JPH068118A - Processing method and processing device for beltlike metal body - Google Patents

Abstract

PURPOSE:To reduce the costs for production and measure against environmental pollution by making the surface grinding of a beltilke metal body with scale on its surface and, after de-greasing and cleaning, applying an acid cleaning treatment with a specified amount of solvent to increase surface quality and also increase the efficiencies of process and treatment. CONSTITUTION:In an in-line grinding device 11, multiple stages of stands each of which is composed of an elastic grinding stone roll 11a and a retaining roll 11b in pairs are arranged, and the front and rear surfaces of beltlike body 2 is ground heavily. In a de-greasing and washing device 12 installed after the in-line grinding device, multiple stands each of which is composed of a brush roll 12a and a retaining roll 11b in pairs are arranged, and further a hot water spray 12c is arranged after that. Then, in a light acid cleaning device 13, acid cleaning treatment is made on the heavily ground band metal body 2 after it has been washed so that the amount of solvent on its surface is adjusted to 0.1 to 30mum. In a cleaning device 14, multiple stages of stands each of which is composed of a brush roll 14a and a retaining roll 14b in pairs are arranged, and further a hot water spray 14c is arranged. Then, after cleaning, the beltlike metal body 2 is rolled out by a tension reel 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a strip-shaped metal body,
When removing surface scales and surface flaws generated in the hot rolling process and thin cast continuous casting process, improve the surface quality of the strip-shaped metal body, pickling treatment, and omit the surface flaw removal process on another line. The present invention relates to a possible method for treating a strip-shaped metal body. In the present specification, the band-shaped metal body refers to a hot-rolled sheet (strip) or a coil produced by a conventional method of stainless steel, ordinary steel, titanium and its alloys, high alloys, etc., or a thin-walled sheet produced by continuous casting ( Band) or wound coil.

[0002]

2. Description of the Related Art In a manufacturing process of a strip-shaped metal body, an oxide scale or a surface flaw is generated on the surface of the strip-shaped metal body due to heating of the slab and subsequent hot rolling or continuous casting of thin slabs. And a process for finishing the surface is required. Conventionally, these methods include shot blasting in which a steel ball having a diameter of 0.2 to 0.6 mm is projected on the surface of a strip-shaped metal body to perform surface layer cleaning to cause cracks and peeling of the scale, and then the nitrofluoride. Descale by pickling with acid, sulfuric acid, hydrochloric acid, etc., and then perform cold rolling to correct the shape of the strip metal body, and then remove the surface flaws of the strip metal body by belt grinding on another line. It was regarded as a typical method.

However, in this conventional process, the pickling process is a continuous line with the annealing process, and the grinding line and the rolling line or the dummy plate welding line are separately arranged, so that the oxide scale and the surface of the strip-shaped metal body are arranged. In order to remove the flaw, it is necessary to pass 2 to 4 lines, and there is a problem that the efficiency is extremely low. The annealing pickling line is inefficient because descaling is performed by pickling, and there are various problems from the viewpoint of productivity, cost and labor saving such as generation of a large amount of waste liquid accompanying pickling. . On the other hand, in order to uniformly remove surface flaws by belt grinding in the width direction of the plate, it is necessary to straighten the shape of the coil by cold working, but this straightening work is performed using a normal cold rolling mill. Therefore, in addition to the original gauge down work (thickness reduction work), an extra shape correction work must be performed, and therefore, there is a problem that not only the efficiency is improved but also the cost is increased. Furthermore, in the grinding line, the method of grinding the surface of the strip-shaped metal body with a rotating endless belt is the main method, but this method requires a low belt passing speed and a short belt life, requiring frequent belt replacement. The sex is bad. Moreover, there is a problem that uniform grinding cannot be performed unless the plate shape before grinding is flat.

Therefore, for the purpose of improving the efficiency of descaling and improving the surface quality of the hot-rolled steel strip, a plurality of pickling treatment steps are provided after the pretreatment step of the tension leveler, and the plurality of pickling treatment steps are performed. Japanese Unexamined Patent Publication (Kokai) No. 59-41482 discloses a descaling line in which a grinding process for removing mainly metal residue and smut is combined. However, although the surface quality of the steel strip is improved to some extent in the descaling line, its effect is limited, and since a large amount of descaling is performed by pickling treatment, a considerably large-scale pickling treatment facility is required. Therefore, the initial investment is large, and it is necessary to treat a large amount of waste liquid accompanying the large-scale pickling. Further, since the grinding process provided between each pickling treatment process is not for actively removing the surface flaws of the steel strip, the steel strip passed through the descaling line is used for removing the surface flaws. The problem arises that the plate has to be passed to another grinding line.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides an in-line grinding apparatus provided in a processing step when removing surface scales or surface flaws of a strip-shaped metal body. Continuation of degreasing and pickling means to improve the surface quality of the strip-shaped metal body and simplify the pickling and surface flaw removal processes to improve the efficiency of the treatment work and simplify the treatment of acid and waste liquid. It is an object of the present invention to provide a method for treating a strip-shaped metal body that does not require a flaw removal work in another line by further reducing the manufacturing cost, reducing the investment such as pollution control, and improving the working environment, and further making continuous treatment.

[0006]

The present invention has been completed as a result of various studies on mechanical descaling and surface conditioning methods and combinations of the methods in order to achieve this object. The summary is as follows. It is as follows. 1. A band-shaped metal body having a scale on its surface is passed through a grinding device having elastic grindstone rolls arranged in multiple stages to perform surface grinding, and after degreasing and cleaning, pickling treatment is performed so that the amount of ablation is 0.1 to 30 μm. 1. A method for treating a strip-shaped metal body, characterized by: After correcting the shape of a band-shaped metal body having a scale on the surface, it is processed by mechanical means to promote cracking or peeling of the surface scale, and then surface grinding is performed by passing it through a grinding machine with elastic grindstone rolls arranged in multiple stages. Is performed, and after degreasing and cleaning, a pickling treatment is performed so that the amount of scraping is 0.1 to 30 μm. The grinding apparatus of the present invention preferably has a structure in which a stand in which a pressing roll facing the elastic grindstone roll is paired, and an elastic grindstone roll that grinds one surface of the strip-shaped metal body is arranged at least three bodies, Further, in the above-mentioned grinding apparatus, it is preferable that at least the first stand for grinding each surface is a laminated type elastic grindstone roll. Further, it is desirable that the abrasive grain count of the final stand for grinding each surface is arranged to be # 240 or more.

In the present invention, as a pretreatment, trimming or grinding of the edge of the strip-shaped metal body having a scale on the surface is performed, and then heating for modifying the surface scale to cause cracking or peeling, if necessary, You may perform a cooling process.

[0008]

The method for treating a strip-shaped metal body according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic explanatory view showing one embodiment of a process line for carrying out the method of the present invention. In the figure, 1 is a pay-off reel for rewinding and feeding a strip-shaped metal body, 2 is a strip-shaped metal body that is hot-rolled or is continuously cast into a thin cast piece, and 3 is a dummy plate for the strip-shaped metal body (hereinafter referred to as a leader) Is a welding machine for carrying out the welding of No. 1 and welding between leaders, and for example, a submerged arc welding machine, a TIG welding machine, a plasma welding machine, a spot welding machine, etc. are used. 4 is a trimmer that cuts and removes edge flaws and hot cracks that occur in the strip-shaped metal body during hot rolling or continuous casting of thin-walled slabs, and 5 grinds and removes relatively small of these flaws and cracks. It is an edge grinder for doing. Reference numeral 6 denotes a heating furnace which is installed if necessary to heat the strip-shaped metal body, and a heating furnace for burning heavy oil or gas is usually used, but an electric heating furnace such as induction heating or direct current heating can also be used. Good. Reference numeral 7 is a cooling zone for cooling the strip-shaped metal body after heating, such as gas cooling, spray cooling, water spray cooling, roll cooling and the like. Each of the above devices is a pretreatment unit in the present invention, and may be arranged as necessary.

Reference numeral 8 is a leveler for bending or pulling a strip-shaped metal body, 9 is a bridle roll for applying a tension necessary for grinding the strip-shaped metal body, and 8 is a steel ball projected on the surface of the strip-shaped metal body. It is a dry or wet shot blast.

Reference numeral 11 denotes an in-line grinding device which is one of the features of the present invention. For example, a plurality of stands, each pair of which is composed of an elastic grindstone roll 11a and a pressing roll 11b, are arranged, and the front and back surfaces of the strip-shaped metal body are stacked. Grind. The elastic whetstone roll referred to here is a roll-shaped whetstone having a certain degree of elasticity in order to easily fit to the shape of the plate, for example, a roll formed by laminating discs coated with abrasive grains ( There are a laminated type), a type in which flap wheels are laminated and formed into a roll shape (flap type), and a nylon resin containing abrasive grains integrally formed in a roll shape (integrated type), and the like, and any of these can be adopted. In an in-line grinding machine having such an elastic whetstone roll, at least three elastic whetstone rolls for grinding one side of the strip-shaped metal body are arranged, and the abrasive grain count of the final stand for grinding each side is # 240 or more. It is desirable to use the elastic grindstone roll which is the above, and it is preferable to arrange the laminated elastic grindstone roll in at least the first stand in the above-mentioned grinding apparatus.

Reference numeral 12 denotes a degreasing / cleaning device installed after the grinding device, for example, a brush roll 12a and a press roll 1.
A plurality of stands, each pairing with 2b, are arranged in a plurality of stages, or brush rolls are provided so that both front and back surfaces of the strip-shaped metal body face each other. This brush roll includes, for example, a roll made of a brush made of nylon fiber containing abrasive grains. Further, the hot water spray 12c is arranged after the degreasing device. Reference numeral 13 is a light pickling device, which has a surface abraded amount of 0.1 to 30 μm after cleaning the band-shaped metal body subjected to heavy grinding
A pickling treatment is carried out to adjust to m. A cleaning device 14 includes, for example, a brush roll 14a and a press roll 1.
4b or a pair of stands, each pairing,
Alternatively, the brush rolls are provided so as to face both sides of the strip-shaped metal body. Further, the hot water spray 14c is arranged after the brush cleaning device. Reference numeral 15 is a tension reel for winding the strip-shaped metal body.

In the process for treating the strip-shaped metal body having such a structure, the strip-shaped metal body 2 is rewound from the payoff reel 1, and first the welding machine 3 welds the leader and then the leader of the preceding material. Then, after removing the flaws and cracks at the edge portion with the trimmer 4 or the edge grinder 5, the scale is cavified in the vicinity of the strip-shaped metal body base by heating in the heating furnace 6 if necessary, and the subsequent cooling is performed. The rapid cooling performed in strip 7 can cause the scale to crack or delaminate due to strains that occur during cooling, which can facilitate subsequent descaling.

A band-shaped metal body having a scale on its surface is passed through a tension leveler 8 to promote cracking or peeling on the scale on the surface, or to further promote it, and to correct the shape of a plate for facilitating uniform grinding and polishing. Bending and bending of the ears are corrected, and the impact force of the steel balls projected onto the surface in the subsequent dry or wet shot blasting 10 treatment further promotes cracking and peeling of the scale.

The strip-shaped metal body in such a state is introduced into the in-line grinding apparatus 11, and the surface layer portion including the scale is ground by the elastic grindstone roll 11a to simultaneously perform descaling and flaw removal. This grinding process imposes a considerable load on the elastic grindstone roll and causes severe wear on a small number of rolls, resulting in a short life.
Therefore, in the present invention, three or more stands having elastic grindstone rolls are arranged on each surface of the strip-shaped metal body in multiple stages to reduce the roll load per pass, extend the roll life, and further improve the grinding efficiency. Further, the reason why the grindstone count of the last stage roll of the elastic grindstone roll is to be # 240 or more is that if the count is smaller than that, the treated surface becomes rough and it becomes difficult to form the surface by cold rolling. is there. Furthermore, it is advisable to install the laminating rolls on at least the first stand of the grinding device, because this can increase the grinding efficiency of scale removal and flaw removal.

Generally, since the thickness of the scale and the depth of the surface flaws generated by annealing in the hot rolling or the subsequent steps or continuous casting of thin slabs are at least about 5 to 10 μm, in order to remove the scale and the surface flaws. Is at least 10 μm
Grinding exceeding the above is required. In order to perform more reliable grinding, it is desirable to exceed 20 μm. Further, when R _max exceeds 30 μm in the surface roughness after heavy grinding, deep grinding marks such as scratches occur, and in order to sufficiently remove this, the load of the surface conditioning in the subsequent step increases. It is desirable to set R _max ≦ 20 μm, for which the grinding is performed on one side in a plurality of passes as described above, preferably 3 passes.
It is possible to adjust the surface roughness by making the number of passes or more to reduce the load per pass and further making the abrasive grain count of the last pass to # 240 or more.

After grinding, the strip-shaped metal body is passed through a degreasing / cleaning device to remove oil, metal residue, scale powder, etc. adhering to the surface, and then subjected to pickling treatment.

The strip-shaped metal body that has been descaled and scratched sufficiently and efficiently in the grinding process is further lightly abraded by pickling treatment, and the ground surface is smoothed or smoothed.
Blurring is applied. The amount of fusing is 0.1 to 0.1
The reason why it is carried out within the range of 30 μm is that burrs and biting abrasive grains generated during grinding cannot be sufficiently removed when the thickness is less than 0.1 μm, and when it exceeds 30 μm, the surface pit-like unevenness of the etch pit becomes severe, This is because it will be difficult to build by cold rolling after that. By such pickling treatment, sharp grinding lines are not rounded and the surface profile is improved, and the material containing a work-affected layer during grinding can be removed if necessary. The surface quality is further improved. For pickling, it is desirable to use sulfuric acid, nitric acid, and nitric hydrofluoric acid individually or in plural treatments, depending on the target material. After pickling, wash the pickling solution and wind it on a tension reel.

[0018]

EXAMPLES In accordance with the process shown in FIG. 1, a strip-shaped metal body was subjected to in-line grinding and pickling treatment under the conditions shown in Table 1 and
Investigate the surface quality and the quality of cold rolled and annealed products after lapping and cutting,
The evaluation was performed and the results are also shown in Table 1. The conditions and methods for heat treatment and pretreatment before in-line grinding are also described. In this table, the amount of grinding and the amount of fusing were measured before and after the treatment, and the removed thickness was calculated from the specific gravity. For the surface roughness, a sample was taken after each treatment and measured in the plate width direction with a roughness meter, and the maximum roughness R _max was used. The evaluation of descaling and flaw removal was performed as follows. ◯: No scale remains and no surface flaws. Δ: No scale remains, but surface flaws remain. X: Scale and surface flaws remain. The surface quality of cold rolled and annealed products depends on the degree of gloss,
It was evaluated by 4 ranks of D, and B rank or higher was regarded as the first grade.
The conditions for cold rolling annealing were normal conditions. As is clear from this table, the evaluation results of the strip-shaped metal bodies according to the method of the present invention are all good, and the average life of the elastic grindstone is improved by making the elastic grindstone multiple or multi-stage of the laminated roll, No scale residue or surface flaws were found on the surface after grinding, and the product after cold rolling annealing had good surface properties, and the product yield was also improved.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

As is apparent from the above, in the present invention, when removing the surface scale and surface flaws, the grinding apparatus is made in-line and the pickling treatment is made continuous to treat the strip-shaped metal body. Improves the surface quality of the strip-shaped metal body and simplifies descaling and surface flaw removal processes and pickling treatment to further improve efficiency, and simplifies acid and waste liquid treatment to reduce manufacturing costs and pollution control costs. Can be reduced and the working environment can be improved. Also, it became possible to omit the flaw removal on another line by continuous processing.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an embodiment for carrying out the present invention.

[Explanation of symbols]

 1 Payoff reel 2 Band-shaped metal body 3 Welding machine 4 Trimmer 5 Edge grinder 6 Heating furnace 7 Cooling zone 8 Leveler 9 Bridle roll 10 Dry or wet shot blasting 11 In-line heavy grinding device 11a Elastic grindstone roll 11b Pressing roll 12 Degreasing cleaning device 12a Brush Roll 12b Presser roll 12c Spray 13 Light pickling device 14 Cleaning device 14a Brush roll 14b Presser roll 14c Spray 15 Tension reel

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[Procedure amendment]

[Submission date] December 24, 1992

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Patent application title: Processing method and processing apparatus for band-shaped metal body

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a strip-shaped metal body,
When removing surface scales and surface flaws generated in the hot rolling process and thin cast continuous casting process, improve the surface quality of the strip-shaped metal body, pickling treatment, and omit the surface flaw removal process on another line. Possible method for treating strip metal and
And a processing device . In the present specification, the band-shaped metal body refers to a hot-rolled sheet (strip) or a coil produced by a conventional method of stainless steel, ordinary steel, titanium and its alloys, high alloys, etc., or a thin-walled sheet produced by continuous casting ( band)
Alternatively, it means a coil that is wound up.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides an in-line grinding apparatus provided in a processing step when removing surface scales or surface flaws of a strip-shaped metal body. Continuation of degreasing and pickling means to improve the surface quality of the strip-shaped metal body and simplify the pickling and surface flaw removal processes to improve the efficiency of the treatment work and simplify the treatment of acid and waste liquid. The purpose of the present invention is to reduce the manufacturing cost, reduce investment such as pollution control, improve the working environment, and provide a method and apparatus for treating a strip-shaped metal body that does not require flaw removal work in another line due to continuous treatment. And

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

The present invention has been completed as a result of various studies on mechanical descaling and surface conditioning methods and combinations of the methods in order to achieve this object. The summary is as follows. It is as follows. 1. A band-shaped metal body having a scale on its surface is passed through a grinding device having elastic grindstone rolls arranged in multiple stages to perform surface grinding, and after degreasing and cleaning, pickling treatment is performed so that the amount of ablation is 0.1 to 30 μm. processing method of the strip metal body, characterized in Oyo
And device , 2. After correcting the shape of a band-shaped metal body having a scale on the surface, it is processed by mechanical means to promote cracking or peeling of the surface scale, and then surface grinding is performed by passing it through a grinding machine with elastic grindstone rolls arranged in multiple stages. The method and apparatus for treating a strip-shaped metal body are characterized in that after performing degreasing and cleaning, a pickling treatment is performed so that the amount of abrasion is 0.1 to 30 μm. The grinding apparatus of the present invention preferably has a structure in which a stand in which a pressing roll facing the elastic grindstone roll is paired, and an elastic grindstone roll that grinds one surface of the strip-shaped metal body is arranged at least three bodies, Further, in the above-mentioned grinding apparatus, it is preferable that at least the first stand for grinding each surface is a laminated type elastic grindstone roll. Further, it is desirable that the abrasive grain count of the final stand for grinding each surface is arranged to be # 240 or more.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

The method and apparatus for treating a strip-shaped metal body according to the present invention.
The arrangement will be described below in detail with reference to the drawings. Figure 1
FIG. 3 is a schematic explanatory view showing an embodiment of a process line for carrying out the method of the present invention. In the figure, 1 is a pay-off reel for rewinding and feeding a strip-shaped metal body, 2 is a strip-shaped metal body that is hot-rolled or is continuously cast into a thin cast piece, and 3 is a dummy plate for the strip-shaped metal body (hereinafter referred to as a leader) Is a welding machine for carrying out the welding of No. 1 and welding between leaders, and for example, a submerged arc welding machine, a TIG welding machine, a plasma welding machine, a spot welding machine, etc. are used. 4 is a trimmer that cuts and removes edge flaws and hot cracks that occur in the strip-shaped metal body during hot rolling or continuous casting of thin-walled slabs, and 5 grinds and removes relatively small of these flaws and cracks. It is an edge grinder for doing. Reference numeral 6 denotes a heating furnace which is installed if necessary to heat the strip-shaped metal body, and a heating furnace for burning heavy oil or gas is usually used, but an electric heating furnace such as induction heating or direct current heating can also be used. Good. Reference numeral 7 is a cooling zone for cooling the strip-shaped metal body after heating, such as gas cooling, spray cooling, water spray cooling, roll cooling and the like. Each of the above devices is a pretreatment unit in the present invention, and may be arranged as necessary.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

[0018]

EXAMPLE In-line grinding and pickling treatment were performed on a strip-shaped metal body under the conditions shown in Table 1 in accordance with the manufacturing process by the processing equipment row shown in FIG. Was investigated and evaluated, and the results are also shown in Table 1. The conditions and methods for heat treatment and pretreatment before in-line grinding are also described. In this table,
The amount of grinding and the amount of fusing were measured before and after the treatment, and the removed thickness was calculated from the specific gravity. The surface roughness is obtained by taking a sample after each treatment and measuring it in the plate width direction with a roughness meter to obtain the maximum roughness R _max.
Was used. The evaluation of descaling and flaw removal was performed as follows. ◯: No scale remains and no surface flaws. Δ: No scale remains, but surface flaws remain. X: Scale and surface flaws remain. The surface quality of cold rolled and annealed products depends on the degree of gloss,
It was evaluated by 4 ranks of D, and B rank or higher was regarded as the first grade.
The conditions for cold rolling annealing were normal conditions. As is clear from this table, the evaluation results of the strip-shaped metal bodies according to the method of the present invention are all good, and the average life of the elastic grindstone is improved by making the elastic grindstone multiple or multi-stage of the laminated roll, No scale residue or surface flaws were found on the surface after grinding, and the product after cold rolling annealing had good surface properties, and the product yield was also improved.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takahiro Fujiwara 3434 Shimada, Hikari City, Yamaguchi Prefecture, Nippon Steel Works, Ltd., Hikari Steel Works (72) Inventor, Kazuyuki Takagi 3434 Shimada, Hikari City, Yamaguchi Prefecture, Japan Inside the Kogaku Steel Works

Claims (5)

[Claims] 1. A strip-shaped metal body having a scale on its surface,
The surface is ground through a grinding machine that has elastic grindstone rolls arranged in multiple stages, and after degreasing and cleaning, the amount of fusing is 0.1 to 30 μm.
A method for treating a strip-shaped metal body, which comprises performing a pickling treatment as follows. 2. A strip-shaped metal body having a scale on its surface,
After the shape is corrected, the mechanical scale is used to promote the cracking or peeling of the surface scale, and then the surface is ground through a grinding machine with elastic grindstone rolls arranged in multiple stages. A method for treating a strip-shaped metal body, which comprises performing pickling treatment so that the value is 0.1 to 30 μm. 3. As the grinding device, a stand in which a pressing roll facing the elastic whetstone roll is paired, and a grinding device in which at least three elastic whetstone rolls for grinding one surface of a strip-shaped metal body are arranged are used. The method for treating a strip-shaped metal body according to claim 1 or 2, characterized in that. 4. The belt-shaped strip according to claim 1, wherein at least the first stand for grinding each surface of the strip-shaped metal body in the grinding device is a laminated type elastic grindstone roll. Metal body processing method. 5. The treatment of the strip-shaped metal body according to claim 1, wherein the abrasive grain count of the final stand for grinding each surface of the strip-shaped metal body is # 240 or more. Method.