JP2001239446A - Device and method for grinding metallic belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and a method for grinding a metallic belt capable of preventing a crack and a rupture of an end part in the direction of width of the metallic belt in the next cold rolling process even after the metallic belt like a thin cold rolled steel belt having a thickness of 0.8 mm or less is ground. SOLUTION: This grinding device 1 is provided with a tension providing means 4 flattening the metallic belt S by providing a tension having a predetermined value for the metallic belt S and a grinding means 5 grinding the metallic belt S flattened by the tension providing means 4 by applying a tension having a predetermined value. Preferably, a scope of the predetermined value of tension is 70 to 250 Mpa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for grinding a metal strip such as a stainless steel strip, particularly a metal strip such as a cold rolled steel strip having a thickness of 0.8 mm or less. About.

[0002]

2. Description of the Related Art Conventionally, metal strips, for example, stainless steel strips have been used for refining, casting of steel ingot (slab), hot rolling, annealing,
It is manufactured by a series of processes such as pickling, cold rolling, finish annealing, pickling, temper rolling, and refining. by the way,
A metal strip, which is elongated by rolling through many processes and has a large surface area, for example, a stainless steel strip, has a quality problem of suppressing the formation of scratches during manufacturing.

[0003] In order to solve this problem, conventionally, the surface of the stainless steel strip is inspected on the exit side of the equipment in the main process to cut off a flawed portion, and in some cases, to locally remove the surface. In the case where the surface is ground or removed or the degree of flaw is severe, the entire surface may be ground. In addition, depending on the type of stainless steel, it is necessary to cut off grain boundary erosion holes formed during pickling of hot-rolled steel strip and hindering the gloss, in order to secure the surface gloss after cold rolling, or to have high oxidation resistance. In some cases, the scale (oxidized layer) of the hot-rolled steel strip cannot be sufficiently removed by pickling, so that the entire surface must be ground for reasons such as surface grinding.

[0004] As such a continuous grinding line for full-surface grinding, for example, the one shown in FIG. 7 is known (see Japanese Patent Application Laid-Open No. Hei 8-25202). This continuous grinding line 10
0 is a payoff reel 102 and a feed leveler 103
, A tension applying device 104, a grinding device 105, and a tension reel 112. The tension applying device 104 is configured by combining a plurality of bridle rolls 104a. The grinding device 105 includes a grinding belt 108 wound endlessly between a contact roll 107 and an idler roller 106, and a steel strip 10.
1. A grinder composed of a billy roll 109 provided at a position facing the contact roll 107 with 1 interposed therebetween,
It is configured with multiple arrangements. And Billy Roll 1
09 is raised and lowered by the lifting device 110. In FIG. 7, reference numeral 111 denotes a deflector roll for changing the conveying direction of the steel strip 101.

[0005] In the continuous grinding line 100, the steel strip 101 is rewound from a payoff reel 102,
The shape is corrected by the feed leveler 103 with the tension adjusted by the tension applying device 104. Next, the steel strip 101 whose shape has been corrected is adjusted to a tension suitable for grinding by the tension applying device 104 and the tension reel 112,
The surface defects are removed by the grinding device 105.

[0006]

Incidentally, in the production of a stainless steel strip, there is a case where rolling of a stainless steel foil is required. This "foil" is 0.1mm in the steel industry
(100 μm) or less, which is characterized in that the cold-rolled steel sheet is much thinner than the generally known sheet thickness of about 0.8 mm.

This stainless steel foil has a thickness of 0.3 mm (300 mm).
μm) is manufactured by grinding a cold-rolled stainless steel strip to a thickness of not more than a few times and then repeatedly cold-rolling the strip to make it thinner. In producing a stainless steel foil, there are various problems because the thickness of the foil is extremely thin as described above. One is that when the ground and cold-rolled stainless steel strip is further thinly and cold-rolled, a crack occurs at the widthwise end of the stainless steel strip during rolling. When this crack was severe, the crack propagated from the crack as a starting point, eventually breaking the stainless steel strip, and stopping production for a long time in some cases. Also, even if it does not break, if a crack occurs at the widthwise end of the stainless steel strip during rolling, the rolling is interrupted at that point,
The stainless steel strip was brought to another slitting line and the cracked end was cut off over the entire length of the steel strip so as to cut off the crack, and it had to be re-rolled, resulting in a large yield loss. Had become.
The present inventors have conducted various investigations and found that a stainless steel strip having a crack at the end in the width direction occurs when the thickness of the end at the width direction is thinner than a certain thickness at the center in the width direction. And such thinness of the width direction end is,
It was found that the shape of the stainless steel strip was generated by grinding with the ear extended. Then, when the thin stainless steel strip at the end in the width direction was rolled, it was found that the center in the width direction became flared and the end in the width direction was pulled, resulting in tensile fracture. In the process of manufacturing a product having a product thickness of 0.1 mm or less, such as a foil, the problem of excessively thin end portions in the width direction becomes apparent and cracks are likely to occur.

In a continuous grinding line 100 shown in FIG. 7, when a steel strip 101 having a thickness of about 3 mm to 5 mm such as a hot-rolled steel strip, a warp or a shape is effectively corrected by a feed leveler 103. sell. However, as the thickness of the steel strip to be straightened becomes thinner, the rigidity of the steel strip decreases, so that the steel strip simply passes along the leveler roll, making it difficult to correct the shape by the feed leveler 103, and in the width direction. It was found that the edge became too thin due to over-grinding. By the way, when thinning such as a 0.8 mm cold-rolled steel strip, which was performed by the inventors before rolling for rolling of stainless steel foil, the straightening effect was almost lost, and the width direction end portion was lost. Was found to be too thin by over-grinding.

Accordingly, the present invention has been made to solve the above problems, and has as its object after grinding a metal strip such as a cold rolled steel strip having a thickness of 0.8 mm or less. In particular, it is an object of the present invention to provide a metal strip grinding apparatus and a grinding method capable of preventing cracks and breaks at the width direction ends of the metal strip in the next cold rolling step.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a metal band grinding apparatus according to claim 1 of the present invention is provided.
A tension applying means for flattening the metal band by applying a predetermined value of tension to the metal band, and grinding the metal band flattened by the tension applying means while applying the predetermined value of tension. And grinding means.

Further, in the metal band grinding apparatus according to claim 2 of the present invention, in the invention according to claim 1, a range of the predetermined value of the tension is 70 to 250 Mpa. If the tension is less than 70 MPa, the metal band S
Is not sufficient to prevent over-grinding of the edge in the width direction by the next grinding means and to prevent cracks caused by the over-grinding. On the other hand, if the tension exceeds 250 Mpa, the metal band is locally narrowed due to the tension, and if it is severe, the metal band is broken.

Further, in the metal band grinding apparatus according to claim 3 of the present invention, in the invention according to claim 1 or 2, the shape of the metal band before grinding is set before the grinding means in the transport direction. It is characterized in that a shape measuring means for measuring is provided, and the tension applied by the tension applying means is determined in accordance with a value measured by the shape measuring means. In the method of grinding a metal band according to claim 4 of the present invention, the metal band is flattened by applying a predetermined value of tension to the metal band, and the flattened metal band is subjected to the predetermined value. It is characterized by grinding while applying tension.

According to a fifth aspect of the present invention, in the metal band grinding method according to the fourth aspect, the predetermined value of the tension is in a range of 70 to 250 Mpa. The metal band grinding method according to claim 6 of the present invention is characterized in that the grinding is performed while adjusting the tension applied according to the shape of the metal band before grinding.

According to a seventh aspect of the present invention, in the metal band grinding method according to the sixth aspect, the tension is determined by the following equation.

[0015]

(Equation 2)

Here, T: tension (Mpa) E: Young's modulus (Mpa) of the metal band λ: shape (steepness) of the metal band before grinding (%) If it is too large, the metal band will be constricted due to tension, and it will be more likely to break out of the order plate thickness and plate width, or to be broken. The effect of correcting the shape of the band is not sufficient, and it is not sufficient to prevent over-grinding of the end in the width direction and cracks caused thereby.

[0017]

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 metal band grinding apparatus according to the present invention. Grinding device 1 shown in FIG.
Is to grind a flaw formed on the front surface and / or the back surface of the metal band S before the cold rolling in the next step, and the payoff reel 2 on which the metal band S is rewound and the metal band S The apparatus includes a tension applying means 4 for applying a predetermined value of tension, a grinding means 5 for grinding the metal band S while applying a predetermined value of tension, and a tension reel 12 for winding the metal band S.
In FIG. 1, reference numerals 3 and 11 are deflector rolls.

Here, the tension applying means 4 comprises a plurality of bridle rolls 4a, and applies a tension of a predetermined value described below to the metal band S rewound from the payoff reel 2, thereby flattening the metal band S. Become For example, the edge extending shape of the width direction end S2 formed at the time of manufacturing the metal strip S shown in FIG. 4 is flattened as shown in FIG. The range of the predetermined value of the tension applied to the metal strip S is preferably 70 to 250 Mpa. If it is less than 70 Mpa, the effect of correcting the shape of the metal strip S is not sufficient, and it is not sufficient to prevent over-grinding of the width direction end by the next grinding means 5 and cracks caused thereby. On the other hand, if it exceeds 250 Mpa, the metal band S is locally constricted due to tension, and if it is severe, it breaks. In addition, as a tension giving means, instead of the bridle roll 4a,
As shown in FIG. 2, a pinch roll 13 may be provided.

The grinding means 5 includes a contact roll 7
A grinding belt 8 wound endlessly between the metal belt S and a backup roll (also referred to as a billy roll) 9 provided at a position facing the contact roll 7 with the metal band S interposed therebetween. Are arranged in a plurality. The backup roll 9 is raised and lowered by a lifting device 10. And
The grinding belt 8 of the grinding means 5 grinds the metal band S flattened by the tension applying means 4 while applying the predetermined value of tension. This is shown in FIG.

As shown in FIG. 3, the flattened metal band S
Is ground by the grinding belt 8 of the grinding means 5 while applying a predetermined value of tension T, the surface of the metal band S is ground substantially uniformly in the width direction, and the thickness of the width direction end S1 is the thickness of the width center portion. This is almost the same as the above, and it is possible to prevent the portion corresponding to the ear extension at the width direction end S1 from being excessively thinned due to excessive grinding. For this reason, when the metal strip S after the grinding is subjected to the next step of cold rolling, it is possible to prevent cracks at the width direction ends,
Long-term production stoppage and yield loss can be avoided. Even when the metal strip S is a thin metal strip such as a cold-rolled steel strip having a thickness of 0.8 mm or less, the surface is substantially uniform in the width direction because the metal strip S is flattened. The thickness at the end in the width direction becomes substantially the same as the thickness at the center in the width, and it is possible to prevent the portion corresponding to the ear extension at the end in the width direction from being excessively thinned by over-grinding. Then, after the grinding, it is possible to prevent cracks and breaks at the width direction end of the metal strip in the next cold rolling step.

On the other hand, as shown in FIG.
When the metal band S whose width-direction end S2 is elongated due to insufficient tension or insufficient tension due to insufficient tension is ground by the grinding belt 8 of the grinding means 5, the width-direction end S3
Is excessively ground, and the thickness of the portion is locally reduced. As a result, in the next cold rolling step, cracks occur at the widthwise end of the metal strip S. The reason will be described in detail with reference to FIG.

As shown in FIG. 5B, the width direction end S3
If the thickness of the part is too thin due to over-grinding,
The plate thickness at the center in the width direction is relatively thick. The thick central portion in the width direction is further extended in the longitudinal direction by a large volume (collapse rolling) due to the subsequent cold rolling. On the other hand, the widthwise end portion S3 having a relatively small thickness has a relatively small extension in the longitudinal direction due to the small volume. For this reason, a tensile force is generated in the width direction end portion S3 in the length direction due to the effect that the width direction center portion is excessively extended in the length direction. When this tensile force exceeds the tensile breaking stress, a crack S4 is formed in the width direction edge S3.
Will occur.

On the other hand, as shown in FIG. 5A, the thickness of the end portion S1 in the width direction is made substantially the same as the thickness of the central portion in the width direction by appropriate grinding, that is, grinding while applying a predetermined tension. In this case, the subsequent cold rolling uniformly extends in the longitudinal direction at any portion in the width direction, and the width direction end S1 does not crack. In addition, in FIG.5 (a) and FIG.5 (b), the code | symbol 20 is a work roll of a cold rolling mill.

Next, a second embodiment of the metal band grinding apparatus according to the present invention will be described with reference to FIG. The grinding device 30 shown in FIG. 6 has substantially the same configuration as the grinding device 1 shown in FIG. 1, but before the grinding means 5 in the transport direction, the shape meter 14 (which measures the shape of the metal band S before grinding). Shape measuring means)
Is different from the grinding device 1. The grinding device 30 is for grinding the metal band S while adjusting the tension to be applied according to the shape of the metal band S before grinding, and is provided by a tension applying unit (not shown) according to the value measured by the shape meter 14. The tension is determined. According to this, the metal band S can be appropriately and efficiently flattened and ground in accordance with the shape of the metal band S before grinding, and the metal band S after grinding can be used for cold rolling in the next step. It is possible to prevent cracks and breaks at the width-direction end portions when provided. And 0.
Even after grinding a metal strip such as a thin cold-rolled steel strip having a thickness of 8 mm or less, it is possible to prevent the widthwise end of the metal strip from cracking or breaking in the next cold rolling step.

The tension applied in the grinding device 30 preferably follows the following equation.

[0026]

(Equation 3)

Here, T: tension (Mpa) E: Young's modulus of metal band (Mpa) λ: shape (steepness) (%) of metal band before grinding The tension applied in the grinding device 30 is expressed by T If it is larger than the above, the metal band S will be constricted due to tension, and the quality of the sheet will be out of order thickness and width. However, the effect of correcting the shape of the metal band S is not sufficient, and it is not sufficient to prevent over-grinding of the end in the width direction and cracks caused thereby.

The type of the shape meter 14 is preferably a laser type, but is not limited to this.

[0029]

EXAMPLE A steel mainly composed of 20Cr-5Al was melted and continuously cast to form a slab, then hot-rolled to a thickness of 2 mm, and then annealed and pickled to a thickness of 0.3 mm. Rolled. This was subjected to whole surface grinding. At this time, since the shape had a steepness of 1.1% in a no tension state, grinding was performed by applying a tension of 200 MPa. This was further cold-rolled and thinned to a sheet thickness of 0.1 mm (100 μm), but no crack was generated at the end in the width direction.

[0030]

As described above, according to the metal strip grinding apparatus of the first aspect of the present invention, the metal strip is flattened by applying a predetermined tension to the metal strip. And a grinding unit for grinding the metal band flattened by the tension applying unit while applying the predetermined value of tension, so that the surface of the metal band is almost uniformly ground in the width direction. In addition, the thickness at the width direction end is substantially the same as the thickness at the width center, and it is possible to prevent the portion corresponding to the ear extension at the width direction end from being excessively thinned due to excessive grinding. Therefore, even after grinding a metal strip such as a cold rolled steel strip having a thickness of 0.8 mm or less, it is possible to prevent the occurrence of cracks at the width direction ends of the metal strip during the next cold rolling process. It is possible to prevent the crack from propagating from the crack as a starting point to break the metal band. For this reason, production does not stop for a long time, and yield loss does not occur.

According to the metal band grinding apparatus of the second aspect of the present invention, in the invention of the first aspect, the predetermined value range of the tension is 70 to 250 Mpa. The shape correction (flattening) of the metal band can be effectively performed without being constricted or broken by pulling. Further, according to the metal band grinding apparatus according to claim 3 of the present invention, in the invention according to claim 1 or 2, the shape of the metal band before grinding is measured before the grinding means in the transport direction. Since the shape measuring means is provided, and the tension applied by the tension applying means is determined according to the value measured by the shape measuring means, the metal strip is appropriately and efficiently formed according to the shape of the metal strip before grinding. Flattening and grinding can be performed, and cracks and breaks at the width direction end portions when the ground metal band is subjected to the next step of cold rolling can be prevented.

According to the method of grinding a metal band according to claim 4 of the present invention, the metal band is flattened by applying a predetermined tension to the metal band, and the flattened metal band is applied. Grinding while applying the tension of the predetermined value,
Similar to the grinding device according to claim 1, even after grinding a metal strip such as a cold-rolled steel strip having a thin plate thickness of 0.8 mm or less, the width direction end of the metal strip in the next rolling step is not removed. The generation of cracks can be prevented, and the propagation of the cracks starting from the cracks can be prevented, and the metal strip can be prevented from breaking.

According to the method of grinding a metal band according to claim 5 of the present invention, in the invention according to claim 4, the range of the predetermined value of the tension is 70 to 250 Mpa. As in the case of the described grinding apparatus, the shape correction (flattening) of the metal band can be performed effectively without narrowing or breaking the metal band by pulling.

According to the metal band grinding method according to the sixth aspect of the present invention, the grinding is performed while adjusting the tension to be applied according to the shape of the metal band before grinding. The metal band can be flattened and ground appropriately and efficiently according to the shape, preventing cracks and breakage at the width direction ends when the ground metal band is subjected to the next step of cold rolling. can do. And the thickness of the metal strip is 0.8mm
In the following cases, appropriate depending on the shape of the metal band before grinding,
In addition, the metal strip can be efficiently flattened and ground.

In addition, according to the method of grinding a metal band according to claim 7 of the present invention, in the invention according to claim 6,
Since the tension is determined by the following equation, the shape correction (flattening) of the metal band can be effectively performed without causing the metal band to be narrowed or broken by the tension.

[0036]

(Equation 4)

Where: T: tension (Mpa) E: Young's modulus of metal band (Mpa) λ: shape (steepness) of metal band before grinding (%)

[Brief description of the drawings]

FIG. 1 is a schematic view of a first embodiment of a metal band grinding apparatus according to the present invention.

FIG. 2 is a schematic view showing a modified example of the grinding device shown in FIG.

FIG. 3 is a schematic view showing a grinding method by the grinding device shown in FIG.

FIG. 4 is a schematic diagram showing a grinding state when a metal band is extended.

5A and 5B show a rolled state of a metal band, FIG. 5A is an explanatory diagram of a rolled state when the metal band is appropriately ground, and FIG. 5B is a rolled state when an end in the width direction of the metal band is overground. FIG.

FIG. 6 is a schematic view of a second embodiment of the metal band grinding apparatus according to the present invention.

FIG. 7 is a schematic view of a conventional grinding apparatus.

[Explanation of symbols]

 1, 30 is a grinding device 2 is a pay-off reel 3, 11 is a deflector roll 4 is a tension applying means 4a is a bridle roll 5, a grinding means 6, a winding roll 7, a contact roll 8, a grinding belt 9, a backup roll 10, and a lifting device 12 is a tension reel 13 is a pinch roll 14 is a shape gauge (shape measuring means) 20 is a work roll S is a metal band

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinobu Shinmaru 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Inside the Chiba Works, Chiba Works (72) Inventor Hirohiro Yamaguchi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Address Kawasaki Steel Corporation Chiba Works (72) Inventor Toshiya Hagiwara 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Corporation Chiba Works F term (reference) 3C034 AA07 CA05 CA22 CB20 DD20 3C043 BB06 BB11 CC05 DD06 EE04 3C058 AA05 AB06 AC02 BA09 BB03 BB09 BC01 CA01 CB02 CB03

Claims (7)

[Claims] 1. A tension applying means for flattening the metal band by applying a predetermined value of tension to the metal band, and applying the tension of the predetermined value to the metal band flattened by the tension applying means. And a grinding means for grinding while stretching the metal strip. 2. The method according to claim 1, wherein the predetermined value of the tension ranges from 70 to 250.
2. The metal strip grinding apparatus according to claim 1, wherein the metal strip is Mpa. 3. A shape measuring means for measuring the shape of the metal strip before grinding is provided before the grinding means in the transport direction,
3. The apparatus for grinding a metal band according to claim 1, wherein the tension applied by the tension applying unit is determined according to a value measured by the shape measuring unit. 4. The method according to claim 1, further comprising: applying a predetermined value of tension to the metal band to flatten the metal band, and grinding the flattened metal band while applying the predetermined value of tension. Grinding method for metal strip. 5. The range of the predetermined value of the tension is 70 to 250.
5. The method for grinding a metal band according to claim 4, wherein the metal band is Mpa. 6. A method for grinding a metal band, wherein the grinding is performed while adjusting the tension applied according to the shape of the metal band before grinding. 7. The method according to claim 6, wherein the tension is determined by the following equation. (Equation 1) Here, T: tension (Mpa) E: Young's modulus of metal band (Mpa) λ: shape (steepness) of metal band before grinding (%)