JPS5947011A - Descaling method of steel strip - Google Patents

Abstract

PURPOSE:To descale a steel strip with min. energy and good efficiency by measuring the degree of descaling between a liquid honing device and a pickling tank, controlling the degree of descaling in the liquid honing to be constant and controlling the traveling speed of the steel strip in the pickling tank from the measured value thereof. CONSTITUTION:A detector 16 for degree of descaling is provided between a liquid honing device 7 and a pickling tank 8. Said detector measures the degree of descaling on the surface of a steel strip 1A by liquid honing and outputs the measurement signal to a discrimination device 18 for degree of descaling. The device 18 compares the degree of descaling with a set value, and outputs the result of the discrimination to a control device 17, from which a control signal is oututted to a setter 19 for honing conditions thereby controlling the degree of scaling by the device 7 to be constant. The device 17 outputs further the control signal to line speed setters 20, 21 in accordance with the signal of the device 18 to drive and control bridle rolls 12, 13 on the inlet and outlet sides of the descaling lines with motors 12A, 12B, so that the immersion time of the strip 1A in the tank 8 is controlled to a prescribed value.

Description

[Detailed Description of the Invention] This optical space 1. This invention relates to the improvement of the t (11 Hiiragi's removal/7-rule f) method for removing scales colored by fq on the surface of 1L steel strip.

Rolled in 9'! , : The surface of Noritai (2 (Jl, one of the Nobility 1 or a mark! Zo is Ranchi ((2)) This Ω9 oxidized skin 11Q (the mechanical and chemical properties are different from the steel strip ↑4 and the color is r4, so this is removed.
J straw, it has to be descaled.

One of the methods for this descaling is the descaling line, in which the surface of the copper strip that is continuously fed is subjected to small-Jung processing using a liquid honing device, and then passed through a pickling tank to be pickled. be.

As shown in FIG. Next, reject the defective part of J, and then connect J3 to soil router b and connect it with the first plate to form a continuous tM ni' I A, and pass through the entrance louver No. 6 (, Kl one honing device 7 and M' first +98<8△, 813), J,
Rinarullf? Scale 17- (remove the scale covering the surface of steel strip 1△, nsx scale), wash tank 9 odor ('?'l Gi ¥ + L, 1~Lier 10 After being finished, it is wound onto the tension reel 11 and sent to the next process.
2. 13 and -14 received Bril~Roll, and 15 received exit side Shi■-, respectively.

The liquid honing device 7 in the descaling device includes:
For example, (a wet shot method in which an abrasive material such as J iron sand is blown onto the surface of a steel strip 1△ together with a liquid at high pressure) is generally used. There is.

Further, the pickling tank 8 is operated by the liquid honing device 7 by immersing the steel strip 1A in an acidic liquid such as hydrochloric acid.
This method chemically dissolves and removes the remaining scale that has been mechanically removed.

In such a descaling method, it is important to balance the ratio of mechanical descaling by the liquid honing device 7 and chemical descaling in the pickling tank 8. This has a significant impact on whether or not the processing capacity, quality, and cost of the equipment can be optimized. The descaling ratio and the required time for descaling in tank 8 were determined based on data classified according to the material, dimensions, etc. of steel strip 1A.

For example, if 100% descaling is performed using the liquid honing device 7, the power consumption will be excessive, the roughness of the surface of the steel strip 1A will increase, and the abrasive material such as iron sand will be removed from the steel strip 1A. Since it may partially dig into the scalp, it is said that the descaling rate by the liquid honing device 7 is preferably 70 to 80%. Therefore, the remaining 30 to 20% of the scale was removed chemically using hydrochloric acid or the like in the pickling tank 8.

However, if complete descaling is aimed at using the conventional method described above, it is necessary to provide sufficient descaling capacity in the pickling tank 8, to reduce the processing speed of the pickling tank 8, or to reduce the processing speed of the liquid honing device 7. This necessitates countermeasures such as setting the injection conditions (pressure, flow rate) to the excessive side (one tax scale rate too high), and there is a problem that the throughput, quality, and cost of the scale line cannot be maximized.

Moreover, even with this method, it is not always possible to achieve complete descaling.

This invention was made in view of the above-mentioned conventional problems, and it is possible to optimize the performance, quality, and performance of the descaling line, and to achieve perfect scale. The purpose of this invention is to provide a method for descaling copper strips.

This invention provides a method for descaling a copper strip in which the surface of a continuously fed copper strip is subjected to 1J1-Jung processing using a liquid honing device, and then passed through a pickling tank to be subjected to a -C pickling treatment.
IBJ on the surface of the copper strip after liquid honing and before pickling
Measure the degree of scale, and based on this measurement value, feedback control the liquid honing projection pressure etc. so that the degree of descaling by the liquid honing device is a constant value, and based on the measurement 1iQ, Objective 1 above is achieved by calculating the required immersion time of the steel strip in the pickling tank for complete descaling and controlling the strip passing speed so that the required immersion time is 1.7 times. .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for carrying out the copper strip descaling method according to the present invention will be described below with reference to the drawings.

Here, regarding the apparatus for carrying out the method according to the present invention shown in FIG. The explanation of the same reference numerals will be omitted.

In this embodiment, as shown in FIG. 2, the surface of a continuously fed steel strip 1Δ is honed by a liquid honing device 7, and then a steel strip 1A is passed through a pickling tank 8 for pickling treatment. In an apparatus for carrying out a descaling method,
After the liquid honing process and before the pickling process, the degree of descaling on the surface of the steel strip 1A is measured by the descaling degree detector 16, and based on this measured value, the degree of descaling by the liquid honing device 7 becomes a constant value. In this way, the liquid honing projection pressure, etc. is feedback-controlled via the control device 17, and based on the measured value, +tjl is added to the a9 washing tank 8 for complete descaling via the control device 17.
The required immersion time for the steel strip 1A is determined, and the threading speed is controlled so as to obtain the required immersion time.

Descaling 1. The lt detector 16 projects a ray light, which is used in surface angle 1 objects, etc., onto the surface of the steel strip, measures the intensity of the reflected light, and calculates the degree of the intensity ( Specifically, it consists of a measuring device that continuously measures the degree of descaling based on the ratio of the black remaining area of the scale on the surface of the strip 1A to the area of the removed portion, and sends the measurement signal to the descaling degree determiner 18. This is what is output.

This descaling degree determiner 18 is set in advance to a predetermined degree of descaling, and the signal from the C1 descaling degree detector 16 indicates that the scale on the surface of the steel strip 1A is determined by the liquid honing device @7 at a predetermined rate. - (determines whether or not descaling has been performed and outputs the determination result to the control device 17).

This control device 17 controls the liquid honing condition setting device '1 based on the output signal from the descaling degree determination device 18.
A signal is output to (,), and there is a certain amount of leakage so that the degree of descaling by the liquid honing device 7 is constant (direct).

Furthermore, based on the signal from the descaling degree determiner 1B, the control device i7+j controls the descaling line inlet and outlet priddles 12 and 13 for driving the priddles 12 and 13. 12A and 13△ are outputted as control signals to the control line speed setter 20.21, thereby controlling the threading speed of the steel strip 1A in the pickling tank 8, and increasing the speed of the steel strip 1△. This is to ensure that the immersion time in the pickling tank 8 is the required value.

This required value is such that the sum of the descaling rate by the liquid honing device 7 and the descaling degree in the pickling tank 8 is 100%.

Next, the function of the above-mentioned descaling line will be explained.

Now, let us consider the case where the descaling line is operated with the goal of complete descaling, with the degree of mechanical descaling by the liquid honing device 7 being 80% and the degree of descaling in the pickling tank 8 being 20%.

Even if the liquid honing device 7 is operated with the descaling rate set to 80% in advance, the scale composition of the steel strip 1A will vary between needle coils or within the same coil even if the manufacturing conditions are the same. There are also changes between the longitudinal directions, so
Even if conditions such as energy and other factors remain unchanged in the liquid honing device 7, the degree of scale changes.

For example, in the case of scale composition a as shown in Fig. 3, even if j descaling rate is 80%, scale composition a
', the descaling rate will be less than 8096.

Therefore, the liquid honing device 7 when the scale composition is a
Nomix Scale I Nell-f-b (K W
l-1,' ]112) Even if the scale composition is a
', the descaling energy, specifically 4.16
71'+? The projection pressure angle of material A must be increased so that the descaling energy becomes 1).

Here, the pitch q dimension 1 channel X = -N (K ~ 1.
/102 ) (-th -13/2 -'V (H:
There is a relationship compared to the pressure (1): speed of the plate).

The scale composition changed from a to a' (this decrease in the descaling rate was determined by the descaling leak detector 16). The liquid honing device 7 continuously measures the area ratio of the remaining area to the removed portion, and uses the liquid honing device 7
If the degree of descaling is too low, a signal is output to the liquid honing condition setting device 19 via the control device 17 to increase the projection pressure of the liquid honing device 7 to increase the descaling rate. As a result, feedback control is performed so that the descaling rate by the liquid honing device 7 remains constant.

At this time, the steel strip IA (where the degree of descaling is determined to be too low by the descaling degree determiner 18) is controlled by the control device 17 to The speed of the steel strip 1A passing through the washing tank 8 is determined based on the required descaling degree known in advance as shown in FIG. 4, the pickling time d3 and the acidic liquid 11i.
From the relationship with 1 degree, the chemical 1j; 2 scale achieved by pickling 118 and the mechanical descaling degree in the liquid honing device 7 will be 100%.'' I can't help but notice the degree of descaling.

Therefore, due to the feedback, the liquid honing device 7
According to (the steel strip 1 passed through the liquid honing excess 7 during the transition period when the geometric 1 yen scale degree returns to 8096)
Even if there is one in A, chemical descaling is performed in the pickling tank 8 so that only scale remains.

By continuously performing the above control, this invention can reduce the amount of steel due to excessive liquid honing! T! It is possible to continuously prevent the deterioration of surface quality and the occurrence of disturbances caused by insufficient liquid flow, and to skewer steel plates with stable surface quality.

Here, let us compare the descaling energy between the +η method and the method of the present invention.'' Conventionally, when aiming for a complete 1-eight scale, it was necessary to By keeping the value on the J3 scale constant in the device, and keeping the pickling speed lower than the theoretical rate,
In addition to this, there is a provision for when the degree of descaling by the liquid honing device is low 1; (for example, 1 in Figure 3)'〉
There may be cases where it gets stuck.

The latter method is common, and when comparing this method with the method of the present invention, in the conventional latter method, 43
The energy projected by the liquid honing device must be kept at a constant value b - over the entire range of the coil.
In the case of the method of the present invention, only 1/41' of both ends in the longitudinal force direction of the coil are descaled, and in the central 1./2 length range, the descaling energy key is Therefore, the method of the present invention can reduce -C' and IIR scale energy by about 10% compared to the conventional method.

In the above embodiment, the degree of descaling applied to the liquid honing device 7 is controlled by reducing the projected energy of the honing (A), but the present invention Although the invention is not limited to this, the invention is not limited to this, but it is possible to use a liquid 1-229 Article 1![il, II] such that the liquid hornink technique order 7 is 1 yen scale key or constant. b O) Te-that (, f well, child (, example (Jl,; Iitai 11 ＼-ning 7 in the 1ilt sweep q' earth channel 1'-1 constant doji(,
The liquid・1\-Jung Station 1ffi 7 Ni a3 Kel 1
1'l'! f! ”I A (1) 通（k speeda @
J'li decrease c: t! It is also possible to do something like this. Father above fruit 1! ! For example, the controller ζ6 may be the controller fi '171.

The present invention achieves complete 114 C of steel strip as shown in F.
j;2 scale? Therefore, it is said that high-quality steel strips with low X, IsL, and iq values are too high.

[Brief explanation of drawings]

Figure '1 shows the 11;2/7-run-in of the conventional steel plate. Figure 3 shows the relationship between (13 x 11; 3 scale - t' and 1 grind scale upper energy) in the liquid honing device. Figure 4 shows 1 in the pickling tank.
00% descaling ■, 1, pickling time and hydrochloric acid solution 11i
This is a line diagram that shows the relationship with 1 degree. 1Δ... Steel strip, 7... Liquid honing device, 8... Pickling tank, 16... Descaling degree detector, 17... Control device, 1B... Descaling degree determiner , 19...Liquid honing condition setting device, 20.21...
・Line and speed setting device. Agent Keisuke Matsuyama (1 person) Fig. 1 8 Le 2 (”<1 Fig. 3 (%) Monthly scale 27 ru 6-(KwH/汀-)ri・4 fig. H(J ('/, 1

Claims (1)

[Claims] (1) The surface of the continuously fed steel strip is subjected to a small-Jung processing process in a Honinking machine, and then passed through a pickling process to remove pickling ash. , 15 (,
Liquid honing IJI 11 - Post-pickling treatment] Before the first step, measure the degree of scale according to Table 1111, and based on this measurement, the degree of scale in the δ body small-nick device is constant. Based on the measuring head, the person who controls the liquid 1, small-throwing, throwing 1-Y force, etc., is placed in the pickling tank for complete descaling, so that the (Determine the soaking time for the steel strip, and control the threading speed so that the required soaking time is reduced.)
Descaling method for Sudori steel strip.