JPS61262427A - Straightening method for steel plate - Google Patents

Abstract

PURPOSE:To obtain the necessary plastic yield factor with good efficiency and one time of plate pass by controlling with correction the rolling reduction quantity of a roller leveller based on the difference in the corrected load calculated in advance based on the necessary plastic yielding factor and surveyed load. CONSTITUTION:The rolling reduction quantity of the rolling reduction device 6, 7 at the inlet side and outlet side in a roller leveller 1 is obtd. by respectively fitted load detector 8, 9 in order to obtain the necessary plastic yielding factor by controlling the rolling reduction quantity of the roller leveller with the feedback of the difference in the corrected load and surveyed load. Based on the difference in this surveyed load and the corrected load in the rolling reduction device 6, 7 calculated in advance based on the necessary plastic yielding factor the control of the rolling reduction quantity is performed by a control device 10 to obtain the necessary plastic yield factor. By so doing the necessary plastic yield factor is surely obtd. without performing a re-plate passing, etc. and the good steel plate that the deflection is straightened can be obtd.

Description

[Detailed description of the invention]

FIELD OF INDUSTRIAL APPLICATION 1 This invention relates to an improvement in a method for correcting warpage of a steel plate using a roller leveler. [Prior Art] Conventionally, as one of the means for straightening a steel plate, it consists of a plurality of rolls 2 arranged in a staggered manner as shown in FIG. There is a roller leveler 1 for correcting. Such straightening conditions of the roller leveler 1 are generally determined by the amount of reduction on the entrance side and the amount of reduction on the exit side. That is, as shown in FIG. 3, the upper roll group 3 and the lower roll group 4 are arranged on the same straight line, and
When straightening the steel plate 5 by applying a so-called tilting reduction that tilts the straight line toward the exit side, the residual stress strain of the steel plate 5 after straightening is determined by the entry side reduction amount δ1, and the warpage is determined by the exit side pressure. It is determined by the lower amount δ2. Roller leveler 1
The straightening effect is evaluated by the plastic yield rate, and the reduction amounts on the input side and the outlet side are set so as to obtain the plastic yield rate according to the conditions of the plate to be straightened. Here, in the conventional roller leveler, the reduction amount is set before threading the steel plate and is not adjusted during threading. However, during actual operation, if the elongation of the housing of the O-leveler and the unevenness of the rolling screw are incorrectly predicted, the necessary plastic yield rate cannot be obtained, and the plate must be rethreaded. It is often done to obtain the desired plastic yield rate. Therefore, there is a problem that work efficiency and energy efficiency are low.

[Problems to be solved by the invention]

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a method for straightening a steel plate that can efficiently obtain the necessary plastic yield rate in - times of passing. shall be. Means for Solving the Problems [0013] The present invention provides a method for straightening a steel plate in which warpage is corrected using an O-layer leveler, in which the rolling teeth of the roller leveler are subjected to a straightening load calculated in advance based on the required plastic yield rate. The above object is achieved by performing control based on the difference between the actual load and the actual load to obtain the required plastic yield rate.

[Effect]

In this invention, the reduction amount of the roller leveler is controlled by feeding back the difference between the straightening load and the measured load, so that the required plastic yield rate can be reliably obtained.

【Example】

The method for straightening a steel plate according to the present invention will be explained below with reference to FIG. 1, which shows an apparatus for carrying out the method. As shown in FIG.
The reduction teeth of the entry side reduction @M6 and the exit side reduction amount @7 are set to the entry side reduction amount W! ! The input side reduction 11M6 and the exit side reduction amount are calculated in advance based on the actually measured load obtained by the load detector 8.9 attached to each of the 6 and the exit side reduction device 17, and the required plastic yield rate! ! Based on the difference from the straightening load at 7, the control device 110 adjusts the input side rolling down device 6 and the exit side rolling down amount r! By controlling the reduction amount of 17,
This is to obtain the required plastic yield rate. Reference numeral 5 in the figure indicates a steel plate which is a plate to be straightened. The straightening cylinders 111F1 and F2 in the entry side rolling down device 6 and the exit side rolling down device 7 provided in advance to the control device 10 are determined by the following equations (1) and (2): an entry side rolling amount δ1, an exit side rolling amount δ2, It is expressed as a function of the thickness H1 of the plate to be straightened and the yield stress σY. F+-ft(δ1, δ2, H1σY)...(1) F2
-1'z(δ1, δ2, H1σY) ... (2)
This is also supported experimentally. Moreover, the correction load F1. F2 is expressed by Equations (3) and (4), where the plastic yield rate is η. F+−f+−(η, H1σY) ・・・・・・・・・(
3) Fz−F2−(η, H1σY) ・・・・・・・・・
-(4) That is, the straightening loads Fl and F2 are expressed as functions of the yield rate η. The control bag [10 is an inlet roll 11 and an outlet roll 1
Calculate the differences Δδ1 and Δδ2 between the inlet side reduction amount and the outlet side reduction amount in 2 and the actual reduction l from the following equations (5) and (6), and calculate the inlet side reduction amount W16 and the outlet side reduction by the difference. @!
! The pressure is adjusted by 7. here,
Fl- and F2- indicate the actual rolling loads at the inlet rolling device 6 and the outlet rolling device 7 detected by the load detector 8.9. Δδ1=(Fl-Ft)/(f1/8δ1)...
......(5) Δ62-(Fz-F2), /(a fz/86z)
(6) Here, a 1'+/a6+ and af2/aδ2 are determined by the above equations (1) and (2). According to experiments conducted by the present inventor, the following results were obtained. Board thickness 301, board width 5000F! hot steel plate ((Fy-6,
5m, /d), the straightening conditions to obtain a plastic yield rate of 80% are calculated to be an input side reduction of 3n and an exit side reduction! ! Onw, the straightening load on the entrance side is 300 tons and the straightening load on the exit side is 100 tons. When straightening was performed using the conventional method with the entry side reduction II set to 3 days and the exit side reduction amount Oπ, the average correction load on the entry side was 25 Qton.
, the average load on the exit side is 5 Q ton, and the residual steepness is:
It was 0.5%. On the other hand, the initial setting is 13 m for the entry side reduction and 11 Oi for the exit side reduction, and the reduction tooth is dynamically adjusted so that the difference between the set orthodontic load and the actual load on each of the entrance and exit sides during correction becomes zero. When the steel plate was controlled to have a residual steepness of 0°2%, a good steel plate was obtained.

【Effect of the invention】

Since the present invention is constructed as described above, it has the excellent effect of being able to reliably obtain the required plastic skewer using a roller leveler without performing re-threading or the like.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a roller leveler for carrying out the steel plate straightening method according to the present invention, including some blockage;
FIG. 2 is a perspective view showing the arrangement of rolls in a general roller leveler, and the third factor is a side view of the same. 1... Roller leveler, 2... Straightening roll, 3
...Upper roll group, 4...Lower O-roll group, 5
... steel plate, 6 ... entry side rolling down device, 7
...Output side lowering device, 8.9...Load detector, 10...Control device, 1
1... Entry side roll, 12... Output side roll.

Claims (1)

[Claims] (1) In a steel plate straightening method in which warpage is straightened using a roller leveler, the reduction amount of the roller leveler is corrected and controlled based on the difference between the straightening load calculated in advance based on the required plastic yield rate and the actually measured load. A method for straightening a steel plate, characterized by obtaining a required plastic yield rate.