JP2017186671A - Method for producing molten aluminum plated steel wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a molten aluminum plated steel wire that prevents a thin portion of a plating film from occurring and also prevents an aluminum lamp from being attached on the surface.SOLUTION: The method is characterized in that: a steel wire 2 is immersed in a molten aluminum plating bath 1, and after that, at a boundary between a molten aluminum plated steel wire 3 pulled up from the molten aluminum plating bath 1 and a bath surface 10 of the molten aluminum plating bath 1, a stabilization 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; a nozzle 12 for spraying inert gas is disposed at a position facing the stabilization member 11 across the molten aluminum plated steel wire 3; and inert gas having a temperature of 600-1000°C is sprayed at the pressure of 0.01-10 kPa from a tip 12a of the nozzle 12 to the boundary.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a hot-dip aluminized steel wire. In more detail, this invention relates to the manufacturing method of the hot dip aluminized steel wire which can be used conveniently for the wire harness etc. of a motor vehicle, for example.

  In this specification, the hot-dip aluminum-plated steel wire is a steel wire that has been subjected to aluminum plating by continuously pulling the steel wire from the hot-dip aluminum plating bath after the steel wire is immersed in the hot-dip aluminum plating bath. Means. The molten aluminum plating bath means a molten aluminum plating solution.

  Conventionally, copper wires have been used for electric wires used in automobile wire harnesses and the like. However, in recent years, since weight reduction is required, development of an electric wire using a metal wire that is lighter than a copper wire is desired.

  As a metal wire that is lighter than a copper wire, a hot-dip Al-plated steel wire in which a hot-dip aluminum plating is applied to a steel core wire has been proposed (for example, refer to claim 1 of Patent Document 1). The molten Al-plated steel wire is made of a steel core wire, or a material steel wire having a galvanized layer or a nickel-plated layer on the surface of the steel core wire is immersed in a molten aluminum plating bath, and then continuously in a gas phase space. And is pulled up (see, for example, paragraph [0024] of Patent Document 1).

  Moreover, as a method of manufacturing a molten aluminum plated steel wire, a method of manufacturing a molten aluminum plated steel wire by continuously pulling up the steel wire from the molten aluminum plating bath after the steel wire is immersed in the molten aluminum plating bath When the steel wire is immersed in a molten aluminum plating bath and then pulled up from the molten aluminum plating bath, the steel wire is stable to the bath surface and the steel wire at the boundary between the molten aluminum plating bath and the bath surface of the molten aluminum plating bath. And a nozzle having an inner diameter of 1 to 15 mm is disposed so that the tip of the nozzle is located at a location 1 to 50 mm away from the steel wire, and 200 to 800 from the tip of the nozzle. An inert gas having a temperature of ° C. is blown toward the boundary between the steel wire and the bath surface of the molten aluminum plating bath at a volume flow rate of 2 to 200 L / min. Method for producing a molten aluminum-plated steel wire characterized by attaching has been proposed (e.g., see Patent Document 2). According to the said manufacturing method, the wire diameter is uniform and the outstanding effect that the aluminum aluminum plating steel wire to which an aluminum lump cannot adhere easily to the surface can be manufactured efficiently is produced. However, when a hot dip galvanized steel wire is produced by the above-described method, there is a possibility that a portion having a thin plating film is formed on the hot dip galvanized steel wire.

  The temperature of the molten aluminum plating bath is preferably lower in consideration of thermal efficiency. However, when the temperature is 20 ° C. or higher than the melting point of the molten aluminum plating bath, There is a possibility that an aluminum lump may adhere (see Comparative Examples 1, 2, 6, and 7 in this specification).

  When a hot-dip aluminum-plated steel wire having a thin part of the plating film or a hot-dip aluminum-plated steel wire with an aluminum lump attached to the surface is subjected to wire drawing, its internal steel wire is exposed to the outside, There is a possibility that the drawing resistance of the hot dip galvanized steel wire fluctuates during the wire drawing and the hot dip galvanized steel wire is broken.

JP 2014-185355 A Japanese Patent Laying-Open No. 2015-134961

  The present invention has been made in view of the above prior art, and even when the bath temperature of a molten aluminum plating bath is low, a portion with a thin plating film is unlikely to be formed, and an aluminum lump is adhered to the surface. It is an object of the present invention to provide a method for producing a hot-dip aluminum-plated steel wire, which can efficiently produce a hard-working hot-dip aluminum-plated steel wire.

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 pulling up the steel wire from the molten aluminum plating bath, wherein the steel wire is made of the molten aluminum After dipping in the plating bath, the stabilizing member is connected to the boundary between the molten aluminum plating steel wire pulled up from the molten aluminum plating bath and the molten aluminum plating bath, and the molten aluminum plating bath and molten A nozzle for bringing an inert gas into contact with the aluminum-plated steel wire and spraying an inert gas at a position facing the stabilizing member via the molten aluminum-plated steel wire is provided from the tip of the nozzle to the boundary portion. It is characterized by spraying an inert gas having a temperature of 1000 ° C. at a pressure of 0.01 to 10 kPa. A method for producing a hot-dip aluminized steel wire,
(2) The method for producing a hot-dip aluminized steel wire according to (1), wherein the steel wire is a steel wire made of carbon steel or stainless steel,
(3) The method for producing a molten aluminum plated steel wire according to (1) or (2) above, wherein the bath temperature of the molten aluminum plating bath is adjusted to be 15 ° C. or higher than the melting point of the molten aluminum plating bath, and (4) After dipping the steel wire in the molten aluminum plating bath, when the steel wire is continuously pulled up from the molten aluminum plating bath, the wire speed of the steel wire is adjusted to 10 to 200 m / min (1 ) To a method for producing a hot-dip aluminized steel wire according to any one of (3).

  According to the method for producing a hot-dip aluminum-plated steel wire of the present invention, even if the bath temperature of the hot-dip aluminum plating bath is low, a portion having a thin plating film is hardly formed, and aluminum lump is adhered to the surface. The outstanding effect that a difficult-to-use hot-dip aluminized steel wire can be produced efficiently is exhibited.

It is a schematic explanatory drawing which shows one embodiment of the manufacturing method of the hot dip galvanized steel wire of this invention. It is a schematic sectional drawing which shows one embodiment of the steel wire introduction part control apparatus shown by FIG. It is a schematic sectional drawing which shows one embodiment of the bath surface control apparatus used for the steel wire introduction part control apparatus shown by FIG. 1 and FIG. In the manufacturing method of the molten aluminum plating steel wire of this invention, it is a schematic explanatory drawing of the boundary part of the steel wire at the time of pulling up a steel wire from a molten aluminum plating bath, and the bath surface of a molten aluminum plating bath. It is a schematic explanatory drawing which shows one embodiment of the method of measuring the average thickness of the plating film of the hot-dip aluminum plating steel wire obtained by each Example and each comparative example.

  As described above, the method for producing a hot-dip aluminum-plated steel wire of the present invention includes hot-dip aluminum-plated steel by continuously pulling the steel wire from the hot-dip aluminum plating bath after the steel wire is immersed in the hot-dip aluminum plating bath. A method of manufacturing a wire, which is stable at the boundary between the molten aluminum plating steel wire pulled up from the molten aluminum plating bath and the bath surface of the molten aluminum plating bath after the steel wire is immersed in the molten aluminum plating bath And a nozzle for spraying an inert gas to a position facing the stabilizing member through the molten aluminum plated steel wire, with the stabilizing member brought into contact with the bath surface of the molten aluminum plated bath and the molten aluminum plated steel wire. Inactive having a temperature of 600-1000 ° C. from the tip of the nozzle to the boundary Wherein the blowing gas at a pressure of 0.01～10KPa.

  According to the method for producing a hot-dip aluminum-plated steel wire of the present invention, since the above-described operation is adopted, even if the bath temperature of the hot-dip aluminum plating bath is low, a portion having a thin plating film may occur. In addition, it is possible to efficiently produce a hot-dip aluminum-plated steel wire in which an aluminum lump is difficult to adhere to the surface.

  In this specification, the temperature at which the bath temperature of the molten aluminum plating bath is low is a temperature at which 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, It means that the temperature is 20 ° C. or higher than the melting point.

  Below, although the manufacturing method of the hot dip galvanized steel wire of this invention is demonstrated based on drawing, this invention is not limited only to the embodiment as described in the said drawing.

  FIG. 1 is a schematic explanatory view showing one embodiment of a method for producing a hot-dip aluminized steel wire of the present invention.

  In the manufacturing method of the hot dip aluminum plating steel wire of the present invention, after the steel wire 2 is immersed in the hot dip aluminum plating bath 1, the steel wire 2 is continuously pulled up from the hot dip aluminum plating bath 1 to thereby obtain hot dip aluminum plating steel. Line 3 is manufactured.

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

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

  Carbon steel is a steel material containing 0.02% by mass or more of carbon (C). Examples of carbon steel include steel materials specified in the standard of hard steel wire rods of JIS G3506, steel materials specified in the standard of mild steel wire rods of JIS G3505, and the present invention is limited to such examples only. Is not to be done. Specific examples of carbon steel include hard steel and mild steel, but the present invention is not limited to such examples.

  Among the steel materials, stainless steel and carbon steel are preferable from the viewpoint of increasing the tensile strength of the hot-dip aluminized steel wire 3.

  The diameter of the steel wire 2 is not specifically limited, It is preferable to adjust suitably according to the use of the hot-dip aluminum plating steel wire 3. FIG. For example, when the hot-dip aluminum-plated steel wire 3 is used for an application such as an automobile wire harness, the diameter of the steel wire 2 is usually preferably about 0.05 to 0.5 mm.

  The steel wire 2 may be degreased before hot-dip aluminum plating is performed. The steel wire 2 is degreased by, for example, a method of degreasing the steel wire 2 by immersing the steel wire 2 in an alkaline degreasing solution, washing with water, neutralizing the alkali content adhering to the steel wire 2, and washing again with water. It can be performed by a method in which electrolytic degreasing is performed by energizing the steel wire 2 with the wire 2 immersed in an alkaline degreasing solution. The alkali degreasing solution may contain a surfactant from the viewpoint of improving the degreasing power.

  In FIG. 1, a steel wire 2 is sent out from a delivery device 4, continuously passed in the direction of arrow A, and immersed in a molten aluminum plating bath 1 in a plating bath 5.

  In addition, when the steel wire 2 is the steel wire 2 which consists of carbon steel, even if the steel wire 2 is degreased, there is a possibility that rust may be generated on the surface of the steel wire 2 before performing hot-dip aluminum plating. The steel wire 2 is preferably degreased between the delivery device 4 and the molten aluminum plating bath 1. 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.

  In the molten aluminum plating bath 1, only aluminum may be used, and if necessary, other elements may be contained within a range not impairing the object of the present invention. Examples of the other elements include nickel, chromium, zinc, silicon, copper, and iron, but the present invention is not limited to such examples. When these other elements are contained in aluminum, the mechanical strength of the plating film can be increased, and as a result, the tensile strength of the hot-dip aluminum-plated steel wire 3 can be increased. Among the other elements, although depending on the type of the steel wire 2, formation of an iron-aluminum alloy layer having brittleness between iron contained in the steel wire 2 and aluminum contained in the plating film Silicon is preferable from the viewpoint of efficiently plating the steel wire 2 by reducing the melting point and increasing the mechanical strength of the plating film and lowering the melting point of the molten aluminum plating bath 1.

  A plated coating (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 plating film is 0% by mass, but preferably 0.3% by mass or more, more preferably 0 from the viewpoint of sufficiently expressing the properties of the other element. 0.5% by mass or more, more preferably 1% by mass or more, and preferably 50% by mass or less, more preferably 20% by mass or less, and still more preferably 15% from the viewpoint of suppressing potential difference corrosion due to contact with the aluminum wire. It is below mass%.

  In addition, elements such as nickel, chromium, zinc, copper, and iron may be inevitably mixed into the molten aluminum plating bath 1.

  According to the present invention, an operation of spraying an inert gas having a temperature of 600 to 1000 ° C. at a pressure of 0.01 to 10 kPa on a boundary portion between a steel wire 2 and a bath surface of the molten aluminum plating bath 1 described later is adopted. Therefore, even when the bath temperature of the molten aluminum plating bath 1 is low, a portion having a thin plating film is hardly formed and an aluminum lump does not easily adhere to the surface. Can be manufactured efficiently.

  The lower limit value of the bath temperature of the hot-dip aluminum plating bath 1 is such that, from the viewpoint of efficiently producing the hot-dip aluminum-plated steel wire 3 in which a thin portion of the plating film is unlikely to be formed and an aluminum lump is difficult to adhere to the surface. It is preferable to adjust so as to be 15 ° C. or higher than the melting point of the molten aluminum plating bath 1.

  The upper limit of the bath temperature of the molten aluminum plating bath 1 is preferably adjusted to a temperature not higher than 150 ° C. higher than the melting point of the molten aluminum plating bath 1 from the viewpoint of improving thermal efficiency. It is more preferable to adjust the temperature to 120 ° C. or higher, and it is even more preferable to adjust the temperature to 80 ° C. or higher than the melting point of the molten aluminum plating bath 1. Is more preferably adjusted to a temperature not higher than 50 ° C., more preferably adjusted to a temperature not higher than 25 ° C. higher than the melting point of the molten aluminum plating bath 1, and more preferably than the melting point of the molten aluminum plating bath 1. It is particularly preferable to adjust the temperature to 20 ° C. or higher.

  In addition, the bath temperature of the molten aluminum plating bath 1 is a molten aluminum at a position about 300 mm deep from the bath surface of the molten aluminum plating bath 1 by inserting a temperature sensor into a protective tube for protecting the thermocouple. It is a value when immersed in the vicinity of the steel wire 2 pulled up from the plating bath 1 and measured.

  In the present invention, from the viewpoint of efficiently producing a hot-dip aluminum-plated steel wire 3 in which a thin portion of the plating film is unlikely to be formed and an aluminum lump is difficult to adhere to the surface, the hot-dip aluminum plating bath 1 A steel wire introduction part for hot-dip aluminum plating having a heating device 6 for heating the steel wire 2 and a bath surface control device 7 for preventing the oxide film from adhering to the surface of the steel wire 2 before being immersed in the steel wire 2 It is preferable to pass the steel wire 2 through the control device 8.

  Examples of the steel wire introduction unit control device 8 include the steel wire introduction unit control device 8 shown in FIG. 2, but the present invention is not limited to such examples. FIG. 2 is a schematic cross-sectional view showing an embodiment of the steel wire introduction section control device 8 shown in FIG. The steel wire introduction unit control device 8 includes a heating device 6 and a bath surface control device 7.

  As shown in FIG. 2, the heating device 6 includes a tubular heating device body 6a made of a steel material such as stainless steel. The interior 6b of the heating device body 6a is hollow in order to pass the steel wire 2 in the direction of arrow B. A branch pipe 6e having a heating gas vent 6c for ventilating the heating gas is disposed on the side surface of the heating device body 6a.

  Examples of the heating gas vented to the heating device 6 include air, inert gases such as nitrogen gas, argon gas, and helium gas, but the present invention is not limited to such examples. Absent. In these, the heated gas discharged | emitted from the lower end 6d of the heating apparatus 6 is ventilated into the inside from the inlet of the upper end 7a of the bath surface control apparatus 7 arrange | positioned under the said heating apparatus 6, The inside From the viewpoint of preventing the molten aluminum plating bath 1 in the bath surface control device 7 from being oxidized, an inert gas is preferable. Since the temperature of the heated gas varies depending on conditions such as the type and diameter of the steel wire 2 used, the wire speed, and the flow rate of the heated gas, it cannot be determined unconditionally. It is preferable to adjust so that is heated appropriately.

  The heating temperature of the steel wire 2 is preferably 60 ° C. or higher, more preferably 80 ° C. or higher, more preferably 150 ° C. or higher, even more preferably 200 ° C. or higher, from the viewpoint of efficiently producing the hot-dip aluminized steel wire 3. The upper limit varies depending on the type of the steel wire 2 and cannot be determined unconditionally. However, in consideration of energy efficiency, it is usually preferably 1000 ° C. or less, more preferably 900 ° C. or less, and further preferably 800 ° C. or lower. In addition, the said heating temperature is a temperature when it measures based on the method as described in a following example.

  The length of the heating device main body 6a shown in FIG. 2 is not particularly limited as long as the length can be adjusted so that the steel wire 2 is heated to a predetermined temperature. 1 to 5 m. Moreover, since the diameter of the inside 6b of the heating apparatus main body 6a differs depending on the diameter and type of the steel wire 2 to be used, it cannot be determined unconditionally. It is about twice. If the example shows, for example, when using the steel wire 2 whose diameter of the steel wire 2 is 0.2 mm, it is preferable that the diameter of the inside 6b of the heating apparatus main body 6a is about 0.3-10 mm.

  A branch pipe 6e having a heated gas vent 6c is disposed on the side surface of the heating apparatus body 6a. By ventilating the heating gas from the heating gas vent 6c of the branch pipe 6e, the steel wire 2 passed through the heating device 6 can be heated, and a heater (not shown) is provided in the branch pipe 6e. The heating gas vented into the branch pipe 6e may be heated by the heater. In the embodiment shown in FIG. 2, seven branch pipes 6e are provided. However, the number of branch pipes 6e is not particularly limited, and the number of branch pipes 6e may be only one. Or about 2-10 may be sufficient.

  In the embodiment shown in FIG. 2, a gap D is provided between the lower end 6 d of the heating device 6 and the upper end 7 a of the bath surface control device 7 disposed below the heating device 6. The gap D is preferably about 3 to 10 mm from the viewpoint of efficiently discharging the heated gas from the gap D. Note that the gap D is not necessarily provided, and the heating device 6 and the bath surface control device 7 may be configured as separate members, and may be integrated by, for example, screw fitting. When the heating device 6 and the bath surface control device 7 are integrated, if necessary, an outlet (not shown) for discharging the heated gas vented into the heating device 6 is provided in the heating device 6 or You may provide in the side surface of the bath surface control apparatus 7. FIG.

  In the present invention, for example, an electric heating device, an induction heating device, or the like can be used instead of the heating device 6.

  Examples of the bath surface control device 7 include the bath surface control device 7 shown in FIG. 3, but the present invention is not limited to such examples. FIG. 3 is a schematic cross-sectional view showing an embodiment of the bath surface control device 7 used in the steel wire introduction portion control device 8 shown in FIGS. 1 and 2.

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

  The tubular body 9 has an immersion region 9b for immersing in the molten aluminum plating bath 1 from the end of one end on the side immersed in the molten aluminum plating bath 1 to a virtual line P shown in FIG. 3 along the longitudinal direction. . The length of the immersion region 9b is usually preferably 2 to 20 mm, more preferably 5 to 15 mm or more.

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

  Ratio of the area of the opening of the through hole 9a of the tubular body 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) [of the through hole 9a of the tubular body 9 The value of the area of the opening / the area in the cross section of the steel wire 2 is preferably 3 or more from the viewpoint of smoothly introducing the steel wire 2 into the through hole 9a of the tubular body 9, and is oxidized to the steel wire 2 From the viewpoint of preventing the film from attaching, it is preferably 4000 or less, more preferably 3000 or less, still more preferably 2000 or less, and still more preferably 1000 or less.

  The shape of the opening part of the through-hole 9a which the tubular body 9 has is arbitrary, circular shape may be sufficient as it, and other shapes may be sufficient as it. The gap (clearance) between the opening of the through hole 9a of the tubular body 9 and the steel wire 2 is preferably 10 μm or more from the viewpoint of preventing sliding between the inner wall of the through hole 9a of the tubular body 9 and the steel wire 2. More preferably, it is 20 μm or more, more preferably 50 μm or more, and still more preferably 100 μm or more.

  As shown in FIG. 3, the opening of the through-hole 9 a of the tubular body 9 includes the opening 9 d in the introduction port 9 c for introducing the steel wire 2 to one end of the tubular body 9, and the tubular body 9. It is the opening part 9f in the discharge port 9e for discharging | emitting the steel wire 2 at an end. The area and shape of the opening 9d and the opening 9f may be the same or different, but the steel wire 2 is smoothly passed through the through hole 9a of the tubular body 9, and the tubular body 9 From the viewpoint of efficiently producing a hot-dip aluminum-plated steel wire 3 in which a plating film is formed on the entire surface, avoiding sliding between the inner wall of the through-hole 9a and the steel wire 2, as shown in FIG. The area and shape of the opening 9d and the opening 9f are preferably the same.

  If necessary, the steel wire 2 that has passed through the steel wire introduction part control device 8 is immersed in the molten aluminum plating bath 1.

  The wire speed of the steel wire 2 is preferably 10 m / min or more, more preferably 30 m / min or more, and even more preferably 50 m / min or more from the viewpoint of efficiently producing the molten aluminum-plated steel wire 3. From the viewpoint of efficiently producing a hot-dip aluminum-plated steel wire 3 in which the oxide film formed on the bath surface of the plating bath 1 does not easily scatter and the oxide film does not easily adhere to the surface, it is preferably 200 m / min or less, more preferably It is 150 m / min or less, more preferably 120 m / min or less.

  The time during which the steel wire 2 is immersed in the molten aluminum plating bath 1 (plating time) is adjusted so that the thickness of the plating film formed on the surface of the steel wire 2 becomes a predetermined thickness. Although the time (plating time) in which the steel wire 2 is immersed in the molten aluminum plating bath 1 varies depending on the required thickness of the plating film, the bath temperature of the molten aluminum plating bath 1, etc., it cannot be generally determined. Usually, it is about 1 to 3 seconds.

  Next, as shown in FIG. 1, the steel wire 2 immersed in the molten aluminum plating bath 1 is pulled up from the bath surface 10 of the molten aluminum plating bath 1, whereby the molten aluminum plating bath 1 is formed on the surface of the steel wire 2. A plating film is formed, and a hot-dip 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 arrow E, the bath surface of the plating bath 1 accompanying the molten aluminum plated steel wire 3 pulled up from the molten aluminum plating bath 1. The meniscus 17 is formed by lifting 10. When the tip 17a of the meniscus 17 extends upward, the tip 17a of the meniscus 17 is solidified to form an aluminum lump, and the aluminum lump may adhere to the plating film 18 of the hot dip galvanized steel wire 3 as a foreign matter.

  Accordingly, in order to prevent foreign matter such as an aluminum lump from adhering to the surface of the molten aluminum plated steel wire 3 by suppressing the tip 17a of the meniscus 17 from extending excessively upward, a molten aluminum plating bath 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 at the boundary between the molten aluminum plated steel wire 3 pulled up from 1 and the bath surface 10 of the molten aluminum plating bath 1. A nozzle 12 for spraying an inert gas is disposed at a position facing the stabilizing member 11 via the hot-dip aluminized steel wire 3.

  FIG. 4 shows a boundary portion between the steel wire 2 and the bath surface 10 of the molten aluminum plating bath 1 when the steel wire 2 is pulled up from the molten aluminum plating bath 1 in the method for producing a molten aluminum plated steel wire of the present invention. It is a schematic explanatory drawing.

  Examples of the stabilizing member 11 include a stainless steel square bar having a heat-resistant cloth material 11a wound around the surface thereof. Examples of the heat-resistant cloth material 11a include woven fabrics and non-woven fabrics containing heat-resistant fibers such as ceramic fibers, carbon fibers, aramid fibers, and imide fibers, but the present invention is limited only to such examples. is not. The heat-resistant cloth material 11a has a surface (new surface) on the surface of the heat-resistant cloth material 11a to which aluminum is not adhered to the surface of the molten aluminum-plated steel wire 3 to prevent the aluminum lump from adhering. It is preferable to contact with.

  The stabilizing member 11 is preferably brought into contact with both the bath surface 10 of the molten aluminum plating bath 1 and the molten aluminum plated steel wire 3 simultaneously. Thus, when the stabilizing member 11 is simultaneously brought into contact with both the bath surface 10 of the molten aluminum plating bath 1 and the molten aluminum plated steel wire 3, the pulsation of the bath surface 10 of the molten aluminum plating bath 1 is suppressed. As a result, the pulsation of the meniscus 17 is suppressed, so that the plating film 18 can be uniformly formed on the surface of the steel wire 2. When the stabilizing member 11 is brought into contact with the hot dip galvanized steel wire 3, tension is applied to the hot dip galvanized steel wire 3 as necessary from the viewpoint of suppressing minute vibration of the hot dip aluminum plated steel wire 3. In order to do so, the stabilizing member 11 may be lightly pressed against the hot-dip aluminized steel wire 3.

  A nozzle 12 for spraying an inert gas is disposed at a position facing the stabilizing member 11 via the hot-dip aluminum-plated steel wire 3. The tip 12 a of the nozzle 12 is disposed so that an inert gas can be blown onto the boundary between the molten aluminum plated steel wire 3 and the bath surface 10 of the molten aluminum plating bath 1. The distance (shortest distance) from the molten aluminum plated steel wire 3 to the tip 12a of the nozzle 12 avoids contact between the tip 12a of the nozzle 12 and the molten aluminum plated steel wire 3, and efficiently produces the molten aluminum plated steel wire 3. In view of the above, the molten aluminum is preferably 1 mm or more, and even when the bath temperature of the molten aluminum plating bath 1 is low, the thin portion of the plating film is hardly formed, and the aluminum lump is hardly attached to the surface. From the viewpoint of obtaining the plated steel wire 3, it is preferably 50 mm or less, more preferably 40 mm or less, still more preferably 30 mm or less, still more preferably 10 mm or less, and even more preferably 5 mm or less.

  The inner diameter of the tip 12a of the nozzle 12 is melted by accurately blowing the inert gas discharged from the tip 12a of the nozzle 12 to the boundary portion between the molten aluminum plating steel wire 3 and the bath surface 10 of the molten aluminum plating bath 1. From the viewpoint of efficiently producing the aluminum-plated steel wire 3, it is preferably 1 mm or more, more preferably 1.5 mm or more, and there is almost no thin portion of the plating film 18 and almost no aluminum lump adheres to the surface. From the viewpoint of obtaining the hot-dip aluminum-plated steel wire 3, it is preferably 18 mm or less, more preferably 15 mm or less, and even more preferably 12 mm or less.

  For example, the inert gas can be supplied to the nozzle 12 from the inert gas supply device 13 shown in FIG. 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.

  An inert gas means a gas that is inert to the molten aluminum. Examples of the inert gas include nitrogen gas, argon gas, helium gas, and the like, but the present invention is not limited to such examples. Of the inert gases, nitrogen gas is preferred. Note that the inert gas may contain, for example, oxygen gas, carbon dioxide gas, or the like within a range that does not impair the object of the present invention.

  The pressure of the inert gas discharged from the tip 12a of the nozzle 12 is adjusted to 0.01 to 10 kPa, and the temperature of the inert gas is adjusted to 600 to 1000 ° C. In the present invention, after the steel wire 2 is immersed in the molten aluminum plating bath 1, when the steel wire 2 is pulled up from the molten aluminum plating bath 1, the molten aluminum plated steel wire 3 and the molten aluminum plating bath 1 are bathed from the tip 12 a of the nozzle 12. While adjusting the pressure of the inert gas for spraying on the boundary with the surface 10 to 0.01 to 10 kPa and adjusting the temperature of the inert gas to 600 to 1000 ° C., the bath temperature of the molten aluminum plating bath 1 is Even at a low temperature, it is possible to efficiently obtain a hot-dip galvanized steel wire 3 in which a portion with a thin thickness of the plating film 18 hardly occurs.

  Further, in the present invention, the pressure of the inert gas at the tip 12a of the nozzle 12 is adjusted to 0.01 to 10 kPa, the temperature of the inert gas is adjusted to 600 to 1000 ° C. When the speed is adjusted to 200 m / min or less, since the scattering of the oxide film formed on the bath surface of the molten aluminum plating bath 1 is suppressed, the bath temperature of the molten aluminum plating bath 1 is low. In addition, it is possible to efficiently obtain a hot-dip aluminum-plated steel wire 3 in which a portion with a thin thickness of the plating film 18 does not occur and an aluminum lump hardly adheres to the surface.

  The pressure of the inert gas discharged from the tip 12a of the nozzle 12 is such that even if the bath temperature of the molten aluminum plating bath 1 is low, a molten aluminum plated steel wire 3 with almost no aluminum lump adhering to the surface is obtained. From the viewpoint of obtaining a hot-dip aluminum-plated steel wire 3 in which a portion having a thin thickness of the plating film 18 is hardly generated even when the bath temperature of the hot-dip aluminum plating bath 1 is low, 0.01 kPa or more. , Preferably 8 kPa or less, more preferably 5 kPa or less.

  The pressure of the inert gas discharged from the tip 12a of the nozzle 12 is a stainless steel having an inner diameter of 0.5 mm in the inert gas in the nozzle 12 at a distance of 2 mm from the tip 12a of the nozzle 12. This is a value when a manufactured tube is inserted so that the tip of the tube and the tip 12a of the nozzle 12 face each other, and the gas pressure of the inert gas applied to the tip of the tube is measured by a pressure sensor.

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

  On the other hand, in the present invention, even when the bath temperature of the molten aluminum plating bath 1 is low, the temperature of the inert gas discharged from the tip 12a of the nozzle 12 is adjusted to 600 ° C. or higher. A hot-dip galvanized steel wire 3 can be obtained in which aluminum lumps hardly adhere to the surface.

  Even when the temperature of the inert gas discharged from the tip 12a of the nozzle 12 is a low temperature of the molten aluminum plating bath 1, a portion with a thin thickness of the plating film 18 is hardly generated, and an aluminum lump is formed on the surface. From the viewpoint of obtaining a molten aluminum-plated steel wire 3 that hardly adheres, it is 600 ° C. or higher, preferably 620 ° C. or higher, and if it is too high, the thermal efficiency decreases, so that it is 1000 ° C. or lower, preferably 800 ° C. or lower, More preferably, it is 750 degrees C or less.

  The temperature of the inert gas discharged from the tip 12a of the nozzle 12 is, for example, a sheath thermoelectric having a diameter of 1.6 mm in the inert gas at a distance of 2 mm from the tip 12a of the nozzle 12. It is a value when measured by inserting a thermocouple for temperature measurement such as a pair.

  The volume flow rate of the inert gas discharged from the tip 12a of the nozzle 12 is preferably 5 L (liter) / min or more, more preferably 8 L / min or more, more preferably from the viewpoint of efficiently preventing oxidation of the surface of the meniscus 17. Preferably, it is 10 L / min or more, and even when the bath temperature of the molten aluminum plating bath 1 is low, a portion with a thin thickness of the plating film 18 is hardly formed, and an aluminum lump is hardly adhered to the surface. From the viewpoint of obtaining the steel wire 3, it is preferably 150 L / min or less, more preferably 120 L / min or less, still more preferably 100 L / min or less.

  The pulling speed at the time of pulling up the molten aluminum plated steel wire 3 from the bath surface 10 of the molten aluminum plating bath 1 is not particularly limited, and exists on the surface of the molten aluminum plated steel wire 3 by appropriately adjusting the pulling speed. Since the average thickness of the plating film 18 can be adjusted, it is preferable to adjust appropriately according to the average thickness of the plating film 18.

  In order to cool the hot-dip aluminum-plated steel wire 3 in the process of lifting the hot-dip aluminum-plated steel wire 3 and to solidify the plating film 18 formed on the surface efficiently, as shown in FIG. The cooling device 15 may be disposed above the nozzle 12. In the cooling device 15, for example, the molten aluminum plated steel wire 3 can be cooled by spraying gas, liquid mist, or the like onto the molten aluminum plated steel wire 3.

  As shown in FIG. 1, the hot-dip aluminized steel wire 3 manufactured as described above can be collected by, for example, a winding device 16.

  The average thickness of the plating film 18 existing on the surface of the hot-dip aluminum-plated steel wire 3 suppresses the base steel wire 2 from being exposed to the outside during stranded wire processing, caulking processing, etc. From the viewpoint of increasing the mechanical strength, it is preferably about 5 to 10 μm.

  Further, the minimum thickness of the thin portion of the plating film 18 existing on the surface of the hot-dip aluminum-plated steel wire 3 suppresses the base steel wire 2 from being exposed to the outside during stranded wire processing, caulking processing, and the like. From the viewpoint of increasing the mechanical strength per unit diameter, it is preferably 1 μm or more, more preferably 2 μm or more.

  From the viewpoint of efficiently forming a smooth plating film 18 on the steel wire 2, the surface of the steel wire 2 may be pre-plated before the steel wire 2 is immersed in the molten aluminum plating bath 1. . Examples of the metal constituting the pre-plating treatment include zinc, nickel, chromium, and alloys thereof, but the present invention is not limited to such examples. Moreover, the plating 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 plating films 18 made of the same or different metals.

  The hot-dip aluminized steel wire 3 obtained above may be subjected to wire drawing using a die or the like, if necessary, so as to have a desired outer diameter.

  The hot-dip aluminum-plated steel wire 3 obtained by the method for manufacturing hot-dip aluminum-plated steel wire of the present invention can be suitably used for, for example, an automobile wire harness.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to this Example.

Examples 1 to 98 and Comparative Examples 1 to 11
In each Example and each Comparative Example, a hot dip galvanized steel wire was manufactured according to the embodiment of the method of manufacturing the galvanized steel wire shown in FIG.

  Steel wires having the diameters shown in the following tables as the steel wires and made of the steel types shown in each table, and the surface of the steel wires not subjected to galvanizing treatment (of "pre-Zn" in each table) Columns with “No” in the column) or those having a galvanized film with an average thickness of 5 μm or less (indicated with “Presence” in the “Pre-Zn” column of each table) were used. 37A described in the column of steel types in Tables 4 and 5 means a steel wire made of hard steel containing 0.37% by mass of carbon.

  The steel wire not subjected to galvanization was degreased by dipping in a sodium orthosilicate degreasing solution containing a surfactant before dipping in a molten aluminum plating bath.

  Further, before the steel wire was immersed in the molten aluminum plating bath, the steel wire was passed through the steel wire introduction part control device 8 shown in FIG. 2, and the steel wire was preheated to about 400 ° C. by the heating device 6. Nitrogen gas was used as the heating gas. The preheating temperature was measured by preparing a steel wire connected to a thermocouple and passing the thermocouple together with the steel wire through a heating device 6 maintained at a predetermined temperature.

  Further, as the bath surface control device 7 used in the steel wire introduction portion control device 8 shown in FIG. 2, as shown in FIG. 3, the opening 9d and the exhaust port 9d in the introduction port 9c of the through hole 9a of the tubular body 9 are provided. The ratio of the area of the opening of the through-hole 9a of the tubular body 9 to the area of the cross section of the steel wire using the bath surface control device 7 having the same shape, size and area of the opening 9f at the outlet 9e [ The area of the opening of the through-hole 9a of the tubular body 9 / the area in the cross section of the steel wire] is set to 57, and the steel wire is immersed in a molten aluminum plating bath for 1 to 3 seconds via the bath surface control device 7 I let you.

  As a molten aluminum plating bath, a molten aluminum plating bath (aluminum purity: 99.7% or more, indicated as “Al” in the column of “type of molten Al plating” in each table), a molten containing 4% by mass of silicon Aluminum plating bath (indicated as “4% Si” in the “Type of molten Al plating” column in each table), molten aluminum plating bath containing 8% by mass of silicon (“Type of molten Al plating” in each table) Column, “8% Si”), a molten aluminum plating bath containing 11% by mass of silicon (indicated as “11% Si” in the “type of molten Al plating” column in each table), or 13% by mass Using a molten aluminum plating bath containing silicon (indicated as “13% Si” in the column of “type of molten Al plating” in each table), the wire speed (steel wire) shown in each table at the bath temperature shown in each table At the lifting speed) After immersion line in the molten aluminum plating bath, raised from the molten aluminum plating bath.

  At that time, a stabilizing member having a width of 40 mm was brought into contact with the bath surface and the molten aluminum plating steel wire at the boundary between the molten aluminum plating steel wire pulled up from the molten aluminum plating bath and the bath surface of the molten aluminum plating bath. In addition, the contact length of the hot-dip aluminum plating steel wire and the heat resistant cloth material was adjusted to 5 mm using a stainless steel square bar with a heat resistant cloth material wound on the surface as a stabilizing member.

  In addition, a nozzle having the inner diameter of the tip shown in each table is arranged so that the tip of the nozzle is located at a position 2 mm away from the hot-dip aluminized steel wire, and the temperature shown in each table is adjusted from the tip of the nozzle. The inert gas (nitrogen gas) was sprayed on 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 each table.

  By performing the above operations, a hot-dip galvanized steel wire on which a plating film having the average thickness and the minimum thickness of the thin portion shown in each table was formed was obtained.

  In addition, the measuring method of the average thickness of a plating film is shown below. Moreover, the measuring method of the minimum thickness of a thin part is described in the column of the following "(2) Measurement of the minimum thickness of the thin part of a plating film".

[Measurement method of average thickness of plating film]
The measurement of the average thickness of the plating film of the hot-dip aluminum-plated steel wire obtained in each example and each comparative example was performed based on the embodiment shown in FIG. FIG. 5 is a schematic explanatory view showing one embodiment of a method for measuring the average thickness of the plated film of the hot-dip aluminum-plated steel wire obtained in each example and each comparative example.

  As shown in FIG. 5, the wire-type steel wire diameter measuring device 19 is arranged in the horizontal direction at a center portion between a pair of pulleys 19c and 19d arranged in the vertical direction and between the pulley 19c and the pulley 19d. A wire-type steel wire diameter measuring device 19 having two optical outer diameter measuring instruments [manufactured by Keyence Corporation, product number: LS-7000] having a pair of light emitting section 19a and light receiving section 19b provided was used. A pair of light-emitting portions 19a and light-receiving portions 19b are opposed to each other, and the adjacent light-emitting portions 19a and light-receiving portions 19b are disposed at an angle of 90 ° as shown in FIG.

  Melting while running between the pulley 19c and the pulley 19d in the direction of arrow F at a speed of 100 m / min through the 100 m long molten aluminized steel wire 3 obtained in each example or each comparative example The outer diameter of the hot-dip aluminum-plated steel wire 3 was measured by a through-wire-type steel wire diameter measuring device 19 at intervals of about 1.4 mm in the length direction of the aluminum-plated steel wire 3. In addition, the number of measurement points of the outer diameter was about 71,000 points.

  Next, the average value of the outer diameter of the hot-dip aluminized steel wire measured above is obtained, and the diameter of the steel wire before forming the plating film (the diameter of the steel wire shown in each table below) is subtracted from the average value. Then, the average value of the plating film was determined by dividing the obtained value by 2. The results are shown in each table.

[Evaluation of plating film performance]
As the performance of the hot-dip galvanized steel wire obtained above, the adhesion of the aluminum block and the stability of the minimum thickness of the thin part of the plating film were examined based on the following methods. The results are shown in each table.

(1) Adhesiveness of aluminum lump A 300 m long molten aluminum plated steel wire is run at a line speed of 100 m / min, and the outer diameter of the molten aluminum plated steel wire is measured over the entire length of the molten aluminum plated steel wire. The presence or absence of a convex portion having a locally increased outer diameter was examined. It was visually observed whether or not the aluminum lump was attached to the convex portion having a locally large outer diameter, and the adhesion of the aluminum lump was evaluated based on the following evaluation criteria. In addition, the outer diameter of the hot-dip aluminum-plated steel wire was measured using an optical outer diameter measuring instrument [manufactured by Keyence Corporation, product number: LS-7000].

(Evaluation criteria)
○: Adhesion of aluminum lump is not recognized.
X: Adhesion of aluminum lump is recognized.

(2) Measurement of the minimum thickness of the thin part of the plating film In order to obtain the minimum thickness of the thin part of the plating film, the cross section of the hot-dip aluminized steel wire was observed. More specifically, a 300 mm test specimen was arbitrarily cut out from a hot-dip aluminized steel wire, and after six test pieces were further cut out from the test specimen, the test specimen was embedded in a resin and embedded. By cutting the resin and polishing the cut surface, the cross section of the hot-dip aluminized steel wire was exposed. This cross section was observed with an optical microscope (magnification: 500 times), and the minimum thickness of the thin portion of the plating film was measured. Of the minimum thicknesses of the thin portions of the plating film measured for the six test pieces, the smallest thickness was defined as the minimum thickness of the thin portion of the plating film.

(3) Stability of the minimum thickness of the thin part of the plating film From the minimum thickness of the thin part of the plating film obtained above, the stability of the minimum thickness of the thin part of the plating film is determined based on the following evaluation criteria. evaluated.

(Evaluation criteria)
A: The minimum thickness of the thin part of the plating film is 2 μm or more. ○: The minimum thickness of the thin part of the plating film is 1 μm or more and less than 2 μm. X: The minimum thickness of the thin part of the plating film is less than 1 μm.

(4) Comprehensive evaluation Based on the evaluation result of the adhesiveness of an aluminum lump and the stability of the minimum thickness of the thin part of a plating film, comprehensive evaluation was performed according to the following evaluation criteria.

(Evaluation criteria)
(Double-circle): The evaluation of the adhesiveness of an aluminum lump is (circle), and the evaluation of the stability of the minimum thickness of the thin part of a plating film is (double) (excellent).
○: The aluminum lump adhesion and the evaluation of the plating film are both good (excellent).
X: The evaluation of x exists in the evaluation of adhesion of an aluminum lump and a plating film (failure).

  According to each Example, as shown in Tables 1 to 4, the pressure of the inert gas for spraying on the boundary between the steel wire and the bath surface of the molten aluminum plating bath is adjusted to 0.01 to 10 kPa. In addition, since the temperature of the inert gas is adjusted to 600 to 1000 ° C., it is difficult to produce a thin part of the plating film, and it is efficient to use a molten aluminum plated steel wire in which aluminum lump is difficult to adhere to the surface. It turns out that it can manufacture well. Furthermore, according to Example 35, Example 39, Example 43, Example 49, and Example 53, as described in Table 2, the bath temperature of the molten aluminum plating bath is higher than the melting point of the molten aluminum plating bath. Even if the temperature is higher than 15 ° C. and lower than 20 ° C. higher than the melting point of the molten aluminum plating bath, a portion having a thin plating film is hardly formed, and the surface is made of aluminum. It turns out that the hot dip aluminized steel wire to which a lump cannot adhere easily can be manufactured efficiently.

  On the other hand, according to Comparative Example 1, Comparative Example 2, Comparative Example 6 and Comparative Example 7, as shown in Table 5, the non-sprayed spray was applied to the boundary between the steel wire and the bath surface of the molten aluminum plating bath. Since the temperature of the active gas is lower than 600 ° C., the molten aluminum plating bath is difficult to adhere to the surface when the bath temperature of the molten aluminum plating bath is 20 ° C. or higher than the melting point of the molten aluminum plating bath. It turns out that a plated steel wire cannot be manufactured.

  Further, according to Comparative Examples 3 to 5 and Comparative Examples 8 to 11, as shown in Table 5, the bath temperature of the molten aluminum plating bath is adjusted to a temperature 20 ° C. higher than the melting point of the molten aluminum plating bath. Even though the pressure of the inert gas sprayed on the boundary between the steel wire and the bath surface of the molten aluminum plating bath is outside the range of 0.01 to 10 kPa, a portion with a thin plating film is generated. It can be seen that it is difficult to produce a hot-dip aluminized steel wire in which aluminum lump is difficult to adhere to the surface.

  The hot-dip aluminized steel wire obtained by the production method of the present invention can be suitably used for, for example, an automobile wire harness.

DESCRIPTION OF SYMBOLS 1 Hot dip aluminum plating bath 2 Steel wire 3 Hot dip aluminum plating steel wire 4 Delivery device 5 Plating bath 6 Heating device 6a Heating device main body 6b Heating device main body 6c Heating device main body heating gas vent 6d Heating device main body lower end 6e Heating Branch pipe of apparatus body 7 Bath surface control device 7a Upper end of bath surface control device 8 Steel wire introduction part control device 9 Tubular body 9a Tubular through-hole 9b Tubular body immersion area 9c Tubular body inlet 9d Tubular body introduction Opening portion in the mouth 9e Exhaust port of the tubular body 9f Opening portion in the discharge port of the tubular body 10 Bath surface of the molten aluminum plating bath 11 Stabilizing member 11a Heat resistant cloth material of the stabilizing member 12 Nozzle 12a Nozzle tip 13 Inert gas supply Device 14 Piping 15 Cooling device 16 Winding device 17 Meniscus 17a Meniscus tip 18 Plating film 19 Wire-type steel wire diameter measuring device 19a Light-emitting portion 19b of wire-type steel wire diameter measuring device Light-receiving portion 19c of wire-type steel wire diameter measuring device Pulley 19d Wire-type steel wire diameter measuring device 19d Wire-type steel wire diameter Measuring device pulley

Claims (4)

  A method for producing 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, wherein the steel wire is immersed in the molten aluminum plating bath. After dipping, the stabilizing member is attached to the boundary between the molten aluminum plated steel wire pulled up from the molten aluminum plating bath and the molten aluminum plating bath, and the molten aluminum plated bath and the molten aluminum plated steel. A nozzle for injecting an inert gas at a position facing the stabilizing member via the hot-dip aluminum-plated steel wire, and 600 to 1000 ° C. from the tip of the nozzle to the boundary portion It is characterized by spraying an inert gas having a temperature at a pressure of 0.01 to 10 kPa. Method for producing a fusion aluminum plated steel wire.   The method for producing a hot-dip galvanized steel wire according to claim 1, wherein the steel wire is a steel wire made of carbon steel or stainless steel.   The manufacturing method of the hot dip aluminum plating steel wire of Claim 1 or 2 which adjusts the bath temperature of a hot dip aluminum plating bath so that it may become 15 degreeC or more higher than melting | fusing point of the said hot dip aluminum plating bath.   The steel wire is immersed in a molten aluminum plating bath, and then the wire speed of the steel wire is adjusted to 10 to 200 m / min when the steel wire is continuously pulled up from the molten aluminum plating bath. The manufacturing method of the hot dip galvanized steel wire in any one.

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