JPH03230810A - Drawing method of wire rod and covered composite wire rod of zinc-aluminum alloy - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is for efficiently drawing a zinc-aluminum alloy wire or a zinc-aluminum alloy coated composite wire to a good quality state without generating surface cracks. The present invention relates to a wire drawing method.

[Prior Art] Aluminum-coated steel wire exhibits excellent corrosion resistance in extremely corrosive environments such as coastal areas, but depending on the purpose of its use, the corrosion resistance may not necessarily be sufficient.

As a material that can greatly improve such corrosion resistance, Zn containing 1 to 15% AJ was previously developed by the applicant.
-A corrosion-resistant zinc-aluminum alloy coated steel wire coated on the outer periphery of an AJ gold alloy steel wire has been proposed, and its excellent corrosion resistance has been demonstrated.

In order to manufacture a composite wire by continuously extrusion coating the outer periphery of Zn-AJ gold alloy steel wire in this way, the ram extrusion method can be used, but an extrusion method called the conform method is generally used. The quality of the wire will be more stable if it is.

In other words, this conform method involves forming a transport passage for feeding the material by a rotating wheel having an endless groove on its outer circumferential surface and a fixed shoe block that engages with the endless groove. disposing an abutment that closes the passage, feeding the material into the transport passage by rotating the rotary wheel, and generating high pressure in the material near the abutment due to frictional resistance of contact between the endless cleaning surface and the material;
Depending on the high pressure, the material is continuously extruded and coated around a steel wire that is separately fed through a nipple through a die.

Therefore, in the above-mentioned conform method, the coating material is supplied in the form of a Zn-Aj alloy rough wire into the above-mentioned transport passage, and the rough wire for the supply must first be manufactured.

Furthermore, a composite bus bar is manufactured by coating a thick Zn-A1 alloy on a steel wire, and the composite bus bar is drawn to manufacture a Zn-An alloy coated steel wire having a predetermined outer diameter and coating thickness. This is also being done.

[Problems to be Solved by the Invention] However, the above-mentioned Zn-Al! Alloys are also known as materials that are prone to hot embrittlement.

The rough drawn wire supplied in the conform method is manufactured by hot extruding S billets, but there is a problem in that the extrusion speed cannot be increased due to the hot brittleness described above. If you try to forcefully increase the extrusion speed, surface cracks will occur on the surface of the extruded material due to brittleness, and depending on the extrusion length, seizure will occur on the die surface, causing the dimensions of the extruded material to be smaller than expected. arise.

To solve the above problems, reduce the extrusion ratio, extrude to a wire diameter larger than the required wire diameter, and then draw the wire to the required wire diameter (for example, normally supplied in the conform method). However, the material after extrusion is brittle and cannot be drawn under normal wire drawing conditions, resulting in wire breakage. There was a problem with putting it away.

In addition, the problem is similar when drawing composite busbars; although composite busbars can be manufactured by extrusion, it is difficult to draw composite wires with large differences in deformation resistance, and in addition, Zn-Aj alloy There is also the problem that the coating layer tends to crack due to the brittleness described above, resulting in quality defects, and the reality is that this wire drawing requires a lot of effort.

The purpose of the present invention is to solve the problems of the prior art as described above, and to avoid defects caused by hot embrittlement.
The object of the present invention is to provide a novel method for drawing Zn-Al alloy wire and composite wire that can stably produce wire-drawing materials of Zn-Aj alloy wire or Zn-Aj alloy coated steel wire of good quality. .

[Means for Solving the Problems] The present invention provides a method for drawing a zinc-aluminum alloy wire rod or a zinc-aluminum alloy coated composite bus bar to reduce its diameter using a die, by heating the wire on the drawing side to The wire is drawn while being heated to 250°C.

[Function] When attempting to wire-draw the wire-drawn material at room temperature under normal wire-drawing conditions, deformation heat is generated in the die part due to large deformation resistance, and the temperature reaches the hot brittle temperature of the ZnAJI alloy. This can lead to cracks or wire breaks due to brittleness.

However, if the material to be drawn is heated to 100 to 250°C and then drawn, the deformation resistance will be greatly reduced and the generation of processing heat will be greatly reduced, allowing the wire drawing material to be drawn smoothly and stably with good quality. It becomes possible to draw the wire.

[Example] The present invention will be described below with reference to Examples.

First, drawing of the rough wire supplied in the conform method will be explained.

As exemplified above, the wire diameter of the supplied rough wire in the conform method is approximately 8.3 mm, but if you try to extrude directly from the billet to this wire diameter, the extrusion ratio will be large and processing heat will be generated. The above-mentioned hot embrittlement occurs and surface cracks occur.

In the present invention, in order to solve the above-described problem during extrusion, a large-sized roughing bus bar is manufactured by once extruding the wire to a size larger than the wire diameter of the required roughing wire.

Specifically, for the rough drawing line with a diameter of 8.3 mm, the outer diameter is 2
Extrusion manufacture of 0m+ rough busbar.

If you extrude in a large size like this, the extrusion ratio will become smaller,
It generates less processing heat and can be extruded at a relatively low temperature.The extrusion temperature can be lowered, and the hot embrittlement described above is less likely to occur even when extruded at high speeds, which improves productivity and enables efficient extrusion. It becomes possible to implement it.

However, when drawing the rough generatrix extruded to a large size to the required outer diameter by reducing the diameter, using the normal wire drawing method and conditions, cracks due to brittleness may occur as explained earlier. wire breakage may occur, making it impossible to draw the wire satisfactorily.

The inventors heated the material to be drawn during wire drawing,
We focused on the fact that this could significantly reduce deformation resistance. That is, when the wire-drawn material is heated to, for example, about 200° C., its deformation resistance is reduced to about 1/10 of that at room temperature. If the deformation resistance is reduced in this way, the generation of processing heat will inevitably be reduced, and there will be no risk of the workpiece being heated to a temperature that would cause hot embrittlement.

The figure is an explanatory view showing how wire is drawn by the wire drawing method according to the present invention based on the above knowledge.

As shown in the figure, an energization heating device 3 is installed between the die 1 and the energization roll 2, and the wire drawing material 1 that is not sent out from the payoff 4 is heated by energization heating, and the diameter is reduced by the die 1 to make the wire drawing material. 11, and is wound up by a winding machine 5.

Table 1 shows the results of heating a large-sized rough drawing bus bar with an outer diameter of 20 mm manufactured by extrusion to each temperature shown in Table 1 as shown in the figure, and determining whether or not it can be drawn based on appearance and other factors. It is something.

As is clear from Table 1, when the heating temperature is low, the deformation resistance is large, causing wire breakage and making wire drawing impossible.

However, if the wire is drawn after being heated to a temperature in the range of 100 to 250°C, the generation of processing heat will be reduced due to the reduction in deformation resistance, and as a result, the heat generation in the wire drawing section can be reduced, resulting in a good result. It becomes possible to stably obtain a drawn wire material having a surface condition.

If this heating temperature exceeds 250°C, the temperature of the wire rod itself becomes too high, and the lubricating oil film breaks due to the lack of heat resistance of the wire drawing lubricating oil, causing die seizure and making it impossible to draw the wire again. becomes. Therefore, the heating temperature during wire drawing is 1
It is appropriate to set the temperature in the range of 00 to 250°C, and the temperature may be selected within this range by considering the area reduction rate of one pass.

Table 1 When selecting the bath area reduction rate, Zn extruded at high temperature
-Since the grain size of Al1 alloy is large and the elongation is small,
If the area reduction rate is too large, it will break brittle. Therefore,
Even if electrical heating is performed, it is necessary to reduce the initial area reduction rate and increase the area reduction rate after some processing has been applied, and in this way, the amount of elongation due to processing softening will also increase. However, wire drawing becomes easier.

EXAMPLE A rough busbar having an outer diameter of 20 mm was produced by extrusion, sent out from a payoff, heated to 150° C. by heating with electricity using a device as shown in the figure, and supplied to a die. The shape of the die is trumpet-like, and the outer diameter after drawing is 1.
When the wire drawing conditions were set to 9nlI11 with a reduction in area of 10% and the wire drawing speed was 10m/l1in, the surface of the wire drawing material was very smooth and the wire drawing was performed stably and smoothly. No particular problems were found. Thereafter, the wire was further drawn in 10% increments to reduce the outer diameter to the required outer diameter of 8.3 fins, but no problems were observed during this process, and the wire could be drawn smoothly.

In addition, although the above explanation was about drawing the Zn-Aj alloy wire itself, the rough drawing wire obtained as described above is fed to a conform type extrusion device, and the outer periphery of the steel wire is drawn. A composite bus bar is manufactured by applying a thick Zn-A, 11 alloy coating, or a composite bus bar is manufactured using the conventional ram extrusion method, and then drawn down by wire drawing to achieve a predetermined wall thickness and outer diameter. Zn-A having a diameter, l! When producing alloy-coated steel wire, the composite bus bar is heated to 100 to 250°C during wire drawing.
Numerous other experiments have also confirmed that if the wire is heated between the wires and then drawn, it is possible to obtain a composite wire of good quality without the occurrence of microcracks.

[Effects of the Invention] As described above, the wire drawing method according to the present invention can produce Zn-Al alloy wire or Zn-Al alloy wire, which has been extremely difficult in the past.
The drawing of Al1 alloy coated steel wire can be facilitated, the drawing speed can be increased several times, and products with good quality can be stably and efficiently produced.

[Brief explanation of drawings]

The figure is an explanatory view showing how the wire drawing method according to the present invention is being carried out. 1: Dice, 2: Current roll, 2 Double current heating device, : Wire-drawn material, 11: Wire-drawn material.

Claims (2)

[Claims] (1) When drawing a zinc-aluminum alloy wire rod to reduce its diameter using a die, the wire on the side to be drawn is electrically heated to a 100%
A method for drawing a zinc-aluminum alloy wire rod while heating it to ~250°C. (2) Manufacture a zinc-aluminum alloy coated bus bar by continuously extruding and coating zinc-aluminum alloy through a die through a die around the steel wire fed through the nipple, and heat the bus bar to 100 to 250°C by electrical heating. A method for drawing a zinc-aluminum alloy coated composite wire, which involves drawing the wire and drawing it into a composite wire having the required outer diameter and coating thickness.