JPS635817A - Continuous descaling cold rolling mill - Google Patents

Abstract

PURPOSE:To make a pickling device compact, to eliminate intermediate handling, and to directly rolling a strip by installing a mechanically descaling device in which a hot rolled strip is rubbed by rolls having a speed different from a feed speed. CONSTITUTION:The surface of a hot rolled strip is rubber by lightly rolling rolls 7a, 7b having respective rotating speeds V1, V2 different from a feed speed (v) and is mechanically descaled in a cold lightly rolling descaling device 16. Therefore, the succeeding stage of a lightly pickling device 21 requires a mere liquid volume enough to descale a small amount of residual scales and the device 21 is made to be compact. A handling device for winding and rewinding is installed between the device 21 and a continuous cold rolling mill 22 in a conventional line, but it is not necessary to install the handling device because of the small pickling device. Thus, a directly continuous cold rolling work is performable.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention involves removing surface scale from a hot-rolled metal strip produced by hot rolling, and subjecting the scale-removed hot-rolled metal strip to cold rolling. The present invention relates to a continuous descaling cold rolling apparatus that continuously produces cold rolled metal strips.

[Prior Art] Conventionally, cold-rolled metal strips are produced by pickling and descaling hot-rolled metal strips that have scales on the surface due to hot rolling in an independent pickling treatment device. It was produced by cold rolling in a cold rolling machine.

In the conventional pickling process, cold light rolling is performed before pickling to crack the surface scale 11 of the hot rolled metal strip as shown in FIG. 10, and the acid solution is allowed to penetrate into the cracks 13 that have formed. Scale was removed by dissolving and peeling. However, since this pickling treatment removes scale in the pickling tank, the acid solution also dissolves the peeled off scale, and therefore requires large equipment with a large pickling tank that consumes a large amount of pickling solution. Ta.

In addition, since this conventional pickling treatment equipment is an independent facility, it has an input device that unwinds the hot-rolled metal strip formed into a coil, welds it with the preceding hot-rolled metal strip, and sends it out as a continuous hot-rolled metal strip. , is equipped with an exit device that cuts the hot-rolled metal strip after pickling treatment into the required length and winds it into a coil shape, and the conventional continuous cold rolling device is also uniquely equipped with the same method as the above-mentioned pickling treatment device. It was equipped with an inlet device and an outlet device.

Furthermore, the pickling treatment equipment and the continuous cold rolling equipment are each installed as separate equipment in a factory, in parallel or orthogonally,
Or they were placed apart due to some other arrangement.

[Problems to be Solved by the Invention] The present invention has been developed in view of the above-mentioned circumstances.1) In the conventional pickling treatment, the scale of the hot-rolled metal strip is dissolved in a pickling tank, and the scale dissolved in the acid is removed. The entire pickling process was a large piece of equipment because the washing liquid was regenerated outside the pickling tank and the pickling liquid was reused.

2) In addition, in the process of producing cold-rolled strip from hot-rolled metal strip, conventional equipment performs the operations of unwinding the coil and winding the coil twice, and then pickling and winding the strip. The productivity was low because the coils were being conveyed to the input side of the continuous cold rolling equipment, so we decided to combine the smaller pickling treatment equipment and the continuous cold rolling equipment to make them continuous, thereby increasing productivity. The object of the present invention is to provide a continuous descaling cold rolling device that has high productivity, is compact, has low construction and maintenance costs, and is easy to maintain.

[Slow measures to solve the problem] The present invention provides a rolling roll that rotates a hot-rolled metal strip on the surface of which scale produced by hot rolling is attached at a speed different from the feeding speed of the hot-rolled metal strip. a cold light rolling descaling device that mechanically removes scale from the hot rolled metal strip by scraping while cold rolling it;
A light pickling device that dissolves and removes a small amount of scale remaining on the surface of the hot rolled metal strip from which scale has been removed by the cold light rolling descaling device using a pickling solution; and a light pickling treatment using the light pickling device. A continuous cold rolling apparatus is provided for cold rolling the hot-rolled metal strip to a required thickness, thereby making it a continuous descaling cold rolling apparatus.

[Function] Therefore, in the present invention, the surface scale of the hot-rolled metal strip is cracked and destroyed by cold-light rolling without rubbing with rolling rolls using a cold-light rolling descaling device, and most of the surface scale is sheared. After mechanically removing and dissolving a small amount of scale remaining in a light pickling device, the hot rolled metal strip is cold rolled to a required thickness in a continuous cold rolling device,
Continuous production of cold rolled metal strip.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show one embodiment of the present invention.

The inlet coil handling device 5 includes two payoff reels 2 that alternately rewind a coiled hot rolled metal strip l, and a tip of the hot rolled metal strip 1 unwound from the payoff reels 2 and a preceding hot rolled metal strip. A welder 3 welds the rear end of the metal strip l at a fixed position to make it continuous, and a looper 4 for continuously feeding the hot rolled metal strip l to the downstream side even during welding work in the welder 3. It is configured.

The cold light rolling descaling device 1B, as shown in detail in FIG. As shown in FIG. 3, the hot rolled metal strip 1 is rubbed with a bride roll 6 that applies tension on the exit side and rubbed at different rotational speeds V l and V 2 for 2 to 3 seconds.
The scale 11 on the surface of the hot-rolled metal strip 1 as shown in FIG. 6 is cracked and sheared off as shown in FIGS. rolling rolls 7a and 7b for mechanically removing the scale; nozzles 7c for jetting water onto the surface of the hot rolled metal strip 1 on the upper and lower sides of the exposed side to wash off the scale removed as it cools; the upper and lower rolling rolls 7a; A rolling descaling device 7 equipped with a roll body surface correction device 7d for correcting the roll body surface of 7b, and a scale removed by the rolling descaling device 7 (
A nozzle 8a for washing the upper and lower surfaces of the hot-rolled metal strip 1 with water, a brush roll 8b, and a brush roll 8b to prevent the hot-rolled metal strip 1 from adhering to the hot-rolled metal strip 1 and being carried out (see FIG. 3), and squeezing out the water adhering to the surface. A cleaning device 8 is provided with a ringer roll 8d for cleaning, and a blower header 9a and an exhaust port 9b are provided for blowing and drying high-temperature air on the upper and lower surfaces of the hot-rolled metal strip 1 that has been cleaned by the cleaning device 8. a dryer 9, a rolling load control device 10a for setting the elongation of the hot-rolled metal strip l and crack failure of the surface scale 11 to predetermined values under the rolling load of the rolling descaling device 7, and a rolling load control device 10a for controlling the speed of the priddle roll 6 and the hot rolling The rolling rolls 7a, 7 of the rolling descaling device 7 in relation to the rubbing speed of the metal strip 1
A speed control device 10b that allows setting the speed, etc. of b.
It is made up of.

The light pickling device 21 is similar to the cold light rolling descaling device 16.
A short pickling tank 17 in which a small amount of scale 11 remaining on the hot rolled metal strip 1 from which most of the scale 11 has been removed is lightly pickled with a lightly concentrated pickling solution to dissolve and remove it; A water tank 1 for washing and neutralizing the pickling liquid adhering to the hot rolled metal strip 1.
8, a cleaning device 19 for washing with water the upper and lower surfaces of the hot-rolled metal strip 1 that has been washed and neutralized in the water tank, and a dryer that dries the upper and lower surfaces of the hot-rolled metal strip 1 that have been washed in the washing device 19. It consists of 20.

The continuous cold rolling device 22 cold-rolls the hot-rolled metal strip 1 from which the scale has been completely removed in the light pickling device 21 to a required thickness to form a continuous cold-rolled metal strip L. It consists of a series of tandem mills (four in the figure).

The exit coil handling device 25 includes a flying shear 23 that splits the continuous cold-rolled metal strip 1 cold-rolled in the continuous cold-rolling device 22 into required lengths by cutting the continuous cold-rolled metal strip 1 into required lengths; It is comprised of two tension reels 24 that alternately wind the cold-rolled metal strip divided into coils.

When operating the apparatus of the invention, in the inlet coil handling device 5, two payoff reels 2 alternately unwind the coiled hot-rolled metal strip 1. Thereafter, the empty payoff reel 2 is sequentially replenished with the coiled hot rolled metal strip l. The leading end of the rewound hot-rolled metal strip 1 is welded to the rear end of the preceding hot-rolled metal strip 1 by a welder 3 to make it continuous. looper 4
The hot rolled metal strip 1 is continuously fed to the downstream side even during welding work in the welder 3.

The hot rolled metal strip fed from the inlet coil handling device 5 is descaled by a cold light rolling descaling device. When performing a scale removal operation, first the hot rolled metal strip l unwound from the priddle roll 6
The water projected from the nozzle 7c of the rolling descaling device 7 is applied to the surface, and then the rolling load control device 10
As described above, the strip is cold rolled at a rolling load set to such an extent that the scale 11 cracks and breaks, as described above, and at the rubbing speed set by the speed control device Job, that is, hot rolling. A rolling roll 7a controlled to rotate at a speed different from that of the metal strip 1
and 7b and the speed of the hot-rolled metal strip l. As a result, the surface scale 11 of the hot rolled metal strip 1 is rubbed and removed as shown in FIG.

At this time, as shown in the figure, the speed of the rolling roll 7a is vl, the speed of the rolling roll 7b is v2, and the speed of the hot rolled metal strip l is υ, and the rolling roll 7a,
7b, for example, the rolling roll 7a is set to V,>υ
, the rolling roll 7b is set to v2<υ, the rubbing speed of the upper surface of the hot-rolled metal strip is ffl'U+-V+ -"U1, the rubbing speed of the lower surface of the hot-rolled metal strip 1 is A"U2-'U-Vz
, 1A"U+1-Lj"LJ21, and the directions of the rubbing forces acting on the upper and lower surfaces of the hot-rolled metal strip 1 are set in opposite directions, so that the upper surface rubbing force of the hot-rolled metal strip 1 F1-up heat Rubbing force on the lower surface of rolled metal strip l F2--u-p However, U
: Friction coefficient p: Rolling pressure If we consider that the friction coefficients of the upper and lower surfaces are equal, then Fl + F2-0 In other words, since the rubbing forces of the upper and lower surfaces are canceled out inside the hot rolled metal strip 1, the priddle roll 8 The load of rubbing force is less likely to be applied to the feeding device of the hot rolled metal strip roll 1 such as the above. Further, the rolling rolls 7a and 7b are worn out due to the above-mentioned rubbing, but since the roll body surfaces of the rolling rolls 7a and 7b are constantly polished and cleaned by the roll body surface correction device 7d during rolling, it is easy to remove scale. It will not cause any trouble.

In addition, in this apparatus, the hot rolled metal strip 1 is lightly rolled and rubbed as described above, so that the bending in the width direction of the hot rolled metal strip 1 and the unevenness on the surface can be eliminated by the light rolling, and the entire surface is in contact. In addition, the amount of polishing by rubbing can be set to the amount necessary for scale removal by adjusting the rotational speed of the rolling rolls 7a and 7b.

When rolling is performed with a speed difference between the rolling rolls and the hot-rolled metal strip 1 as described above, the scale is divided by fracture cracks and its surface is rubbed by the rolling rolls. Due to this rubbing, a frictional force based on the rolling pressure acts on the scale surface, the scale surface is ground, and internal cracks of the divided scale are sheared. During light rolling and rubbing, the state is as shown in FIG. 7, where 14 is a sheared part where scale is missing, and 15 is scale that has been sheared and adhered. If the amount of abrasion is small, the scale is removed after rolling by dividing, grinding, or shearing as shown in FIG. 8, and the scale remains on the surface of the hot rolled metal strip 1 depending on the degree of abrasion. If the amount of rubbing is large, the scale is removed and the surface of the hot rolled metal strip 1 is ground as shown in FIG. The hot-rolled metal strip l descaled by the rolling descaling device 7 then enters a cleaning device 8 where it is cleaned of dirt with a brush roll 8b while being sprayed with water from a nozzle 8a, and then the hot-rolled metal strip 1 is cleaned by water spray from the nozzle 8c,
Water adhering to the surface is squeezed and removed by the ringer roll 8d. The hot-rolled metal strip 1 leaving the cleaning device 8 is dried in a dryer 9 and then wound around a priddle roll 6.
It is sent to a light pickling device 21.

In the light pickling device 21, the hot-rolled metal strip l from which most of the scale 11 has been removed by the cold light rolling descaling device is introduced into a short pickling tank 17 containing a lightly concentrated pickling solution to remove a small amount of remaining scale. After dissolving and removing the hot-rolled metal strip l, the pickling liquid adhering to the hot-rolled metal strip l is washed with water to neutralize it in the water tank 18, and the upper and lower surfaces of the hot-rolled metal strip l are washed in the cleaning device 19 and dried in the dryer 20.

The hot-rolled metal strip 1 from which the scale has been completely removed in the light pickling device 21 is sent to the continuous cold-rolling device 22, where it is sequentially cold-rolled in a plurality of consecutive tandem mills to obtain a cold-rolled metal strip 1 of a required thickness. It is said that

The cold-rolled metal strip 1 that has been cold-rolled is sent to the exit coil handling device 25, where it is run-cut into required lengths by a flying shear 23, and the divided cold-rolled metal strip 1 is transferred to two tension reels 24. are wound alternately.

FIG. 4 shows another example of the rolling descaling device used in the present invention, in which the hot rolled metal strip l is rolled onto rolling rolls 7a and 7b.
The hot-rolled metal strip l is wound around the rolling roll 7a.
, 7b to perform light rolling while rubbing.

FIG. 5 shows still another example of the rolling descaling device 7 used in the present invention, in which rolling rolls 7a and 7b have different diameters.

It should be noted that the present invention is not limited to the above-mentioned embodiments,
Hot-rolled metal strips can be applied to various materials such as ordinary steel, steel, and non-ferrous metals that generate scales with similar properties. The length of the pickling tank and the concentration of the pickling solution can be changed depending on the nature of the scale, which varies depending on the method, etc., and the residual scale of the hot rolled metal strip in the cold light rolling descaling equipment in the previous process. Of course, the rolling rolls 7a and 7b can be moved in the axial direction, and various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As described above, the apparatus of the present invention can produce various excellent effects as described below.

(D) Light pickling equipment takes the strip with a small amount of residual scale after mechanically removing most of the scale into the pickling tank and dissolves and removes it with the pickling solution, so the pickling solution is not used. Only a small amount is required, and there is less pollution.

<n> Since the amount of pickling liquid used is small, the pink ring tank is short and the pickling liquid supply/drainage device, waste acid recovery device, etc.
The acid solution treatment equipment is small.

■ There is no coil handling device between the light pickling device and the continuous cold rolling device for winding and unwinding the strip.
Compared to conventional single pickling equipment or continuous cold rolling equipment, handling time is shorter and productivity is higher, and the equipment is also smaller.

■ Rolling descaling equipment can be handled using similar technology to rolling technology, and there are many devices and devices that can be used in common.

■ Because the equipment is small, construction and maintenance costs are low, and maintenance is easy.

It is possible to continuously produce cold-rolled metal strips directly from hot-rolled metal strips.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of a cold light rolling descaling device used in the present invention, Fig. 3 is an explanatory diagram of a state in which scale is removed, and Fig. 4 is an explanatory diagram of an embodiment of the present invention. The figure is an explanatory diagram when a hot rolled steel strip is wound around a rolling roll in an S-shape in the rolling descaling device used in the present invention, and Figure 5 shows the diameter of the upper and lower rolling rolls in the rolling descaling device used in the present invention. Fig. 6 is a state diagram of a scaled strip before rolling, and Fig. 7 is a diagram of a descaling state during rubbing by a rolling roll during cold light rolling using the apparatus of the present invention. , Fig. 8 is a state diagram of the residual scale of a strip with a small amount of abrasion by the rolls in the apparatus of the present invention, Fig. 9 is a state diagram of the strip with a large amount of abrasion by the rolls in the apparatus of the present invention, and Fig. 10 is a state diagram of the strip when the amount of abrasion by the rolls is large in the apparatus of the present invention. FIG. 2 is a state diagram of a scale after light cold rolling by a conventional device. In the figure, 1 is a hot-rolled metal strip, 2 is a payoff reel, and 3 is a hot-rolled metal strip.
is a welder, 4 is a looper, 5 is an inlet coil handling device, 7 is a rolling descaling device, 8 is a cleaning device, 9
is a dryer, 16 is a cold light rolling descaling device, 17
is the pickling tank, 18 is the water tank, 19 is
is a cleaning device, 20 is a dryer, 21 is a light pickling device, 2
2 is a continuous cold rolling device, 23 is a flying shear, 24
2 is a tension reel, and 25 is an exit coil handling device.

Claims (1)

[Claims] 1) A hot-rolled metal strip on which scale generated by hot rolling has adhered to its surface is rubbed while being lightly cold-rolled by a roll that rotates at a speed different from the feeding speed of the hot-rolled metal strip. A cold light rolling descaling device that mechanically removes scale from the strip, and a pickling solution to dissolve a small amount of scale remaining on the surface of the hot rolled metal strip from which scale has been removed by the cold light rolling descaling device. A continuous de-pickling device characterized in that it is provided with a light pickling device for removing the metal, and a continuous cold rolling device for cold rolling the hot-rolled metal strip subjected to the light pickling treatment in the light pickling device to a required thickness. Scale cold rolling equipment.