KR20180126499A - Manufacturing method of molten aluminum plated steel wire - Google Patents

Abstract

After the steel wire 2 is immersed in the molten aluminum plating bath 1, the boundary between the molten aluminum plated steel wire 3 pulled from the molten aluminum plating bath 1 and the bath surface 10 of the molten aluminum plating bath 1 The stabilizing member 11 is brought into contact with the bath surface 10 of the molten aluminum plating bath 1 and the molten aluminum plated steel wire 3 and the stabilizing member 11 The inert gas having a temperature of 600 to 1000 占 폚 is blown from the tip end 12a of the nozzle 12 to the boundary at a pressure of 0.1 to 20 kPa, Wherein said method comprises the steps of:

Description

Manufacturing method of molten aluminum plated steel wire

The present invention relates to a method of manufacturing a molten aluminum plated steel wire. More particularly, the present invention relates to a method of manufacturing a molten aluminum-plated steel wire which can be preferably used for a wire harness for automobiles, for example.

In the present specification, the molten aluminum plated steel wire refers to a steel wire which is plated with aluminum by immersing the steel wire in a molten aluminum plating bath and then continuously pulling the steel wire from the molten aluminum plating bath. Further, the molten aluminum plating bath means a molten aluminum plating solution.

Conventionally, copper wires are used for electric wires used in wire harnesses and the like of automobiles. However, in recent years, development of a wire using a metal wire that is lighter than a copper wire has been required from the viewpoint of weight reduction.

As a metal wire which is lighter than a copper wire, there has been proposed a molten Al-plated steel wire in which molten aluminum plating is applied to a steel wire (for example, see claim 1 of patent document 1). The molten Al-plated steel wire is manufactured by immersing a material steel wire having a zinc plated layer or a nickel plated layer on the surface of a material steel wire or a thick steel wire made of a steel wire into a molten aluminum plating bath and then continuously raising it to the vapor phase space (See paragraph [0024] of Patent Document 1).

The present invention also provides a method of producing a molten aluminum plated steel wire by immersing a steel wire in a molten aluminum plating bath and then continuously raising the steel wire from the molten aluminum plating bath, The stabilizing member is brought into contact with the bath surface and the steel wire at the boundary portion between the steel wire and the bath surface of the molten aluminum plating bath so that the steel wire is pulled out from the steel wire at a distance of 1 to 50 mm An inert gas having a temperature of 200 to 800 DEG C is injected from the tip of the nozzle at a volume flow rate of 2 to 200 L / min through a steel wire and molten aluminum plating And the molten aluminum-plated steel wire is blown toward the boundary of the bath surface of the bath. There has been proposed a method (for example, see Patent Document 2). According to the above production method, an excellent effect is obtained in that a wire rod having uniform line diameter and capable of efficiently producing a molten aluminum plated steel wire which is less likely to adhere to the surface of aluminum can be obtained. However, when the molten aluminum-plated steel wire is produced by the above-described method, there is a possibility that a thin portion of the plated metal film is formed on the molten aluminum plated steel wire.

The bath temperature of the molten aluminum plating bath is preferably low in consideration of thermal efficiency, but when the temperature is 20 ° C higher than the melting point of the molten aluminum plating bath, there is a possibility that the aluminum ingot adheres to the surface of the molten aluminum plated steel wire (See Comparative Examples 1, 2, 6 and 7 of this specification).

A hot-dip galvanized steel wire having a plated film having a thin portion or a hot-dip galvanized steel wire having an aluminum ingot on its surface is subjected to wire drawing when the steel wire is exposed to the outside, There is a possibility that the molten aluminum plated steel wire is broken due to fluctuation of the pulling resistance of the molten aluminum plated steel wire.

Japanese Patent Application Laid-Open No. 2014-185355 Japanese Patent Application Laid-Open No. 2015-134961

The present invention has been made in view of the above-mentioned prior art, and it is an object of the present invention to provide a method for manufacturing a hot-dip galvanized steel wire which is less likely to have a thin thickness portion of a plated film even if the bath temperature of the hot- And a method of manufacturing a molten aluminum-plated steel wire.

According to the present invention,

(1) A method for producing a molten aluminum plated steel wire by immersing a steel wire in a molten aluminum plating bath and then continuously raising the steel wire from the molten aluminum plating bath, comprising the steps of immersing a steel wire in the molten aluminum plating bath, The stabilizing member is brought into contact with the bath surface of the molten aluminum plating bath and the molten aluminum plated steel wire at the boundary between the molten aluminum plated steel wire drawn from the molten aluminum plating bath and the bath surface of the molten aluminum plating bath, Wherein a nozzle for blowing an inert gas is provided at a position facing the member and the inert gas having a temperature of 600 to 1000 占 폚 is blown from the tip end of the nozzle to the boundary at a pressure of 0.1 to 20 kPa A method of manufacturing a plated steel wire,

(2) The method for producing a molten aluminum-plated steel wire according to (1), wherein the steel wire is a steel wire made of carbon steel or stainless steel, and

(3) A method for manufacturing a hot-dip galvanized steel wire according to (1) or (2), wherein the bath temperature of the hot-dip aluminum plating bath is adjusted to be higher than the melting point of the hot-dip galvanizing bath by 15 ° C or more.

According to the method of manufacturing a molten aluminum-plated steel wire of the present invention, even if the bath temperature of the molten aluminum plating bath is low, a thin portion of the plated film is hardly generated, and the molten aluminum plated steel wire, It is possible to produce an excellent effect that can be produced.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory diagram showing one embodiment of a method for manufacturing a molten aluminum-plated steel wire of the present invention.
Fig. 2 is a schematic cross-sectional view showing an embodiment of a steel wire lead-in control apparatus shown in Fig. 1. Fig.
3 is a schematic sectional view showing an embodiment of a bath control device used in the steel wire lead-in control device shown in Figs. 1 and 2. Fig.
4 is a schematic explanatory diagram of a boundary between a steel wire and a bath surface of a molten aluminum plating bath when a steel wire is pulled up from a molten aluminum plating bath in the method of manufacturing a molten aluminum plated steel wire of the present invention.
5 is a schematic explanatory diagram showing one embodiment of a method for measuring the average thickness of the plated film of the molten aluminum-plated steel wire obtained in each of the examples and comparative examples.

The method of producing a molten aluminum plated steel wire of the present invention is a method of manufacturing a molten aluminum plated steel wire by immersing a steel wire in a molten aluminum plating bath and then continuously pulling the steel wire from the molten aluminum plating bath, After the steel wire is immersed in the molten aluminum plating bath, the stabilizing member at the boundary between the molten aluminum plated steel wire pulled from the molten aluminum plating bath and the bath surface of the molten aluminum plating bath is sandwiched between the bath surface of the molten aluminum plating bath and the molten aluminum- And an inert gas having a temperature of 600 to 1000 占 폚 is supplied to the boundary from the tip of the nozzle at a rate of 0.1 Blowing at a pressure of ~ 20 kPa It characterized.

According to the manufacturing method of the molten aluminum-plated steel wire of the present invention, since the operation is adopted, even if the bath temperature of the molten aluminum plating bath is low, a thin portion of the plating film is hardly generated, The molten aluminum plated steel wire can be efficiently produced.

In the present specification, the low temperature of the molten aluminum plating bath means that the bath temperature of the molten aluminum plating bath is 15 ° C or more higher than the melting point of the molten aluminum plating bath and 20 ° C or less higher than the melting point of the molten aluminum plating bath ≪ / RTI >

Hereinafter, a method of manufacturing a molten aluminum-plated steel wire of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments described in the drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory diagram showing one embodiment of a method for manufacturing a molten aluminum-plated steel wire of the present invention.

In the method of manufacturing a molten aluminum plated steel wire of the present invention, after the steel wire 2 is immersed in the molten aluminum plating bath 1, the steel wire 2 is continuously pulled up from the molten aluminum plating bath 1, A plated steel wire 3 is produced.

Examples of the steel material constituting the steel wire 2 include stainless steel and carbon steel, but the present invention is not limited to these examples.

Stainless steel is an alloy steel containing 10% by mass or more of chromium (Cr). Examples of the stainless steel include austenitic steels, ferritic steels, martensitic steels, and the like specified in JIS G4309, but the present invention is not limited to these examples. Specific examples of stainless steels include stainless steels such as SUS301 and SUS304 which are generally stable to austenite phase; Stable austenitic stainless steels such as SUS305, SUS310, and SUS316; Ferritic stainless steels such as SUS405, SUS410L, SUS429, SUS430, SUS434, SUS436, SUS444 and SUS447; And manganese-based stainless steels such as SUS403, SUS410, SUS416, SUS420, SUS431, and SUS440, and chromium-nickel-manganese-based stainless steels classified into the SUS200 range, but the present invention is not limited to these examples .

Carbon steel is a steel containing 0.02 mass% or more of carbon (C). Examples of carbon steels include steels specified in JIS G3506 standard for hard steel wire and steels specified in JIS G3505 standard for soft steel wire, but the present invention is not limited thereto It is not. Specific examples of the carbon steel include hard and soft steels, but the present invention is not limited to these examples.

Among the above steels, stainless steel and carbon steel are preferable from the viewpoint of enhancing the tensile strength of the molten aluminum plated steel wire (3).

The diameter of the steel wire 2 is not particularly limited, and it is preferable to adjust it appropriately in accordance with the use of the molten aluminum plated steel wire 3. For example, when the molten aluminum-plated steel wire 3 is used for a wire harness or the like of an automobile, the diameter of the steel wire 2 is preferably about 0.05 to 0.5 mm.

The steel wire 2 may be degreased before molten aluminum plating is performed. The degreasing of the steel wire 2 can be carried out by, for example, a method of performing degreasing by immersing the steel wire 2 in an alkaline degreasing solution and rinsing it with water, neutralizing the alkali component attached to the steel wire 2, A method in which electrolytic degreasing is carried out by energizing the steel wire 2 in a state in which the substrate 2 is immersed in an alkali degreasing solution. Further, the alkali degreasing solution may contain a surfactant from the viewpoint of improving the degreasing power.

1, the steel wire 2 is fed out from the feeding device 4, continuously passed through in the direction of the arrow A, and is immersed in the molten aluminum plating bath 1 in the plating bath 5.

In the case where the steel wire 2 is a steel wire 2 made of carbon steel, even if the steel wire 2 is degreased, there is a risk of rusting the surface of the steel wire 2 before molten aluminum plating is performed. It is preferable to perform degreasing of the steel wire 2 between the feeding device 4 and the molten aluminum plating bath 1. [ The degreasing of the steel wire 2 made of carbon steel can be performed by the same method as the degreasing of the steel wire 2.

Aluminum alone may be used for the molten aluminum plating bath 1, and if necessary, other elements may be contained within a range not hindering the object of the present invention. Examples of the other element include nickel, chromium, zinc, silicon, copper, and iron, but the present invention is not limited to these examples. When these other elements are contained in aluminum, the mechanical strength of the plated film can be increased, and further, the tensile strength of the molten aluminum plated steel wire 3 can be increased. It is possible to suppress generation of an iron-aluminum alloy layer having brittleness between the iron contained in the steel wire 2 and the aluminum contained in the plated film, depending on the kind of the steel wire 2, Silicon is preferably used from the viewpoint of increasing the mechanical strength of the steel wire 2 and lowering the melting point of the molten aluminum plating bath 1 so as to efficiently plastify the steel wire 2. [

A plating film (not shown) made of aluminum or an aluminum alloy is formed on the surface of the molten aluminum plated steel wire 3. The lower limit of the content of the other element in the plated film is 0% by mass, but it is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, still more preferably 0.5% by mass or more from the viewpoint of sufficiently exhibiting the properties of the other element Is preferably not less than 50% by mass, more preferably not more than 20% by mass, further preferably not more than 15% by mass from the viewpoint of suppressing corrosion of potential difference caused by contact with the aluminum strand.

Further, the molten aluminum plating bath 1 may inevitably contain elements such as nickel, chromium, zinc, copper, and iron.

According to the present invention, since the operation is performed by blowing an inert gas having a temperature of 600 to 1000 占 폚 at a pressure of 0.1 to 20 kPa at a boundary between a steel wire 2 and a bath surface of a molten aluminum plating bath 1 , Even when the bath temperature of the molten aluminum plating bath 1 is low, it is possible to efficiently manufacture the molten aluminum plated steel wire 3 in which the thickness of the plating film is not thin, and the aluminum ingot is hardly adhered to the surface.

From the viewpoint of efficiently producing a molten aluminum plated steel wire 3 in which the thickness of the plating film is less likely to occur and the aluminum ingot is hardly adhered to the surface, the lower limit value of the bath temperature of the molten aluminum plating bath 1 is, It is preferable to adjust it so that it is higher than the melting point of the plating bath 1 by 15 DEG C or more.

The upper limit of the bath temperature of the molten aluminum plating bath 1 is preferably adjusted to a temperature of 150 DEG C or higher than the melting point of the molten aluminum plating bath 1 from the viewpoint of improving the thermal efficiency, More preferably 120 ° C higher than the melting point of the molten aluminum plating bath 1 and more preferably 80 ° C higher than the melting point of the molten aluminum plating bath 1, More preferably 50 ° C higher than the melting point of the molten aluminum plating bath 1, more preferably 25 ° C higher than the melting point of the molten aluminum plating bath 1, It is particularly preferable to adjust the temperature to 20 DEG C or more higher than the melting point of the resin (1).

The bath temperature of the molten aluminum plating bath 1 is set such that the temperature sensor in which the thermocouple is inserted into the protective tube for protecting the thermocouple is removed from the molten aluminum plating bath 1 at a position about 300 mm deep from the bath surface of the molten aluminum plating bath 1 Is a value obtained by immersing it in the vicinity of the pulled up steel wire (2).

In the present invention, in order to efficiently produce a molten aluminum plated steel wire (3) which is less likely to have a thin plated film and to which an aluminum ingot is difficult to adhere to the surface, the steel wire (2) A steel wire inlet part control device 8 having a heating device 6 for heating the steel wire 2 and a bath control device 7 for preventing the oxide film from adhering to the surface of the steel wire 2, It is preferable to pass the steel wire 2 through the wire 2.

As the steel wire lead-in portion control device 8, for example, the steel wire lead-in portion control device 8 shown in Fig. 2 and the like are listed, but the present invention is not limited to these examples. Fig. 2 is a schematic cross-sectional view showing an embodiment of the steel wire lead-in control device 8 shown in Fig. 1. Fig. The steel wire lead-in control device 8 has a heating device 6 and a bath control device 7.

As shown in Fig. 2, the heating device 6 has, for example, a tubular heating device body 6a made of a steel material such as stainless steel. The inside 6b of the heating apparatus main body 6a is communicated with the steel wire 2 in order to conduct the wire 2 in the direction of the arrow B. A branch pipe 6e having a heating gas vent 6c for allowing a heating gas to pass therethrough is provided on the side surface of the heating apparatus main body 6a.

Examples of the heating gas to be passed through the heating device 6 include air, inert gas such as nitrogen gas, argon gas, and helium gas, but the present invention is not limited to these examples. Among them, the heating gas discharged from the lower end 6d of the heating device 6 is passed from the inlet of the upper end 7a of the bath control device 7 provided below the heating device 6 to the inside thereof , And an inert gas atmosphere is preferably employed from the viewpoint of preventing the molten aluminum plating bath 1 in the bath control device 7 from being oxidized. Since the temperature of the heating gas differs depending on the conditions such as the type and diameter of the steel wire 2 to be used, the conduction velocity, the flow rate of the heating gas, etc., the temperature of the heating gas can not be uniformly determined. It is preferable to adjust it.

The heating temperature of the steel wire 2 is preferably 60 占 폚 or higher, more preferably 80 占 폚 or higher, further preferably 150 占 폚 or higher, and still more preferably 10 占 폚 or higher from the viewpoint of efficiently producing the molten aluminum- Is not lower than 200 deg. C and its upper limit differs depending on the kind of the steel wire 2 and therefore can not be uniformly determined. However, in view of energy efficiency, it is usually not higher than 1000 deg. C, more preferably not higher than 900 deg. Lt; / RTI > The heating temperature is a temperature measured based on the method described in the following examples.

The length of the heating apparatus main body 6a shown in Fig. 2 is not particularly limited, as long as it can be adjusted so that the steel wire 2 is heated to a predetermined temperature, and is, for example, about 1 to 5 m. The diameter of the inside 6b of the heater main body 6a differs depending on the diameter and kind of the steel wire 2 to be used and therefore can not be determined uniformly but is usually 1.5 to 50 times the diameter of the steel wire 2 Respectively. For example, in the case of using a steel wire 2 having a diameter of 0.2 mm, it is preferable that the diameter of the inside 6b of the heater main body 6a is about 0.3 to 10 mm.

A branch pipe 6e having a heating gas vent 6c is provided on a side surface of the heating device main body 6a. It is possible to heat the steel wire 2 passed through the heating device 6 by passing the heating gas through the heating gas vent 6c of the paper tube 6e and also to heat the steel wire 2 in the paper tube 6e with a heater And the heating gas that is introduced into the branch pipe 6e by the heater may be heated. In the embodiment shown in Fig. 2, seven branch tubes 6e are provided, but there is no particular limitation on the number of branch tubes 6e, and the number of the branch tubes 6e may be one or two to ten do.

A gap D is provided between the lower end 6d of the heating device 6 and the upper end 7a of the bath control device 7 provided below the heating device 6 in the embodiment shown in Fig. . The gap D is preferably about 3 to 10 mm from the viewpoint of efficiently discharging the heating gas from the gap D. The gap D does not necessarily have to be formed, and the heating device 6 and the bath control device 7 may be formed as separate members, and they may be integrated by, for example, screw fitting or the like. When the heating device 6 and the bath control device 7 are integrated, a discharge port (not shown) for discharging the heated gas inside the heating device 6 is connected to the heating device 6 or the bath surface It may be provided on the side surface of the control device 7.

Further, in the present invention, for example, a conduction heating apparatus, an induction heating apparatus, or the like can be used in place of the heating apparatus 6. [

The bath control device 7 includes, for example, the bath control device 7 shown in Fig. 3, but the present invention is not limited to these examples. Fig. 3 is a schematic sectional view showing an embodiment of the bath control device 7 used in the steel wire lead-in control device 8 shown in Figs. 1 and 2. Fig.

As shown in Fig. 3, the bath control device 7 has a tubular body 9 having a through hole 9a for passing the steel wire 2 in the direction of the arrow C inside. The total length L of the bath control device 7 is usually 30 to 500 mm, more preferably 40 to 300 mm, and still more preferably 50 to 100 mm.

The tubular member 9 is immersed in the immersion area for immersion in the molten aluminum plating bath 1 from the end of one end of the side immersed in the molten aluminum plating bath 1 to the imaginary line P shown in FIG. 9b. The length of the immersion area 9b is usually preferably 2 to 20 mm, more preferably 5 to 15 mm or more.

In the longitudinal direction of the tubular member 9, the length of the portion not immersed in the molten aluminum plating bath 1 is usually at least 5 mm, more preferably at least 10 mm.

The ratio of the area of the opening of the through hole 9a of the tubular member 9 to the area of the cross section of the steel wire 2 used for hot-dip aluminum plating (so-called cross section of the steel wire 2) (The area of the opening of the through-hole 9a of the tubular body 9) / the area of the cross-sectional surface of the steel wire 2] of the steel wire 2 from the viewpoint of smoothly introducing the steel wire 2 into the through- Preferably 3 or more and preferably 4000 or less, more preferably 3000 or less, further preferably 2000 or less, still more preferably 1000 or less, from the viewpoint of preventing the oxide film from adhering to the steel wire 2 to be.

The shape of the opening of the through hole 9a of the tubular member 9 is arbitrary, and may be circular or other shape. The clearance between the opening of the through hole 9a of the tubular member 9 and the steel wire 2 is set to be in a range from the viewpoint of preventing sliding of the inner wall of the through hole 9a of the tubular member 9 and the steel wire 2 , Preferably not less than 10 mu m, more preferably not less than 20 mu m, further preferably not less than 50 mu m, further preferably not less than 100 mu m.

3, the opening of the through hole 9a of the tubular body 9 has an opening portion 9c in the inlet 9c for introducing the steel wire 2 into one end of the tubular body 9 9d and an opening 9f in the discharge port 9e for discharging the steel wire 2 to the other end of the tubular member 9. [ The steel wire 2 smoothly passes through the through hole 9a of the tubular body 9 and the tubular body 9 is smoothly passed through the through hole 9a of the tubular body 9, From the viewpoint of avoiding the sliding of the inner wall of the through hole 9a of the through hole 9a and the steel wire 2 and efficiently manufacturing the molten aluminum plated steel wire 3 having the plated coating formed on the entire surface, 9d and the opening 9f are preferably the same in area and shape.

The steel wire 2 that has passed through the steel wire lead-in control device 8 is immersed in the molten aluminum plating bath 1 if necessary.

The conduction speed of the steel wire 2 is 100 m / min or more from the viewpoint of efficiently producing the molten aluminum plated steel wire 3, suppressing scattering of the oxide film formed on the surface of the molten aluminum plating bath 1, It is preferably 1000 m / min or less, more preferably 800 m / min or less from the viewpoint of efficiently producing a molten aluminum plated steel wire 3 to which an oxide film hardly adheres.

The time (plating time) during which the steel wire 2 is immersed in the molten aluminum plating bath 1 is adjusted so that the thickness of the plating film formed on the surface of the steel wire 2 becomes a predetermined thickness. The time (plating time) during which the steel wire 2 is immersed in the molten aluminum plating bath 1 varies depending on the thickness of the required plating film, the bath temperature of the molten aluminum plating bath 1, etc. Therefore, 0.3 to 1 second.

1, the steel wire 2 immersed in the molten aluminum plating bath 1 is lifted from the bath surface 10 of the molten aluminum plating bath 1, A plated film of the molten aluminum plating bath 1 is formed and a molten aluminum plated steel wire 3 is obtained.

As shown in Fig. 4, when the steel wire 2 is pulled up from the molten aluminum plating bath 1 in the direction of the arrow E, the molten aluminum plated steel wire 3 pulled up from the molten aluminum plating bath 1, The meniscus 17 is formed by lifting the bath surface 10 of the plating bath 1. When the tip 17a of the meniscus 17 is extended upwardly, the tip 17a of the meniscus 17 solidifies to form an aluminum ingot, and the aluminum ingot becomes a molten aluminum plated steel wire 3) on the surface of the plated film (18).

Therefore, since the distal end 17a of the meniscus 17 is prevented from being excessively stretched in the upward direction, foreign matter such as aluminum lumps can be prevented from adhering to the surface of the molten aluminum plated steel wire 3, The stabilizing member 11 is sandwiched between the bath face 10 of the molten aluminum plating bath 1 and the bath face 10 of the molten aluminum plating bath 1 at the boundary portion between the molten aluminum plated steel wire 3 pulled up from the bath 1 and the bath face 10 of the molten aluminum plating bath 1. [ There is provided a nozzle 12 for contacting the molten aluminum plated steel wire 3 and blowing the inert gas at a position opposite to the stabilizing member 11 through the molten aluminum plated steel wire 3. [

4 is a view showing a method of manufacturing a molten aluminum plated steel wire according to the present invention in which the steel wire 2 is pulled up from the molten aluminum plating bath 1 and the steel wire 2 is pulled up from the bath surface of the molten aluminum plating bath 1 10 of the present invention.

As the stabilizing member 11, for example, square rods made of stainless steel in which a heat resistant cross member 11a is wound on the surface are listed. Examples of the heat resistant cross member 11a include woven fabrics and nonwoven fabrics containing heat-resistant fibers such as ceramic fibers, carbon fibers, aramid fibers and imide fibers, but the present invention is not limited to these examples. The heat resistant cross member 11a is formed by melting the surface (new surface) on which the aluminum is not attached (new surface) of the heat resistant cross member 11a from the viewpoint of suppressing the adhesion of the aluminum ingot to the surface of the molten aluminum plated steel wire 3 It is preferable to make contact with the aluminum plated steel wire 3.

It is preferable that the stabilizing member 11 contacts both the bath surface 10 of the molten aluminum plating bath 1 and the molten aluminum plated steel wire 3 at the same time. When the stabilizing member 11 is simultaneously brought into contact with both the bath face 10 of the molten aluminum plating bath 1 and the molten aluminum plated steel wire 3 in this way, the pulsation of the bath face 10 of the molten aluminum plating bath 1 The plating film 18 can be uniformly formed on the surface of the steel wire 2 because the pulsation of the meniscus 17 is suppressed. When the stabilizing member 11 is brought into contact with the molten aluminum plated steel wire 3, tension is applied to the molten aluminum plated steel wire 3, if necessary, from the viewpoint of suppressing microvibration of the molten aluminum plated steel wire 3 The stabilizing member 11 may be lightly pressed against the molten aluminum plated steel wire 3 so as to be applied.

A nozzle 12 for blowing an inert gas is provided at a position opposite to the stabilizing member 11 through the molten aluminum plated steel wire 3. The tip end 12a of the nozzle 12 is installed to blow an inert gas to the boundary between the molten aluminum plated steel wire 3 and the bath surface 10 of the molten aluminum plating bath 1. The distance (the shortest distance) from the molten aluminum plated steel wire 3 to the tip end 12a of the nozzle 12 avoids contact between the tip end 12a of the nozzle 12 and the molten aluminum plated steel wire 3, The thickness of the plating film 18 is hardly generated even if the bath temperature of the molten aluminum plating bath 1 is low, Preferably not more than 50 mm, more preferably not more than 40 mm, still more preferably not more than 30 mm, further preferably not more than 10 mm from the viewpoint of obtaining a molten aluminum plated steel wire (3) Preferably 5 mm or less.

The inner diameter of the tip end 12a of the nozzle 12 is set so that the inert gas discharged from the tip end 12a of the nozzle 12 can be accurately and uniformly supplied to the molten aluminum plated steel wire 3 and the bath surface 10 of the molten aluminum plating bath 1. [ Is preferably 1 mm or more, more preferably 2 mm or more from the viewpoint of efficiently producing the molten aluminum plated steel wire 3 by blowing the molten aluminum plating bath 1 to the boundary portion, and even if the bath temperature of the molten aluminum plating bath 1 is low, Preferably 15 mm or less, more preferably 10 mm or less, and most preferably 10 mm or less, from the viewpoint of obtaining a molten aluminum plated steel wire (3) Is 5 mm or less.

The inert gas can be supplied from the inert gas supply device 13 shown in Fig. 1 to the nozzle 12 through the pipe 14, for example. In order to adjust the flow rate of the inert gas, for example, a flow rate control device (not shown) such as a valve may be provided in the inert gas supply device 13 or the pipe 14.

The inert gas means a gas inert to the molten aluminum. Examples of the inert gas include nitrogen gas, argon gas, and helium gas, but the present invention is not limited to these examples. In the inert gas, nitrogen gas is preferable. The inert gas may contain, for example, oxygen gas, carbon dioxide gas or the like within a range not hindering the object of the present invention.

The pressure of the inert gas discharged from the tip end 12a of the nozzle 12 is adjusted to 0.1 to 20 kPa and the temperature of the inert gas is adjusted to 600 to 1000 deg. In the present invention, when the steel wire 2 is immersed in the molten aluminum plating bath 1 and then pulled up from the molten aluminum plating bath 1, the molten aluminum plated steel wire 3 and the molten aluminum plated steel wire 3 are drawn from the tip end 12a of the nozzle 12 Since the pressure of the inert gas for blowing to the boundary of the bath surface 10 of the molten aluminum plating bath 1 is adjusted to 0.1 to 20 kPa and the temperature of the inert gas is adjusted to 600 to 1000 캜, Even if the bath temperature of the bath 1 is low, the thinned portion of the plating film 18 hardly occurs, and the molten aluminum plated steel wire 3 in which the aluminum ingot is hardly adhered to the surface can be obtained.

The pressure of the inert gas discharged from the tip end 12a of the nozzle 12 is lowered from the viewpoint of obtaining a molten aluminum plated steel wire 3 in which the aluminum ingot is hardly adhered to the surface even if the bath temperature of the molten aluminum plating bath 1 is low , Preferably not more than 20 kPa from the viewpoint of obtaining a molten aluminum plated steel wire 3 in which a thin portion of the plating film 18 hardly occurs even if the bath temperature of the molten aluminum plating bath 1 is at least 0.1 kPa, Is 2 kPa or less.

The pressure of the inert gas discharged from the tip end 12a of the nozzle 12 is set such that the inert gas in the nozzle 12 at a position spaced 2 mm from the tip end 12a of the nozzle 12 has an inner diameter of 0.5 mm Is a value obtained by inserting a stainless steel tube of a stainless steel tube so that the tip of the tube is opposed to the tip end 12a of the nozzle 12 and the gas pressure of the inert gas applied to the tip of the tube is measured with a pressure sensor.

In general, the bath temperature of the molten aluminum plating bath 1 is preferably low in consideration of thermal efficiency. However, when the bath temperature of the molten aluminum plating bath 1 is low, an aluminum ingot is liable to be generated on the surface of the molten aluminum plated steel wire 3.

On the other hand, in the present invention, even if the bath temperature of the molten aluminum plating bath 1 is low, since the temperature of the inert gas discharged from the tip end 12a of the nozzle 12 is adjusted to 600 占 폚 or more, The molten aluminum plated steel wire 3 is hardly adhered.

The temperature of the inert gas discharged from the tip end 12a of the nozzle 12 is substantially the same as the temperature of the aluminum plating bath 1 when the bath temperature of the molten aluminum plating bath 1 is low, From the viewpoint of obtaining a molten aluminum plated steel wire 3 to which the lumps are hardly adhered, it is 600 DEG C or higher and 1000 DEG C or lower, preferably 800 DEG C or lower, more preferably 750 DEG C or lower, from the viewpoint of improving thermal efficiency.

The temperature of the inert gas discharged from the tip end 12a of the nozzle 12 is set to be 1.6 mm in diameter in the inert gas at a position distant from the tip end 12a of the nozzle 12 by 2 mm, Is a value measured by inserting a thermocouple for sideways such as a sheath thermocouple.

The volume flow rate of the inert gas discharged from the tip end 12a of the nozzle 12 is preferably 2 L (liters) / min or more, more preferably 2 L (liters) / min or more from the viewpoint of effectively preventing oxidation of the surface of the meniscus 17 Is not less than 5 L / min, more preferably not less than 10 L / min, and even if the bath temperature of the molten aluminum plating bath 1 is low, a thin portion of the plating film 18 is hardly generated, It is preferably not more than 200 L / min, more preferably not more than 150 L / min, still more preferably not more than 100 L / min, from the viewpoint of obtaining a molten aluminum plated steel wire 3 which is hardly adhered.

The lifting speed at which the molten aluminum plated steel wire 3 is pulled up from the bath surface 10 of the molten aluminum plating bath 1 is not particularly limited and the molten aluminum plated steel wire 3 can be adjusted by suitably adjusting the lifting speed, It is preferable to appropriately adjust the average thickness of the plating film 18 present on the surface of the plating film 18 in accordance with the average thickness of the plating film 18. [

1, in order to cool the molten aluminum plated steel wire 3 in the course of pulling up the molten aluminum plated steel wire 3 and to effectively solidify the plated metal film 18 formed on the surface, The cooling device 15 may be provided on the upper portion of the nozzle 12, if necessary. In the cooling device 15, the molten aluminum plated steel wire 3 can be cooled, for example, by blowing gas, liquid mist, or the like onto the molten aluminum plated steel wire 3.

As shown in Fig. 1, the molten aluminum plated steel wire 3 manufactured as described above can be recovered by, for example, the winding device 16 or the like.

The average thickness of the plated film 18 present on the surface of the molten aluminum plated steel wire 3 is such that the steel wire 2 of the base metal is prevented from being exposed to the outside during twisting or caulking, But it is preferably about 5 to 10 mu m from the viewpoint of increasing the mechanical strength per diameter.

The minimum thickness of the thinned portion of the plated coating 18 present on the surface of the molten aluminum plated steel wire 3 is such that the steel wire 2 is prevented from being exposed to the outside during twisting or caulking, From the viewpoint of enhancing the mechanical strength per unit diameter, it is preferably 1 占 퐉 or more, and more preferably 2 占 퐉 or more.

The surface of the steel wire 2 is subjected to pre-plating treatment before the steel wire 2 is immersed in the molten aluminum plating bath 1 from the viewpoint of efficiently forming a smooth plated coating 18 on the steel wire 2 . As the metal constituting the pre-plating treatment, for example, zinc, nickel, chromium, an alloy thereof and the like are listed, but the present invention is not limited to these examples. The plated film 18 formed on the surface of the steel wire 2 by the pre-plating treatment may be formed of only one layer, or may be a plurality of plated films 18 made of the same or different metals.

The molten aluminum-plated steel wire 3 obtained above may be subjected to a drawing process using dies or the like in order to have a desired outer diameter if necessary.

The molten aluminum plated steel wire 3 obtained by the method of producing a molten aluminum plated steel wire of the present invention can be preferably used for wire harnesses for automobiles, for example.

Example

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Examples 1 to 100 and Comparative Examples 1 to 11

In each of the Examples and Comparative Examples, a molten aluminum plated steel wire was produced in accordance with the embodiment of the method for producing a molten aluminum plated steel wire shown in Fig.

As the steel wire, a steel wire having a diameter shown in each of the following tables and made of the steel grade shown in each of the tables is used, and the surface of the steel wire is not subjected to the galvanizing treatment (in the column of "free Zn" No "), or those having a zinc plated film having an average thickness of 5 μm or less (" Yu "in the column of" free Zn "in each table) were used. 37A described in the columns of steel in each table means a steel wire made of hard steel containing 0.37 mass% of carbon.

The steel wire not subjected to the galvanizing treatment was degreased by immersing it in a degreasing solution of sodium orthosilicate containing a surfactant before immersing in a molten aluminum plating bath.

Before the steel wire was immersed in the molten aluminum plating bath, the steel wire was passed through the steel wire lead-in control device 8 shown in Fig. 2, and the steel wire was preheated to about 400 캜 by the heating device 6. Nitrogen gas was used as the heating gas. The preheating temperature was measured by providing a thermocouple connected to the steel wire and passing the thermocouple along with the steel wire among the heating devices 6 held at a predetermined temperature.

3, as the bath control device 7 used in the steel wire guide control device 8 shown in Fig. 2, the tubular body 9 is provided with an inlet 9c of the through hole 9a The size and area of the opening 9f in the opening 9d of the tubular body 9 are the same as those of the opening 9f of the tubular body 9 and the opening 9f of the tubular body 9, (The area of the opening of the through hole 9a of the tubular body 9 / the area of the cross section of the steel wire) of the area of the tubular body 9 and the cross section of the steel wire is set to 57, ) To immerse the steel wire in the molten aluminum plating bath for 0.3 to 1 second.

As the molten aluminum plating bath, a molten aluminum plating bath (purity of aluminum: 99.7% or more, "Al" in the column of "type of molten Al plating" in each table) and 4 mass% (Denoted by "4% Si" in the column of "type of molten Al plating" in each table), a molten aluminum plating bath containing 8% by mass of silicon ("8% (Denoted by "11% Si" in the column of "type of molten Al plating" in each table) or 13% by mass of silicon containing molybdenum aluminum (13% Si " in the column of " molten Al plating " in each table) was used as the plating bath, and the steel wire was melted at the conduction velocity (steel wire pulling rate) After immersing in an aluminum plating bath, the molten aluminum He pulled up from the bath.

At that time, the bath surface and the stabilizing member having a width of 40 mm were brought into contact with the bath surface and the above-mentioned molten aluminum plated steel wire at the boundary between the molten aluminum plated steel wire drawn from the molten aluminum plating bath and the bath surface of the molten aluminum plating bath. Further, as a stabilizing member, a square bar made of stainless steel in which a heat-resistant cross-member was wound around the surface was used, and the contact length between the hot-dip coated aluminum wire and the heat resistant cross member was adjusted to 5 mm.

A nozzle having an inner diameter at the tip end shown in each table was provided so that the tip of the nozzle was positioned at a position 2 mm away from the molten aluminum plated steel wire. An inert gas (nitrogen gas ) Was blown into the boundary between the molten aluminum-plated steel wire and the bath surface of the molten aluminum plating bath at the volume flow rate and pressure shown in the respective tables.

By performing the above operation, a hot-dip coated aluminum wire having a plated film having an average thickness and a minimum thickness of a thin-wall portion as shown in the respective tables was obtained.

A method of measuring the average thickness of the plated film is described below. The method of measuring the minimum thickness of the thin portion is described in the column of " (2) Measurement of the minimum thickness of the thin portion of the plating film ".

[Method of measuring the average thickness of the plated film]

The measurement of the average thickness of the plated film of the molten aluminum-plated steel wire obtained in each example and each comparative example was performed based on the embodiment shown in Fig. 5 is a schematic explanatory diagram showing one embodiment of a method for measuring the average thickness of the plated film of the molten aluminum-plated steel wire obtained in each of the examples and comparative examples.

As shown in Fig. 5, the wire-threaded steel wire diameter measuring device 19 includes a pair of pulleys 19c and 19d arranged in the vertical direction and a pair of pulleys 19c and 19d disposed at the central portion between the pulleys 19c and 19d A wire-threaded steel wire diameter measuring device 19 having two optical-type outer diameter measuring instruments (manufactured by KEYENCE CORPORATION, product number: LS-7000) having a pair of light emitting portions 19a and a light receiving portion 19b provided in the horizontal direction was used. The pair of light emitting portions 19a and the light receiving portion 19b are opposed to each other and the adjacent light emitting portion 19a and the light receiving portion 19b are arranged at an angle of 90 degrees as shown in Fig.

The hot-dip coated steel wire 3 having a length of 100 m obtained in each example or each comparative example was passed between the pulley 19c and the pulley 19d in the direction of the arrow F at a conveying speed of 100 m / And the outer diameter of the molten aluminum plated steel wire 3 was measured at a distance of about 1.4 mm in the longitudinal direction of the plated steel wire 3 with the wire type steel wire diameter measuring device 19. [ In addition, the measurement score of the outer diameter was set at about 71,000 points.

Then, the average value of the outer diameters of the molten aluminum-plated steel wires measured above was obtained, the diameters of the steel wires before forming the plating film (the diameters of the steel wires shown in the following tables) were subtracted from the average values, To obtain an average thickness of the plated film. The results are shown in the respective tables.

[Evaluation of performance of plating film]

The adhesion of the aluminum ingot and the stability of the minimum thickness of the thin-walled portion of the plated film were examined based on the following methods as the performance of the hot-dip coated aluminum wire obtained above. The results are shown in the respective tables.

(1) Adhesion of aluminum ingot

A hot-dip galvanized steel wire having a length of 300 m was run at a conduction speed of 100 m / min, the outer diameter of the molten aluminum plated steel wire was measured over the entire length of the hot-dip galvanized steel wire, and the presence or absence of a convex portion having a larger outer diameter was investigated . Whether or not the aluminum ingot was locally attached to the convex portion having a large outer diameter was visually observed, and the adhesion of the aluminum ingot was evaluated based on the following evaluation criteria. The outer diameter of the molten aluminum plated steel wire was measured using an optical type outer diameter measuring instrument (manufactured by KEYENCE CORPORATION, part number: LS-7000).

(Evaluation standard)

○: The adhesion of the aluminum ingot is not confirmed.

X: Attachment of the aluminum ingot is confirmed.

(2) Measurement of the minimum thickness of the thin portion of the plated film

In order to obtain the minimum thickness of the thin portion of the plated film, the cross section of the molten aluminum plated steel wire was observed. More specifically, a test specimen of 300 mm in length was cut out from a molten aluminum-plated steel wire, and six test specimens were cut out from the test specimen, the specimen was embedded in the resin, the formed resin was cut, A section of the molten aluminum plated steel wire was exposed. This section was observed with an optical microscope (magnification: 500 times) and the minimum thickness of the thinned portion of the plated film was measured. The smallest thickness among the minimum thicknesses of the thin-walled portions of the plating films measured on the six test pieces was defined as the minimum thickness of the thin-walled portions of the plating film.

(3) Stability of minimum thickness of thin part of plating film

Based on the following evaluation criteria, the stability of the minimum thickness of the thin-walled portion of the plated film was evaluated from the minimum thickness of the thinned portion of the plated film obtained above.

(Evaluation standard)

&Amp; cir &: The minimum thickness of the thinned portion of the plated film is 2 mu m or more

?: The minimum thickness of the thinned portion of the plated film is 1 占 퐉 or more and less than 2 占 퐉

X: The minimum thickness of the thinned portion of the plated film was less than 1 mu m

(4) Overall evaluation

Based on the evaluation results of the adhesion of the aluminum ingot and the stability of the minimum thickness of the thinned part of the plated film, the following evaluation criteria were used for the comprehensive evaluation.

(Evaluation standard)

?: Evaluation of the adhesion of the aluminum ingot was?, And evaluation of the stability of the minimum thickness of the thinned part of the plated film was? (Excellent).

?: The adhesion of the aluminum ingot and the evaluation of the plating film were all? (Good).

X: There is an evaluation of x in the adhesion of the aluminum ingot and evaluation of the plating film (rejection).

According to each embodiment, as shown in Tables 1 to 5, the pressure of the inert gas for blowing to the boundary between the steel wire and the bath surface of the molten aluminum plating bath is adjusted to 0.1 to 20 kPa, and the temperature of the inert gas It is confirmed that the thinned portion of the plated film is hardly generated and the molten aluminum plated steel wire which is difficult to adhere to the surface of the aluminum can be efficiently produced. According to Examples 32, 36, 40, 46, 50, and 96 to 100, as shown in Tables 2 and 5, the bath temperature of the molten aluminum plating bath is lower than the melting point Even if the temperature is 15 ° C or more higher than the melting point of the aluminum plating bath and the temperature is 20 ° C or more higher than the melting point of the molten aluminum plating bath, a thin portion of the plating film is hard to occur, It is confirmed that the molten aluminum plated steel wire which is difficult to adhere can be efficiently produced.

On the other hand, according to Comparative Example 1, Comparative Example 6 and Comparative Example 7, as shown in Table 6, since the temperature of the inert gas blown to the interface between the steel wire and the bath surface of the molten aluminum plating bath is lower than 600 占 폚, It is confirmed that it is not possible to produce a hot-dip coated aluminum wire in which the aluminum mass is hardly adhered to the surface at a temperature higher than the melting point of the hot-dip galvanizing bath by 20 占 폚.

Further, according to Comparative Example 2, as shown in Table 6, even if the pressure and temperature of the inert gas blown to the interface between the steel wire and the bath surface of the molten aluminum plating bath were adjusted to the desired pressure and temperature, It is confirmed that since the bath temperature is lower than the melting point of the molten aluminum plating bath by 15 占 폚, the molten aluminum plated steel wire which is difficult to adhere to the surface of the aluminum can not be produced.

Further, according to Comparative Examples 3 to 5 and Comparative Examples 8 to 11, even if the bath temperature of the molten aluminum plating bath is adjusted to 20 ° C or more higher than the melting point of the molten aluminum plating bath as shown in Table 6, Since the pressure of the inert gas blown to the boundary surface of the bath surface of the molten aluminum plating bath is out of the range of 0.1 to 20 kPa, a thinned portion of the plating film is hard to occur and the molten aluminum plated steel wire, It is confirmed that it can not be manufactured.

Industrial availability

The molten aluminum-plated steel wire obtained by the production method of the present invention can be preferably used for wire harnesses for automobiles, for example.

1: molten aluminum plating bath
2: Steel wire
3: Molten aluminum plated steel wire
4:
5: Plating bath
6: Heating device
6a: Heating device body
6b: inside of the heating device body
6c: Heating gas vent of the heating device body
6d: the bottom of the heating device body
6e: Branch pipe of the heating apparatus main body
7: Bath control system
7a: top of bath control unit
8: Steel wire lead-in control device
9: Tubular body
9a: Through-hole of the tubular body
9b: Immersion area of the tubular body
9c: inlet of tubular body
9d: opening in the inlet of the tubular body
9e: outlet of the tubular body
9f: opening at the outlet of the tubular body
10: Bath surface of molten aluminum plating bath
11: Stabilization member
11a: Heat resistant cross member of the stabilizing member
12: Nozzle
12a: the tip of the nozzle
13: Inert gas supply device
14: Piping
15: Cooling unit
16: retractor
17: Meniscus
17a: Meniscus's fleet
18: Plating film
19: Linear type steel wire diameter measuring device
19a: Light emitting portion of the wire-threaded steel wire diameter measuring device
19b: the light receiving portion of the wire-threaded steel wire diameter measuring device
19c: Pulley wire diameter measuring device pulley
19d: Pulley wire diameter measuring device pulley

Claims (3)

A method for producing a molten aluminum plated steel wire by immersing a steel wire in a molten aluminum plating bath and continuously raising the steel wire from the molten aluminum plating bath, comprising the steps of immersing a steel wire in the molten aluminum plating bath, The stabilizing member is brought into contact with the bath surface of the molten aluminum plating bath and the molten aluminum plated steel wire at the boundary between the molten aluminum plated steel wire drawn from the bath and the bath surface of the molten aluminum plating bath, And an inert gas having a temperature of 600 to 1000 占 폚 is blown from the tip of the nozzle to the boundary at a pressure of 0.1 to 20 kPa. Gt; The method according to claim 1,
Wherein the steel wire is a steel wire made of carbon steel or stainless steel. 3. The method according to claim 1 or 2,
Wherein the bath temperature of the molten aluminum plating bath is adjusted to be higher than the melting point of the molten aluminum plating bath by 15 ° C or more.

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