JPS6047006B2 - Online correction rolling method for roll profile - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rolling method for on-line correction of roll profile.

Generally, as rolling progresses, the amount of wear on rolling rolls increases, causing deterioration of the roll surface skin and seriously affecting product quality, making it difficult to continue rolling and requiring roll replacement. Rolling operations are interrupted due to roll rearrangement, which is a major obstacle to improving work efficiency and production efficiency.

In order to eliminate the above drawbacks, JP-A-54-145356
Deterioration of the surface skin inside the housing during rolling due to issues such as
Alternatively, an online roll grinding device for grinding abnormally worn rolling rolls has been proposed.

When using these online roll grinding devices, a method is adopted in which grinding is carried out gradually from the start of rolling to the progress of rolling, or during idle time, when the rolled material is not being passed through the plate. ing.

When grinding the roll surface gradually from the beginning of rolling,
Grinding occurs even if the roll surface has a normal profile, leading to over-grinding of the roll.

In addition, if a method is adopted in which the grinding time is delayed to avoid such over-grinding and the grinding is performed after rolling has progressed to a certain level, the quality of the finished product may be affected depending on the timing of the selection of the grinding time. Furthermore, there is a risk that the abnormal wear of the rolls will progress more than expected, far exceeding the grinding capacity of the grinding device, and that rolling will have to be stopped and the rolls replaced. The present invention has been made to advantageously solve these problems, and its characteristics are that, when rolling a strip, the profile of the strip immediately after rolling is detected online during rolling;
From the profile, changes in the profile of the rolling roll are detected during rolling, and the actual values of detected abnormal protrusions or crowns on the strip are compared and calculated with their tolerance values, and grinding is performed within the grinding capacity range of the online roll grinding device. The present invention relates to an online correction rolling method for a roll profile, which is characterized in that roll grinding is performed by determining the timing, and rolling is performed while correcting changes in the roll profile as the rolling progresses.

Further, the present invention will be explained based on the drawings.

FIG. 1 shows a layout diagram of an online profile meter and an online grinding device in a finishing stand for continuous hot rolling.

In the figure, 1 is an online profile meter that measures the cross-sectional shape of the strip in the width direction during rolling, 2 is an online roll grinding device built into the rolling stand, 3 is the strip, and 4 is the finishing stand vertically operating rolls F1 to F7.
represents finishing stand No. 1 to finishing stand No. 7. (
Note that the backup roll is omitted) 10 is the profile, -
A computer that receives information about the rolled material from the host computer, predicts the progress of wear and profile, and issues the grinding amount, grinding position, and grinding command.

Reference numeral 11 indicates a control panel of an online roll grinding device that controls the amount of grinding and the grinding position.

According to conventional rolling, when the profile of the strip becomes abnormally deteriorated, when the F4 to F7 operating rolls are rearranged at the same time and the rolling is restarted, the profile of the strip returns to normal. From this experience, it is predicted that the stands that greatly affect the strip profile are the latter stands F4 to F7 of the seven finishing stands. On the other hand, as a cause of the deterioration of the strip profile, there is also a phenomenon in which the rough surface of the front rolls F1 to F3 is transferred to the strip surface and stretched in the rear stand.

In such a case, the online roll grinding device 2
~ It is preferable to install 3 in F3 as well. The change in profile of the strip is caused by the profiling of the rolling rolls, and typical examples include abnormal protrusions due to abnormal wear and crown reduction due to overall wear of the rolls as rolling progresses.

In addition to the deterioration of the profile due to wear, there are also abnormal protrusions due to local thermal expansion of the roll or crown reduction due to thermal expansion of the entire roll. FIG. 2a shows abnormal wear 5 of the roll, and if such an abnormally worn roll is used, the product will have the profile shown in FIG. 3, and abnormal protrusions (O-marked portions) will occur.

An example of crown reduction is shown in Fig. 4. As rolling progresses, the crown decreases from 1 when it is a new roll due to roll wear or roll thermal expansion, and when it reaches crown 1, rolling must be terminated and the rolls must be replaced. . The roll wear situation in such a case is shown in FIG. 2b, where 6 is the worn part. Since these abnormal protrusions and crown reduction have a negative effect on the rolled shape in the next step of cold rolling, it is necessary to prevent or promptly remove the abnormal protrusions and maintain the crown at an appropriate level. Therefore, the present invention detects the strip profile using an online profile meter or the like, and when the quality of the strip profile (abnormal protrusions and crowns) exceeds the permissible limit, the strip profile is detected by an online roll grinding device located in the rolling mill, especially from F4 to F7. The shape of the roll surface is modified by grinding the surface of the roll.

That is, based on the profile detection and judgment flow sheet shown in Fig. 5, if an abnormal protrusion is found in the detected strip profile, the occurrence position and amount of the abnormal protrusion are determined, and it is determined whether the occurrence position is at the end of the strip or not. If it is found, it is determined that it is caused by uneven wear of the roll, and if it is in the center of the strip, it is determined that it is caused by thermal expansion of the roll. At the same time, a comparison is made with a standard value that is an acceptable range for quality, and the following two measures are taken. 1 If the profile is outside the standard, use a calculator (see
0), and if the result is negative, the rolling is stopped and the rolls are changed.

On the other hand, when a profile within the standard is obtained, Yanghe calculates which stand and how much to grind, and then performs roll grinding by setting the depth of cut at each point in the roll barrel direction of the online roll grinding device. 2. If the profile is within the standard, the growth of abnormal protrusions and the reduction of the plate crown are predicted using a computer (10 in Figure 1) based on the future rolling conditions, and it is estimated how many rolls will be rolled that will fall outside the standard.

At the same time, although it is within the standard considering the grinding capacity (grinding depth/times) of the online roll grinding device, it is necessary to start grinding early, etc., and as in case 1, which part of which stand Grinding is performed after calculating how much to grind.
When roll grinding is performed, the area around the rolling roll corresponding to the position of abnormal protrusion is locally (2 to 2 times the width of the abnormal protrusion)
3 times the area) and smooth it. In addition, if a large reduction in crown is observed from the detected strip profile, it is assumed that this is due to roll wear or thermal expansion, and the same judgment is made as in the case of abnormal protrusions. By grinding over a length of ~200T0rL), deterioration in the shape of the roll surface is corrected.
More specifically, since abnormal protrusions due to roll wear gradually become larger, the profile is detected periodically (for example, within several rolls) and the rolls are ground periodically.

On the other hand, since abnormal protrusions caused by non-uniform thermal expansion occur suddenly, it is preferable to perform roll grinding as soon as an abnormality is detected. Since the crown gradually deteriorates with little sudden change, it is periodically adjusted according to the capacity of the online roll grinding equipment.
It is possible to decide the grinding timing.

Therefore, the vertically operating rolls F4 to F7 are ground to remove abnormally worn parts or restore the crown of the roll to continue rolling smoothly.

Here, the online roll grinding device is a rotary grindstone type that can move parallel to the axis of the roll and can control the depth of cut, or a support member that can move a large number of grindstones in and out in the longitudinal direction of the roll. Fix it and press the whetstone L
It is possible to use a type that attaches to the base, but the present invention is not limited to these. That is, if the profile of the strip is detected and an abnormal protrusion is found, the abnormal protrusion can be removed at an early stage by, for example, removing the shaded area 7 in FIG. 2A by polishing.

On the other hand, as mentioned above, the crown decreases from 1 to 1'' in Figure 4, but for example, when changing from 1 to 2, F4
When the online roll grinding device located at F7 is activated and the shaded area 8 in Fig. 2b is ground, the crown gradually recovers from 2'' to 2'', and when the crown recovers to 2'', grinding is stopped and rolling is stopped. Continue, then crown 2″ is 3
When it decreases to 3", roll grinding is performed online again, and when it recovers to 3", grinding is stopped and rolling is continued.Then, the above-mentioned procedure is repeated to correct the change in roll profile and continue rolling while maintaining a good roll crown. As described above, the advantage of the present invention is that the roll profile can be improved by grinding the periphery of the abnormally worn part or non-uniform thermal expansion part of the rolling roll corresponding to the abnormally deteriorated part of the strip profile detected by the online profile meter. Modify online while rolling.

In addition, the transition of the strip profile during rolling is detected,
Then, the transition of the crown is determined, and the crown is restored during rolling by grinding the end and body of the roll using an online roll grinding device according to the amount of decrease in the crown, thereby reducing the number of roll changes and producing rolling. It is possible to improve performance. Furthermore, the grinding timing and grinding amount can be determined based on changes in the profile of the strip during rolling.
It is possible to accurately grasp the roll to be ground, and the grinding conditions can be set freely according to the grinding capacity of the online roll grinding device.As a result, the crown always has an appropriate profile with no abnormal protrusions. be able to.

Next is the implementation.

Example 1 A hot finishing mill with the equipment arrangement shown in Figure 1 has a plate width of 940 mm.
When 89mm tinplate material from wt was rolled and rolled on 30 axis in terms of NE, the strip profile at 30km was 6th.
Abnormal protrusions 3 and 8 shown in Figure A (before grinding correction) were detected, and since the actual values were larger than the standard values, online roll grinding was immediately performed from positions 8 and 8 at a distance of ±4 (g) and ±2'', respectively. Using device 2, all 3 parts of F4 to F7 and stands were ground 7 times at 3μ once, and 8 parts were ground at 3μ once.
When the strip was ground and removed five times, the strip profile for the next rolling was a good profile with no abnormal protrusions, as shown in FIG. 6b (after grinding correction).

Example 2 When a hot finishing rolling mill with the equipment arrangement shown in Figure 1 rolls a cold thin material with a plate width of 160 to 98 hours to a length of 80 mm in terms of NE, the strip profile with a plate width of 11007 nm near the 40 axis is as follows. As shown in Fig. 7a (before grinding correction), the crown is becoming abnormal and it is predicted that it will deviate from the standard, so the online grinding device 2 immediately
When the range of ±650Tnm from the roll center of all the rolling rolls 4 of F7 stand was ground 12 times at 3μ per time, the strip profile of the next rolling was good as shown in Figure b (after grinding correction). .

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the equipment arrangement for carrying out the present invention, Fig. 2 shows a typical example of a worn roll profile, where a indicates abnormal wear (or uneven thermal expansion), and b indicates normal FIG. 3 is an explanatory diagram showing the profile of a strip in which abnormal projections have occurred, and FIG. 4 is an explanatory diagram showing crown reduction and crown recovery by grinding. Figure 5 is a flow sheet for detecting strip profile and determining grinding timing. 6 and 7 show an embodiment of the present invention, FIG. 6 is an explanatory view showing abnormal protrusion correction rolling, and FIG. 7 is an explanatory view showing abnormal crown correction rolling. 1...
・・Online profile meter, 2・・・Online roll grinding device, 3・・・Strip, 4・
...Vertical operation roll.

Claims (1)

[Claims] 1. When rolling a strip in a continuous rolling facility in which each rolling stand is equipped with an online roll grinding device, the profile of the strip immediately after rolling is detected online during rolling, and changes in the profile of the rolling roll are detected from the profile. The actual values of abnormal protrusions or crowns detected during rolling are compared with their allowable values, and if the actual values are outside the allowable range, it is determined whether or not they can be brought within the allowable range by grinding. If not, stop rolling and change the rolls, and if the actual value is within the allowable range, or if the actual value is within the allowable range, determine when the actual value will exceed the allowable range and require grinding based on future rolling conditions. The amount of grinding, the grinding stand, and the grinding position are determined when the predicted grinding results in an acceptable range or at the predicted grinding time, and roll grinding is performed using an online roll grinding device accordingly to determine the progress of rolling. 1. A rolling method for online correction of a roll profile, characterized in that rolling is performed while correcting changes in the roll profile caused by changes in the roll profile.