JP2001191106A - Cold-rolling equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide cold-rolling equipment for surely and properly removing flaws which are unexpectedly formed on the surface and/or back face of a steel strip during hot-rolling and cold-rolling and intergranular corrosion grooves which are formed on the surface and/or back face when pickling the strip after the hot-rolling in the cold-rolling equipment. SOLUTION: In the cold-rolling equipment 1, a grinding device 5 is installed on a rolling line having a cold-rolling mill 4. The grinding device 5 has a grinding means 6 for grinding the flaws and/or intergranular corrosion grooves which are formed on the surface and/or back face of the steel strip S, a contacting and separating means 7 for bringing the grinding means 6 into contact and separating it, a flaw detecting means 8 for detecting the positions of flaws and moreover their depths, a tracking means for tracking the flaws, a setting means 9 for preliminarily setting the depth of the intergranular corrosion grooves and a control means 10 for controlling the operation of the contacting and separating means 7 based on the flaw-position signals or depth signals from the flaw detecting means 8 and the tracking means or the depth signals of the intergranular corrosion grooves which are preliminarily set by the setting means 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling facility in which a device for grinding a surface flaw or a grain boundary erosion groove formed on the front surface and / or the back surface of a steel strip is installed.

[0002]

2. Description of the Related Art Generally, a steel strip is manufactured by a process of pickling, cold rolling and annealing after hot rolling. In the case of stainless steel strips requiring surface gloss, after a series of steps of hot rolling, annealing, pickling, and cold rolling, those with particularly severe surface gloss are subjected to bright annealing. In some cases, polishing is performed after pickling following annealing.

Here, pickling after hot rolling is performed for the purpose of removing oxide scale formed on the surface layer of the hot rolled material. However, since the pickling equipment is expensive, and the pickling process forms a line independent of cold rolling, it is necessary to arrange operating personnel separately from the rolling line, which increases operating costs. Because it has disadvantages,
As a conventional technique for solving these drawbacks, there is known a cold rolling facility in which a descaling apparatus for removing oxide scale formed on the surface layer of a hot-rolled material is installed in a rolling line (Japanese Patent Laid-Open No. 58-1983). 9710). This cold rolling equipment is shown in FIG.

[0004] This cold rolling equipment 100 comprises a payoff reel 101, a dull roll 102a and a support roll 102.
b, and a plurality of grinding rolls 1
Descaling device 103 having the same 03a and cleaning device 10
4, a cold rolling mill 105 and a winder 106. The steel strip S after hot rolling unwound from the payoff reel 101 is first rolled to a predetermined elongation by the pre-treatment rolling mill 102. During this rolling, the dull roll 102
The oxide scale Sc of the surface layer is crushed by a to be turned into small pieces and powder. Then, the steel strip S that has been subjected to the pre-treatment rolling enters the descaling device 103 provided on the same line.
The oxide scale Sc crushed by 3a is cleaned. Thereafter, the steel strip S enters the cleaning device 104, and the cleaning device 1
Numeral 04 wash away grinding debris, dust, etc. of the oxide scale Sc adhered to the steel strip S after grinding.

[0005] The steel strip S from which the oxide scale Sc has been removed through the above steps enters a cold rolling mill 105 provided on the same line as the pretreatment rolling mill 102 and the descaling device 103, where it is rolled and wound. It is taken up by the take-up machine 106.
As described above, in this cold rolling equipment 100, since the descaling device 103 is provided in a rolling line having the cold rolling mill 105, the hot-rolled material that has not been pickled is directly cold-rolled. Since it can be put into the line and work can be continuously performed, there is an advantage that the cost of the pickling equipment and the operating personnel can be reduced.

[0006]

By the way, in the manufacturing process of the steel strip, in addition to the formation of oxide scale after hot rolling, the surface and / or the back surface suddenly occur during hot rolling or cold rolling. Flaws may be formed on the surface. The flawed steel sheet has a problem in surface quality and needs to be removed. This flaw is not formed on the entire surface of the steel strip after hot rolling,
The hot-rolled material is often scattered in some places in the longitudinal direction. The depth of the flaws varies depending on the type of steel and the manufacturing process. For example, in a steel strip after hot rolling of an austenitic stainless steel represented by SUS304, about 10 μm, and a ferritic stainless steel represented by SUS430 are exemplified. The thickness of the steel strip after hot rolling is about 100 μm. The depth of this flaw is different from the depth of the oxide scale, which generally has a depth of about 10 μm (JP-A-7-26).
No. 6207).

Further, during hot rolling and / or annealing, a Cr-free layer is formed in the vicinity of the crystal grain boundary of the hot-rolled material. Erosion grooves are formed. This grain boundary erosion groove remains without disappearing even after further cold rolling the steel strip after hot rolling, and a desired gloss may not be obtained. In some cases, it may be necessary to remove them. The problem is the depth of the grain boundary erosion groove, which depends on the type of steel, hot rolling conditions, annealing conditions, and pickling conditions. In the case of austenitic stainless steel, the depth varies from about 3 μm to about 15 μm. . Incidentally, the width of the grain boundary erosion groove is about 1 μm to about 7 μm (see JP-A-8-269549).

Now, a conventional cold rolling equipment 10 shown in FIG.
Depending on the value of 0, even if the flaws formed on the front and back surfaces of the steel strip after hot rolling are removed, it may not be performed properly. That is, the cold rolling equipment 100 continuously grinds the entire length of the steel strip with the descaling device 103 so as to remove the oxide scale Sc formed on the surface layer of the steel strip S after hot rolling. Flaws scattered in the longitudinal direction of the steel strip,
As described above, the depth is different from the depth of the oxide scale,
In most cases, if the flaws are to be removed, it is necessary to grind the steel strip to a normal part after hot rolling, and the yield may be significantly deteriorated.

In most cases, the depth of the grain boundary erosion groove is also deeper than the depth of the oxide scale Sc. Therefore, depending on the cold rolling equipment 100, the grain boundary erosion groove formed in the hot-rolled material may be appropriately adjusted. May not be removed. Accordingly, an object of the present invention is to appropriately form flaws formed on the front surface and / or the back surface of the steel strip, which are formed during hot rolling or cold rolling.
It is an object of the present invention to provide a cold rolling facility that can be reliably removed.

Another object of the present invention is to provide, in a rolling line with a cold rolling mill, a grain boundary erosion groove formed on the front and / or back surface of a stainless steel strip formed during pickling after hot rolling. An object of the present invention is to provide a cold rolling equipment that can be appropriately and reliably removed. Still another object of the present invention is to form on a front and / or back surface of a stainless steel strip which is formed unexpectedly during hot rolling or cold rolling in a rolling line having a cold rolling mill. Cold rolling equipment capable of coping with the case of removing the formed flaws and the case of removing the grain boundary erosion grooves formed on the front surface and / or the back surface formed at the time of pickling after hot rolling. Is to provide.

[0011]

In order to solve the above-mentioned problems, a cold rolling equipment according to claim 1 of the present invention is a grinding means for grinding flaws formed on the front surface and / or the back surface of a steel strip. , Separating means for separating the grinding means from the steel strip,
Flaw detection means for detecting the position or depth of the flaw, tracking means for tracking the flaw, and operation of the separation / contact means based on the flaw position signal or further depth signal from the flaw detection means and tracking means And a control means for controlling the control.

Further, the cold rolling equipment according to claim 2 of the present invention is characterized in that a grinding means for grinding a grain boundary erosion groove formed on a front surface and / or a back surface of a stainless steel strip; Separation / contact means for separating / contacting the band, setting means for presetting the depth of the grain boundary erosion groove, and the separation / contact means based on a preset depth signal of the grain boundary erosion groove from the setting means And a control means for controlling the operation of.

Further, the cold rolling equipment according to claim 3 of the present invention is characterized in that the grinding means for grinding flaws and grain boundary erosion grooves formed on the front and / or back surfaces of the stainless steel strip, Detachment and disengagement means for contacting and disengaging the stainless steel strip, flaw detection means for detecting the position or further depth of the flaw,
The tracking means for tracking the flaw, the setting means for presetting the depth of the grain boundary erosion groove, and the flaw detection means, the flaw position signal from the tracking means or further depth signal or the preset by the setting means the said Control means for controlling the operation of the separation / contact means based on a depth signal of the grain boundary erosion groove is provided.

According to a fourth aspect of the present invention, in the cold rolling equipment according to any one of the first to third aspects, the cold rolling equipment is a Sendzimir rolling equipment. And

[0015]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a schematic view of a first embodiment of a cold rolling facility according to the present invention. The cold rolling equipment 1 in FIG. 1 performs cold rolling of a steel strip S that has been subjected to annealing and pickling steps after hot rolling, and a cold rolling mill is provided between a payoff reel 2 and a tension reel 3. 4 and a grinding device 5 is installed on each of the entry side and the exit side of the rolling mill 4.

The rolling mill 4 comprises upper and lower work rolls 4a for rolling a steel strip S reciprocating between the payoff reel 2 and the tension reel 3 at a predetermined reduction rate, and a plurality of intermediate rolls surrounding these work rolls 4a. 4b and a reciprocating rolling mill having a backup roll 4c surrounding the intermediate roll 4b. In addition, each grinding device 5
Has a pair of grinding means 6 which are arranged on the front side and the back side of the steel strip S and grind flaws and grain boundary erosion grooves formed on the front side and / or the back side of the steel strip S. Each of the grinding means 6 includes a first rotating shaft 6a rotatably supported, a second rotating shaft 6b rotatably disposed so as to be able to be separated from and attached to the steel strip S, and a first rotating shaft 6a. And a grinding belt 6c that is provided around the second rotating shaft 6b and grinds flaws and / or grain boundary erosion grooves formed on the surface of the steel strip S. The first rotating shaft 6a and the second rotating shaft 6b are rotated by a drive motor (not shown) so that the grinding belt 6c rotates in the transport direction of the steel strip S or in a direction opposite to the transport direction. When the grinding belt 6c rotates in the direction opposite to the direction in which the steel strip S is transported, the ability to grind flaws and grain boundary erosion grooves is improved. here,
The polishing count of the grinding belt 6c is # 20 to # 1000.
(JIS R 6001). Each second rotating shaft 6b is provided with a cylinder (separating means) 7 for separating the second rotating shaft 6b from the steel strip S. On the other hand, on the front side and the back side of the steel strip S, a flaw detecting means 8 for detecting the position or depth of a flaw formed on the front side and the back side of the steel strip S is provided. And setting means 9 for presetting the depth of the grain boundary erosion groove formed on the back surface. The pinch roll 13 is provided with a tracking means (not shown) for tracking the flaw by counting pulses emitted from a pulse generator (not shown). The depth of the grain boundary erosion groove varies depending on the steel type, hot rolling conditions, annealing conditions, and pickling conditions.However, the conditions under which hot rolling, annealing, and pickling are performed with any steel type are largely determined in operation. Since the depth of the grain boundary erosion groove is known in advance empirically, the setting of the grain boundary erosion groove depth by the setting means 9 is preferably performed based on the empirical value of the steel type. . Of course, the present invention is not limited to this, and logic for correcting the depth may be added according to the fluctuation or variation in the hot rolling condition or the annealing condition as described above. The pair of cylinders 7 on the front and back sides of the steel strip S, the pair of flaw detection means 8, the tracking means and the setting means 9 are connected to the control means 10. The control means 10 controls the operation of the cylinder 7 based on a flaw position signal from the flaw detection means 8 and the tracking means or a further depth signal or a preset depth signal of the grain boundary erosion groove from the setting means 9. It has become. In addition, each of the grinding devices 5 is provided with a cleaning spray 11 for cleaning the grinding dust ground by the grinding belt 6. FIG.
Reference numeral 12 denotes a cleaning filter for the cleaning liquid supplied to the cleaning spray 11.

Next, a method of cold rolling of the steel strip S that has been subjected to annealing and pickling steps after hot rolling will be described. On the front and back surfaces of the steel strip S that has been subjected to the annealing and pickling steps after hot rolling, usually, flaws of various depths are scattered in some places in the longitudinal direction of the steel strip. In the case of such a steel type, grain boundary erosion grooves are formed over substantially the entire area of the front and back surfaces of the steel strip.

There are various grades of stainless steel required for surface gloss, from mild to severe. First, the case of stainless steel whose quality required for surface gloss is relatively moderate will be described. In this case, it is necessary to appropriately remove the flaws, even if not removing the grain boundary erosion grooves. In this case, the operation of the setting means 9 is stopped, and the position or further depth of the flaw formed on the front and back surfaces of the stainless steel strip S unwound from the payoff reel 2 is changed to the front side of the stainless steel strip S and the flaw. The flaw is tracked by being detected by a pair of flaw detection means 8 provided on the back side and counting pulses emitted from a tracking means, for example, a pulse generator (not shown) provided on the pinch roll 13. The flaws detected here include both flaws generated during hot rolling and flaws generated during cold rolling. Then, a flaw position signal or a further depth signal from the flaw detection means 8 and the tracking means is transmitted to the control means 10.
Sent to The control means 10 controls the operation of the cylinder 7 based on the flaw position signal or the depth signal from the flaw detection means 8 and the tracking means. That is, the control means 1
0 indicates that the second rotating shaft 6b is brought closer to the stainless steel strip S by operating the cylinder 7 when the flaw passes the position of the grinding belt 6 based on the flaw position signal from the flaw detection means 8 and the tracking means. . The control means 10 operates the cylinder 7 based on the depth signals from the flaw detection means 8 and the tracking means to control the gap between the grinding belts 6c and the pressing force of the grinding belt 6c against the stainless steel strip S. Adjust according to the depth of the flaw. Alternatively, the maximum depth known from experience may be ground each time. The reason is that the depth measurement may have an error. Further, even if the maximum depth of experience is ground every time, only the position with a flaw is ground in a spot-like manner, and the entire length is not ground, so that the yield loss does not increase. For this reason, the flaws formed at various depths scattered on the front and back surfaces of the stainless steel strip S can be reliably and appropriately ground by the grinding belt 6. Then, the ground grinding dust is cleaned by the cleaning liquid from the cleaning spray 11. The stainless steel strip S from which the grinding debris has been washed is sent to the rolling mill 4 through the pinch roll 13.

In the rolling mill 4, one side (left side in FIG. 1)
The cold rolling of the stainless steel strip S whose flaw has been ground by the grinding device 5 is performed, and the pinch roll 1 is attached to the grinding device 5 on the opposite side.
The stainless steel strip S is sent out through 3. Then, the stainless steel strip S is wound up by the tension reel 3. The stainless steel strip S on which the above-mentioned flaw grinding and cold rolling have been performed throughout the entire length is rewound in reverse from the tension reel 3 and enters the above-described grinding apparatus 5 on the opposite side. In this grinding device 5, in the same procedure as the above-described one-side grinding device 5, flaws remaining on the front and / or back surfaces of the stainless steel strip S (including flaws generated by cold rolling by the rolling mill 4). Is performed, and the stainless steel strip S is sent to the rolling mill 4 again through the pinch roll 13.

The rolling mill 4 performs cold rolling again on the stainless steel strip S whose flaws have been ground by the grinding device 5 on the opposite side.
The stainless steel strip S is sent out to the grinding device 5 on one side via the pinch roll 13. Then, the stainless steel strip S is wound up from the grinding device 5 on one side by a payoff reel.

The cold rolling of the sunless steel strip S is performed by repeating the cold rolling operation by the reciprocating rolling mill 4 and the flaw grinding operation by the grinding devices 5 arranged on both sides of the rolling mill 4 a plurality of times. Is completed. It is preferable to grind the flaws of the stainless steel strip S in the case of the grinding device 5 on the exit side of the rolling by the reciprocating type rolling mill 4 in the case where it corresponds to the exit side on the final pass.

Next, the case of the stainless steel strip S requiring excellent surface gloss will be described. In this case, it is necessary to remove the grain boundary erosion groove. In this case, the operation of the flaw detection means 8 is stopped, and the control means 10 controls the operation of the cylinder 7 based on a preset depth signal of the grain boundary erosion groove from the setting means 9. That is, the control means 10 operates the cylinder 7 based on the preset depth signal of the grain boundary erosion groove from the setting means 9 to bring the second rotating shafts 6b closer to the stainless steel strip S, and The pressing force on the gap between 6c and the stainless steel strip S is adjusted according to the depth of the grain boundary erosion groove.

When the stainless steel strip S unwound from the payoff reel 2 passes between the grinding belts 6c of the grinding device 5, the grain boundary erosion grooves formed on the front and back surfaces of the stainless steel strip S are used for grinding. Belt 6c ensures
Properly ground. Then, the ground grinding dust is cleaned by the cleaning liquid from the cleaning spray 11. The stainless steel strip S in which the grain boundary erosion grooves have been ground is
To the rolling mill 4.

In the rolling mill 4, one side (the left side in FIG. 1)
Cold rolling is performed on the stainless steel strip S whose grain boundary erosion grooves have been ground by the grinding device 5 described above, and the stainless steel strip S is sent out via the pinch roll 13. In the opposite grinding device 5,
The grain boundary erosion groove of the stainless steel strip S may or may not be ground, and the stainless steel strip S is taken up by the tension reel 3. The grinding of the grain boundary erosion groove by the grinding device 5 on one side is performed over substantially the entire length of the stainless steel strip S. The stainless steel strip S that has been subjected to grinding and cold rolling of the grain boundary erosion groove over substantially the entire length is rewound reversely from the tension reel 3 and enters the above-described grinding device 5 on the opposite side. It may or may not be performed, and is sent to the rolling mill 4 again through the pinch roll 13.

The rolling mill 4 cold rolls the stainless steel strip S again, and sends out the stainless steel strip S to the grinding device 5 on one side via the pinch roll 13. The grinding device 5 on one side may or may not grind the stainless steel strip S, and the stainless steel strip S is wound up by the payoff reel 2. Thereafter, the cold rolling of the sunless steel strip S is completed by repeating the cold rolling operation by the reciprocating rolling mill 4 a plurality of times.

It is sufficient that the grain boundary erosion grooves have been removed after the final pass of the rolling performed a plurality of times. In the above example, one side (FIG. 1)
Although the description has been given of the case where the grinding is mainly performed using the grinding device (left side in FIG. 3), the grinding may be mainly performed using the grinding device on the opposite side. As described above, in the present embodiment, during the cold rolling, when removing the flaws formed on the front and back surfaces of the steel strip S during hot rolling or cold rolling, It is possible to cope with the case where the grain boundary erosion grooves formed on the front and back surfaces of the stainless steel strip S formed at the time of pickling after rolling are removed.

When removing the flaw of the steel strip S, the flaw detecting means 8 detects the presence and depth of the flaw in the grinding device 5, and the flaw is tracked by the tracking means. Based on the position signal or the depth signal, the operation of the cylinder 7 for moving the grinding belt 6c to and away from the steel strip S is controlled.
The grinding timing of the grinding belt 6c is adjusted to the position of the flaw, and the gap between the grinding belts 6c and the pressing force of the grinding belt 6c against the steel strip S are adjusted according to the depth of the flaw.
Therefore, during cold rolling, flaws formed at various depths scattered on the surface and / or the back surface of the steel strip S can be reliably and appropriately ground by the grinding means.

In the case of removing the grain boundary erosion grooves of the stainless steel strip S, a preset depth signal of the grain boundary erosion grooves is sent from the setting means 9 to the control means 10 in the grinding device 5, and the control means 10 10 controls the operation of the cylinder 7 for moving the grinding belt 6c toward and away from the stainless steel strip S based on the signal, so that the gap between the grinding belts 6c and the grinding belt 6c with respect to the stainless steel strip S are controlled. Adjust the pressing force according to the depth of the grain boundary erosion groove. For this reason, in the rolling line having the reciprocating rolling mill 4, the grain boundary erosion grooves formed on the front and / or back surfaces of the stainless steel strip S can be reliably and appropriately ground by the grinding belt 6c.

In the present embodiment, the grinding device 5 for grinding the flaws and grain boundary erosion grooves of the stainless steel strip S is provided on the same line as the reciprocating rolling mill 4.
In addition to reducing the cost of equipment for performing each grinding, the cost of equipment for performing pickling, and the cost of operating personnel required for each grinding and pickling, cold rolling of another line after starting processing at the grinding equipment The time it takes to start processing at the equipment can be reduced,
Production time can be reduced.

In the embodiment of the present invention, it is preferable to use a Sendzimir rolling mill as the cold rolling mill. For the purpose of realizing excellent dimensional accuracy at an extremely high rolling reduction, the Sendzimir rolling mill is extremely slow in rolling and conveying speed of the stainless steel strip S. When the grinding device 5 is installed on the same rolling line as the cold rolling mill, the lower the transport speed of the stainless steel strip S, the easier it can be controlled.

In this embodiment, both the flaw detecting means 8 and the setting means 9 are provided. However, when only the flaws of the steel strip S are ground, only the flaw detecting means 8 is provided and the setting means 9 is provided. On the other hand, when grinding only the grain boundary erosion grooves of the stainless steel strip S, the flaw detection means 8 may be omitted only by providing the setting means 9. In the case of the present embodiment,
The pair of flaw detection means 8 is provided on the front side and the back side of the steel strip S. However, when grinding only the front side flaws of the steel strip S, the flaw detection means 8 arranged on the back side is required. In the case where only the flaws on the back side of the steel strip S are ground, the flaw detection means 8 on the front side may be omitted. The pair of grinding means 6 are provided on the front side and the back side of the steel strip S. However, when grinding only the flaws on the front side of the steel strip S, the grinding means 6 arranged on the back side are used. When grinding only the flaws on the back side of the steel strip S, the grinding means 6 on the front side may be omitted. In this case, by controlling the operation of the cylinder 7 by the control means 10, the vertical position of the grinding belt 6c with respect to the stainless steel strip S and the pressing force of the grinding belt 6c with respect to the stainless steel strip S are changed to the flaw depth and grain boundary erosion. It is preferable to adjust according to the depth of the groove.

The grinding means in each grinding device 5
A flaw formed on the front surface and / or the back surface of the steel strip S is not limited to the one including the first rotation shaft 6a, the second rotation shaft 6b, and the grinding belt 6c shown in FIG. If it can grind the grain boundary erosion groove,
As shown in FIG. 1, a grinding pad 14 composed of a pad-type grindstone is used, or a grinding roll composed of a roll-type grindstone rotating in the conveying direction of the steel strip S or in the opposite direction is used. Is also good. The polishing count of the grinding pad 14 is # 20 to # 1000 (JIS R 6001).
The grinding number of the grinding roll is # 20 to # 1000 (JIS
R 6001).

Next, a second embodiment of the cold rolling equipment according to the present invention will be described with reference to FIG. The cold rolling equipment 21 illustrated in FIG. 3 performs cold rolling of the steel strip S that has been subjected to annealing and pickling steps after hot rolling, similarly to the cold rolling equipment 1 illustrated in FIG. The cold rolling equipment 1 of FIG. 1 is provided with a reciprocating rolling mill 4 whereas the cold rolling equipment 21 of FIG. 3 is greatly different in that a tandem rolling mill 24 is provided.

The cold rolling equipment 21 shown in FIG. 3 is provided with a tandem rolling mill 24 between a pay-off reel 22 and a tension reel 23, and a grinding device 2 is provided on the entrance side of the tandem rolling mill 24.
5 are installed. Therefore, in the cold rolling equipment 21, the grinding device 25 is provided on the same rolling line as the tandem rolling mill 24 as a cold rolling mill. here,
The tandem rolling mill 24 includes a plurality of (five in the present embodiment) stands F _{1 to} F ₅ that roll the steel strip S to be conveyed from the payoff reel 22 in the direction of the tension reel 23 at a predetermined reduction rate. Have.

When the steel strip S is a steel type such as stainless steel, the grinding device 25 is disposed on the front side and the back side, and the flaws and grain boundary erosion grooves formed on the front and back sides of the stainless steel strip S are provided. Has a pair of grinding means 26 for grinding.
Each grinding means 26 is a grinding pad composed of a pad-type grindstone, and its grinding number is # 20 to # 1000 (JI
SR 6001). The grinding means 26 is provided with a cylinder (separating means) 27 for separating and contacting the grinding means 26 with the stainless steel strip S. On the other hand, on the front side and the back side of the stainless steel strip S, a pair of flaw detection means 28 for detecting the position or the depth of the flaw formed on the front side and the back side of the stainless steel strip S is provided. A setting means 29 is provided for presetting the depths of the grain boundary erosion grooves formed on the front and back surfaces of the stainless steel strip S. Further, the payoff reel 22 is provided with a tracking means (not shown) for tracking the flaw by counting pulses emitted from a pulse generator (not shown).
The depth of the grain boundary erosion groove depends on the type of steel, hot rolling conditions, annealing conditions, and pickling conditions.However, under what conditions, hot rolling, annealing, and pickling should be performed with any steel type under operating conditions Since the depth of the grain boundary erosion groove is known empirically in advance, the setting of the grain boundary erosion groove depth by the setting means 29 is performed based on the empirical value of the steel type. Is preferred. Of course, the present invention is not limited to this, and logic for correcting the depth may be added according to the fluctuation or variation in the hot rolling condition or the annealing condition as described above. The pair of cylinders 27 on the front and back sides of the stainless steel strip S, the pair of flaw detection units 28, the tracking unit and the setting unit 29 are connected to the control unit 30. The control means 30 controls the operation of the cylinder 27 based on a flaw position signal or a further depth signal or a preset depth signal of the grain boundary erosion groove from the setting means 29. Further, the grinding device 25 is provided with a cleaning spray 31 for cleaning the grinding dust ground by the grinding means 26. In FIG. 3, reference numeral 32 denotes a cleaning filter for the cleaning liquid supplied to the cleaning spray 31.

Next, a method of cold rolling of the stainless steel strip S which has been subjected to annealing and pickling steps after hot rolling will be described. First, a description will be given of a case of a stainless steel strip S whose quality required as surface gloss is relatively moderate. In this case, it is necessary to appropriately remove the flaws, even if not removing the grain boundary erosion grooves.

In this case, the operation of the setting means 29 is stopped, and the position or even the depth of the flaw formed on the front and back surfaces of the stainless steel strip S to be rewound from the payoff reel 2 is reduced. The flaws are tracked by being detected by a pair of flaw detection means 28 provided on the front surface side and the back surface side and counting pulses emitted from a tracking means, for example, a pulse generator (not shown) provided on the payoff reel 22. The flaws detected here include both flaws generated during hot rolling and flaws generated during cold rolling. Then, a flaw position signal or a further depth signal from the flaw detection means 28 and the tracking means is sent to the control means 30. The control means 30 includes the flaw detection means 2
8. The operation of the cylinder 27 is controlled based on a flaw position signal or a depth signal from the tracking means. That is, based on the flaw position signals from the flaw detection means 28 and the tracking means, the control means 30 activates the cylinder 27 when the flaw passes through the position of the grinding means 26 to move the grinding means 26 to the stainless steel strip S. Get closer. Control means 3
0 indicates that the cylinder 27 is operated based on the depth signals from the flaw detection means 28 and the tracking means, and the grinding means 26 is operated.
The pressing force between the gap and the stainless steel strip S of the grinding means 26 is adjusted in accordance with the depth of the flaw. Alternatively, the maximum depth known from experience may be fixedly ground every time. The reason is that the depth measurement may have an error. Further, even if the maximum depth of experience is ground every time, only the position with a flaw is ground in a spot-like manner, and the entire length is not ground, so that the yield loss does not increase. Therefore, the stainless steel strip S
The flaws formed at various depths scattered on the front surface and the back surface can be surely and appropriately ground by the grinding means 26. The ground debris is cleaned by the cleaning liquid from the cleaning spray 31. The stainless steel strip S from which the grinding dust has been washed is sent to a tandem rolling mill 24.

In the tandem rolling mill 24, the stainless steel strip S whose flaws have been ground by the grinding device 25 is cold-rolled, and the stainless steel strip S is wound up by the tension reel 23. Thereby, the cold rolling of the sunless steel strip S is completed. Next, the case of the stainless steel strip S requiring excellent surface gloss will be described. In this case, it is necessary to remove the grain boundary erosion groove.

In this case, the operation of the flaw detecting means 28 is stopped, and the control means 30 controls the operation of the cylinder 27 based on a preset depth signal of the grain boundary erosion groove from the setting means 29. That is, the control means 30 operates the cylinder 27 based on the preset depth signal of the grain boundary erosion groove from the setting means 29 to bring the grinding means 26 closer to the stainless steel strip S, and The pressing force on the gap and the stainless steel strip S is adjusted according to the depth of the grain boundary erosion groove.

When the stainless steel strip S unwound from the pay-off reel 2 passes between the grinding means 26 of the grinding device 25, the grain boundary erosion grooves formed on the front and back surfaces of the stainless steel strip S are removed by the grinding means 26. It is surely and appropriately ground. The ground debris is cleaned by the cleaning liquid from the cleaning spray 31. The stainless steel strip S in which the grain boundary erosion grooves have been ground is sent to a tandem rolling mill 24.

In the tandem rolling mill 24, the stainless steel strip S whose flaws have been ground by the grinding device 25 is cold-rolled, and the stainless steel strip S is wound up by the tension reel 23. The grinding of the grain boundary erosion groove by the grinding device 25 is performed over substantially the entire length of the stainless steel strip S. Thereby, the cold rolling of the sunless steel strip S is completed. As described above, even when the tandem rolling mill 24 is used as an embodiment of the present invention, the case where the flaws formed on the front and back surfaces of the steel strip S are removed and the case where the surface and / or It is possible to cope with the case where the grain boundary erosion groove formed on the back surface is removed.

When removing the flaws of the steel strip S, a rolling line having a tandem rolling mill 24 as a cold rolling mill is scattered at various positions on the front and back surfaces of the steel strip S to have various depths. The flaws formed on the surface are ground by the grinding means 26.
It can be reliably and appropriately ground. Further, when removing the grain boundary erosion groove of the stainless steel strip S, the stainless steel strip S is placed on a rolling line in which a tandem rolling mill 24 is installed.
The grain boundary erosion grooves formed on the front and back surfaces of
Thus, the grinding can be performed more reliably and appropriately.

In the present embodiment, the grinding device 25 for grinding flaws and grain boundary erosion grooves of the stainless steel strip S includes:
Since it is provided on the same rolling line as the tandem rolling mill 24, it is possible to reduce the equipment cost for performing each grinding, the equipment cost for performing the pickling, and the operating personnel cost required for each grinding and pickling. In addition, the time from the start of processing in the grinding equipment to the start of processing in the cold rolling equipment of another line can be reduced, and the production time can be reduced.

In the case of the present embodiment, the flaw detecting means 28
In the case of grinding only the flaws of the steel strip S, the setting means 29 may be omitted only by providing the flaw detection means 28, while the grain boundary of the stainless steel strip S is provided. When grinding only the erosion groove, the flaw detection means 28 may be omitted only by providing the setting means 29. Further, in the case of the present embodiment, the pair of flaw detection means 28 is provided on the front side and the back side of the steel strip S. However, when grinding only the front side flaw of the steel strip S, the pair of flaw detection means 28 is provided on the back side. When the disposed flaw detection means 28 is omitted and only the flaws on the back side of the steel strip S are ground, the flaw detection means 28 on the front side may be omitted. And although a pair of grinding means 26 is provided on the front side and the back side of the steel strip S, when grinding only the front side flaw of the steel strip S,
When the grinding means 26 arranged on the back side is omitted and only the flaws on the back side of the steel strip S are ground, the grinding means 26 on the front side is used.
May be omitted. In this case, by the operation control of the cylinder 27 by the control means 30, the vertical position of the grinding means 26 with respect to the steel strip S and the pressing force of the grinding means 26 with respect to the steel strip S are adjusted according to the depth of the flaw.

In the present embodiment, the grinding device 25 and the pair of flaw detecting means 28 are installed on the entry side of the tandem rolling mill 24, and these are mounted on the tandem rolling mill as shown in FIG. 24, or between the stands of the tandem rolling mill 24 (not shown). As shown in FIG. 4, when the grinding device 25 and the pair of flaw detection means 28 are installed on the output side of the tandem rolling mill 24, the surface and / or the back surface of the steel strip S after the cold rolling by the tandem rolling mill 24 is provided. The formed flaw can be ground.

In this embodiment, the grinding means 26 in the grinding device 25 is a grinding pad composed of a pad-type grindstone. However, the grinding means 26 is connected to a cylinder 27, and the front and / or back surface of the steel strip S is provided. As long as it can grind the flaws and grain boundary erosion grooves formed in the first, as shown in FIG.
Grinding made up of a rotating shaft 6a, a second rotating shaft 6b, and a grinding belt 6c, or a roll-type grindstone that rotates in the transport direction of the steel strip S or in the opposite direction as shown in FIG. The use roll 26a may be used. In this case, the grinding count of the grinding belt 6c is # 20 to # 10.
00 (JISR 6001) and the grinding number of the grinding roll 26a are preferably # 20 to # 1000 (JISR 6001).

[0047]

As described above, according to the cold rolling equipment according to the first aspect of the present invention, the position or depth of the flaw is detected by the flaw detection means, and the flaw is tracked by the tracking means. The control means controls the separation / separation means for separating / separating the grinding means from / to the steel strip based on the flaw position signal or further depth signal from the flaw detection means, so that the grinding timing of the grinding means is set to the position of the flaw or Further, the position in the thickness direction or the pressing force on the steel strip is adjusted according to the depth. For this reason, flaws formed at various depths on the surface and / or back surface of the steel strip, which are formed suddenly during hot rolling or cold rolling, are surely and appropriately formed. Can be removed.

Further, according to the cold rolling equipment according to claim 2 of the present invention, a preset depth signal of the grain boundary erosion groove is sent from the setting means to the control means, and the control means outputs the signal. Is controlled based on the distance between the grinding means and the stainless steel strip in the thickness direction of the stainless steel strip, and the pressing force of the grinding means on the stainless steel strip S is subjected to grain boundary erosion. Adjust according to the depth of the groove. Therefore, formed at the time of pickling after hot rolling,
The grain boundary erosion grooves formed on the front surface and / or the back surface of the stainless steel strip can be reliably and appropriately removed by the grinding means.

Further, according to the cold rolling equipment according to claim 3 of the present invention, a flaw detecting means for detecting a position or a depth of a flaw, a tracking means for tracking the flaw, and a depth of a grain boundary erosion groove. A stainless steel strip based on a flaw detection signal, a flaw position signal from the tracking means or a further depth signal or a depth signal of the grain boundary erosion groove preset by the setting means. Since it has control means for controlling the separating means for separating and contacting the grinding means, it is formed on the front and / or back surface of the stainless steel strip S which is formed suddenly during hot rolling or cold rolling. It is possible to cope with the case where the flaws are removed and the case where grain boundary erosion grooves formed on the front surface and / or the back surface of the stainless steel strip S formed at the time of pickling after hot rolling are removed.

According to the cold rolling equipment according to claim 4 of the present invention, in the invention according to any one of claims 1 to 3, the cold rolling equipment is a Sendzimir rolling equipment. It is suitable when the grinding device is installed in a stainless steel cold rolling facility and used.

[Brief description of the drawings]

FIG. 1 is a schematic view of a first embodiment of a cold rolling facility according to the present invention.

FIG. 2 is a schematic diagram showing a modification of the cold rolling equipment of FIG.

FIG. 3 is a schematic view of a second embodiment of the cold rolling equipment according to the present invention.

FIG. 4 is a schematic view showing a modification of the cold rolling equipment of FIG.

FIG. 5 is a schematic view of a conventional cold rolling facility.

[Explanation of symbols]

 1, 21 is a cold rolling equipment 2, 22, a pay-off reel 3, 23 is a tension reel 4, a rolling mill (cold rolling mill) 5, 25 is a grinding device 6, 26 is a grinding means 6a is a first rotating shaft 6b The second rotating shaft 6c is a grinding belt 7, 27 is a cylinder (separating / contacting means) 8, 28 is a flaw detecting means 9, 29 is a setting means 10, 30 is a control means 11, 31 is a cleaning spray 12, 32 is a cleaning filter 13 is a pinch roll 14 is a grinding pad 24 is a tandem rolling mill (cold rolling mill) 26a is a grinding roll S is a steel strip Sc is an oxide scale

Claims (4)

[Claims] 1. A grinding means for grinding a flaw formed on the front surface and / or the back surface of a steel strip, a separation / contact means for moving the grinding means toward and away from the steel strip, and detecting a position or a depth of the flaw. Flaw detection means, tracking means for tracking the flaw, and control means for controlling the operation of the separation / contact means based on the flaw position signal or further depth signal from the flaw detection means, tracking means. Characteristic cold rolling equipment. 2. A grinding means for grinding a grain boundary erosion groove formed on a front surface and / or a back surface of a stainless steel strip, a separation / contact means for separating the grinding means from / to the stainless steel strip, and the grain boundary erosion groove. Setting means for presetting the depth of the grain boundary, and control means for controlling the operation of the separation / contact means based on a preset depth signal of the grain boundary erosion groove from the setting means. Cold rolling equipment. 3. Grinding means for grinding flaws and grain boundary erosion grooves formed on the front surface and / or back surface of the stainless steel strip, separation / separation means for separating the grinding means from / to the stainless steel strip,
Flaw detection means for detecting the position or depth of the flaw, tracking means for tracking the flaw, setting means for presetting the depth of the grain boundary erosion groove, and flaw detection means, flaw position from the tracking means A cold rolling facility, further comprising control means for controlling the operation of the separation / contact means based on a signal or a depth signal or a depth signal of the grain boundary erosion groove preset by the setting means. 4. The cold rolling plant according to claim 1, wherein said cold rolling plant is a Sendzimir rolling plant.