JP6228259B2 - Hot-dip aluminized steel wire - Google Patents

Description

  The present invention relates to a hot-dip aluminized steel wire. More specifically, the present invention relates to a hot dip galvanized steel wire that is excellent in twistability and can be suitably used for, for example, an automobile wire harness, and a method for manufacturing the same.

  In the present specification, “molten aluminum plating” in a hot-dip aluminum-plated steel wire indicates the type of aluminum plating, and the hot-dip aluminum-plated steel wire is obtained by immersing the steel wire in a hot-dip aluminum plating bath. The steel wire by which aluminum plating was given by pulling up a steel wire from the said molten aluminum plating bath continuously is meant. Moreover, twistability means the property which is not easily broken when twisting occurs in the steel wire.

  For electric wires used in automobile wire harnesses, etc., multiple hot-dip aluminum-plated steel wires, such as seven or nineteen, that have been subjected to hot-dip aluminum plating on steel core wires, are twisted into the hot-dip aluminum-plated steel wires. The twisted wire obtained by giving is used. When producing a stranded wire, twisting occurs in the molten aluminum plated steel wire constituting the stranded wire, and when the twist of the molten aluminum plated steel wire increases, the molten aluminum plated steel wire comes to break, An index is required to prevent the twisted fracture from occurring in the hot-dip aluminized steel wire.

As a hot-dip galvanized steel wire with improved resistance to twisting, a hot-dip galvanized steel wire that has not been subjected to wire drawing after hot-dip aluminum plating and has a steel core wire with a diameter of 0.05 to 0.50 mm as a core material. The average diameter D _A (mm) and the minimum diameter D _MIN (mm) in the longitudinal direction are _expressed by the formula (1):
(D _A −D _MIN ) / D _A ≦ 0.10 (1)
There has been proposed a hot-dip aluminum-plated steel wire in which the amount of hot-dip aluminum plating is made uniform so as to satisfy the requirements (see claims 1 and 2 of Patent Document 1). In the hot dip galvanized steel wire, it is required to satisfy the above formula (1) in order to ensure the twist resistance that the number of times of rupture twist per 100 mm of the hot dip galvanized steel wire is 50 times or more. (See paragraph [0022] of Patent Document 1).

JP 2014-185355 A

  In the hot-dip aluminum-plated steel wire, a hard steel wire is used as the element wire (see paragraph [0034] of Patent Document 1). The elongation of the hard steel wire is approximately 5% or less, and when the hard steel wire is subjected to wire drawing to a hot-dip aluminized steel wire used as a strand, the twistability is significantly reduced. The hot-dip aluminized steel wire is used in a state in which no wire drawing is performed (see paragraph [0023] of Patent Document 1).

  However, when hot-dip aluminum plating is applied to a steel wire having an elongation at break of 30% or more, such as an austenitic stainless steel wire, which is longer than a hard steel wire, the relationship represented by the above formula (1) is satisfied. Even if not, the number of twists at the time of breaking per 100 mm length of the hot-dip aluminum-plated steel wire is often several hundred times, and the hot-dip aluminum-plated steel wire has a certain degree of twist even if it is drawn. Has roundness.

  In recent years, steel wires that are stretched more than hard steel wires have been used for strands used in stranded wire processing, and wire drawing processing that is superior in twistability when performing stranded wire processing has been performed. Development of hot-dip aluminized steel wire is desired.

  This invention is made | formed in view of the said prior art, and it aims at providing the hot dip galvanized steel wire excellent in the twist property at the time of performing a twisted wire process, and its manufacturing method.

The present invention
(1) A hot-dip galvanized steel wire having a plating layer on the surface of a steel wire having a diameter of 0.1 to 0.4 mm, the elongation at break being 5 to 30%, and the hot-dip galvanized steel wire The ratio of the average diameter per 100 mm length of the steel wire from which the plating layer is removed from the minimum diameter of the steel wire is represented by the formula (I):
[Minimum diameter / average diameter] ≧ [1- (Elongation at break (%) / 100)] (I)
(In the formula, the elongation at break is the elongation at break of the hot-dip aluminized steel wire after wire drawing, in accordance with “Metal Material Tensile Test Method” stipulated in JIS Z2241, the original gage distance is 100 ± 1 mm. The distance between the grips is set to 150 mm, and it is described in the column of Appendix C “Types of linear or bar-shaped specimens used for lines and bars having a diameter or side of less than 4 mm” in JIS Z2241. (Shown when measured using a 9A test piece)
And (2) a method for producing a molten aluminum plated steel wire having a plating layer on the surface of a steel wire having a diameter of 0.1 to 0.4 mm, wherein the molten aluminum plated steel wire is melted. The ratio of the average diameter per 100 mm length of the steel wire from which the plating layer has been removed from the aluminum-plated steel wire to the minimum diameter of the steel wire is represented by the formula (I):
[Minimum diameter / average diameter] ≧ [1- (Elongation at break (%) / 100)] (I)
(In the formula, the elongation at break is the elongation at break of the hot-dip aluminized steel wire after wire drawing, in accordance with “Metal Material Tensile Test Method” stipulated in JIS Z2241, the original gage distance is 100 ± 1 mm. The distance between the grips is set to 150 mm, and it is described in the column of Appendix C “Types of linear or bar-shaped specimens used for lines and bars having a diameter or side of less than 4 mm” in JIS Z2241. (Shown when measured using a 9A test piece)
And a hot-dip galvanized steel wire is subjected to wire drawing so that the elongation at break of the hot-dip galvanized steel wire is 5 to 30%.

  ADVANTAGE OF THE INVENTION According to this invention, the hot dip aluminized steel wire excellent in the twist property at the time of performing a twisted wire process, and its manufacturing method are provided.

It is a schematic explanatory drawing which shows one embodiment at the time of manufacturing the hot-dip aluminized steel wire of this invention. When manufacturing the hot-dip aluminum plating steel wire of this invention, it is a schematic sectional drawing of the boundary part of the steel wire and the bath surface of a hot-dip aluminum plating bath when pulling up a steel wire from a hot-dip aluminum plating bath. It is a schematic explanatory drawing of the twist test apparatus of the hot-dip aluminum plating steel wire used by each Example and each comparative example of this invention.

  Hereinafter, an embodiment of a method for producing a hot-dip aluminized steel wire of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment.

  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. FIG. 2 is a schematic cross-sectional view of the boundary between the steel wire and the bath surface of the molten aluminum plating bath when the steel wire is pulled up from the molten aluminum plating bath when the hot-dip aluminum plated steel wire of the present invention is manufactured.

  In the present invention, after the steel wire 2 is immersed in the molten aluminum plating bath 1, the molten aluminum plated steel wire 3 is manufactured by continuously pulling up the molten aluminum plated steel wire 3 from the molten aluminum plating bath 1. Can do.

  Examples of the steel material constituting the steel wire 2 include stainless steel and mild 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 stainless steel, ferritic stainless steel, martensitic stainless steel and the like as defined in JIS G4309, but the present invention is limited only to such examples. is not. 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, SUS410, 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.

  Examples of the mild steel include steel materials defined in JIS G3532 iron wire and steel materials defined in JIS G3505 mild steel wire standards, but the present invention is not limited to such examples.

  Among the steel materials 2, stainless steel is preferable from the viewpoint of increasing the tensile strength of the hot dip galvanized steel wire 3.

  The diameter of the steel wire 2 before the wire drawing is not particularly limited, and it is preferable to adjust appropriately according to the use of the hot-dip aluminized steel wire 3. For example, when the hot-dip aluminized steel wire 3 is used for an application such as an automobile wire harness, the diameter of the steel wire 2 before wire drawing is usually preferably about 0.2 to 0.4 mm.

  In FIG. 1, a steel wire 2 is sent out from a feeding device 4 for the steel wire 2, continuously conveyed in the direction of arrow A, and immersed in a molten aluminum plating bath 1 in a plating bath 5. By pulling the steel wire 2 immersed in the molten aluminum plating bath 1 vertically upward from the bath surface 6 of the molten aluminum plating bath 1, the molten aluminum plated steel wire 3 having the molten aluminum plating bath 1 attached to the surface of the steel wire 2. Is obtained.

  Since the coating (plating layer) to which the molten aluminum plating bath 1 adheres is formed on the surface of the molten aluminum plated steel wire 3, the molten aluminum plated steel wire 3 is adhered to the aluminum strand. Excellent in tensile strength and electrical resistance over time.

  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 coating can be increased, and as a result, the tensile strength of the hot dip galvanized steel wire 3 can be increased. Among the other elements, although it depends on the type of steel wire, it suppresses the formation of an iron-aluminum alloy layer having brittleness between iron contained in the steel wire and aluminum contained in the coating. From the viewpoint of efficiently plating the steel wire 2 by increasing the mechanical strength of the plating film and lowering the melting point of the molten aluminum plating bath 1, silicon is preferable.

  The lower limit of the content of the other element in the coating is 0% by mass, but preferably 0.3% by mass or more, more preferably 0.8% from the viewpoint of sufficiently expressing the properties of the other element. 5% by mass or more, more preferably 1% by mass or more, and preferably 50% by mass or less, more preferably from the viewpoint of suppressing potential difference corrosion due to contact with an aluminum strand used when producing a stranded wire. It is 20 mass% or less, More preferably, it is 15 mass% or less.

  In addition, elements such as Fe, Cr, Ni, Zn, and Cu may be inevitably mixed into the molten aluminum plating bath 1.

  When the steel wire 2 is pulled up from the molten aluminum plating bath 1, as shown in FIG. 2, the stabilizing member 7 is attached to the steel wire 2 at the boundary between the steel wire 2 and the bath surface 6 of the molten aluminum plating bath 1. Is preferably brought into contact.

  Examples of the stabilizing member 7 include a stainless steel square bar having a heat-resistant cloth wound around the surface. The heat resistant cloth wound around the stabilizing member 7 has a new surface (new surface) of the stabilizing member 7 as a steel wire 2 from the viewpoint of suppressing adhesion of molten aluminum lump to the surface of the molten aluminum plated steel wire 3. It is preferable to contact with. The new surface (new surface) of the stabilizing member 7 is, for example, using the stabilizing member 7 on which a heat-resistant cloth is wound in advance, and pulling up the steel wire 2 while bringing the stabilizing member 7 into contact with the steel wire 2. Sometimes, the heat-resistant cloth can be formed by winding up sequentially.

  The stabilizing member 7 is preferably brought into contact with both the bath surface 6 of the molten aluminum plating bath 1 and the steel wire 2 simultaneously. When the stabilizing member 7 is simultaneously brought into contact with both the bath surface 6 of the molten aluminum plating bath 1 and the steel wire 2, pulsation of the bath surface 6 of the molten aluminum plating bath 1 is suppressed, and the steel wire When the steel wire 2 is pulled up while being in contact with the stabilizing member 7, it is possible to suppress the fine vibration of the steel wire 2. As a result, the coating of the molten aluminum plating bath 1 can be uniformly formed on the surface of the steel wire 2. . In addition, when making the stabilization member 7 contact the steel wire 2, from the viewpoint of suppressing the minute vibration of the steel wire 2, the stabilization member 7 is used in order to apply tension to the steel wire 2 as necessary. May be pressed lightly against the steel wire 2.

  In the embodiment shown in FIG. 1, a nozzle 8 is provided for blowing an inert gas toward the boundary between the steel wire 2 and the bath surface 6 of the molten aluminum plating bath 1. For example, the inert gas can be supplied from the inert gas supply device 9 to the nozzle 8 via the pipe 10. In order to adjust the flow rate of the inert gas in the inert gas supply device 9 or in the pipe 10, for example, a flow rate control device (not shown) such as a valve may be provided.

  In the present invention, the distance from the steel wire 2 to the tip 8a of the nozzle 8 (shortest distance) and the temperature of the inert gas discharged from the tip 8a of the nozzle 8 are appropriately controlled, and the tip of the nozzle 8 is Since the inner diameter and the volume flow rate of the inert gas discharged from the nozzle 8 are appropriately controlled, the molten aluminum plated steel wire 3 having a uniform wire diameter and almost no molten aluminum lump attached to the surface can be efficiently obtained. Can be manufactured.

  The inner diameter of the tip of the nozzle 8 is determined by spraying an inert gas discharged from the tip 8a of the nozzle 8 onto the boundary between the steel wire 2 and the bath surface 6 of the hot-dip aluminum plating bath 1 so that the hot-dip aluminum-plated steel is obtained. From the viewpoint of efficiently producing the wire 3, preferably 1 mm or more, more preferably 2 mm or more, from the viewpoint of obtaining a molten aluminum-plated steel wire 3 having a uniform wire diameter and almost no molten aluminum lump adhering to the surface. Preferably it is 15 mm or less, More preferably, it is 10 mm or less, More preferably, it is 5 mm or less.

  The distance (shortest distance) from the steel wire 2 to the tip 8a of the nozzle 8 is preferably 1 mm or more from the viewpoint of avoiding contact with the steel wire 2 and efficiently producing the hot-dip aluminized steel wire 3. From the viewpoint of obtaining a molten aluminum-plated steel wire 3 having a uniform diameter and almost no molten aluminum lump attached to the surface, it is preferably 50 mm or less, more preferably 40 mm or less, still more preferably 30 mm or less, and even more preferably 10 mm or less. is there.

  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 volume flow rate of the inert gas discharged from the tip 8a of the nozzle 8 is preferably 2 L (liter) from the viewpoint of obtaining a molten aluminum-plated steel wire 3 having a uniform wire diameter and almost no molten aluminum lump adhering to the surface. / Min or more, more preferably 5 L / min or more, and even more preferably 10 L / min or more, and the viewpoint of suppressing adhesion of molten aluminum lump to the surface of the molten aluminum plated steel wire 3 due to scattering of the molten aluminum plating bath 1 Therefore, it is preferably 200 L / min or less, more preferably 150 L / min or less, and still more preferably 100 L / min or less.

  The temperature of the inert gas discharged from the tip 8a of the nozzle 8 is preferably 200 ° C. or higher from the viewpoint of obtaining a molten aluminum-plated steel wire 3 having a uniform wire diameter and almost no molten aluminum lump attached to the surface. Preferably it is 300 degreeC or more, More preferably, it is 400 degreeC or more, and since heat efficiency will fall when too high, Preferably it is 800 degrees C or less, More preferably, it is 780 degrees C or less, More preferably, it is 750 degrees C or less. The temperature of the inert gas discharged from the tip 8a of the nozzle 8 is measured by inserting a thermocouple for temperature measurement into the inert gas at the tip 8a portion of the nozzle 8 discharged from the tip 8a of the nozzle 8. This is the value when

  The pulling speed at the time of pulling up the molten aluminum plated steel wire 3 from the bath surface 6 of the molten aluminum plating bath 1 is not particularly limited, and is present on the surface of the molten aluminum plated steel wire 3 by appropriately adjusting the pulling speed. Since it is possible to adjust the average thickness of the molten aluminum plating film, it is preferable to appropriately adjust according to the average thickness of the molten aluminum plating film.

  In order to cool the hot-dip aluminum-plated steel wire 3 in the process of being pulled up and to efficiently solidify the aluminum plating film formed on the surface, as shown in FIG. May be. In the cooling device 11, the molten aluminum plated steel wire 3 can be cooled by spraying, for example, gas, liquid mist or the like onto the molten aluminum plated steel wire 3.

  The hot dip galvanized steel wire 3 manufactured as described above can be collected by, for example, the winding device 12.

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

  In addition, the plating layer may be formed as an intermediate | middle layer between the steel wire 2 of the hot-dip aluminum plating steel wire 3, and the hot-dip aluminum plating film. Examples of the metal constituting the plating layer include zinc, nickel, chromium, and alloys thereof, but the present invention is not limited to such examples. Moreover, the molten aluminum plating film may be formed of only one layer, or a plurality of plating films made of the same or different metals may be formed.

  The hot-dip galvanized steel wire 3 obtained above can be drawn using, for example, a die so that the wire diameter becomes 0.1 to 0.4 mm.

  Further, the elongation at break of the hot-dip aluminum-plated steel wire 3 is 5% or more, preferably 10% or more, more preferably 15 from the viewpoint of improving the twistability of the hot-dip aluminum-plated steel wire 3 after wire drawing. From the viewpoint of improving the twistability of the hot-dip aluminized steel wire 3 after wire drawing, it is 30% or less.

  In addition, the elongation at break of the hot-dip aluminized steel wire 3 after wire drawing is adjusted according to “Metal Material Tensile Test Method” defined in JIS Z2241, and the distance between the grips is adjusted to 100 ± 1 mm. Is set to 150 mm, and using the No. 9A test piece described in the column of Annex C “Types of linear or bar-shaped test pieces used for wires and bars having a diameter or side of less than 4 mm” in JIS Z2241 This is the value when measured.

  In this invention, the average diameter per 100 mm length of the steel wire from which the plating layer was removed from the hot-dip aluminum-plated steel wire after wire drawing and the minimum diameter of the steel wire are measured.

  There is no particular limitation on the method for removing the plating layer from the hot-dip aluminum-plated steel wire after wire drawing. For example, the hot-dip aluminum-plated steel wire is immersed in 5-10% hydrochloric acid having a liquid temperature at room temperature for about 10 minutes. By doing, a plating layer can be removed from the said hot-dip aluminized steel wire.

  The present inventors measured the wire diameter of the aluminized stainless steel wire after hot-dip aluminum plating for the hot-dip aluminum-plated stainless steel wire, examined the dispersion of the coating amount of the plating layer, and drawn the aluminum-plated stainless steel wire to the aluminum-plated stainless steel wire. After measuring the elongation of the aluminum-plated stainless steel wire subjected to wire drawing, the elongation of the aluminum-plated stainless steel wire after wire drawing and the plating layer The effect of variation in the amount of adhesion on the twistability was investigated. As a result, it has been found that the twistability of the hot-dip aluminized stainless steel wire is as shown below.

(1) Under conditions where the adhesion amount of the plating layer is the same, the twisting property tends to decrease as the variation in the thickness of the plating layer increases.
(2) As the elongation of the hot-dip aluminum-plated stainless steel wire after wire drawing decreases, the twistability tends to decrease.

  When the thickness of the plated layer of the hot-dip aluminum plating stainless steel wire is completely uniform, the minimum diameter of the stainless steel wire of the hot-dip aluminum plating stainless steel wire is the same as the average diameter of the stainless steel wire. When the hot-dip aluminum-plated stainless steel wire is twisted, the entire hot-dip aluminum-plated stainless steel wire is twisted uniformly, so that the number of twists is maximized.

  However, it is difficult to make the thickness of the plating layer completely uniform when manufacturing a hot-dip aluminized stainless steel wire. When a hot-dip aluminum-plated stainless steel wire with a uniform outer diameter is drawn by drawing a hot-dip aluminum-plated stainless steel wire with a non-uniform plating layer thickness, the stainless steel wire Since the area ratio between the wire and the plating layer does not change before and after the wire drawing, the cross-sectional area of the stainless steel wire after the wire drawing is relatively smaller than the cross-sectional area of the stainless steel wire before the wire drawing. Therefore, the wire diameter of the stainless steel wire is relatively small in the portion where the thickness of the plated layer of the hot-dip aluminum plated stainless steel wire is large.

  Therefore, when twisting is performed on a hot-dip aluminum-plated stainless steel wire whose plating layer thickness is not uniform, the twisted hot-dip aluminum-plated stainless steel wire breaks at the portion where the wire diameter of the stainless steel wire is the smallest It becomes like this.

  The place where the diameter of the hot-dip aluminum plated stainless steel wire is the smallest is the place where the plating layer is the thickest, but the plating layer is made of aluminum, and the aluminum is lower in strength than stainless steel. , Hardly contribute to the improvement of torsion.

  The present inventors estimated the number of twists necessary for twisting a hot-dip aluminized stainless steel wire from the twisted wire processing conditions.

  The standard twist pitch of the stranded wire of the galvanized stainless steel wire is 20 to 40 times the wire diameter of the galvanized stainless steel wire. That is, one twist is applied to the hot-dip aluminum-plated stainless steel wire at this pitch. In order to prevent breakage due to twisting in hot-dip galvanized stainless steel wire, the wire is not broken in a state where a twist of one rotation is applied at a pitch 10 times the wire diameter of the hot-dip galvanized stainless steel wire. However, since it is considered that there is no problem in actual use, it is considered that the acceptance criteria are satisfied.

  Thus, for example, when the wire diameter of the hot-dip aluminum plated stainless steel wire is 0.2 mm, if the steel wire does not break even when twisted 50 times or more per 100 mm length of the hot-dip aluminum plated stainless steel wire, the acceptance criteria When the wire diameter of the hot-dip aluminum plated stainless steel wire is 0.32 mm, when there is no breakage of the steel wire even by 32 or more twists per 100 mm of the hot-dip aluminum plated stainless steel wire, Meet the acceptance criteria.

  Based on the above acceptance criteria, the relationship between the variation in the coating amount of the plated layer of the hot-dip aluminum plated stainless steel wire and the elongation at break of the hot-dip aluminum plated stainless steel wire after wire drawing was examined.

As a result, the relationship between the minimum wire diameter / average wire diameter of the stainless steel wire after removing the plated layer of the hot-dip aluminum plated stainless steel wire after wire drawing and the elongation of the hot-dip aluminum plated stainless steel wire is expressed by the formula (I ):
[Minimum diameter / average diameter] ≧ [1- (Elongation at break (%) / 100)] (I)
When satisfying the above, it was found that the hot-dip aluminized stainless steel wire after wire drawing does not break even when twisted at a pitch 10 times the diameter of the hot-dip aluminized stainless steel wire.

  Therefore, in the present invention, the elongation at break is 5 to 30%, and the average diameter per 100 mm length of the steel wire from which the plating layer is removed from the hot-dip aluminized steel wire and the minimum diameter of the steel wire It is recognized that the hot-dip aluminized steel wire satisfying the above formula (I) is excellent in twistability.

  The hot-dip aluminized 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 1-8 and Comparative Examples 1-9
A hot-dip aluminized steel wire was produced based on the embodiment shown in FIG.
As the steel wire, a stainless steel wire made of SUS304 having the wire diameter before plating shown in Table 1 and having the elongation at break shown in Table 1 was used. The stainless steel wire is preheated in nitrogen gas, then passed through a molten aluminum plating bath, pulled up vertically from the bath surface, and a heat-resistant cloth is brought into contact with the meniscus formed around the steel wire at the pulled-up portion from the bath surface. The amount of plating deposited was stabilized by blowing heated nitrogen gas onto the contact portion. The line speed was 300 m / min.

  The wire diameter of the hot-dip aluminized steel wire obtained as described above was measured. In addition, the wire diameter of the hot-dip aluminized steel wire is the diameter cross section of the steel wire at intervals of 0.08 mm in the length direction using an optical outer diameter measuring instrument [manufactured by Keyence Co., Ltd., product number: LS-7000]. The wire diameter was measured 10 times from two orthogonal directions, and the average value was taken as the wire diameter. The wire diameter of the hot-dip aluminum-plated steel wire is shown in the column of “Wire diameter after plating” in Table 1.

  Next, the hot-dip aluminum-plated steel wire was passed through a die so that the hot-dip aluminum-plated steel wire was drawn so as to have the wire diameter shown in the column of “wire diameter after wire drawing” in Table 1. .

  A part (length: 100 mm) of a hot-dip aluminum plated steel wire that has been subjected to wire drawing is cut out, and the hot-dip aluminum plated steel wire is immersed in 10% hydrochloric acid having a liquid temperature at room temperature for about 10 minutes. The stainless steel wire was taken out by removing the plating layer from the hot-dip aluminum plated steel wire, and the wire diameter of the stainless steel wire was examined in the same manner as described above. The results are shown in the column of “Wire diameter of steel wire after wire drawing” in Table 1.

  Next, the tensile test was performed 5 times with respect to 100 mm of the hot-dip aluminized steel wire obtained above, and the elongation at break was measured from the average. The results are shown in the column of “Elongation at break” in Table 1.

  Moreover, the twist test of the hot-dip aluminum plating steel wire obtained above was done using the twist tester of the hot-dip aluminum plating steel wire shown in FIG. FIG. 3 is a schematic explanatory diagram of a twist test apparatus for hot-dip aluminized steel wire.

  More specifically, the test line 13 of the torsion tester is grasped by the chucks 14a and 14b, the distance between the chuck 14a and the chuck 14b is set to 100 mm, and is fixed to the carriage 16 on the test table 15. A load with a weight 17 (mass: 50 g) was applied so that the test line 13 did not bend. Next, the chuck 14b was rotated in the direction of arrow B, and the number of rotations until the test line 13 broke was obtained as an integer value, which was used as the number of twists. The measurement results are shown in the column “Number of twists” in Table 1.

[Evaluation]
It is examined whether or not the hot-dip aluminized steel wire obtained in each example and each comparative example satisfies the formula (I). When not satisfied, “x” is described in the “discriminant” column of “twistability” in Table 1.

  Further, the case where the measured value of the number of twists measured above is not less than the target value shown in Table 1 is evaluated as “◯”, and the case where it is not so is evaluated as “X”. ”In the“ Measured ”column.

  From the results shown in Table 1, it can be seen that according to each example, a hot-dip galvanized steel wire that has been subjected to wire drawing that is excellent in twistability when performing stranded wire processing can be obtained.

  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 Molten aluminum plating bath 2 Steel wire 3 Molten aluminum plating steel wire 4 Delivery apparatus 5 Plating bath 6 Bath surface of molten aluminum plating bath 7 Stabilizing member 8 Nozzle 8a Nozzle tip 9 Inert gas supply device 10 Piping 11 Cooling device 12 Winding device 13 Test line 14a chuck 14b chuck 15 Test table 16 Cart 17 Weight

Claims (2)

It is a hot dip galvanized steel wire having a plating layer on the surface of a steel wire having a diameter of 0.1 to 0.4 mm, and has an elongation at break of 5 to 30%. The ratio of the average diameter per 100 mm length of the steel wire from which the steel has been removed to the minimum diameter of the steel wire is represented by the formula (I):
[Minimum diameter / average diameter] ≧ [1- (Elongation at break (%) / 100)] (I)
(In the formula, the elongation at break is the elongation at break of the hot-dip aluminized steel wire after wire drawing, in accordance with “Metal Material Tensile Test Method” stipulated in JIS Z2241, the original gage distance is 100 ± 1 mm. The distance between the grips is set to 150 mm, and it is described in the column of Appendix C “Types of linear or bar-shaped specimens used for lines and bars having a diameter or side of less than 4 mm” in JIS Z2241. (Shown when measured using a 9A test piece)
A hot-dip aluminized steel wire characterized by satisfying A method for producing a hot-dip aluminum-plated steel wire having a plating layer on the surface of a steel wire having a diameter of 0.1 to 0.4 mm, the length of the steel wire having a plating layer removed from the hot-dip aluminum-plated steel wire of 100 mm The ratio of the average diameter per round to the minimum diameter of the steel wire is the formula (I)
[Minimum diameter / average diameter] ≧ [1- (Elongation at break (%) / 100)] (I)
(In the formula, the elongation at break is the elongation at break of the hot-dip aluminized steel wire after wire drawing, in accordance with “Metal Material Tensile Test Method” stipulated in JIS Z2241, the original gage distance is 100 ± 1 mm. The distance between the grips is set to 150 mm, and it is described in the column of Appendix C “Types of linear or bar-shaped specimens used for lines and bars having a diameter or side of less than 4 mm” in JIS Z2241. (Shown when measured using a 9A test piece)
The method for producing a hot-dip aluminum-plated steel wire is characterized by subjecting the hot-dip aluminum-plated steel wire to wire drawing so that the elongation at break is 5 to 30%.

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