JPH02137646A - Method and apparatus for producing fine wire composed of difficult-to-working alloy - Google Patents

Abstract

PURPOSE:To produce a fine wire in a simple process and to improve the yield by introducing molten alloy flowing out from fine hole in a vessel into a high frequency induction furnace and drawing out from a metallic mold while developing cooling temp. gradient to the alloy. CONSTITUTION:The fine hole 2 is arranged at a lower part of a melting furnace 1 and a nozzle 3 as the metallic mold is set. The nozzle 3 has cylindrical shape composed of refractory of alumina, boron nitride, etc., and a large diameter hole 4 at the upper part thereof is communicated with the fine hole 2 and the lower part of the large diameter hole is made to taper and communicated with the small diameter hole 5. By allowing high frequency current to flow in a high frequency induction coil 8 in the high frequency induction furnace from a power source 9, the nozzle 3 is heated and temp. gradient is developed in the nozzle axial direction to adjust the alloy temp. The molten metal in the small diameter hole 5 becomes semi-molten state at the upper part and solidifying state at the lower part and drawn out downward from an opening hole 5a as the wire rod 10. As the obtd. wire rod can adjust the temp. gradient, the structure is close, and the quality is made to the constant without only a little variation of mechanical property. By this method, the waste of the cast wire becomes little and the yield can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for manufacturing a thin wire of a difficult-to-work alloy.

(Prior technology) It is difficult to manufacture thin wires made of difficult-to-work alloys such as stellite rods by cold or warm drawing. Thin wires of a predetermined shape are made by a type of suction casting in which negative pressure is created and the molten alloy is sucked into a mold and cooled.

For example, a stellite rod, which is a difficult-to-work alloy, is slightly softer than hardened high-speed steel at room temperature, but harder than quenched high-speed steel at temperatures above 600°C, so depending on the cutting conditions, the cutting ability may actually be greater than that of high-speed steel. Because it has high wear resistance and high-temperature hardness, and has a thermal expansion coefficient and melting temperature close to that of steel, it is widely used for valve seat fillets and the like.

(Problems to be Solved by the Invention) However, in the conventional method for manufacturing fine wires of difficult-to-work alloys using the so-called suction method, the mold preparation work is complicated, and cleaning up after cutting the mold requires labor. There were problems in that workability was poor, and there were many runner layers, resulting in low yield and high manufacturing costs.

The present invention was made to solve these problems, and by continuously manufacturing thin wires made of difficult-to-work alloys, it streamlines mold insertion and mold cutting operations and improves yield. It is an object of the present invention to provide a method and apparatus for manufacturing a thin wire that is difficult to process and which reduces costs.

(Means for Solving the Problems) For this purpose, the method for producing a difficult-to-process fine wire according to the first aspect of the present invention is to flow the molten alloy flowing out from the pores of a container into a high-frequency induction furnace, and then conduct the alloy in the high-frequency induction furnace. The method is characterized in that the alloy is pulled out from the mold while creating a cooling temperature gradient.

The apparatus for manufacturing a difficult-to-process fine wire according to the second invention of the present invention includes:
A container for storing molten alloy, a mold into which the molten metal flows out from the pores of the container, a high-frequency induction furnace that applies a temperature gradient to the alloy in the mold, and the alloy cooled in the mold is pulled out. It is characterized by comprising a pulling means. As the container, a melting furnace such as a high frequency induction furnace or a ladle such as a tundish can be used.

(Function) According to the thin wire manufacturing method of the present invention, the molten alloy flowing out from the pores of the container is cooled with a temperature gradient by heating by high frequency induction, and the thin wire is made by drawing, so that the molten metal is not drawn into the mold. , mold setting, mold cutting, etc., can be omitted, the work can be streamlined, and the yield can be improved.

(Example) Embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment of a thin wire manufacturing apparatus to which the present invention is applied.

A pore 2 is provided in the lower part of the melting furnace 1, and a nozzle 3 as a mold is placed in the pore 2. The nozzle 3 has a cylindrical shape made of a refractory material such as alumina or boron nitride, and has a large diameter hole 4 at the top communicating with the aforementioned small hole 2.
The lower part thereof gradually becomes tapered and communicates with the small diameter hole 5.

The nozzle 3 provided in the high-frequency induction furnace 7 has a high-frequency induction coil 8 wound around its outer periphery. The high-frequency induction coil 8 in the high-frequency induction furnace 7 heats the nozzle 3 when a high-frequency current is applied by a power source 9, and adjusts the temperature of the alloy so that a temperature gradient is created inside the nozzle in the axial direction of the nozzle. .

The alloy stored in the large diameter hole 4 becomes a molten metal, and the small diameter hole 5
The molten metal stored in the molten metal normally becomes a semi-molten state in the upper part, solidified state in the lower part, and is drawn out as a wire rod 10 downward through the opening hole 5a. Although not shown in FIG. 1, a pulling means for pulling the wire rod 10 vertically downward is installed below the mold 3.

The molten metal stored in the melting furnace 1 flows into the large-diameter hole 4 of the mold 3 through the small hole 2, becomes semi-molten in the small-diameter hole 5, becomes solidified with an extremely thin surface portion, and is pulled out from the open hole 5a. The advancing speed of the wire 10 during drawing is kept constant, and the stopping time is adjusted to keep the surface temperature of the drawn product constant. Melting furnace l while continuing drawing
When the amount of molten metal in the melting furnace 1 falls below a certain amount, the molten metal in the melting furnace 1 is replenished. This allows continuous drawing for several hours.

According to this first embodiment, the wire rod 10 drawn out from the opening hole 5a is cut to a predetermined length, and can be processed into a wire rod having a desired length. The obtained wire rod has good quality and has few internal defects such as shrinkage cavities. In addition, according to this thin wire manufacturing method, the temperature gradient of the wire drawn by the induction coil 8 can be adjusted, so that the structure is dense even inside the wire, there is little change in mechanical properties, the quality is constant, and the length of the wire can be adjusted. It has the advantage that it can be adjusted freely.

FIG. 2 shows a second embodiment of the horizontal thin wire manufacturing apparatus.

A pore 2 is formed in the side wall of the melting furnace 1, and a large diameter hole 4 of a nozzle 3 is connected to the pore 2 so that the runner is horizontal. The temperature of the molten alloy flowing from the small hole 2 into the large-diameter hole 4 of the nozzle 3 gradually decreases as it goes to the right inside the nozzle 3, and the wire l drawn out from the small-diameter hole 5 through the open hole 5a.
O is extracted with the surface layer solidified. The drawn wire lO is transported by transport rollers 11.

According to this second embodiment, as with the first embodiment, the die cutting operation can be streamlined and the yield can be improved, and since it is a horizontal type, the equipment cost is relatively low. It also has the effect of being superior in terms of safety.

It should be noted that a tundish may be used in place of the melting furnace 1 of the embodiment described above, and it goes without saying that a water cooling device for cooling the mold 3 may be attached to the lower part of the induction coil 8.

(Effects of the Invention) As explained above, according to the method and apparatus for manufacturing a fine wire made of a difficult-to-work alloy of the present invention, a hard-to-work fine wire can be manufactured in a simple process by drawing it from a molten metal. This has the effect of omitting mold preparation work, reducing the number of runner layers, and improving yield.

Further, the resulting fine wire product has few internal defects, has a dense structure even inside, has good mechanical properties, has constant quality, and can easily be obtained with a freely adjustable length. Conventionally, negative pressure was created in a mold immersed in molten metal using a suction method, etc., and the molten metal was sucked into the mold by this negative pressure and cooled to cast fine wire that was difficult to process. The present invention has the effects of omitting such a suction action, reducing work effort, improving yield, and lowering manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of a vertical thin wire manufacturing apparatus of the present invention, and FIG. 2 is a schematic diagram showing an embodiment of a horizontal thin wire manufacturing apparatus of the present invention. ...melting furnace (container), ...pore, ...nozzle (mold), ...high-frequency induction furnace, ...induction coil.

Claims (2)

[Claims] (1) A difficult-to-process alloy characterized by flowing the molten alloy from the pores of the container into a high-frequency induction furnace, and drawing the alloy from the mold while creating a cooling temperature gradient for the alloy in the high-frequency induction furnace. A method for manufacturing thin wire consisting of. (2) A container for storing molten alloy, a mold into which the molten metal flowing out from the pores of the container flows, a high-frequency induction furnace that applies a temperature gradient to the alloy in the mold, and an alloy cooled in the mold. 1. A device for manufacturing a thin wire made of a difficult-to-work alloy, comprising a drawing means for drawing the wire.