JP4405037B2 - Steel strip grinding method and apparatus - Google Patents

Description

【００２３】
【発明の効果】
本発明は、パスラインを走行中の熱延ステンレス鋼帯の表面酸化スケールを研削ブラシロールによって研削除去する方法において、研削能力を高めた場合に発生するパスライン上流側及び下流側における張力変動を解消することができる。その結果、張力変動により発生する(1) 通板性の悪化により鋼帯エッジがガイド等と接触して鋼帯や設備を損傷する、(2) 張力制御の狂いにより焼鈍炉においてカテナリーの減少による板切れ、カテナリーの増大により鋼帯が炉底接触して疵付く、という問題を解消できる。
【００２４】
その結果、研削能力を高めることで連続焼鈍酸洗設備におけるショットブラスト処理及び酸洗処理の負荷が軽減するから、通板速度を上げることで生産能率が向上する。また、ショットブラスト処理においては、ショット粒の消耗を軽減するとともにショット粒による鋼帯表面の凹凸を解消できる。一方、酸洗処理においては、酸液の劣化が少ないから、酸洗費用が少なくて済み、廃酸処理の負荷も軽減する。
【図面の簡単な説明】
【図１】本発明を実施するためのステンレス鋼帯連続焼鈍酸洗設備の一例を示す図。
【図２】本発明の請求項１及び３に沿う鋼帯研削ブラシロール装置を示す図。
【図３】本発明の請求項２及び４に沿う鋼帯研削ブラシロール装置を示す図。
【符号の説明】
１…ペイオフリール
２…入側シャー
３…ウエルダー
４…入側ルーパー
５…連続焼鈍炉
６…冷却装置
７…ショットブラスト装置
８…鋼帯研削ブラシロール装置
９…研削ブラシロール
１０…研削ブラシロール
１１…水プレーノズル
１２…Ｃ反り矯正ロール
１３…硫酸槽
１４…硝弗酸槽
１５…洗浄装置
１６…ドライア
１７…出側ルーパ
１８…分割シャー
１９…テンションリール
２０…研削ブラシロール
２１…研削ブラシロール
２２…鋼帯研削ブラシロール装置
ｓ…ステンレス鋼帯[0001]
BACKGROUND OF THE INVENTION
The present invention relates to grinding of a steel strip surface with a grinding brush roll, and particularly relates to descaling of a hot-rolled stainless steel strip after hot rolling and annealing.
[0002]
[Prior art]
The scale on the surface of the hot-rolled stainless steel strip after annealing is dense and very hard, and it is difficult to remove compared with the scale of general carbon steel. Therefore, the descaling method generally employs a method in which the destruction of the oxide scale layer by shot blasting and the pickling treatment with sulfuric acid, nitric hydrofluoric acid, nitric acid or the like are combined.
[0003]
However, this descaling method has the following difficulties. (1) Since it takes time to remove the dense and thick oxide scale, the production capacity cannot be increased. (2) In shot blasting, the surface of the steel strip is uneven and the surface properties are impaired, and the shot grains are heavily consumed. (3) In pickling treatment, there are many problems in the treatment of exhaust gas and waste liquid, and the surface properties are impaired due to irregularities on the steel strip surface due to intergranular corrosion.
[0004]
Therefore, as a method for solving these problems, a method of grinding the surface of a hot-rolled stainless steel strip after annealing with a grinding brush roll in which bristles containing abrasive grains are planted is disclosed in, for example, JP-A-7-51728. Are known. Since this grinding method has a very high descaling efficiency, it is possible to reduce the load of the shot blast treatment and pickling treatment. As a result, the above problems can be solved, and the finished surface is dense. In addition to the fact that the belt grinding process in the post-process can be omitted, the surface properties of the product are excellent.
[0005]
[Problems to be solved by the invention]
However, when descaling the steel strip surface with the above grinding brush roll, increasing the rolling force or rotational speed to increase the grinding ability results in an increase in frictional force between the grinding brush roll and the steel strip. Tension fluctuation occurs. As a result of this tension fluctuation becoming a disturbance in tension control, the plateability of the front and rear equipment is deteriorated, and the steel strip edge comes into contact with the guides and the like and damages the steel strip and the equipment. In addition, when the lap weld of the steel strip passes through the grinding brush roll, the grinding brush roll is separated from the steel strip, resulting in a large tension fluctuation in the steel strip, which causes a large deviation in tension control. In the side annealing furnace, there is a problem that the plate is cut due to a decrease in catenary, or the catenary is increased and comes into contact with the bottom of the furnace.
[0006]
Accordingly, an object of the present invention is to eliminate fluctuations in the tension of the steel strip generated by the frictional force between the grinding brush roll and the steel strip in an apparatus for grinding with a grinding brush roll that rotationally drives the surface of the steel strip traveling on the pass line. The task is to do.
[0007]
[Means for Solving the Problems]
The steel strip grinding method of the present invention provides a grinding brush roll device on the upstream side and the downstream side of the steel strip pass line, and cancels the frictional force between the brush roll and the steel strip between the upstream side and the downstream side. It is configured to eliminate the fluctuation of frictional force between band grinding and non-grinding.
(1) A grinding brush roll device is provided on the upstream side and downstream side of the steel strip pass line, the upstream grinding brush roll device is driven to rotate in the direction opposite to the steel strip traveling direction, and the downstream grinding brush roll is the steel strip. It is characterized by being driven to rotate in the same direction as the traveling direction and at a speed faster than the traveling speed of the steel strip.
(2) Grinding brush roll devices are installed on the upstream and downstream sides of the steel strip pass line. The upstream grinding brush roll device is driven to rotate in the same direction as the steel strip traveling direction, and the downstream grinding brush roll is used for the steel strip. It is characterized by being driven to rotate in the direction opposite to the traveling direction.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an example of a stainless steel strip continuous annealing pickling facility for carrying out the present invention. The stainless steel strip s wound around the payoff reel 1 is unwound and the leading end or the trailing end is cut by the entrance shear 2 and then welded to the preceding coil in the welder 3. Then, it passes through the entrance looper 4 and is sent to the continuous annealing furnace 5 where it is heat-treated at a predetermined temperature. Subsequently, the stainless steel strip s is sent to the cooling device 6 and cooled at a predetermined temperature, and then sent to the shot blasting device 7 to destroy the oxide scale layer.
[0009]
Thereafter, the stainless steel strip s is sent to the steel strip grinding brush roll device 8 of the present invention to remove the oxide scale, and then sent to the sulfuric acid tank 13 and the nitric hydrofluoric acid tank 14 to be passivated, It passes through the cleaning device 15 and the dryer 16, passes through the exit side looper 17, is cut into a predetermined size by the divided shear 18, and is wound around the tension reel 19.
[0010]
FIG. 2 is an enlarged view of the steel strip grinding brush roll device 8 according to claims 1 and 3 of the present invention. The steel strip grinding brush roll device 8 includes an oxide scale generated on the surface of the stainless steel strip s. Grinding brush rolls 9 and 10 are arranged in series in pairs.
[0011]
The grinding brush rolls 9 and 10 are, for example, as disclosed in Japanese Patent Laid-Open No. 4-315582, a rod-shaped body made of a nylon synthetic resin having a diameter of 0.5 to 5 mm containing abrasive grains (for example, alumina or silica). Are mounted on the roll shaft in a radial manner. More specifically, for example, a rod-shaped body fixed to the outer periphery of the disk is laminated and compressed.
[0012]
The stainless steel strip s is ground to the steel surface layer by the grinding force of the grinding brush rolls 9 and 10 that are driven to rotate, and the oxide scale on the surface is removed. The water spray nozzle 11 cools the grinding brush rolls 9 and 10 and rinses away the removed oxide scale. The C warpage correction roll 12 corrects the C warpage of the steel strip before and during grinding to eliminate grinding unevenness.
[0013]
The grinding brush roll 9 is rotationally driven in the direction opposite to the traveling direction of the stainless steel strip s, and the grinding brush roll 10 is in the same direction as the traveling direction of the stainless steel strip s and at a speed faster than the traveling speed of the stainless steel strip s. Rotating drive. At this time, by balancing the axial torque of the grinding brush roll 9 and the axial torque of the grinding brush roll 10, the horizontal force generated in the steel strip due to the frictional force between the stainless steel strip s and the grinding brush rolls 9 and 10 is offset. Thus, the tension fluctuation can be eliminated.
[0014]
As a result, by increasing the grinding ability of the grinding brush rolls 9 and 10, the load of shot blasting and pickling treatment is reduced, so the passing speed of the stainless steel strip s in the continuous annealing pickling equipment can be increased. , Improve production efficiency. In shot blasting, wear of shot grains can be reduced and unevenness of the steel strip surface due to shot grains can be eliminated.
[0015]
FIG. 3 is an enlarged view of the steel strip grinding brush roll device 22 according to claims 2 and 4 of the present invention, which is installed in place of the steel strip grinding brush roll device 8 of the apparatus shown in FIG. . The difference from the apparatus shown in FIG. 2 is that the rotational drive direction of the grinding brush rolls 20 and 21 is opposite to that of the grinding brush roll apparatuses 9 and 10 in FIG. Since the name, structure, and function are the same, description thereof is omitted.
[0016]
In FIG. 3, the grinding brush roll 20 is rotationally driven in the same direction as the traveling direction of the stainless steel strip s, and the grinding brush roll 21 is rotationally driven in the direction opposite to the traveling direction of the stainless steel strip s. At this time, the balance between the axial torque of the grinding brush roll 20 and the axial torque of the grinding brush roll 21 cancels out the horizontal force generated in the steel strip by the frictional force between the stainless steel strip s and the grinding brush rolls 20 and 21. Thus, the tension fluctuation can be eliminated.
[0017]
The stainless steel strip s from which the oxide scale has been removed by the steel strip grinding brush roll device of FIG. 2 or 3 is sent to the sulfuric acid tank 13 and the nitric hydrofluoric acid tank 14 to remove the oxide scale. At this time, since most of the oxide scale of the stainless steel strip s is removed by the grinding brush roll, the pickling load is reduced. As a result, since there is little deterioration of an acid solution, the cost of pickling can be reduced and the load of waste acid treatment can be reduced.
[0018]
2 and 3, the upper and lower sides of the stainless steel strip s sandwiching the upper and lower surfaces are ground brush rolls. However, when grinding only one side of the stainless steel strip s, the upper and lower sides are backup rolls (not shown). May be. In addition, although a pair of grinding brush rolls are provided on the upstream and downstream sides of the pass line, a plurality of pairs may be provided.
[0019]
【Example】
In the stainless steel strip continuous annealing pickling equipment shown in FIG. 1, two pairs of grinding brush rolls are provided on the front and back in the pass line between the shot blasting apparatus 7 and the sulfuric acid bath 13, and SUS304 stainless steel is passed through the annealing and Descaling was performed. When the welded portion of the steel strip passed through the grinding brush roll in the plate, the grinding brush roll was opened. In the conventional example of Table 1, the entire grinding brush roll is rotated in the direction opposite to the steel strip traveling direction, and in the present invention example, the grinding brush roll in the first stage of the pass line is rotated in the direction opposite to the steel strip traveling direction. Table 1 shows a comparison of fluctuations in line tension in the same direction as the steel strip traveling direction.
[0020]
As common conditions, the grinding brush roll has a diameter of 400 mm, a length of 1500 mm, the rod-like body is made of nylon synthetic resin with a length of 40 mm, and the rotational peripheral speed of all grinding brush rolls is 1200 rpm. is there. The stainless steel strip has a thickness of 2.0 mm and a width of 1250 mm.
[0021]
The vertical force in Table 1 is the pressing force of the grinding brush roll against the steel strip, and the horizontal force is the force that pushes the steel strip in the pass line direction by the frictional force between the grinding brush roll and the steel strip. Since these values are difficult to measure with an actual machine, they were estimated based on the values measured with a test machine. The total horizontal force is a value obtained by adding the horizontal forces of a pair of grinding brush rolls for two pairs of grinding brush rolls, and 8.74 × 10 ³ N (892 kgf) of the conventional example is two pairs of grinding brush rolls. Is the total force that pushes the steel strip in the direction opposite to its travel direction.
[0022]
The line minimum tension is the minimum tension that can be taken in forming the necessary catenary amount and preventing the plate contact, and is the minimum value of the target line tension range that is normally set. (a) / (b) represents the degree of disturbance with respect to the minimum line tension. In the present invention example where this value is 0, the disturbance is canceled out. In the conventional example 1.43, the disturbance is the target value. It represents that it can be 1.43 times. As this value increases, the controllability decreases and the possibility of plate contact increases.
[Table 1]

[0023]
【The invention's effect】
The present invention is a method of grinding and removing the surface oxidized scale of a hot-rolled stainless steel strip running on a pass line by a grinding brush roll, and the tension fluctuation on the upstream and downstream sides of the pass line that occurs when the grinding ability is increased. Can be resolved. As a result, due to tension fluctuations (1) Steel strip edges come into contact with guides and the like due to deterioration of sheeting property, and the steel strip and equipment are damaged. (2) Catenaries are reduced in the annealing furnace due to tension control failure. It is possible to solve the problem that the steel strip comes into contact with the bottom of the furnace due to the cutting of the plate and the increase in catenary.
[0024]
As a result, since the load of shot blasting and pickling in a continuous annealing pickling facility is reduced by increasing the grinding ability, the production efficiency is improved by increasing the sheet passing speed. In the shot blasting process, the consumption of shot grains can be reduced and the unevenness of the steel strip surface due to shot grains can be eliminated. On the other hand, in the pickling treatment, since the acid solution is less deteriorated, the pickling cost can be reduced and the load of the waste acid treatment can be reduced.
[Brief description of the drawings]
FIG. 1 is a view showing an example of a stainless steel strip continuous annealing pickling facility for carrying out the present invention.
FIG. 2 is a view showing a steel strip grinding brush roll device according to claims 1 and 3 of the present invention.
FIG. 3 is a view showing a steel strip grinding brush roll device according to claims 2 and 4 of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Payoff reel 2 ... Incoming shear 3 ... Welder 4 ... Incoming side looper 5 ... Continuous annealing furnace 6 ... Cooling device 7 ... Shot blasting device 8 ... Steel strip grinding brush roll device 9 ... Grinding brush roll 10 ... Grinding brush roll 11 ... water play nozzle 12 ... C warp correction roll 13 ... sulfuric acid tank 14 ... nitric hydrofluoric acid tank 15 ... cleaning device 16 ... dryer 17 ... exit side looper 18 ... split shear 19 ... tension reel 20 ... grinding brush roll 21 ... grinding brush roll 22 ... Steel strip grinding brush roll device s ... Stainless steel strip

Claims (5)

Grinding brush roll devices are provided upstream and downstream of the steel strip pass line, the upstream grinding brush roll device is driven to rotate in the direction opposite to the steel strip traveling direction, and the downstream grinding brush roll device is disposed in the steel strip traveling direction. A steel strip grinding method, wherein the steel strip is rotationally driven in the same direction and at a speed faster than the steel strip travel speed. A grinding brush roll device is provided on the upstream side and downstream side of the steel strip pass line, the upstream grinding brush roll device is driven to rotate in the same direction as the steel strip traveling direction, and the downstream grinding brush roll device is connected to the steel strip traveling direction. A steel strip grinding method, wherein the steel strip is driven to rotate in the opposite direction. An upstream grinding brush roll that is driven to rotate in the direction opposite to the steel strip traveling direction in the steel strip pass line, and the steel strip traveling speed in the same direction as the steel strip traveling direction on the downstream side adjacent to the upstream grinding brush roll. A steel strip grinding machine comprising a downstream grinding brush roll that is driven to rotate at a faster speed. An upstream grinding brush roll that is rotationally driven in the same direction as the steel strip traveling direction in the steel strip pass line, and a downstream side that is rotationally driven in the direction opposite to the steel strip traveling direction on the downstream side adjacent to the upstream grinding brush roll A steel strip grinding apparatus characterized by comprising a grinding brush roll. The grinding brush roll is a pair of grinding brush rolls sandwiching the front and back surfaces of a steel strip traveling on a pass line, and the pair of grinding brush rolls are provided in at least two locations in the longitudinal direction of the pass line. The steel strip grinding apparatus according to claim 1 or 2.

Images