JPS62156051A - Production of twin roll type rapid cooled thin hoop metal - Google Patents

Abstract

PURPOSE:To uniformize thin hoop width by settling a rolling reduction force standards at a driving side and an operating side for free cooling rolls and correcting the reduction forces based on difference with the actual reduction forces and detecting values of the roll gap. CONSTITUTION:Corresponding to driving and operating chocks 8A, 8B for the free cooling rolls 2, oil pressure sensors 22A, 22B are arranged respectively and also sensors 14A, 14B, which detect the roll gaps l1, l2 for the driving side and operating side, are arranged. A standard rolling reduction force settler 17 settles the standard reduction force P0 and outputs the standard reduction forces P01, P02 for the driving side and the operating side respectively. Based on the deviations between actual reduction forces P1S, P2S measured by the sensors 22A, 22B, and the standard reduction forces and the detected values of roll gaps l1, l2, an arithmetic device 20A, 20B calculate reduction forces to correct, to execute rolling reduction control. As a solidification at width direction is uniformized, width of the thin hoop metal is uniformized.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention provides a twin-roll type quenched metal ribbon that can stably obtain a predetermined width over the entire length of the ribbon, even if the ribbon is wide. The present invention relates to a manufacturing method.

(Prior Art) One of the methods for obtaining an amorphous or crystalline metal ribbon by pouring molten metal onto the surface of a cooling body and forcing the molten metal to rapidly solidify is the twin-roll quenched ribbon manufacturing method.

In this twin-roll quenched ribbon manufacturing method, there are three forms of solidification at the roll scratched portion, as shown in FIGS. 2A to 2C. In the place shown in the figure, molten metal 3 is continuously poured from above into the scratched part of the cooling roll 1.2 rotating in the direction of the arrow, and while this molten metal 3 passes through the kiss part, it is rapidly cooled and becomes thin. The strip 4 is taken out from below. In FIG. 2A, the solidification completion point is above the roll scratched area, and the ribbon 4 undergoes hot deformation at the roll scratched area, so a high rolling force is required (hereinafter referred to as rolling die). In Figure B, since the solidification completion point coincides with the roll scratched part, it can be manufactured with a light rolling force (hereinafter referred to as the "kiss point solidification completion type"). In Figure C, the solidification completion point is below the roll scratched portion, and unsolidified molten metal remains inside the ribbon 4, so breakout occurs and the ribbon does not become a ribbon (hereinafter referred to as unsolidified type).

Among the above three solidification forms, the kiss point solidification completion point type shown in FIG. 2B is the most appropriate, and it is important to maintain this solidification form throughout the width of the ribbon.

However, in the past, screws or springs were used to lower the cooling roll, and the gap between the rolls was preset before casting, so it was extremely difficult to stably maintain the kiss point solidification completed type. .

In this regard, as a solution to the above problem, JP-A-58-
No. 23543 discloses a method of controlling the rolling force to a cooling roll at a constant level using a device as shown in FIG. was suggested.

(Problems to be Solved by the Invention) However, even if the roll gap is controlled at a constant level according to the above method, offsets due to mill rigidity, roll chock sliding, resistance, etc. cannot be avoided. As shown in the figure, the solidification form differs in each cross section in the width direction, and it was almost impossible to stably maintain the kiss point solidification completed type. In other words, "+M c" in FIG.
In the cross section of -c, the solidified form was an unsolidified type as shown in Figure 2C, so the unsolidified portion broke out and scattered just below the roll scratch, forming a narrow ribbon. .

This invention advantageously solves the above-mentioned problems, and can maintain the solidification form of the molten metal uniformly and appropriately in the width direction. The purpose of this paper is to propose a method for manufacturing quenched ribbon that can ensure the width of the sheet.

(Means for Solving the Problems) That is, the present invention aims to direct the molten metal toward the roll scratched portion of a pair of cooling rolls consisting of a fixed roll and a free roll disposed so as to be able to approach and separate from the fixed roll, through its supply nozzle. When manufacturing a thin metal strip by continuously supplying the material from the cooling roll and rapidly solidifying it, the rolling force on the drive side and the operating side of the free cooling roll is adjusted between the cooling rolls with a preset standard rolling direction as the center. The roll gap is increased or decreased based on the amount of change in the roll gap on the driving side and the operating side, and the rolling force correction amount obtained from the difference between the reference rolling force 172 and the actual rolling force on the driving side or the operating side. This is a method for producing twin-roll quenched metal ribbon.

This invention will be specifically explained below in comparison with a conventional method.

In the ribbon manufacturing apparatus using the hydraulic reduction method shown in FIG. A cooling roll 2 is provided, and a sliding chock (provided on the drive side and the operation side respectively)
The structure is such that the back pressure of 8 is applied by hydraulic cylinders 5 (provided on both sides corresponding to each sliding chock) to apply a downward force. A melting furnace 10 is placed above the kiss portion 9 of each roll rotating in the directions of arrows X and Y.
A molten metal stream 12 is continuously supplied from the nozzle 11, rapidly solidified at the roll scratched portion 9, and taken out as a ribbon 13 from below.

Even with such twin rolls using the hydraulic pressure reduction method, as shown in Fig. 4, the generation of heat crown, the difference in the chock sliding resistance between the driving side and the operating side, and the flow rate distribution in the width direction will occur in the production of wide ribbons, as shown in Figure 4. As mentioned above, it is not possible to create a uniform rolled state in the width direction due to non-uniformity.

The feature of this invention is that in order to keep the roll gaps on the driving side and the operating side constant, the amount of change in each roll gap amount and the difference between the standard rolling force of 172 and the measured rolling force on either the driving side or the operating side are The purpose is to control the rolling force around the reference rolling force by adding or reducing a rolling force correction amount proportional to each of them.

Based on the circuit diagram shown in FIG. 1, a specific method for controlling the rolling force according to the present invention will be described.

In FIG. 1, a free cooling roll 2 is rolled down against a fixed cooling roll 1 supported by a drive side chock 7A and an operating side chock 7B, and the molten metal is rapidly solidified at the kissing part 9 of both rolls, thereby producing a ribbon 13. be done.

The free cooling roll 2 is supported by a slidable drive side chock 8A and an operation side chock 8B so as to be able to approach and leave the fixed cooling roll 1, and is lowered onto the fixed roll 1 by hydraulic cylinders 5A and 5B that press each chock. . The free cooling roll 2 is provided with a roll gap sensor 14A that detects the drive side roll gap 1 of the roll, and a roll gap sensor 14B that detects the operation side roll gap 12 of the roll.

On the driving side, among these detection signals, the operating side initial roll gap 102 and the driving side roll gap detection signal I
! , the difference Δ1. =Il, -7! . 2-・(1
) is calculated by the comparator 15A.

Reference numeral 17 is a reference pressure reduction force setter, and the reference pressure reduction force P on the drive side is outputted from this setting device 17. I and the standard pressure reduction force P on the operating side. 2 is output. This P. I and P. 2 is set in advance, and is the standard pressure reduction force P0 and drive side and operation side roll chocks necessary to maintain the solidification form of the kissing point solidification completion type shown in FIG. It is calculated by the following formula based on the sliding resistance F and F2.

Pa=P61 +Poz=A-匈+p++pz
(2) Here, W is the width of the ribbon, and A is the rolling force per unit width necessary to bring the solidification completion point to the appropriate position. Note that the rolling force A per unit width is A = f (
R, E, υ, σ), which is a function of the roll radius R, the Young's modulus E of the roll material, the Poisson's ratio υ, and the deformation resistance σ of the ribbon.

On the other hand, the hydraulic pressure sensors 22A and 22B detect the operating reaction forces, ie, the lowering forces put and P, of the hydraulic cylinders 5A and 5B on the driving and operating sides. is measured.

Difference between the lower half of the reference pressure and the detection signal PZg of the hydraulic pressure sensor on the operating side Δ-2·-P2. ...(3) is calculated by the comparator 15B.

The calculation units 2OA and 20B on the drive side and the operation side are provided with the roll gap change amount Δll""l -102, the load change amount Δ-2"-PZg, and each reference rolling force p.
H1tPOZ is input, and the following calculation is performed to obtain the corrected reduction force setting value Pl+P2.

P+=Po++ΔP, ---(4)
Pz=Poz+ΔPz River (s
lΔP+=Kr+ΔI! l-(6)
ΔP2 knee K PgΔ-2-(7) where ΔP1: Increase/decrease in the reduction force on the driving side ΔP2: Increase/decrease in the reduction force on the operating side Based on the output results of the respective calculators 20A, B, each servo valve 21A, 21B is operated to correct the pressure reduction force setting values p, , p of each hydraulic cylinder 5A, 5B on the drive side and operation side.

It is adjusted to It goes without saying that even if the driving side and the operating side are reversed to the above-mentioned arrangement, the rolling force can be controlled in the same manner.

(Example) Roll diameter 500mm, roll circumferential speed 5n+/s, ribbon material 4.5wtX5i-Fe, manufacturing conditions of ribbon medium 300111I11, rolling reduction rate per unit width A・2kg/arm, gap-rolling force conversion coefficient A control condition of B-10ks/μm was adopted, and a comparative experiment was conducted among three cases: a conventional constant rolling force, a constant rolling force difference control, and a case where the present invention was applied.

FIG. 5 is a graph showing the conventional case of constant pressure reduction, FIG. 6 is a graph showing the case of constant pressure difference control, and FIG. 7 is a graph showing the results when the present invention is applied.

In each drawing, the horizontal axis indicates time from the start of casting in seconds, while the linear axis indicates rolling force (tons) and roll gap (μm). In the figure, curve p shows the rolling force on the driving side, curve P2 shows the rolling force on the operating side, curve 11 shows the roll gap on the driving side, and curve 12 shows the roll gap on the operating side.

In the case of conventional constant pressure reduction, as is clear from Figure 5,
The roll gap difference between the drive side and the operation side was increased early after the start of casting, and a ribbon with a predetermined width of 300 mm was obtained only for a limited time at the beginning.

On the other hand, when constant pressure difference control is performed to zero the difference in the pressure force of the hydraulic cylinders, as shown in Figure 6, although the roll gap difference is smaller than when the pressure is constant, the offset that occurs initially is A roll gap difference of 100 to 200 μm often occurs without being resolved. In this case, the edge part where the roll gap is open is C-C shown in Figure 4.
As in the cross section, breakouts occur, and the edges of the fabricated ribbons are severely oxidized, causing breakout cracks in some cases.

On the other hand, when this invention is applied, as is clear from Fig. 7, although a roll gear difference similarly occurs after the start of casting, the rolling reduction distribution on the drive side and operation side is changed accordingly, and the gap difference is By controlling the process in the direction of eliminating this, it was possible to maintain a uniform and appropriate coagulation form in the width direction, and it was possible to continuously produce thin strips of a predetermined width.

(Effects of the Invention) Thus, according to the present invention, it is possible to maintain a uniform and appropriate solidified form in the middle direction, and it is possible to continuously and stably manufacture a ribbon of a predetermined width.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a control system for carrying out the twin-roll quenched ribbon manufacturing method of the present invention, and FIGS. 2A, B, and C are cross-sectional views showing the solidification form at roll scratches, respectively. Figure 3 is a side view of a twin-roll quenched ribbon manufacturing device that uses the hydraulic reduction method. Figure 4 is an explanatory diagram illustrating a state in which there is a difference in the roll gap on the drive side and operation side. Figure 5 is a constant view. A graph illustrating roll gap changes on the driving side and operating side in the case of rolling force, FIG. 6 is a graph illustrating constant rolling force difference control to make the rolling force difference zero, and FIG. 7 is a case where the present invention is applied. This is a graph showing. 1...Fixed cooling roll 2...Free cooling roll 3
... Molten metal 4 ... Thin strip 5A, 5B.
...Hydraulic cylinder 6...Housing 7A, 7B...
・Chock 8A, 8B...Sliding chock 9・
... Roll scratched part 10 ... Melting furnace 11 ... Nozzle 12 ... Molten metal flow 13 ... Thin strips 14A, 14B ... Roll gap sensor 15A
...Gap difference calculator 15B...Load difference calculator 17...Reference reduction force setting device 20A, B...Reduction force correction value calculator 22A, B.
...Load cell II...Drive side roll gap amount 12...Operation side roll gap amount P1...Drive side rolling force P2...Operation side rolling force P
0...Reference pressure reduction force

Claims (1)

[Claims] 1. Continuously supplying molten metal from a supply nozzle toward the roll scratched portion of a pair of cooling rolls consisting of a fixed roll and a free roll arranged so as to be able to approach and separate from the fixed roll, When producing a metal ribbon by rapid solidification, the rolling force on the driving side and the operating side of the free cooling roll is set at the center of the preset reference rolling force, respectively on the driving side and the operating side between the cooling rolls. The twin rolls are increased or decreased based on the amount of change in the roll gap and the amount of correction for the rolling force obtained from the difference between 1/2 of the reference rolling force and the actual rolling force on the driving side or the operating side. A method for manufacturing a quenched metal ribbon.