JP2010188384A - Method for controlling warpage of tip of hot bar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a table roller from being damaged by the impact force that is generated when a warped tip of a hot bar collides with the table roller. <P>SOLUTION: A warpage sensor 7 for detecting a warpage of the tip of a hot bar is arranged in the outlet side of a rough-rolling mill 1, and thermometers for measuring the temperatures of the upper and lower faces of a hot bar 6 are arranged in the inlet side of a rolling mill 1. A controller controls the supply amount of rolling oil, which is supplied to work rolls 2, based on the warpage amount of the tip of the hot bar. An impact force sensor 12 consisting of load cells is arranged on a table roller 5, and, when the impact force generated by the collision with the tip of the hot bar and detected by the sensor 12 exceeds a set value, the controller decreases the number of rotations of the work rolls, so that deceleration driving is conducted. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention suppresses the warpage of the hot bar tip in rough rolling in the hot rolling process, specifically, a cooling device arranged above and below the rolling line by warping the hot bar tip up and down on the exit side of the roughing mill, Measuring device, descaling hood, table roller, etc. (In this specification, these may be referred to simply as a table roller. Therefore, the table roller in this specification is not only a table roller, but also a cooling device and a measuring device. The present invention relates to a warpage control method for preventing the table roller from being worn out by this impact force.

  If the hot bar tip warps up and down on the exit side of rough rolling, the table roller may be damaged by the collision of the hot bar tip.

  The hot bar tip warpage has many factors such as the temperature difference between the upper and lower surfaces of the hot bar, the frictional state of the roll surface, the diameter difference between the upper and lower rolls of the rough rolling mill, the plate thickness, and the rolling reduction. Various techniques have also been proposed. Examples are shown in Patent Documents 1 and 2, and of these, Patent Document 1 is provided with a warp sensor on the exit side of the roughing mill to measure the warp curvature of the hot bar tip and drive the upper and lower work rolls. A torque sensor is installed on the spindle to measure the torque distribution rate between the upper and lower work rolls, and the vertical difference of the friction coefficient and the vertical temperature difference of the hot bar are estimated from these measured values. A method of eliminating rolling unevenness on the upper and lower sides and supplying rolling oil to the roll side having a large surface roughness is disclosed. Patent Document 2 measures the surface roughness of the upper and lower work rolls with a roughness meter to determine the friction coefficient. Obtain lubricating oil to the upper and lower surfaces of the hot bar to eliminate the difference in friction coefficient, or measure the temperature of the upper and lower surfaces of the hot bar by installing thermometers on the inlet and outlet sides of the roughing mill, Due to temperature difference The method for changing the circumferential speed of the upper and lower work rolls to eliminate the end warpage is disclosed.

JP-A-10-137829 JP 2005-254287 A

  The damage caused by the collision of the hot bar tip with the table roller depends on the impact force at the time of the collision. However, as in the conventional method described above, the hot bar tip warpage is measured, and the work roll torque and friction are measured. Finding the coefficient or the temperature of the hot bar, eliminating uneven burning in the heating furnace, supplying rolling oil, or changing the peripheral speed of the work roll is effective to some extent in suppressing warpage, It cannot be expected that there will be no warpage at all, and the possibility of causing damage by colliding with the table roller due to warpage cannot be resolved.

  An object of the present invention is to provide a method for suppressing warpage of a hot bar tip that can more reliably prevent damage to a table roller in combination with the above-described conventional warpage suppression technology.

The present invention is a method for suppressing warpage of a hot bar tip in rough rolling in a hot rolling process including at least one hot bar tip warpage suppressing method of the following (1) to (3): An impact force sensor is attached to at least the table roller with which the hot bar tip first hits among the plurality of table rollers arranged in parallel, and when the impact value measured by the sensor exceeds a set value, the work roll of the roughing mill The number of rotations is reduced, and rough rolling reduction operation is performed.
(1) Warpage of the hot bar tip is detected by a warpage sensor provided on the exit side of the rough rolling mill, temperature control to the hot bar, control of the amount of rolling oil supplied, and work roll so that the warpage is eliminated A method of performing at least one control among the control of the rotational speed of
(2) The roughness of the work roll surface is measured by means of roughness measuring means installed at the top and bottom of the rough rolling mill, whereby the friction coefficient difference between the upper and lower work rolls is determined, and the rolling oil is applied to the roll so that this difference is eliminated. How to supply,
(3) Measure the temperature of the upper and lower surfaces of the hot bar, and eliminate at least one of temperature control to the hot bar, supply control of rolling oil, and control of the number of rotations of the work roll in order to eliminate the warp due to the temperature difference. How to do.

  Although it is difficult to detect the load on the table roller even if the warpage of the hot bar tip is detected by the warpage sensor or the warpage is detected by other methods, the impact force on the table roller as in the present invention is difficult. It is possible to easily and reliably determine the impact force on the table roller by providing an impact force sensor that measures the damage, and it is possible to prevent damage to the table roller by performing slow rolling reduction operation with the determined impact force. Become.

The figure which shows the curvature by the side of a rough rolling mill. The schematic diagram when the front-end | tip of a hot bar collides with a table roller. The figure which shows an impact force and its generation ratio.

A method for suppressing the warpage of the hot bar tip by the roughing mill 1 shown in FIG. 1 will be described below.
The rough rolling mill 1 includes upper and lower work rolls 2 and 2 and backup rolls 3 and 3. A plurality of (five in the figure) table rollers 5 are provided on the exit side of the rough rolling mill 1 via feed rollers 4. Parallel to the rolling line, immediately before the table roller, warping of the tip of the hot bar 6, that is, raising the tip of the hot bar 6 indicated by a one-dot chain line, or lowering the tip of the hot bar 6 indicated by a solid line in the drawing. A warpage sensor 7 is provided for detecting.

  On the other hand, on the entry side of the rolling mill 1, non-contact type thermometers 8 and 8 that measure the temperature of the upper and lower surfaces of the hot bar 6 above and below the rolling line, and the surface roughness of the work roll are measured and the upper and lower work rolls Roughness measuring means for obtaining the friction coefficient difference of, for example, a laser distance meter 10 (see FIG. 1), or a roughness meter as disclosed in Patent Document 2 are arranged above and below the rolling mill 1 and the upper and lower workpieces. Nozzles 9 and 9 for supplying rolling oil to the rolls 2 and 2 are disposed. The rolling oil may be supplied to the backup roll or to both the work roll and the backup roll instead of the work roll.

  Although not shown, the rough rolling mill 1 also has a function of processing the image detected by the warpage sensor 7 to calculate the amount of warpage of the hot bar tip, and the hot bar 6 measured by the thermometers 8 and 8. A control device composed of a computer having a function of calculating the amount of warpage of the hot bar tip from the temperature difference between the upper and lower surfaces and a function of controlling the amount of rolling oil supplied to the upper and lower nozzles 9, 9. The control of the supply amount of the rolling oil by the control device is performed so that the warpage amount calculated from the temperature difference is eliminated, and feedback from the actual warpage amount on the delivery side of the rolling mill detected by the warpage sensor 7. To be controlled.

  In the warp suppressing method described above, the warp sensor 7 and the thermometer 8 are used to determine the warpage of the hot bar tip, and the warpage is suppressed by controlling the supply amount of rolling oil. In addition to controlling the amount of rolling oil supplied by measuring the surface roughness of the roll, the warpage may be controlled by controlling the temperature with a heating furnace or controlling the rotational speed of the spindle of the work roll 2.

  In the method for suppressing the warpage of the hot bar tip as described above, the table roller 5 is pivoted as shown in FIG. An impact force sensor 12 composed of a strain meter or a load cell is provided on the supporting frame 11 so that the strain or load caused by the impact force when the tip of the hot bar hits the table roller 5 can be measured. The number of rotations of the spindles of the upper and lower work rolls 2 can be controlled.

  The impact force sensor 12 described above is provided for each table roller 5, preferably for all table rollers, at least for the table roller 5 with which the hot bar tip first hits.

  FIG. 3 shows the result of measuring the impact force when the hot bar tip collides with the table roller 5 with a load cell. The variation shown in the figure is the slab mass, rolling speed, steel type or warpage. This is because it depends on the size.

  In this embodiment, when the impact force measured by the load cell that is the impact force sensor 12 reaches the fatigue strength of the table roller 5, the control device performs control so as to decrease the rotation speed of the spindle of the work roll 2.

  In the above embodiment, the impact force sensor 12 is attached to the table roller 5, and the impact force when the hot bar tip collides with the table roller 5 is measured. In another embodiment, rolling is performed above and below the rolling line. Among the various devices or equipment such as a cooling device, a measuring device, and a descaling hood arranged along the line, the impact force sensor 12 is provided in at least a device or equipment that first hits the hot bar tip, The impact force when hitting the apparatus or equipment is measured, and the rotation speed of the work roll is controlled by the impact force.

1. Rolling mill 2. Work roll 3. Backup roll 4. Feed roller 5. Table roller 6. Hot bar 7. Warp sensor 8. Thermometer 9. Rolling oil supply nozzle 10.・ Laser rangefinder 11 ・ ・ Frame 12 ・ ・ Shock force sensor

Claims (1)

Of the following (1) to (3), a hot bar tip warpage suppressing method in rough rolling in a hot rolling process including at least one hot bar tip warpage suppressing method, which is arranged side by side along a rolling line. The impact force sensor is attached to at least the table roller that first hits the hot bar tip among the plurality of table rollers, and when the impact value measured by the sensor exceeds the set value, the rotational speed of the work roll of the roughing mill is determined. A method for suppressing warpage of a hot bar tip, characterized by performing a slowing down operation of rough rolling and roughing.
(1) Warpage of the hot bar tip is detected by a warpage sensor provided on the exit side of the rough rolling mill, temperature control to the hot bar, control of the amount of rolling oil supplied, and work roll so that the warpage is eliminated A method of performing at least one control among the control of the rotational speed of
(2) The roughness of the work roll surface is measured by means of roughness measuring means installed at the top and bottom of the rough rolling mill, whereby the friction coefficient difference between the upper and lower work rolls is determined, and the rolling oil is applied to the roll so that this difference is eliminated. How to supply,
(3) Measure the temperature of the upper and lower surfaces of the hot bar, and eliminate at least one of temperature control to the hot bar, supply control of rolling oil, and control of the number of rotations of the work roll in order to eliminate the warp due to the temperature difference. How to do.