JP2015217399A - Billet width reduction press method, and width reduction press apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a billet width reduction press method capable of reducing a billet efficiently to a predetermined width without being followed by the rise of equipment cost or a yield reduction by a crop loss.SOLUTION: When a width size is reduced all over the length by bringing a pair of press dies 3a and 3b sandwiching a billet 1 close to and apart from each other thereby to width-reduce the billet 1 repeatedly, said paired press dies 3a and 3b are moved in the width direction of said billet 1, to deviate the initial positions of said press dies 3a and 3b thereby to change the rolling reduction at the right and left of said billet.

Description

  The present invention relates to a width reduction press method for steel slabs (slabs, sheet bars, etc.) and a width reduction press apparatus suitable for use in the method.

  In recent years, in order to reduce energy loss, simplify and shorten the line in hot rolling lines, attempts have been made to realize synchronized operation of continuous casting and hot rolling. For synchronized operation with hot rolling, it is useful to adjust the width dimension of the steel slab before hot rolling to a predetermined width. Further, in order to obtain steel slabs having various width dimensions from a slab having a constant width, it is useful to adjust the width dimension of the steel slabs before hot rolling to a predetermined width.

  Therefore, conventionally, there is a width reduction press that uses a pair of press dies that sandwich a steel slab on the left and right sides, and reduces the width dimension over the entire length by reducing the steel slab in the width direction by approaching and separating them. Has been applied.

  As a prior art relating to a width reduction press of a steel slab, Patent Document 1 discloses that a pair of left and right molds having inclined portions on the entry side and the exit side and a parallel portion in the middle are separated by a hydraulic cylinder with a predetermined width reduction interval. In addition, the width of the hot slab is reduced while the hot slab is moved forward and backward between the molds by the roller table on the entrance and exit sides of the mold. There has been proposed a method of centering the uncompressed lower portion at the rear end portion of the hot slab with a side guide provided on the entrance side of the mold.

  In Patent Document 2, the relationship between the tip shape index after pressing and the slab tip stop position at the start of width reduction of the width pressing press used in advance is obtained, and the slab tip stop position is managed as the tip shape index after pressing. A method for suppressing a decrease in yield due to a crop shape at the tip of the slab by initializing within a range and starting width reduction is disclosed in Patent Document 3, and at least on the entry side and the exit side of the sizing press device When a side guide is installed on one side and the side end face of the hot slab is constrained in the width direction, the pressing pressure (side guide support force) of the side guide against the hot slab is used, and the sizing press device uses the hot slab. The method of controlling to a low pressure when transporting the sheet and to a strong pressure when carrying out the width direction press is further disclosed in Patent Document 4, in which the planar shape is not subject to right and left. Upon be reduced width decreased by the width direction pressing Love, how to start the width reduction press the rear end portion of the slab from the centering has been proposed by the side guides prior to the width direction pressing.

Japanese Patent Laid-Open No. 62-183902 JP-A-9-29301 Japanese Patent Laid-Open No. 10-94801 JP 2001-269701 A

  By the way, in the method proposed in the above-mentioned document, the width reduction of the hot slab is interrupted during the width reduction of the hot slab, and the hot slab is moved forward and backward. It is difficult to perform the reduction (Patent Document 1), and during the reduction of the width of the hot slab, the side end face of the rear end of the hot slab is centered by being pinched or restrained by a side guide. It is inevitable that the rotational force of the hot slab that accompanies the width reduction is added to the guide, and there is an inconvenience that an increase in equipment cost is unavoidable from the viewpoint of securing strength that can withstand it (patent) Literature 2-4). Moreover, even if these methods are carried out, when the width reduction amount exceeds 200 mm, the bending of the steel piece tip and the single elongation at the tail end of the steel piece are remarkable, and the shape after the width reduction is not necessarily the same. It is not good, especially the elongation that occurs at the tail end of the steel piece is not eliminated by rolling in the subsequent rough mill, and this part becomes crop loss, so a decrease in yield is inevitable It was in.

  An object of the present invention is to propose a width reduction press method and apparatus capable of efficiently reducing a steel slab to a predetermined width dimension while suppressing a decrease in yield due to crop loss without increasing equipment costs. There is a place to do.

  The present invention repeats the mutual approach from the initial position and the mutual separation to the initial position of the pair of press dies sandwiching the steel slab on the left and right sides, and repeatedly reducing the steel slab in the width direction. In the width reduction press method of a steel slab that reduces the width dimension of the steel slab over its entire length, the pair of press dies are moved in the width direction of the steel slab to shift the initial position of the press dies. It is a width reduction pressing method of a steel piece characterized by changing the amount of reduction on the left and right of the steel piece.

  In carrying out the above method, it is preferable to move the steel slab in the width direction of the press die based on the meandering amount of the steel slab or the temperature deviation between the left and right of the steel slab.

  The present invention also includes a pair of press dies that sandwich the steel slab from the left and right, and a steel slab that reduces the width dimension of the steel slab over its entire length by repeating the mutual approach and separation of the pair of press dies. A width reduction press apparatus for a steel slab comprising a mold moving mechanism for moving the pair of press dies in the width direction of the steel slab and shifting the press core. is there.

  Specifically, a hydraulic cylinder that moves a pair of press dies in the mutually approaching and separating directions can be applied as the die moving mechanism of the above-described width reduction press device.

  According to the width reduction pressing method of the present invention having the above-described configuration, the pair of press dies are appropriately moved in the width direction of the steel slab, and the initial position of the press dies, and thus the press core, are shifted, and Since the amount of rolling on the left and right is changed, even if there is a temperature difference between the left and right of the steel slab, it is possible to reduce the deviation of the rolling amount on the left and right. The half elongation can be reduced.

  In carrying out the above method, the press mold is moved in the width direction of the steel slab based on at least one of the measured values of the meandering amount of the steel slab and the temperature deviation on the left and right sides. It becomes possible.

  Further, according to the width reduction press device of the present invention, since the die moving mechanism for moving the pair of press dies in the width direction of the steel slab and shifting the press core is provided, an increase in the cost of the equipment is suppressed. In spite of this, it is possible to perform an efficient width reduction press of the steel slab.

  If the die moving mechanism of the above-described width reduction press device is constituted by a hydraulic cylinder that moves the pair of press dies in the directions of mutual approach and mutual separation, the structure is relatively simple and the cost of the equipment is reduced. Will not rise.

It is the figure which showed typically the structure of the width reduction press apparatus, (a) is a top view, (b) is AA sectional drawing of (a). It is the figure which showed the other example of the planar shape of a press metal mold | die. It is the figure which showed the change condition of the initial position of a press die.

  1 (a) and 1 (b) are diagrams schematically showing an embodiment of a width reduction press apparatus suitable for use in the implementation of the width reduction press method according to the present invention, and FIG. The plan view, FIG. 1B, is a cross-sectional view taken along the line AA of FIG. In the figure, reference numeral 1 denotes a steel piece (hot slab, sheet bar, etc.) used for the width reduction press, 2 denotes a conveying table for conveying the steel piece 1, and 3a and 3b sandwich the steel piece 1 in between. And a pair of press dies arranged on the left and right.

  The width reduction press device of this embodiment includes a normal reciprocating hydraulic cylinder 4 having a rod position sensor (not shown) as drive means for repeatedly moving the press dies 3a and 3b in directions toward and away from each other, and A hydraulic cylinder control device comprising a normal computer for controlling the reciprocating operation of the hydraulic cylinder 4 through a normal hydraulic circuit based on the piston rod position of the hydraulic cylinder 4 input from the rod position sensor in accordance with a program given in advance. The hydraulic cylinder 4 is controlled by the hydraulic cylinder control device 5 by passing the steel piece 1 by the operation of the transfer table 2 between the press dies 3a and 3b that move toward and away from each other. The reciprocating operation of the steel slab 1 reduces the width W of the slab 1 to W ′ over the entire length.

Press dies 3a, as the 3b, pieces having a inlet side inclined surface _3a 1, 3b ₁ and the entrance side inclined surface _3a 1, 3b ₁ parallel to the width end face of the lead steel piece 1 to a flat surface _3a 2, 3b ₂ Although a trapezoidal shape can be applied, it is also possible to apply a trapezoidal shape as shown in FIG. 2 in which outgoing side inclined surfaces 3a ₃ and 3b ₃ connected to the flat surfaces 3a ₂ and 3b ₂ are formed. The shape (planar shape) of the press dies 3a and 3b to be used is not particularly limited.

  Reference numeral 6 denotes a mold moving mechanism that moves the press dies 3a and 3b together in the width direction of the steel slab 1 and shifts the initial position thereof to change the amount of rolling on the left and right of the steel slab 1.

  Specifically, the mold moving mechanism 6 includes the hydraulic cylinder 4 having a rod position sensor, and the position of the piston rod output from the rod position sensor and the initial position of each of the press dies 3a and 3b are as follows. As will be described later, based on the meandering amount of the steel slab 1, it is controlled to shift in the same direction by a set movement amount (shift amount).

  Here, the initial positions of the press dies 3a and 3b are the positions when the press dies 3a and 3b are in the retracted state that is most separated from each other in the reciprocating operation of the hydraulic cylinder 4. The mutual distance (initial opening degree) L between the processed surfaces of the press dies 3 a and 3 b at the initial position is appropriately set according to the size of the steel slab 1. By shifting the press dies 3a and 3b in the width direction of the steel slab 1 as shown in FIG. 3 while maintaining their initial positions, the press dies O of the press dies 3a and 3b (the mutual distance L The straight line passing through the center of the steel piece 1 is offset with respect to the center (machine core) O ′ in the width direction of the steel slab 1.

  Reference numeral 7 is a side guide installed on the entry side of the press dies 3a and 3b to guide the steel slab 1 to the press dies 3a and 3b. 8b is a meandering amount sensor (for example, the distance from the sensor to the side end surface of the steel piece 1 in a non-contact manner) that is provided on the entry side of the press dies 3a and 3b and detects the amount of meandering at the tail end of the steel piece 1. The hydraulic cylinder control device 5 is a press die based on the meandering amount that these meandering amount sensors 8a and 8b detect and output for one or a plurality of steel pieces 1 of the same lot, for example. The amount of movement (shift amount) of the desired positions 3a and 3b is calculated, and the operation of the mold moving mechanism 6, that is, the hydraulic cylinder 4 is controlled according to the calculated amount of movement, and the expected positions of the press dies 3a and 3b are calculated. Is moved in the width direction of the steel slab 1 and in the same direction by the amount of movement, and the remaining steel slab 1 of the lot is reduced in width. Therefore, the hydraulic cylinder control device 5 also functions as a control device for the mold moving mechanism 6.

  According to this embodiment, the initial position of the press dies 3a and 3b is set by the die moving mechanism 6 by the amount of movement set based on the amount of meandering of the slab 1 in the width direction (DR side or OP side of the slab 1). Since the amount of reduction on the left and right sides of the steel slab 1 is changed by shifting to the side), it is possible to reduce the width while suppressing the occurrence of bending at the front end of the steel slab 1 and elongation at the rear end of the steel slab 1. Therefore, crop loss can be reduced. Moreover, excessive force accompanying the bending of the steel slab 1 is not applied to the side guide 7 during the width reduction of the steel slab 1, and unnecessary strengthening of the equipment itself is not required.

  As a control factor of the mold moving mechanism 6, in addition to the meandering amount of the steel slab 1, it is possible to directly use the left and right temperature deviations of the steel slab 1. The occurrence of bending and unilateral elongation can be prevented, and crop loss can be further reduced. When the movement amount is set based on the meandering amount of the slab 1 and the left and right temperature deviations, the distance sensor and the temperature sensor (for example, the left and right side portions of the slab 1 are disposed on the entry side of the press dies 3a and 3b). (Thermography for optically measuring temperature) may be arranged, and the movement amount may be set based on data obtained by these sensors.

  That is, when the present inventor performed a simulation by finite element analysis (FEM), when the steel piece 1 has a left and right temperature deviation, the press core O of the press dies 3a and 3b and the width direction of the steel piece 1 Even if the center O 'coincides with the center O', it is found that the high temperature side is extended by the width reduction and the tip of the steel slab is bent to the low temperature side, and the press core O of the press dies 3a and 3b is moved in the width direction of the steel slab 1. For example, when the amount of reduction of the lower press die 3b in FIG. 1 is increased with respect to the center O ′ in FIG. 1, the lower tail end of the steel slab 1 does not extend, but the initial reduction starts. The tip of the steel slab 1 is pushed first by the lower press die 3b so that the steel slab 1 rotates horizontally in the clockwise direction in the figure, and the upper tail end of the steel slab 1 is bent downward. Rather, the tail end on the upper side of the steel slab 1 in which the reduction amount of the press die 3a is reduced extends. Found it was.

  In addition, when the steel slab 1 is heated in a heating furnace, the steel slab 1 is usually arranged in a direction transverse to the transfer direction in the heating furnace and transferred by a walking beam or the like. It is also found that the extraction door (DR) side is cooled by the outside air more than the inside of the furnace (OP) side, and the left and right temperature deviations are generated in the steel piece 1 because it is exposed to the outside air from the extraction door. In view of these points, the present inventor performed the width reduction press of the following examples and comparative examples.

  In the hot rolling line, the sheet bar (thickness 220 mm, width 1500 mm) extracted from the heating furnace is subjected to a width reduction press with a reduction amount of 300 mm, and a single elongation generated at the rear end of the sheet bar ( Crop length) was investigated. In this investigation, the length of the inclined surface on the entry side is 700 mm (angle formed by the flat surface), the length of the flat surface is 600 mm, and the length of the inclined surface on the output side is 600 mm (angle formed by the flat surface is 19 °). A one-piece press die was used.

  In the case where the press core of the press mold is aligned with the machine core and the width reduction press is performed uniformly from both the left and right sides (Comparative Example 1), the crop length is about 414 mm on the DR side. When the width was reduced by moving the initial position (moving the press core 10 mm to the DR side) (Comparative Example 2), the crop length was about 492 mm on the DR side and increased rather. On the other hand, the movement amount is set based on the amount of meandering to the OP side of the leading end of the sheet bar measured manually, and the initial position of the press die is moved by the movement amount (the press core is moved to the OP side). The width of the crop is about 317 mm on the DR side, and when the press core is moved to the DR side, of course, the width is evenly reduced from both the left and right sides. It was confirmed that the crop length was reduced even by comparison.

As mentioned above, although demonstrated based on the example of illustration, the width reduction press method and width reduction press apparatus of this invention are not limited to the said example, It can change suitably within the description range of a claim. For example, the die moving mechanism 6 of the width reduction press device is not a hydraulic cylinder 4 that reciprocally moves the pair of press dies 3a and 3b to reduce the width of the steel slab 1, but a pair of press dies 3a, The cylinder 3b may be constituted by a hydraulic cylinder or a crank mechanism that moves together with the hydraulic cylinder 4 for reciprocal movement thereof, and the pair of press dies 3a and 3b are reciprocated in order to reduce the width of the steel piece 1. The moving mechanism may also be constituted by a crank mechanism like a normal press device. And the meandering amount sensor for detecting the meandering amount of the steel slab 1 may be installed on the exit side of the press dies 3a, 3b, or installed on both the entry side and the exit side of the press dies 3a, 3b. Also good.

  ADVANTAGE OF THE INVENTION According to this invention, the width reduction press method and its apparatus which can reduce a steel slab efficiently to a predetermined width without accompanying the increase in equipment cost, the yield fall by crop loss, etc. can be provided.

DESCRIPTION OF SYMBOLS 1 Steel slab 2 Conveying table 3a, 3b Press die 3a1, 3b1 Inlet side inclined surface 3a2, 3b2 Flat surface 3a3, 3b3 Outlet side inclined surface 4 Hydraulic cylinder 5 Hydraulic cylinder controller 6 Mold moving mechanism 7 Side guide 8a, 8b Meander amount sensor W Width L L

Claims (5)

The pair of press dies sandwiching the steel slab on the left and right sides are repeatedly approached from the initial position and separated from each other at the initial position. In the width reduction press method of a steel piece for reducing the width dimension of the steel piece,
A width reduction press for a steel slab characterized by changing the amount of reduction on the left and right of the steel slab by moving the pair of press dies in the width direction of the steel slab and shifting the initial position of the press dies. Method.   The movement in the width direction of the steel slab of the press die is performed based on at least one of the meandering amount of the steel slab and the temperature deviation of the left and right of the steel slab. Width reduction press method for steel pieces. A steel sheet width reduction press device comprising a pair of press dies sandwiching a steel slab from the left and right, and reducing the width dimension of the steel slab over its entire length by repeating the mutual approach and separation of the pair of press dies. There,
A steel strip width reduction press apparatus comprising a die moving mechanism for moving the pair of press dies in the width direction of the steel slab and shifting the press core.   4. The width reduction press apparatus for a steel slab according to claim 3, wherein the mold moving mechanism is constituted by a hydraulic cylinder that moves a pair of press dies in the directions of mutual approach and mutual separation.   The said metal mold | die movement mechanism has a control apparatus which sets the movement amount of the said press metal mold | die based on at least one of the meandering amount of a steel piece, and the temperature deviation of the left and right of a steel piece. The steel sheet width reduction press device described in 1.

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