JPS62101355A - Production of wire - Google Patents

Abstract

PURPOSE:To obtain a wire which obviates disconnection trouble and has excellent productivity by casting a solidified rod having casting structure in which columnar grains are developed diagonally in the longitudinal direction of the rod and subjecting the rod to direct cold drawing. CONSTITUTION:The molten metal bath M in a molten metal holding furnace 2 is passed through the inlet end of a casting mold 4 which projects into the both M and is kept heated. The molten metal is then drawn by pinch rolls 8 from the other end of the casting mold 4 which is held in contact with a cooling structural body 6. The solidified rod R obtd. in the above-mentioned manner has the casting structure in which the crystal grains are developed diagonally as shown in the figure. Said rod exhibits the wire drawing performance substantially equal to the case when a unidirectionally solidified rod is used. The rod also exhibits the wire drawing performance which is better than by ordinary solidification and much better than by the conventional method. The angle alpha for forming the above-mentioned columnar grain structure is 25-65 deg., more particularly 30-60 deg. in the longitudinal direction. The rods of Cu, Al, Au, Ag, Zn, Pb, Sn, etc., and the alloys thereof are also produced by the above-mentioned working method.

Description

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a cross-sectional view along the longitudinal direction +i+ of the iron rod, illustrating the casting structure of the diagonally solidified rod. Columnar height 7 ridge formation angle α (α
represents the average growth direction of columnar crystals excluding the skin part (chill layer) and central part, 1-0, that is, the angle with the longitudinal direction of the grain boundary of the relevant part. ) is 25~ in the longitudinal direction
A diagonal coagulation rod having an angle of 65 degrees, preferably 50 to 60 degrees is defined herein. In unidirectional solidification, α is 0~
It is in the range of 10 degrees. On the other hand, in normal coagulation, α is about 8
It is in the range of 0 to 90°.

FIG. 2 shows an example of an apparatus for manufacturing obliquely solidified rods. A molten metal bath M is held within the molten metal holding furnace 2 . The inlet end of the mold 4 projects into the molten metal bath and is thereby heated, while the other end of the mold rests against the cooling structure 6. The solidified rod R is extracted by a vinyl roll 8. As the material for the mold, it is preferable to use a refractory material with good thermal conductivity, such as hardened silicon, silicon carbide, graphite, etc. Although the rod is shown as being withdrawn into water, it may also be withdrawn vertically downward. The drawing of the rod is preferably carried out by pulse drawing.

Using the above equipment, rods of copper, aluminum, gold, silver, zinc, lead, tin, etc. and alloys thereof are manufactured,
The casting structure can be made into unidirectional solidification, oblique solidification, and continuous solidification structures by controlling (1) drawing speed conditions, (11) cooling conditions, and more preferably (11D molten metal temperature conditions at mold inlet). You can change it freely.

Pure copper and copper alloys ((:'u -0,3X Fe -o,
Taking 1%P-(L1%In) as an example, the relationship between the casting structure and casting conditions established using the apparatus shown in FIG. 2 will be illustrated for reference. It has a water-cooled structure using a graphite mold, and the temperature of the molten metal at the mold entrance is T, and the distance from the interface between the a-lift and solidification part in the mold to the cooling structure! 4. Cooling conditions and molten metal temperature conditions were determined using the mold outlet side thickness 12 and rod diameter d. The drawing was performed by pulse drawing, that is, by pulling out for a predetermined period of time and then stopping by tightening and turning. Rod stop time t
Let the rod withdrawal time be tD, and the average true speed be S.
The drawing speed conditions were determined based on three factors: /lD and the drawing length. Table 1 shows the condition range.

The above data varies depending on the target metal type, the structure and material of the device, etc., so it is necessary to set each condition according to the specific situation.

In any case, by using the above-mentioned apparatus and setting the above-mentioned casting conditions, a rod having an oblique solidification structure can be manufactured.

The diagonally solidified rod thus produced is directly subjected to a cold wire drawing process without hot rolling. The wire drawing process is the conventional one using wire drawing dies.
. To begin with stable drawing performance, the area reduction rate for each die must be 5.
It is preferably 5% or less. If it exceeds 35X, grain boundary warping tends to occur (and stable drawing performance cannot be obtained, especially in ultra-fine wire drawing).

In this way, the valley-roasted metal wire including fine wire and ultra-fine wire is manufactured.

Effects of the invention t Since the diagonally solidified rod has extremely few cracks, pinholes, inclusions, etc., and no inclusions due to embedding of oxide scale due to hot rolling, the grain boundary portion perpendicular to the longitudinal direction of the rod is Since there are almost no
Wire breaks due to foreign matter and grain boundary cracks are extremely reduced,
A good wire drawing process can be carried out.

2. Wire rods with excellent mechanical strength, conductivity, and surface smoothness can be manufactured.

3. Cold wire drawing is easy.

4. Productivity is maintained at a high level.

5. Fine wires and ultra-fine wires can be manufactured easily and inexpensively.

Reference Example: One-way solidification (α km°) was performed using the equipment shown in Figs.
), oblique solidification (α 45°) and normal solidification (α medium 8
Table 2 shows the casting condition values under which 00) was carried out. These values correspond to the condition ranges indicated above.

The diagonal coagulation rod is unidirectional # [approximately 4 times that of JD Rollo]
'Can be manufactured at linear speed.

Examples and Comparative Examples Electrical copper ingots were melted in a graphite crucible under a non-rt-forming atmosphere, and then melted using a graphite # type and a water-cooled structure as shown in FIG. 71+1
A 1φ rod was manufactured. The columnar crystal formation angles were controlled to be 08.45° and 80° by setting the conditions as shown in the reference example. This rod was subjected to initial wire drawing using a wire drawing die in a lubricant with area reduction rates of 25% and 35% to obtain a 5.7 diameter wire rod. For this wire, the average area reduction rate for each die from 5.7uφ to 1 field φ is 25×11π1φ to 0.1 fiber φ, and the average area reduction rate for each die from 5.7 uφ to 1 field φ is 15%, and 0.1 side φ to o , ultrafine powder processing was performed with an average area reduction rate of 10''X for each die up to osmφ, and the wire drawing amount/tv'r number of wires (wire drawing performance) was counted.

The results are shown in Table 3.

The conventional method in Table 3 has an ingot cut area of 4500 nt2,
After 10 m/minute in a cooling shower, the material was rolled to 8 mm diameter with 15 hot rolling rolls, and was made into 5.7 chick diameter winning material by slight cold initial elongation (0.1 mt peeling was performed 3 times). After that, the same processing as above was performed.

The present invention exhibits slitting performance that is almost comparable to the use of unidirectionally solidified rods, better than ordinary hardened rods, and much better drawing performance than conventional methods.

FIG. 1 is an explanatory diagram illustrating the oblique solidification casting structure, FIG. 2 is a cross-sectional view showing an example of a rod casting apparatus for carrying out the method of the present invention, and FIG. 6 is an enlarged view of a part of FIG. 2. .

2: Furnace 4: Mold 6: Cooling structure 8: Vinty roll R: Rod M: Molten metal bath 1'1 Name of agent Motohiro Kurauchi (, 1゛'-3-0
−□ ゛Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1) A method for producing a wire rod, which comprises casting a solidified rod having a cast structure in which columnar crystals are developed obliquely with respect to the longitudinal direction of the rod, and directly subjecting the rod to cold wire drawing. 2) Use a mold in which the diagonal solidification rod maintains a temperature at the mold inlet side higher than the melting point of the rod material and a mold outlet side temperature lower than the melting point of the rod material, and introduce the molten metal into the mold inlet and from the mold outlet. 2. A method as claimed in claim 1, in which the rod is cast by drawing it out.