JPS60108143A - Production of quenched thin metallic strip by single roll method - Google Patents

Abstract

PURPOSE:To minimize stagnating time and to eliminate additional heating in production of a quenched thin strip using a nozzle for diagonal upward ejection by determining the diameter and length of a conduit and a head from the pouring rate in a unit time and the permissible stagnating time of a molten metal and making the head in an intermediate tundish less than a specific rate for the total head. CONSTITUTION:The molten metal M in an intermediate vessel 2 is ejected through an inclined conduit 3 from a diagonal upward nozzle 4 to a water-cooled revolving roll 6 and is made into a quenched thin strip S which is coiled on a coiler 7. The permissible stagnating time of the molten metal in the device is determined from the required pouring rate in a unit time and the min. ejection temp. of the molten metal and the diameter (d) and length (l) of the conduit and a total head H are determined. The molten metal head in an intermediate vessel 2 in this stage is made about <=1/5 the total head H. If the molten metal is ejected from the nozzle 4 under such conditions, the need for a heater to be provided on the outside circumference of the conduit is eliminated and the device is made simple.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a rapidly solidified metal ribbon using a single roll method.

(Prior Art) A method for producing a rapidly cooled metal ribbon with excellent material properties by jetting molten metal from a nozzle onto the surface of a cooling roll rotating at high speed is known.

However, in conventional manufacturing methods, when the molten metal in the container is jetted from the nozzle onto the roll surface from above, for example, Japanese Patent Laid-Open No. 57-85657 and Japanese Patent Laid-Open No. 58-16761 [ As stated in this
A method is adopted in which molten metal is jetted from a nozzle with an opening narrowed down to the bottom of the container, while adjusting the pressure inside the container or the molten metal level.If the molten metal is jetted from the side onto the roll surface, for example, As described in Japanese Patent No. 58-29555, a conduit is connected to the opening at the bottom of the container.

A method was adopted in which molten metal was jetted out from a slit nozzle provided at the tip of the conduit.

In the conventional method described above, in order to maintain a constant nozzle back pressure in order to maintain a constant molten metal ejection speed from the nozzle, the pressure inside the molten metal container is adjusted by increasing or decreasing the pressure. The rate of ejection from the molten metal container was adjusted, or the amount of molten metal supplied to the molten metal container was adjusted so that the level of molten metal in the container remained constant.

However, the method of regulating the pressure inside the container is
Due to problems with the sealing properties of the container and the difficulty of replenishing the molten metal, it is only used in cases where a small amount of molten metal, about 9 in 10 or less, is stored in a container and processed in a batch manner.
This method could not be applied to cases in which molten metal of several -,2<g or more per batch was to be processed continuously.

Also, the method of controlling the molten metal level in the container at a constant level is
Although it can be applied to large-volume processing, in this conventional method, most of the head of molten metal that falls into one nozzle is kept by the molten metal in the container, so compared to 1 conduit. This means that a large amount of molten metal is constantly retained in a container with a much larger cross-sectional area, which means that the time it takes for the molten metal poured into the container to be ejected from the nozzle force becomes longer. Therefore, the temperature drop of the molten metal is correspondingly large, and for this reason, there is a problem in that it is essential to provide a heating device for heating the molten metal in the dedicated pipe section.

(Purpose of the Invention) In view of the above, the present invention provides an intermediate container equipped with a conduit and a nozzle, in which a large amount of molten metal is continuously processed to produce a quenched metal ribbon. It is an object of the present invention to provide a method for reducing the temperature drop by shortening the elapsed time in the nozzle jet 1.

(Construction and Effect of the Invention) The method of the present invention to achieve this object is a method for manufacturing a rapidly solidified metal ribbon by jetting molten metal from a nozzle onto a rotating roll table (1) at an angle from the lower end of an intermediate container. A long conduit is provided that extends downward, and a nozzle is provided at the tip of the conduit, and the ejection direction is diagonally upward. A method for producing quenched metal ribbon by a single roll method, characterized in that the amount of molten metal supplied to the intermediate container is adjusted so that the height of the molten metal in the intermediate container is below Z. be.

That is, the present invention connects the lower end of the intermediate container and the nozzle with a long conduit, secures most of the desired molten metal head at the nozzle spout f through the conduit, and directs the molten metal in the intermediate container. By reducing the amount, the residence time of the molten metal in the intermediate container is shortened, the temperature drop of the molten metal is reduced, and a heating device for the molten metal in the conduit portion is not required.

Hereinafter, the present invention will be explained in detail based on the illustrated embodiments.

FIG. 1 is a diagram (partially shown) showing the main structure of an apparatus for producing rapidly cooled metal thin pieces according to an embodiment of the present invention. In the figure, ■ is a ladle, 2 is an intermediate container, 3 is a conduit, 4 is a nozzle, 5 is a pedestal, and 6 is a cooling roll.

7 is a winding machine. The molten metal Mζ is supplied from the ladle 1 to the intermediate container 2 via a known sliding nozzle or the like, passes through a special pipe 3 extending diagonally downward from the lower end of the intermediate container 2, and then diagonally upwards from the nozzle 4 at the tip. It is ejected toward the surface of the cooling roll 6. The spouted molten metal is
It is rapidly cooled by the cooling roll 6 to become thin @S, and is rolled up by the winding machine 7. In the case of this embodiment device, the molten metal head at the nozzle [prize outlet ζ] is H in the dimensional relationship diagram of FIG. 2, and most of the head H (more than 415) is secured by the molten metal in the conduit, The remaining portion (approximately 1/20 to V40 of the head H in this embodiment) is maintained by the molten metal in the intermediate container 2. In this device, the flow rate of the molten metal spouted from the nozzle 4 is Q, and the conduit 3
The inner diameter of the pipe is d, the length of the conduit 3 is t, and the inner diameter of the intermediate container 2 is %D.
Then, the head H is expressed by g: Acceleration of gravity γ: Specific gravity of molten metal C: A constant determined by the way the molten metal flows, such as the inclination angle of the conduit, and the time required for the molten metal to flow through the dead conduit 3. The time t is −□ ・・・・・・・・・・・・・・・ (2) Q γ・π・d2 Therefore, the flow rate Q determined by the manufacturing conditions, −#specific gravity γ of the molten metal, The length t and inner diameter d of the conduit 3 and the required molten metal head Ili can be determined using the time t determined from the allowable drop range of the temperature of the molten metal.・Dimensions determined in this way [The ladle is manufactured so that the flow rate of the molten metal flowing into the intermediate container 2 becomes the desired flow rate Q to be jetted from the nozzle 4. Adjust the amount supplied from l. By doing this, the elapsed time until the molten metal injected into the intermediate container is ejected from the nozzle is shortened, and the conventional heating device for heating the molten metal in the conduit section is no longer required, making it a single operation. All that is required is a device to preheat the conduit before starting. In such a device, if the inner diameter of the intermediate container 2 is made larger than the inner diameter d of the conduit 3, the ladle 1 will increase in proportion to the square of this ratio d/1). The fluctuation rate of the head LI with respect to the fluctuation rate of the amount of molten metal supplied from the molten metal to the intermediate container 2 becomes small, and the fluctuation of the amount of ejection from the nozzle 4 can be reduced.

In addition, in the description of the above embodiment, the inside of the intermediate container and the conduit were described as circular for convenience of explanation.
These inner shapes are not limited to circular shapes, but may of course be oval or square shapes.

(Effects of the Invention) Since the present invention is a method as described above, according to the method of the present invention, the time required for the molten metal poured into the intermediate container from the ladle to reach the reed spouted from the nozzle force S is shortened. This has the practical effect of eliminating the need for a heating device, which is conventionally provided around the outer periphery of the conduit in order to prevent molten metal from solidifying in the middle of the conduit.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of an apparatus in an embodiment of the present invention (partial partial view 9, Fig. 2 is a diagram showing the dimensions of each part of the apparatus of Fig. 1 with symbols. 1: ladle, 2: Intermediate container, 3: Conduit, 4: Nozzle, 5:
Frame, 6: Cooling roll, 7: Winding machine. M: Molten metal, S: Metal ribbon.

Claims (1)

[Claims] A method for producing a quenched metal ribbon by jetting molten metal from a nozzle onto the surface of a rotating roll. A long conduit is provided that extends obliquely downward from the lower end of the intermediate container, and a nozzle whose ejection direction is obliquely upward is provided at the tip of the conduit. A quenched metal ribbon by a single roll method, characterized in that the amount of molten metal supplied to the intermediate container is adjusted so that the height of the molten metal in the intermediate container occupies 1% or less of the head of the manufacturing method.