JPS6340628B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an amorphous alloy ribbon.

The liquid quenching method is being researched as a method for manufacturing amorphous alloy ribbons. In particular, the single roll method is considered suitable for mass production. This is characterized by rapidly cooling the molten metal by pouring it through a narrow slit, usually about 1 mm or less, onto a cooling surface that is moving at high speed.

Certain amorphous alloys have excellent electromagnetic properties and are therefore expected to be used as iron core materials for power transformers. For that, 150
It has a width of about mm or more and must be produced in large quantities at low cost.

Currently, in the case of the most promising Fe-B-Si-C alloy, the manufacturing conditions are as follows:
sec, the optimum plate thickness is 25 to 30 μm, and the specific gravity is about 7.2 g/cm ³ , so assuming a width of 150 mm, the hot water supply rate is about 50 kg/min. The melting point is approximately 1200℃. In the steel industry that handles high-temperature molten metal (especially in continuous casting), the normal water supply rate is 200 to 300 t/h ≒ 3 to 5 t/h.
This is about two orders of magnitude smaller than the average time of 20 minutes.
For this reason, difficult elements remain in the flow control system and temperature control system. Since the optimum temperature is relatively close to the melting point, the disadvantage of being easily cooled and hardened has been highlighted.

A detailed explanation will be given based on FIG. 1, which is based on the continuous casting method of steel. In this method, hot water is supplied from a melting furnace or a ladle 1 to a nozzle tundish 4 via an intermediate tundish 3 provided with a stopper 2 (sliding nozzle in some cases) for flow rate control.
Molten metal A is injected from nozzle 5 of nozzle tundish 4 onto cooling roll 7 to produce ribbon B. In this case, the hot water supply port of the intermediate tundish 3 has a diameter of 10 to 15, and clogging occurs frequently before the flow rate can be controlled by the stopper 2, making production impossible. In order to minimize the amount of remaining hot water at the end of pouring, the nozzle tundish 4 must also have a small capacity. It was also almost impossible to maintain the molten metal level in the housing 4 within the required range of about ±5 mm. 6 is an opening/closing stopper.

The present inventor has come to invent a new hot water supply system that overcomes future problems. A siphon connected to a low pressure tank is disposed between the intermediate tundish and the intermediate tundish into which molten metal is poured, and the molten metal in the intermediate tundish is supplied to the nozzle tundish through the siphon, and the molten metal is spouted onto the cooling roll. A method of manufacturing an amorphous alloy ribbon is characterized by the following.

The present invention will be explained in detail below with reference to the drawings.

In FIG. 2, the nozzle tundish 24 is
Then, the intermediate tundish 23 is filled with a sufficient amount of molten metal A' from the ladle 21 for the subsequent operation, and the liquid level in the intermediate tundish 23 is maintained at a position where the required head in the nozzle tundish 24 can be provided. ,
Put the refractory siphon 29 into both liquid levels,
The interior of the siphon is connected to a constant pressure vacuum tank (not shown) to rapidly reduce and maintain a predetermined constant pressure, thereby communicating the molten metal between both tundishes. Nozzle tundish 24
After the liquid level in both tundishes settles to the same level after a period of time determined by the capacity and siphon capacity, the opening/closing stopper 26 in the nozzle tundish 24 is opened, and the cooling roll 2 is released from the nozzle 25.
7, and the thin ribbon B' is produced. As production progresses, or melting furnace or ladle 2
When the liquid level in the intermediate tundish 23 changes due to the supply of hot water from the intermediate tundish 23, the intermediate tundish 23 is raised and lowered by the lifting device 28 to maintain the liquid level at a predetermined position.

As described above in detail, according to the hot water supply method of the present invention, the liquid level between the intermediate tundish and the nozzle tundish can be extremely reduced, for example, from 500 mm in the conventional method to within 5 mm in the siphon method of the present invention, that is, 1 /
Since it can be reduced to 100, the connection part (siphon)
The flow velocity becomes 1/10, and the inner diameter becomes √10≒
In addition to being able to increase the amount by three times, it also eliminates the need for a stopper midway, which has the effect of completely eliminating the inability to start pouring due to nozzle clogging, which frequently occurred in the conventional method.

Example: In continuous production of 3 tons (about 1 hour) of FeBSiC amorphous thin strip width 150 mm and thickness 25 μm, the cooling roll (1000φ×200W made of water-cooled copper alloy) was rotated at a circumferential speed of 25 mm.
m/sec, nozzle slit 0.6mm x 150mm, nozzle tundish capacity 50Kg (200φ x 300h), intermediate tundish capacity 500Kg (700φ x 300h), and siphon inner diameter 50φ (made of fused silica), it can be manufactured without any problems. Ta.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional schematic diagram of a conventional amorphous alloy ribbon manufacturing apparatus, and FIG. 2 is a partial cross-sectional schematic diagram of an apparatus for implementing the present invention.

Claims (1)

[Scope of Claims] 1. A siphon connected to a low pressure tank is disposed between a nozzle tundish provided close to the cooling roll and an intermediate tundish into which melt is poured from a melting furnace or ladle. A method for producing an amorphous alloy ribbon, characterized in that the molten metal in the tundish is supplied to the nozzle tundish through the siphon and the molten metal is injected onto the cooling roll. 2. The method according to item 1, wherein the intermediate tundish is movable up and down to adjust the height of the hot water level in the intermediate tundish.