapper roll 5 and the guide apron 6. Formed in the coil. After the strip 1 is wound around the mandrel 7 from the tip to the tail end, the rotation of the mandrel 7 is stopped so that the tail end of the strip 1 is located on the lower side of the coil. The coil cart 9 that is standing by is lifted, and the cradle roll 8 on the cart is brought into contact with the tail end portion of the coil, and the wrapper roll 5 is opened after the looseness of the tail end portion is suppressed by the weight of the coil. The mandrel 7 is then withdrawn from the coil, and then the coil is extracted from the coiler housing 11. Thereafter, as shown in FIG. 6, the hot-rolled coil extracted from the coiler housing 11 is a band-shaped steel band binding band 13 in the banding device 12 in order to prevent unwinding during conveyance to a subsequent processing step. The outermost peripheral part of the coil is fixed in an annular shape and transferred to the transfer line of the next process.
As described above, the spring-back deformation of the tail end portion is normally suppressed by the weight of the hot-rolled coil until the hot-rolled coil is extracted from the coiler housing and transferred to the banding device after the winding is completed.

  However, in the thick high strength hot rolled steel sheet represented by the line pipe material particularly targeted in the present invention, the cross section of the steel sheet is large and the strength is very high. As shown in FIG. 7, when winding a thick high strength hot-rolled steel sheet, the rigidity of the material is high, so the springback deformation of the tail end cannot be suppressed by the weight of the hot-rolled coil. During the period from the completion of the removal until the coil is pulled out from the coiler housing and transferred to the banding device, the tail end portion of the coil, particularly the hot rolled steel sheet on the outer periphery side of the coil, is easily unwound due to springback deformation and becomes unstable. If this loosening becomes large, problems such as inability to extract from the coiler housing, unstable vibration during transportation, and unstable posture occur. In severe cases, extract from the coiler housing while mounted on the coil carriage. In the meantime, the coil floats up and falls off the coil carriage.

As described above, there are many problems in winding a thick high-strength steel plate. For example, in Patent Document 1, as a winding method for a thick steel plate, the most advanced part of the thick steel plate is a pinch roll or a wrapper roll. Because it is difficult to bend by, etc., the wrapping property of the most advanced part is not good, but in order to improve this, the mandrel outer diameter is expanded to about 3 turns of the inner winding, and the adhesion between the mandrel and the steel plate is increased. A method for winding a thick steel plate that prevents slipping and suppresses deterioration of the coil winding shape has been proposed (for example, Patent Document 1).
JP 2003-80313 A

  The above-described technique disclosed in Patent Document 1 is a method for winding a thick-walled steel plate that pays attention to the wrapping property of the tip of the steel plate, but corresponds to suppressing winding loosening due to springback deformation after winding. I can't do it. When winding a thick high-strength hot-rolled steel sheet, at the portion other than the tip of the steel sheet, especially at the tail end of the strip on the coil outer peripheral side, winding loosening due to springback deformation is likely to occur after the winding as described above, Various problems have arisen in the extraction of the coil from the coiler housing, transportation to the banding device, and handling.

  For this reason, in a hot rolling (hot strip mill) line equipped with a strong rolling mill capable of rolling high-strength materials, it is possible to suppress unwinding of the coil due to springback to produce a thick-walled high-strength hot-rolled steel sheet. It is no exaggeration to say that it is decided.

The present invention has been made in view of the circumstances as described above, and the coil of the thick high-strength hot-rolled steel sheet after winding can be stably pulled out from the coiler housing while suppressing unwinding due to springback. It is possible to provide a method for winding and extracting a thick-walled, high-strength hot-rolled steel sheet coil and a winding device that can prevent the coil from becoming unstable while being transferred to the banding device in the next process. It is to be an issue.
In the present invention, the thick-walled high-strength hot-rolled steel sheet is intended for those having an API standard of X60 or more and a product thickness of 15 mm or more.

The present invention has been made in view of the above situation, and adopts the following means in order to solve the above problems.
(1) With a winding device (coiler) having a mandrel that can be expanded and contracted in the axial direction, the API standard X60 or more, and the product thickness is 15 mm or more from the leading end to the tail end of a thick high-strength hot-rolled steel sheet A method for winding and extracting a thick-walled high-strength hot-rolled steel sheet coil that is wound around a mandrel and formed into a coil, which is then extracted from the coiler housing and transferred to a banding device. After coiling is completed so that the coil is positioned below the coil, the coil is mounted on the coil carriage, and then the mandrel is stretched with the mandrel inserted into the coil without reducing its diameter, and the coil is pulled from the coiler housing to the coil carriage. It is extracted and transferred to a banding device along with API standard characterized by X60 or more and product thickness of 15mm or more. Winding and extracting method for rolled steel sheet coil.
(2) A winding device used in the method for winding and extracting the thick-walled high-strength hot-rolled steel sheet coil according to (1), wherein the mandrel of the winding device is extendable and contractable in the axial direction. Thus, the coiling device can be extracted from the coiler housing and transferred to the banding device.

  According to the present invention, the coil is mounted on the coil carriage after completing the winding so that the tail end portion of the thick high-strength hot-rolled steel sheet is located on the lower side of the coil, and then the mandrel is not reduced in diameter. With the mandrel inserted, the mandrel is stretched, pulled out from the coiler housing, and transferred to the banding device, so that the coil springback can be prevented from unwinding and stable extraction can be performed from the coiler housing. It is possible to prevent the coil from becoming unstable while being transferred to the banding device of the process.

  As a result of intensive studies on the technology for suppressing coil loosening caused by springback deformation after winding of the thick-walled high-strength hot-rolled steel sheet coil, the present inventors It was found that unwinding can be improved by removing the coil from the coiler housing while the coil is fixed to the coil carriage by its own weight and transferring it to the banding device.

  According to the observations of the present inventors, winding loosening due to springback in a coiled state (winding loosening), when there is a looseness in the outer periphery, first the inner side is loosened first, and then the inner side again, It was found that the winding looseness range rapidly expanded inside. In other words, it is very important to suppress winding looseness as much as possible in the winding state in the range of several turns from the outermost peripheral part, from this viewpoint, from the completion of winding to the next process. The idea is to suppress unwinding due to the springback by maintaining the state that the mandrel is inserted into the coil without reducing the diameter even during the transfer of the coil to the banding device.

  In the conventional winding / transfer method, after the winding of the hot rolled steel sheet is completed, the mandrel stops rotating so that the tail end portion of the strip 1 is located below the coil, and then the coil carriage is raised and the coil carriage is moved. The coil is supported by the cradle roll provided in the above and mounted on the carriage, and after the wrapper roll is retracted, the diameter is reduced and the coil is extracted from the coil. Then, the coil on the coil carriage is extracted from the coiler housing together with the coil carriage and transferred to the banding device.

  When the mandrel is reduced in diameter and pulled out of the coil, the force that fixed the coil between the mandrel and the cradle roll on the carriage disappears, so the coil is spring-backed, and it can be suppressed by the coil's own weight. This is not possible, and winding loosening (winding looseness) occurs on the outer periphery of the coil. If the unwinding is large, the coiler housing cannot be stably extracted as described above. While the coil is mounted on the coil carriage and transferred to the banding device, vibrations and vibrations caused by traveling of the carriage affect the coil, and the coil loosening of the outer periphery of the coil extends to the inner periphery. The unwinding will be expanded more and more. If it becomes like this, the attitude | position of a coil will become unstable and various trouble will arise in the conveyance and handling of a coil.

  On the other hand, in the present invention, the mandrel of the winding device can be expanded and contracted in the axial direction, and after the winding is completed, the mandrel is inserted into the coil on the coil carriage without being reduced in diameter. Holding. While maintaining this state, the mandrel extends in the axial direction, so that the mandrel is extracted from the coiler housing together with the coil carriage and transferred to the banding device.

  For this reason, during the transfer of the coil from the coiler housing to the banding position, the coil is firmly fixed between the mandrel and the coil carriage, so that the occurrence of springback is suppressed and therefore no unwinding occurs. . Therefore, the coil carriage does not become unstable because the vibration or vibration of the coil carriage during coil conveyance hardly induces the vibration or vibration of the coil.

A method for winding and extracting a thick-walled high-strength hot-rolled steel sheet coil and a winding apparatus according to the present invention will be described below with reference to FIG. 4 showing an outline of a winding facility including the winding apparatus for a hot-rolled steel sheet according to the present invention. To do. In this figure, reference numeral 7 denotes a mandrel of a winding device (coiler), which can be expanded and contracted in the axial direction as will be described later. 9 is provided with a cradle roll 8 and waits under the coil during winding, and rises after the winding is completed, and a coil carriage 10 is mounted on the roll to convey the coil. A hot-rolled coil 11 is a housing (coiler housing) of the winding device. A banding device 12 is provided in the vicinity of the side of the winding device, and the coils are bound in a ring shape by a binding band 13, 14 is a driving device that rotationally drives the mandrel, and 15 is a spline shaft.
The winding device of the present invention is basically the same as that shown in FIG. 3 except for the mandrel, and four wrapper rolls are provided on the outer periphery of the mandrel as in the conventional one. The wrapper roll can normally receive 2 to 4 groups, and may be 2 to 3 groups in the present invention.

  The mandrel 7 of the winding device of the present invention can be expanded and contracted in the axial direction by, for example, a spline mechanism having a spline shaft 15 and extends to the banding device as shown in FIG. It can reciprocate between the devices in the axial direction.

Winding and extraction of the hot-rolled coil of the present invention are performed in the following procedure. That is, the strip 1 is wound around the mandrel 7 of the winding device from the front end portion to the tail end portion, and the rotation of the mandrel 7 is stopped so that the tail end portion of the strip 1 is located below the coil. Next, during winding, the coil carriage 9 waiting under the coil is raised, the coil tail end is brought into contact with and supported by the cradle roll 8 on the carriage, the coil is mounted on the carriage, and then the wrapper The roll 5 is released from the coil and retracted. The mandrel 7 is stretched in the axial direction while maintaining the state where the hot rolled coil is fixed to the cradle roll 8 by its own weight while the mandrel 7 is inserted into the coil without reducing the diameter. The coil is extracted from the coiler housing 11 and transferred to the banding device 12 together with the coil carriage 9.
After that, after the mandrel 7 is reduced in diameter and extracted from the coil, the coil can be fixed in an annular shape by the binding band 13. Alternatively, the mandrel 7 can be reduced in diameter and extracted from the coil after the coil is wound around the binding band 13 and fixed.

  FIG. 5 shows a winding state of a coil extracted from a mandrel after winding a thick high-strength hot-rolled steel sheet according to the present invention. Thus, in the present invention, since the hot rolled coil is fixed to the coil carriage with the mandrel that can be expanded and contracted in the axial direction while the mandrel is inserted into the hot rolled coil and the weight of the coil, the outer peripheral portion of the coil This is a banding device that can suppress the spring back of the strip, and can stably extract the hot-rolled coil from the coiler housing without unwinding the tail end of the strip, and the coil posture does not become unstable. Can be transferred to.

  For this reason, the mandrel of the winding device of the present invention needs to have sufficient rigidity to suppress the spring back of the outer periphery of the coil while the coil is transferred to the banding device.

Three kinds of hot-rolled steel sheets (sheet width 1800 mm, coil outer diameter 2000 mm, coil weight 40 tons, coiling temperature 500 ° C.) with an API standard of X60, X70, and X80, with a finished sheet thickness within a range of 15 to 25 mm. As a comparative example, the embodiment of the present invention and the embodiment using the conventional winding / extracting method shown in FIG. 6 are subjected to a winding test, wound by a coiler, and transferred to a banding device. Until then, the coil tail end was investigated.
The mandrel of the winding device of the present invention used here can be expanded and contracted by a spline method, the diameter is 773 mm, and the stretch amount is 3000 mm.

B) Unwinding investigation procedure of the present invention Winding the hot-rolled steel sheet with a coiler so that the tail end is down, the coil carriage is raised, the cradle roll on the carriage is brought into contact with the coil tail end, and the coil is placed on the carriage. After mounting, retract the wrapper roll.
2. Next, the mandrel is stretched in the axial direction with the mandrel inserted without reducing the diameter of the mandrel, the coil is extracted from the coiler housing, and transferred to the binding device together with the coil carriage.
3. Finally, the mandrel is axially reduced and retracted from the coil in the banding device.
Here, the outer diameter of the coil is measured immediately after the procedure 1 and immediately after the procedure 3, and the difference is defined as the coil outer diameter spread amount.

B) Investigation procedure for loosening of the comparative example Winding the hot-rolled steel sheet with a coiler so that the tail end is down, the coil carriage is raised, the cradle roll on the carriage is brought into contact with the coil tail end, and the coil is placed on the carriage. After mounting, retract the wrapper roll.
2. Next, the mandrel is reduced in diameter.
3. The coil is transferred to the banding device together with the coil carriage.
Here, the outer diameter of the coil is measured immediately after the procedure 1 and immediately after the procedure 3, and the difference is defined as the coil outer diameter spread amount.

  In order to evaluate the unwinding of the coil tail end portion (coil outer peripheral portion) of the present invention, the amount of coil outer diameter spread obtained in the above procedure b) was used as a reference for the evaluation. When the coil outer diameter spread amount is 10 mm or more, it is likely to be unstable until the hot-rolled steel sheet is wound by a coiler and then transferred to the banding device. The amount of coil outer diameter spread was less than 10 mm.

  FIG. 2 shows the results of the evaluation for unwinding of the comparative example. As shown in this figure, the X60 grade hot-rolled steel sheet can be stably pulled out of the coiler housing by suppressing the spring back deformation of the coil tail end with its own weight by this conventional winding technology. It is. However, X70 and X80 grade hot-rolled steel sheets, which are higher strength materials, cannot suppress the spring back deformation of the coil tail end with the coil weight when the plate thickness is about 22 mm or more. The outer diameter spread amount increased, and the coil tail end was unwound and became unstable.

  FIG. 1 shows the results of the evaluation of unwinding of the present invention. As shown in this figure, not only the X60 grade, but also X70 to X80 or more, and a thick high strength material coil with a plate thickness of 22 mm or more, from the completion of winding by the coiler to the transfer to the banding device. Outer diameter spread is eliminated. As a result of this embodiment, the mandrel that can be expanded and contracted in the axial direction is stretched in a state where the mandrel is inserted into the thick and high-strength hot-rolled coil without reducing the diameter, and the coiler is fixed in the state where the hot-rolled coil is fixed to the coil carriage. By extracting from the housing and transferring it to the banding device together with the coil carriage, it was confirmed that stable extraction was possible without unwinding the coil.

  As is clear from the above examples, the winding and unwinding method and winding device for the thick and high strength hot rolled steel sheet coil of the present invention suppresses the coil tail end from unwinding and reliably increases the thickness and thickness. Since the high-strength hot-rolled steel sheet coil can be extracted from the winding device and transferred to the banding device, a thick high-strength steel plate coil can be stably produced in the hot rolling line.

The figure which shows the relationship between the intensity | strength of a thick-walled high intensity | strength hot-rolled steel plate by the winding and extraction method of the hot-rolled steel plate coil of this invention, finishing board thickness, and the amount of coil outer diameter spread. The figure which shows the relationship of the intensity | strength of a thick-walled high-strength hot-rolled steel sheet by the conventional coiling and extracting method of a hot-rolled steel sheet coil, the finished sheet thickness, and the amount of coil outer diameter spread. The figure which shows the outline | summary of the winding apparatus of a general hot-rolled steel plate. The figure which shows the outline | summary of one example of the winding equipment containing the winding apparatus of this invention. The figure which shows the outline | summary of one example of the coil without unwinding. The figure which shows the outline | summary of the winding apparatus of the conventional hot-rolled steel plate, and the winding-up and extraction method. The figure which shows the outline | summary of one example of the coil in which winding loosening has arisen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-rolled steel plate 2 Runout table roller 3 Pinch roll 4 Throat guide 5 Wrapper roll 6 Guide apron 7 Mandrel 8 Cradle roll 9 Coil cart 10 Hot-rolled coil 11 Coiler housing 12 Banding device 13 Binding band 14 Drive device 15 Spline shaft

Claims (2)

A winder (coiler) having a mandrel that can be expanded and contracted in the axial direction winds around the mandrel from the tip to the tail end of a thick, high-strength hot-rolled steel sheet with an API standard of X60 or more and a product thickness of 15 mm or more A coiling method for winding and extracting a thick-walled, high-strength hot-rolled steel sheet coil that is extracted from the coiler housing and transferred to a banding device after the coil is taken into a coil, and the tail end of the hot-rolled steel sheet is below the coil After coiling is completed so as to be positioned on the side, the coil is mounted on the coil carriage, and then the mandrel is extended with the mandrel inserted into the coil without reducing the diameter, and the coil is pulled out from the coiler housing together with the coil carriage and banding. Thick, high-strength hot-rolled steel sheet with an API standard of X60 or more and product thickness of 15 mm or more, characterized by being transferred to the equipment Coil winding / extraction method. A winding device used in the winding and extraction method for a thick-walled high-strength hot-rolled steel sheet coil according to claim 1, wherein the mandrel of the winding device can be expanded and contracted in the axial direction. A winding device characterized in that a coil can be extracted from a coiler housing and transferred to a banding device.

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