JP3518459B2 - Cold rolling equipment - Google Patents

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 equipped with a device for grinding a surface flaw and a grain boundary erosion groove formed on the front surface and / or the back surface of a steel strip.

[0002]

2. Description of the Related Art A steel strip is generally manufactured by hot rolling, pickling, cold rolling and annealing. In the case of stainless steel strips that require surface gloss, after a series of steps of hot rolling, annealing, pickling, and cold rolling, bright annealing is performed for those that require particularly severe surface gloss. In some cases, polishing is performed after pickling following annealing.

Here, pickling after hot rolling is carried out for the purpose of removing oxide scale formed on the surface layer of the hot rolled material. However, the pickling equipment is expensive, and since the pickling process constitutes a line independent of cold rolling, it is necessary to arrange operating personnel separately from the rolling line, resulting in higher operating costs. Because it has drawbacks,
As a conventional technique for solving these drawbacks, there is known a cold rolling facility in which a descaling device for removing oxide scale formed on the surface layer of a hot rolled material is installed in a rolling line (JP-A-58-58). 9710). This cold rolling equipment is shown in FIG .

This cold rolling equipment 100 includes a payoff reel 101, a dull roll 102a and a support roll 102.
b, a plurality of grinding rolls 1
Descaling device 103 having 03a and cleaning device 10
4, a cold rolling mill 105, and a winding machine 106. The hot-rolled steel strip S rewound from the payoff reel 101 is first rolled by the pretreatment rolling mill 102 to a predetermined elongation. During this rolling, dull roll 102
The oxide scale Sc on the surface layer is crushed by a, and becomes fine pieces and powder. Then, the pre-rolled steel strip S enters the descaling device 103 provided on the same line, and in the descaling device 103, the plurality of grinding rolls 10 are used.
The oxide scale Sc crushed by 3a is cleaned. After that, the steel strip S enters the cleaning device 104, and this cleaning device 1
Numeral 04 flushes away grinding dust, dust, etc. of the oxide scale Sc attached to the steel strip S after grinding.

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

[0006]

By the way, in the manufacturing process of a steel strip, in addition to the production of oxide scale after hot rolling, the surface and / or the back surface of the steel sheet may be suddenly exposed during hot rolling or cold rolling. Defects may form on the surface. This flawed steel plate has a problem in surface quality and must be removed. This flaw is not formed on the entire surface of the steel strip after hot rolling,
It is often scattered in places in the longitudinal direction of the hot rolled material. Further, the depth of the flaw varies depending on the steel type and the manufacturing process, but as an example, the austenitic stainless steel represented by SUS304 is about 10 μm in the strip after hot rolling, and the ferritic stainless steel represented by SUS430 is represented by 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).
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, and during pickling, this Cr-free layer is melted intensively and the grain boundary is formed at this site. An erosion groove is formed. These intergranular erosion grooves do not disappear even after cold rolling the steel strip after hot rolling, and the desired gloss may not be obtained in some cases, so stainless steel strips with excellent surface gloss are required. In some cases, it may be necessary to remove it. The depth of the intergranular erosion groove is a problem in that, and it depends on the steel type, 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. . By the way, the width of the grain boundary erosion groove is about 1 μm to about 7 μm (see Japanese Patent Laid-Open No. 8-269549).

Now, the conventional cold rolling equipment 10 shown in FIG.
Depending on 0, even if the flaws formed on the front surface and the back surface of the steel strip after hot rolling are removed, it may not be properly performed. That is, the cold rolling facility 100 constantly grinds the entire length of the steel strip by 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. Defects scattered in the longitudinal direction of the steel strip of
As described above, the depth is different from the depth of the oxide scale,
Since it is almost deeper, it is necessary to additionally grind a normal portion of the steel strip after hot rolling in order to remove this flaw, which may significantly reduce the yield.

Since the depth of the grain boundary erosion groove is deeper than the depth of the oxide scale Sc in most cases, depending on the cold rolling equipment 100, the grain boundary erosion groove formed in the hot rolled material is appropriate. Sometimes it cannot be removed. Therefore, the object of the present invention is to appropriately form a flaw formed on the front surface and / or the back surface of the steel strip, which is inadvertently formed during hot rolling or cold rolling,
It is to provide a cold rolling facility that can be reliably removed.

Another object of the present invention is to provide a grain boundary erosion groove on the front surface and / or the back surface of a stainless steel strip which is formed during pickling after hot rolling in a rolling line having a cold rolling mill. It is to provide a cold rolling facility that can be removed appropriately and surely. Still another object of the present invention is to form on the front surface and / or the back surface of a stainless steel strip which is inadvertently formed during hot rolling or cold rolling in a rolling line having a cold rolling mill. Cold rolling equipment that can cope 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 that are formed during pickling after hot rolling To provide.

[0011]

In order to solve the above-mentioned problems, the cold rolling equipment according to claim 1 of the present invention comprises a rolling mill for grinding a flaw formed on the front surface and / or the back surface of a steel strip.
A pair of grinding means installed on the entrance side of the machine, a detaching and contacting means for separating and contacting the grinding means with respect to the steel strip, a flaw detecting means for detecting the position and depth of the flaw, and a tracking for tracking the flaw. Means, and control means for controlling the operation of the contacting / separating means based on the flaw position signal and the depth signal from the flaw detecting means and the tracking means are provided.

The cold rolling equipment according to claim 2 of the present invention is installed on the entrance side of a rolling mill for grinding the grain boundary erosion grooves formed on the front surface and / or the back surface of the stainless steel strip.
A pair of grinding means, a separating and contacting means for separating and contacting the grinding means with respect to the stainless steel strip, a setting means for presetting the depth of the grain boundary erosion groove, and the preset grain from the setting means. It is characterized in that a control means for controlling the operation of the separating / connecting means based on the depth signal of the field erosion groove is provided.

Further, the cold rolling equipment according to claim 3 of the present invention is provided on the inlet side of a rolling machine for grinding flaws and grain boundary erosion grooves formed on the front surface and / or back surface of a stainless steel strip.
A pair of placed grinding means, a contacting / disconnecting means for contacting / separating the grinding means with respect to the stainless steel strip, a flaw detecting means for detecting the position and depth of the flaw, a tracking means for tracking the flaw, the grain Setting means for presetting the depth of the interfacial erosion groove, and the flaw detection means, based on the flaw position signal and depth signal from the tracking means or the depth signal of the grain boundary erosion groove preset by the setting means It is characterized in that a control means for controlling the operation of the separating / connecting means is installed.

According to a fourth aspect of the present invention, in the cold rolling facility according to any one of the first to third aspects, the cold rolling facility is a Sendzimir rolling facility. I am trying.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram 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 the steel strip S that has undergone the annealing and pickling steps after hot rolling, and a cold rolling machine between the payoff reel 2 and the tension reel 3. 4 are installed, and a grinding device 5 is installed on each of the inlet side and the outlet side of the rolling mill 4.
The "entrance side of the rolling mill 4" is wound from the payoff reel 2.
Rolling mill 4 when steel strip S to be returned enters rolling mill 4
Means the entrance side of the rolling mill (left side in FIG. 1).
The “side” means the steel strip S unwound from the tension reel 3.
The entry side of the rolling mill 4 when entering the rolling mill 4 (see FIG. 1b).
The right side), and the grinding device 5 is in accordance with claim 1.
It is installed on the "entrance side of the rolling mill".

Here, the rolling mill 4 includes upper and lower work rolls 4a for rolling the steel strip S reciprocating between the payoff reel 2 and the tension reel 3 at a predetermined reduction ratio, and a plurality of intermediate rolls surrounding the work rolls 4a. An example is a reciprocating rolling mill equipped with 4b and a backup roll 4c surrounding the intermediate roll 4b. Also, each grinding device 5
Has a pair of grinding means 6 arranged on the front surface side and the back surface side of the steel strip S and for grinding the flaws and the grain boundary erosion grooves formed on the front surface and / or the back surface of the steel strip S. Each of the grinding means 6 has a first rotating shaft 6a that is rotatably supported, a second rotating shaft 6b that is rotatably arranged so as to come in contact with and separate from the steel strip S, and these first rotating shafts 6a. And a grinding belt 6c which 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 conveying direction of the steel strip S or in the opposite direction. When the grinding belt 6c rotates in the direction opposite to the conveying direction of the steel strip S, the grinding ability of the flaw and the grain boundary erosion groove is improved. here,
The grinding count of the grinding belt 6c is # 20 to # 1000.
(JIS R 6001) is preferable. A cylinder (contact / separation means) 7 for contacting / separating the second rotating shaft 6b with respect to the steel strip S is attached to each second rotating shaft 6b. On the other hand, on the front surface side and the back surface side of the steel strip S, there are provided flaw detection means 8 for detecting the position and depth of the flaws formed on the front surface and the back surface of the steel strip S, and further, Setting means 9 is provided for presetting the depth of the grain boundary erosion groove formed on the back surface. Further, the pinch roll 13 is provided with tracking means (not shown) for tracking the flaw by counting the pulses emitted from a pulse generator (not shown).
The depth of the intergranular erosion groove depends on the steel type, hot rolling conditions, annealing conditions, and pickling conditions.However, which type of steel is used and under what conditions hot rolling, annealing, and pickling are generally operational. Since the depth of the grain boundary erosion groove is empirically known in advance, it is preferable to set the depth of the grain boundary erosion groove by the setting means 9 based on the empirical value of the steel type. . Of course, the present invention is not limited to this, and a logic for correcting the depth may be added according to the variation or variation of the hot rolling conditions and the annealing conditions as described above. And, a pair of cylinders 7, 1 on the front and back sides of the steel strip S
Paired flaw detection means 8, tracking means and setting means 9
Are connected to the control means 10. This control means 10
Is the flaw position signal from the flaw detection means 8 and the tracking means.
And it is adapted to control the operation of the cylinder 7 based on the depth signal of the intergranular erosion groove preset from the depth signal or setting means 9. Further, each of the grinding devices 5 is provided with a cleaning spray 11 for cleaning the grinding dust ground by the grinding belt 6c . In FIG. 1, reference numeral 12 is a cleaning filter for the cleaning liquid supplied to the cleaning spray 11.

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

There are various grades of stainless steel that are required to have surface gloss, ranging from mild to severe. First, the case of stainless steel whose surface gloss is relatively gentle will be described. In this case, it is necessary to properly remove the flaws even if the grain boundary erosion grooves are not removed. In this case, the operation of the setting means 9 is stopped, and the position and depth of the flaw formed on the front surface and the back surface of the stainless steel strip S rewound from the payoff reel 2 are
The flaws are detected by a pair of flaw detection means 8 provided on the front surface side and the back surface side of the stainless steel strip S, and the flaws are counted by counting the pulses emitted from the tracking means, for example, a pulse generator (not shown) installed on the pinch roll 13. Is tracked. The flaws detected here include both flaws that occur during hot rolling and flaws that occur during cold rolling.
Then, the flaw position signal and the depth signal from the flaw detection means 8 and the tracking means are sent to the control means 10. The control means 10 controls the operation of the cylinder 7 based on the flaw position signal and the depth signal from the flaw detection means 8 and the tracking means. That is, the control unit 10 determines that the flaw is a grinding belt based on the flaw position signals from the flaw detection unit 8 and the tracking unit.
When passing the position 6c , the cylinder 7 is operated to bring the second rotating shaft 6b close to the stainless steel strip S. Further, the control means 10 operates the cylinder 7 based on the depth signal from the flaw detection means 8 and the tracking means to detect the gap between the grinding belts 6c and the pressing force of the grinding belt 6c against the stainless steel. Adjust according to the depth. Alternatively, the maximum depth known from experience may be ground every time. The reason is that the depth measurement may have an error. Further, even if the empirical maximum depth is ground every time, only the spots with flaws are ground in spots, and the entire length is not ground, so that the yield loss does not increase. Therefore, it is possible to surely and properly grind the flaws formed in various depths on the front surface and the back surface of the stainless steel strip S at various depths by the grinding belt 6c . Then, the ground grinding dust is washed with the washing liquid from the washing spray 11. The stainless steel strip S that has been cleaned of the grinding dust is a pinch roll 13
And is sent to the rolling mill 4.

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

Cold rolling of the stainless steel strip S is carried out by repeating the cold rolling work by the reciprocating rolling mill 4 and the flaw grinding work by the grinding machines 5 arranged on both sides of the rolling mill 4 a plurality of times. Is complete .

Next, the case of the stainless steel strip S which is required to have 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 the 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 rotary shafts 6b close to the stainless steel strip S, and the grinding belt. The pressing force against 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 rewound 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. Secured by the belt 6c,
Properly ground. Then, the ground grinding dust is washed with the washing liquid from the washing spray 11. The stainless steel strip S with the grain boundary erosion grooves ground is a pinch roll 13
And is sent to the rolling mill 4.

In the rolling mill 4, one side (left side in FIG. 1)
The stainless steel strip S whose grain boundary erosion grooves have been ground is cold-rolled by the grinding device 5 and the stainless steel strip S is sent out through the pinch roll 13. In the grinding device 5 on the other side,
The grain boundary erosion groove of the stainless steel strip S is not ground, and the stainless steel strip S is wound 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, on which the grain boundary erosion grooves have been ground and cold-rolled over substantially the entire length, is unwound in the opposite direction by the tension reel 3 and enters the grinding device 5 on the opposite side, but is ground. It may or may not be carried out, and is sent to the rolling mill 4 again through the pinch roll 13.

The rolling mill 4 performs cold rolling of the stainless steel strip S again, and sends the stainless steel strip S to the grinding device 5 on one side via the pinch roll 13. The stainless steel strip S is not ground by the one-side grinding device 5, and the stainless steel strip S is wound by the payoff reel 2. After that, cold rolling work by the reciprocating rolling mill 4 is performed.
By repeating a plurality of times, the cold rolling of the stainless steel strip S is completed.

It is sufficient that the grain boundary erosion grooves can be removed after the final pass of rolling performed a plurality of times. In the example above, one side (Fig. 1
Although the case of performing the grinding mainly by using the grinding device on the left side in FIG. 2 has been described, the grinding may be performed by mainly using the grinding device on the opposite side. As described above, in the present embodiment, during cold rolling, during removal of defects formed on the front surface and the back surface of the steel strip S during hot rolling or during cold rolling, and during hot rolling. This can be applied to the case of removing the grain boundary erosion grooves formed on the front surface and the back surface of the stainless steel strip S that are formed during pickling after rolling.

When removing the flaws of the steel strip S, in the grinding device 5, the flaw detecting means 8 detects the presence and the depth of the flaw, the tracking means tracks the flaw, and the control means 10 causes the flaw. Since the operation of the cylinder 7 for separating and contacting the grinding belt 6c with respect to the steel strip S is controlled based on the position signal or the depth signal,
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, it is possible to surely and properly grind the flaws formed at various depths on the front surface and / or the back surface of the steel strip S at various depths by the grinding means.

When the grain boundary erosion groove of the stainless steel strip S is to be removed, the preset depth signal of the grain boundary erosion groove is sent from the setting means 9 to the control means 10 in the grinding device 5, and the control means is controlled. 10 controls the operation of the cylinder 7 for separating and contacting the grinding belt 6c with respect to the stainless steel strip S based on the signal, so that the gap between the grinding belts 6c and the stainless steel strip S of the grinding belt 6c with respect to the stainless steel strip S are controlled. The pressing force is adjusted according to the depth of the grain boundary erosion groove. Therefore, in a rolling line having the reciprocating rolling mill 4, the grain boundary erosion grooves formed on the front surface and / or the back surface of the stainless steel strip S can be surely and appropriately ground by the grinding belt 6c.

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

In the embodiment of the present invention, it is preferable to use a Sendzimir rolling mill as the cold rolling mill. This Sendzimir rolling machine has a very slow rolling and conveying speed of the stainless steel strip S for the purpose of achieving excellent dimensional accuracy with an extremely high rolling reduction. When the grinding device 5 is installed on the same rolling line as the cold rolling mill, the slower the conveying speed of the stainless steel strip S, the easier the control thereof can be.

Further, in the case of the present embodiment, both the flaw detecting means 8 and the setting means 9 are provided, but when only the flaw of the alternation S is ground, the flaw detecting means 8 is only provided and the setting means 9 is provided. On the other hand, when only the grain boundary erosion groove of the stainless steel strip S is ground, the flaw detecting means 8 may be omitted by providing only the setting means 9. In the case of this embodiment,
Although a pair of flaw detection means 8 is provided on the front surface side and the back surface side of the steel strip S, when only the flaw on the front surface side of the steel strip S is ground, the flaw detection means 8 arranged on the back surface side is used. When only the flaws on the back surface side of the steel strip S are to be ground and omitted, the flaw detection means 8 on the front surface side may be omitted .

Further, the grinding means in each grinding device 5 is
It is not limited to the one composed of the first rotary shaft 6a, the second rotary shaft 6b, and the grinding belt 6c shown in FIG. 1, and is a flaw formed on the front surface and / or the back surface of the steel strip S, which is connected to the cylinder 7. And if it can grind the grain boundary erosion grooves,
As shown in, by using a grinding pad 14 composed of a pad type grindstone, or by using a grinding roll composed of a roll type grindstone rotating in the conveying direction of the steel strip S or in the opposite direction. Good. The polishing number of the grinding pad 14 is # 20 to # 1000 (JIS R 6001),
The polishing count of the grinding roll is # 20 to # 1000 (JIS
R 6001) is preferred.

Next, a second embodiment of the cold rolling facility according to the present invention will be described with reference to FIG. The cold rolling equipment 21 shown in FIG. 3 is, similar to the cold rolling equipment 1 shown in FIG. 1, for cold rolling the steel strip S that has undergone the annealing and pickling steps after hot rolling. 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 installed.

In the cold rolling equipment 21 shown in FIG. 3, a tandem rolling mill 24 is installed between a payoff reel 22 and a tension reel 23, and the grinding device 2 is provided at the entrance side of the tandem rolling mill 24.
5 is installed. Therefore, in the cold rolling facility 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 for rolling the steel strip S conveyed from the payoff reel 22 to the tension reel 23 at a predetermined reduction rate. Have

Further, when the steel strip S is a steel type such as stainless steel, the grinding device 25 is arranged on the front surface side and the back surface side of the steel strip S, and has flaws and grain boundary erosion grooves formed on the front surface and the back surface of the stainless steel strip S. 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 polishing count is # 20 to # 1000 (JI
S R 6001) is preferred. A cylinder (contacting / separating means) 27 for contacting / separating the grinding means 26 with respect to the stainless steel strip S is attached to the grinding means 26. On the other hand, on the front surface side and the back surface side of the stainless steel strip S, a pair of flaw detection means 28 for detecting the position and depth of the flaws formed on the front surface and the back surface of the stainless steel strip S.
And setting means 2 for presetting the depth of the grain boundary erosion grooves formed on the front surface and the back surface of the stainless steel strip S.
9 is provided. In addition, the pay-off reel 22
Tracking means (not shown) is provided for tracking the flaws by counting the pulses emitted from a pulse generator (not shown). The depth of the intergranular erosion groove depends on the steel type, hot rolling conditions, annealing conditions, and pickling conditions, but which steel type and under what conditions hot rolling, annealing, and pickling are generally determined in operation. Since the depth of the grain boundary erosion groove is empirically known in advance, the depth of the grain boundary erosion groove is set by the setting means 29 based on the empirical value of the steel type. Is preferred. Of course, the present invention is not limited to this, and a logic for correcting the depth may be added according to the variation or variation of the hot rolling condition or the annealing condition as described above. The pair of cylinders 27, the pair of flaw detection means 28, the tracking means and the setting means 29 on the front and back sides of the stainless steel strip S are connected to the control means 30. The control means 30 controls the operation of the cylinder 27 based on the flaw position signal and the depth signal or the 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 is a cleaning spray.

Next, a method for cold rolling the stainless steel strip S that has undergone the annealing and pickling steps after hot rolling will be described. First, the case of the stainless steel strip S having a relatively gentle surface gloss is described. In this case, it is necessary to properly remove the flaws even if the grain boundary erosion grooves are not removed.

In this case, the operation of the setting means 29 is stopped, and the position and depth of the flaw formed on the front surface and the back surface of the stainless steel strip S rewound from the payoff reel 22 are determined by the surface of the stainless steel strip S. Defects are detected by a pair of flaw detection means 28 provided on the side and the back surface, and the flaws are tracked by counting the pulses emitted from a tracking means, for example, a pulse generator (not shown) installed on the payoff reel 22. The flaws detected here include both flaws that occur during hot rolling and flaws that occur during cold rolling. Then, based on the flaw position signal and the depth signal from the flaw detection means 28 and the tracking means, the cylinder 27
Control the operation of. That is, the control means 30 determines, based on the flaw position signals from the flaw detection means 28 and the tracking means,
When the flaw passes the position of the grinding means 26, the cylinder 27
Is operated to bring the grinding means 26 close to the stainless steel strip S. Further, the control means 30 operates the cylinders 27 based on the depth signals from the flaw detection means 28 and the tracking means to control the gap between the grinding means 26 and the pressing force of the grinding means 26 against the stainless steel strip S. Adjust according to the depth. 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 empirical maximum depth is ground every time, only the spots with flaws are ground in spots, and the entire length is not ground, so that the yield loss does not increase. Therefore, it is possible to surely and properly grind the flaws formed in various depths on the front surface and the back surface of the stainless steel strip S at various depths by the grinding means 26. Then, the ground grinding dust is washed with the washing liquid from the washing spray 31. The stainless steel strip S from which the grinding dust has been washed is sent to the 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 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 that requires 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 28 is stopped, and the control means 30 controls the operation of the cylinder 27 based on the 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 intergranular erosion groove from the setting means 29 to bring the grinding means 26 close to the stainless steel strip S, and the grinding means 26 is moved between them. The pressing force against 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 rewound from the payoff reel 2 passes between the grinding means 26 of the grinding device 25, the grain boundary erosion grooves formed on the front surface and the back surface of the stainless steel strip S are ground by the grinding means 26. Ensures reliable and proper grinding. Then, the ground grinding dust is washed with the washing liquid from the washing spray 31. The stainless steel strip S whose grain boundary erosion grooves have been ground is sent to the 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 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 the embodiment of the present invention, the case where the flaws formed on the front surface and the back surface of the steel strip S are removed, and the surface of the stainless steel strip S and / or This can be applied to the case of removing the grain boundary erosion grooves formed on the back surface.

When the flaws of the steel strip S are to be removed, in the rolling line having the tandem rolling mill 24 as a cold rolling mill, the front and back surfaces of the steel strip S are scattered at various depths. By the grinding means 26, the flaw formed on the
It can surely and properly grind. Further, when removing the grain boundary erosion grooves of the stainless steel strip S, the stainless steel strip S can be used in a rolling line where the tandem rolling mill 24 is installed.
Means 26 for grinding the grain boundary erosion grooves formed on the front and back surfaces of the
This ensures reliable and proper grinding.

Then, in the present embodiment, the grinding device 25 for grinding the flaws and the grain boundary erosion grooves of the stainless steel strip S is
Since it is installed 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 pickling, and the operating personnel cost required for each grinding and pickling. The time from the start of processing in the grinding equipment to the start of processing in the cold rolling equipment in another line can be shortened, and the production time can be shortened.

Further, in the case of this embodiment, the flaw detecting means 28
Although both the setting means 29 and the setting means 29 are provided, the setting means 29 may be omitted by providing only the flaw detecting means 28 when only the flaws of the steel strip S are ground, while the grain boundaries of the stainless steel strip S are not provided. When only the erosion groove is ground, the flaw detecting means 28 may be omitted by providing only the setting means 29. Further, in the case of the present embodiment, the pair of flaw detection means 28 are provided on the front surface side and the back surface side of the steel strip S, but when only the flaws on the front surface side of the steel strip S are ground, they are provided on the back surface side. When the flaw detecting means 28 arranged is omitted and only the flaw on the back surface side of the steel strip S is ground, the flaw detecting means 28 on the front surface side may be omitted .

[0045]

Further, in the case of the present embodiment, the grinding means 26 in the grinding device 25 is a grinding pad composed of a pad type grindstone, but is connected to the cylinder 27, and the front surface and / or the back surface of the steel strip S is connected. If the flaws and grain boundary erosion grooves formed on the
Grinding including a rotary shaft 6a, a second rotary shaft 6b, and a grinding belt 6c, or a roll-type grindstone that rotates in the transport direction of the steel strip S as shown in FIG. 4 or in the opposite direction. The roll 26a for use may be used. The grinding count of the grinding belt 6c in this case is # 20 to # 10.
00 (JISR 6001), and the polishing count of the grinding roll 26a is preferably # 20 to # 1000 (JISR 6001).

[0047]

As described above, according to the cold rolling facility of claim 1 of the present invention, the flaw detection means detects the position and depth of the flaw, and the tracking means tracks the flaw. Based on the flaw position signal and the depth signal from the flaw detection means, the control means controls the contacting / disconnecting means that separates from / contacts the grinding means, so that the grinding timing of the grinding means is adjusted to the position and depth of the flaw, Adjust the position and pressing force in the plate thickness direction with respect to the steel strip. For this reason, it is possible to reliably, properly and appropriately prevent defects formed suddenly during hot rolling or cold rolling, which are formed in various depths on the front surface and / or the back surface of the steel strip. Can be removed.

According to the cold rolling facility of the present invention, the depth signal of the intergranular erosion groove set in advance is sent from the setting means to the control means, and the control means receives the signal. Based on the above, the contacting / disconnecting means for contacting / separating the grinding means with respect to the stainless steel strip is controlled, so that the position of the grinding means in the plate thickness direction with respect to the stainless steel strip and the pressing force of the grinding means with respect to the stainless steel strip S are intergranularly eroded. Adjust according to the depth of the groove. Therefore, it is formed during 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 properly removed by the grinding means.

Further, according to the cold rolling equipment of claim 3 of the present invention, the flaw detecting means for detecting the position and the depth of the flaw, the tracking means for tracking the flaw, the depth of the grain boundary erosion groove Based on the setting means for presetting, and the flaw detection means, the flaw position signal and the depth signal from the tracking means or the depth signal of the grain boundary erosion groove preset by the setting means, with respect to the stainless steel strip Since it has a control means for controlling the separating / connecting means for separating / connecting the grinding means,
Abruptly formed during hot rolling or cold rolling, when removing a flaw formed on the front surface and / or the back surface of the stainless steel strip S, and when formed during pickling after hot rolling, This can be applied to the case of removing the grain boundary erosion grooves formed on the front surface and / or the back surface of the stainless steel strip S.

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

[Brief description of drawings]

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

FIG. 2 is a schematic view showing a modified example of the cold rolling equipment of FIG.

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

FIG. 4 is a schematic diagram of a conventional cold rolling facility.

[Explanation of symbols]

1, 21 are cold rolling equipment 2 and 22 are payoff reels 3 and 23 are tension reels 4 is a rolling mill (cold rolling mill) 5 and 25 are grinding machines 6,26 are grinding means 6a is the first rotating shaft 6b is the second rotating shaft 7 and 27 are cylinders (separating / connecting means) 8 and 28 are flaw detection means 9 and 29 are setting means 10 and 30 are control means 11 and 31 are cleaning sprays 12 and 32 are cleaning filters 13 is a pinch roll 14 is a pad for grinding 24 is a tandem rolling mill (cold rolling mill) 26a is a grinding roll S is steel strip sc is an oxide scale

Claims (4)

(57) [Claims] 1. A pair of grinding means installed on the inlet side of a rolling mill for grinding a flaw formed on the front surface and / or the back surface of a steel strip, and a separating means for separating and contacting the grinding means with respect to the steel strip. Contact method,
Defect detection means for detecting the position and depth of the flaw, tracking means for tracking the flaw, and control of the operation of the contact / separation means based on the flaw detection means and the flaw position signal and the depth signal from the tracking means A cold rolling facility, which is equipped with a control means for controlling. 2. The grain boundary erosion groove formed on the front surface and / or the back surface of a stainless steel strip is ground and installed on the entrance side of a rolling mill.
A pair of grinding means, a contacting / disconnecting means for contacting / separating the grinding means with respect to the stainless steel strip, a setting means for presetting the depth of the intergranular erosion groove, and the preset setting from the setting means. A cold rolling facility, wherein a control means for controlling the operation of the separating / connecting means on the basis of the depth signal of the grain boundary erosion groove is installed. 3. An entry side of a rolling mill for grinding flaws and grain boundary erosion grooves formed on the front surface and / or the back surface of a stainless steel strip.
A pair of grinding means installed in , a contacting / disconnecting means for contacting / separating the grinding means with respect to the stainless steel strip, a flaw detecting means for detecting the position and depth of the flaw, and tracking the flaw. Tracking means, setting means for presetting the depth of the grain boundary erosion groove, and flaw detection means, flaw position signal and depth signal from the tracking means or the depth of the grain boundary erosion groove preset by the setting means A cold rolling facility, characterized in that a control means for controlling the operation of the separating / connecting means based on the signal is installed. 4. The cold rolling facility according to claim 1, wherein the cold rolling facility is a Sendzimir rolling facility.