U.S. patent application number 16/083587 was filed with the patent office on 2019-03-07 for production method for molten-aluminum-plated copper wire.
This patent application is currently assigned to NISSHIN STEEL CO., LTD.. The applicant listed for this patent is NISSHIN STEEL CO., LTD.. Invention is credited to Yasunori HATTORI, Shinichi KAMOSHIDA, Tadaaki MIONO.
Application Number | 20190071760 16/083587 |
Document ID | / |
Family ID | 59789443 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190071760 |
Kind Code |
A1 |
MIONO; Tadaaki ; et
al. |
March 7, 2019 |
PRODUCTION METHOD FOR MOLTEN-ALUMINUM-PLATED COPPER WIRE
Abstract
A production method for molten-aluminum-plated steel wire, the
production method being characterized in that a steel wire (2)
immersion part (6) at which the steel wire (2) is to be immersed in
a molten aluminum plating bath (1) is immersed in the molten
aluminum plating bath (1) after the steel wire (2) has been passed
into a steel wire introduction device (7) while an immersion region
(9a) thereof has been immersed in the molten aluminum plating bath
(1). The steel wire introduction device (7) comprises a tube-shaped
body (9), which has a total length of 10 to 1000 mm and has a
through hole (8) that is for passing the steel wire (2) through the
inside thereof, and includes the immersion region (9a), which is
for immersion in the molten aluminum plating bath (1) to a length
of 2 mm to 400 mm from an end part of one end of the tube-shaped
body (9) along the long direction of the tube-shaped body (9). The
ratio of the area of the opening of the through hole (8) and the
area of a horizontal cross-section of the steel wire (2) (the area
of the opening of the through-hole (8) of the tube-shaped body
(9)/the area of the horizontal cross-section of the steel wire (2))
is 3 to 4000.
Inventors: |
MIONO; Tadaaki; (Tokyo,
JP) ; KAMOSHIDA; Shinichi; (Tokyo, JP) ;
HATTORI; Yasunori; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NISSHIN STEEL CO., LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
NISSHIN STEEL CO., LTD.
Tokyo
JP
|
Family ID: |
59789443 |
Appl. No.: |
16/083587 |
Filed: |
March 7, 2017 |
PCT Filed: |
March 7, 2017 |
PCT NO: |
PCT/JP2017/009036 |
371 Date: |
September 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 2/12 20130101; C23C
2/003 20130101; C23C 2/38 20130101 |
International
Class: |
C23C 2/38 20060101
C23C002/38; C23C 2/12 20060101 C23C002/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 11, 2016 |
JP |
2016-047743 |
Claims
1. A method for producing a hot-dip aluminum-coated steel wire by
dipping a steel wire in molten aluminum, and then continuously
drawing up the steel wire from the molten aluminum, to produce a
hot-dip aluminum-coated steel wire, comprising: introducing a steel
wire into a steel wire-introducing device comprising a tubular body
of 10 mm to 1000 mm in total length having a through hole for
introducing a steel wire into the tubular body, and a dipping
region of 2 mm to 400 mm in length from one end part of the tubular
body in a longitudinal direction of the tubular body for dipping
the dipping region in the molten aluminum, wherein a value of the
ratio of an area of the opening part of the through hole to an area
of the cross section of the steel wire which is used in hot-dip
aluminum plating [area of the opening part of the through hole of
the tubular body/area of the cross section of the steel wire] is 3
to 4000, under a condition that the dipping region of the steel
wire-introducing device is dipped in the molten aluminum, and
thereafter dipping the steel wire in the molten aluminum.
2. The method for producing a hot-dip aluminum-coated steel wire
according to claim 1, wherein the steel wire is a steel wire made
of stainless steel or carbon steel.
3. A steel wire-introducing device used in a dipping area of a
steel wire where the steel wire is dipped in molten aluminum when a
hot-dip aluminum-coated steel wire is produced by dipping the steel
wire in the molten aluminum, and then continuously drawing up the
steel wire from the molten aluminum, comprising a tubular body of
10 mm to 1000 mm in total length having a through hole for
introducing a steel wire into the tubular body, and a dipping
region of 2 mm to 400 mm in length from one end part of the tubular
body in a longitudinal direction of the tubular body for dipping
the dipping region in the molten aluminum, wherein a value of the
ratio of an area of the opening part of the through hole to an area
of the cross section of the steel wire which is used in hot-dip
aluminum plating [area of the opening part of the through hole of
the tubular body/area of the cross section of the steel wire] is 3
to 4000.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for producing a
hot-dip aluminum-coated steel wire. More particularly, the present
invention relate to a method for producing a hot-dip
aluminum-coated steel wire which can be suitably used in, for
example, a wire harness of an automobile, and the like, and a steel
wire-introducing device for hot-dip aluminum plating, which can be
suitably used in the method for producing a hot-dip aluminum-coated
steel wire.
[0002] In the present description, the hot-dip aluminum-coated
steel wire means a steel wire which has been plated with aluminum
by dipping a steel wire in molten aluminum, and then continuously
drawing up the steel wire from the molten aluminum. In addition,
the molten aluminum means a plating liquid of molten aluminum.
BACKGROUND ART
[0003] A copper wire has been hitherto used as an electric wire
which is used in a wire harness of an automobile, and the like. As
an electric wire having a light weight without impairing electric
conductivity in place of the copper wire, it has been desired in
recent years to develop a composite electric wire made of a strand
of an aluminum wire having a weight lighter than the copper wire
and a metal wire having strength higher than the aluminum wire. As
a metal wire having strength higher than the aluminum wire, a
hot-dip Al-coated steel wire obtained by plating a steel wire with
hot-dip aluminum has been proposed (for example, see claim 1 and
paragraph [0004] of Patent Literature 1).
[0004] The above-mentioned hot-dip Al-coated steel wire has been
produced by dipping a steel wire or a steel wire having a zinc
plated layer or a nickel plated layer on its surface as a starting
wire in molten aluminum, and then continuously drawing up the steel
wire from the molten aluminum to the air (see, for example,
paragraph [0024] of Patent Literature 1).
PRIOR ART LITERATURES
Patent Literatures
[0005] Patent Literature 1: Japanese Patent Unexamined Publication
No. 2014-185355
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0006] According to the above-mentioned process, when the starting
wire is the steel wire or the steel wire having a nickel plated
layer on its surface, there is a possibility that an obtained
hot-dip aluminum-coated steel wire has an area where a plating film
is not formed on its surface after dipping the steel wire in molten
aluminum, and then continuously drawing up the steel wire from the
molten aluminum to the air.
[0007] The present invention has been made in view of the
above-mentioned prior art. An object of the present invention is to
provide a method for efficiently producing a hot-dip
aluminum-coated steel wire having a plating film over the whole
surface, and a steel wire-introducing device for hot-dip aluminum
plating, which can be suitably used in the method for producing a
hot-dip aluminum-coated steel wire.
Means for Solving the Problems
[0008] The present invention relates to:
(1) a method for producing a hot-dip aluminum-coated steel wire by
dipping a steel wire in molten aluminum, and then continuously
drawing up the steel wire from the molten aluminum, to produce a
hot-dip aluminum-coated steel wire, which includes:
[0009] introducing a steel wire into a steel wire-introducing
device including a tubular body of 10 mm to 1000 mm in total length
having a through hole for introducing a steel wire into the tubular
body, and a dipping region of 2 mm to 400 mm in length from one end
part of the tubular body in a longitudinal direction of the tubular
body for dipping the dipping region in the molten aluminum, wherein
a value of the ratio of an area of the opening part of the through
hole to an area of the cross section of the steel wire which is
used in hot-dip aluminum plating [area of the opening part of the
through hole of the tubular body/area of the cross section of the
steel wire] is 3 to 4000, under a condition that the dipping region
of the steel wire-introducing device is dipped in the molten
aluminum, and thereafter
[0010] dipping the steel wire in the molten aluminum;
(2) the method for producing a hot-dip aluminum-coated steel wire
according to the above item (1), wherein the steel wire is a steel
wire made of stainless steel or carbon steel; and (3) a steel
wire-introducing device used in a dipping area of a steel wire
where the steel wire is dipped in molten aluminum when a hot-dip
aluminum-coated steel wire is produced by dipping the steel wire in
the molten aluminum, and then continuously drawing up the steel
wire from the molten aluminum, which includes a tubular body of 10
mm to 1000 mm in total length having a through hole for introducing
a steel wire into the tubular body, and a dipping region of 2 mm to
400 mm in length from one end part of the tubular body in a
longitudinal direction of the tubular body for dipping the dipping
region in the molten aluminum, wherein a value of the ratio of an
area of the opening part of the through hole to an area of the
cross section of the steel wire which is used in hot-dip aluminum
plating [area of the opening part of the through hole of the
tubular body/area of the cross section of the steel wire] is 3 to
4000.
Effects of the Invention
[0011] According to the method for producing a hot-dip
aluminum-coated steel wire and the steel wire-introducing device of
the present invention, excellent effects such that a hot-dip
aluminum-coated steel wire having a plating film over the whole
surface can be efficiently produced are exhibited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic view showing one embodiment of a
method for producing a hot-dip aluminum-coated steel wire according
to the present invention.
[0013] FIG. 2 is a schematic cross-sectional view showing one
embodiment of a steel wire-introducing device for hot-dip aluminum
plating according to the present invention.
[0014] FIG. 3 is a schematic explanatory view showing another
embodiment of the method for producing hot-dip aluminum-coated
steel wire according to the present invention.
[0015] FIG. 4 is a schematic explanatory view showing a boundary
portion between a steel wire and a surface of molten aluminum when
the steel wire is drawn up from the molten aluminum in the method
for producing a hot-dip aluminum-coated steel wire according to the
present invention.
[0016] FIG. 5 is a schematic explanatory view showing one
embodiment of a method for determining an average thickness of a
plating film of a hot-dip aluminum-coated steel wire obtained in
each of working examples and comparative examples.
MODE FOR CARRYING OUT THE INVENTION
[0017] The method for producing a hot-dip aluminum-coated steel
wire of the present invention includes a process for dipping a
steel wire in molten aluminum, and then continuously drawing up the
steel wire from the molten aluminum, to produce a hot-dip
aluminum-coated steel wire. The method includes one of
characteristics in introducing a steel wire into a steel
wire-introducing device including a tubular body of 10 mm to 1000
mm in total length having a through hole for introducing a steel
wire into the tubular body, and a dipping region of 2 mm to 400 mm
in length from one end part of the tubular body in a longitudinal
direction of the tubular body for dipping the dipping region in the
molten aluminum, wherein a value of the ratio of an area of the
opening part of the through hole to an area of the cross section of
the steel wire which is used in hot-dip aluminum plating [area of
the opening part of the through hole of the tubular body/area of
the cross section of the steel wire] is 3 to 4000, under a
condition that the dipping region of the steel wire-introducing
device is dipped in the molten aluminum; and thereafter dipping the
steel wire in the molten aluminum, as mentioned above.
[0018] According to the method for producing a hot-dip
aluminum-coated steel wire of the present invention, a hot-dip
aluminum-coated steel wire having a plating film over the whole
surface can be efficiently produced since the above-mentioned
processes are employed in the method.
[0019] In addition, when a hot-dip aluminum-coated steel wire is
produced by using the steel wire-introducing device of the present
invention, it is inhibited that an oxide film generated on the
surface of the molten aluminum is included in the molten aluminum
together with the steel wire at a place where the steel wire is
introduced from the air to the molten aluminum. Thereby reactivity
of the steel wire with the molten aluminum can be improved, and
therefore generation of an area where a plating film is not formed
on the surface of the hot-dip aluminum-coated steel wire can be
suppressed.
[0020] Hereinafter, the method for producing a hot-dip
aluminum-coated steel wire according to the present invention will
be described based on drawings. However, the present invention is
not limited only to those embodiments described in the
drawings.
[0021] FIG. 1 is a schematic explanatory view showing one
embodiment of the method for producing a hot-dip aluminum-coated
steel wire according to the present invention.
[0022] According to the method for producing a hot-dip
aluminum-coated steel wire of the present invention, a steel wire 2
is dipped in molten aluminum 1, and then the steel wire 2 is
continuously drawn up from the molten aluminum 1, to produce a
hot-dip aluminum-coated steel wire 3.
[0023] Examples of steel used in the steel wire 2 include, for
example, stainless steel, carbon steel and the like, and the
present invention is not limited only to those exemplified
ones.
[0024] The stainless steel is an alloy steel containing 10% by mass
or more of chromium (Cr). Examples of the stainless steel include,
for example, austenitic steel materials, ferritic steel materials
and martensitic steel materials defined in JIS G4309, and the like,
and the present invention is not limited only to those exemplified
ones. Specific examples of the stainless steel include stainless
steel in which an austenitic phase is generally considered to be
metastable, such as SUS301 and SUS304; stable austenitic stainless
steel such as SUS305, SUS310 and SUS316; ferritic stainless steel
such as SUS405, SUS410L, SUS429, SUS430, SUS434, SUS436, SUS444 and
SUS447; martensitic stainless steel such as SUS403, SUS410, SUS416,
SUS420, SUS431 and SUS440; chromium-nickel-manganese-based
stainless steel classified into SUS200 series, and the like, and
the present invention is not limited only to those exemplified
ones.
[0025] The carbon steel contains 0.02% by mass or more of carbon
(C). Examples of the carbon steel include, for example, high carbon
steel wire rods defined in JIS G3506, low carbon steel wire rods
defined in JIS G3505, and the like, and the present invention is
not limited only to those exemplified ones. Specific examples of
the carbon steel include high carbon steel, low carbon steel and
the like, and the present invention is not limited only to those
exemplified ones.
[0026] Among the above-mentioned steels, the stainless steel and
the carbon steel are preferred, and the stainless steel is more
preferred, from the viewpoint of increase in tensile strength of
the hot-dip aluminum-coated steel wire 3.
[0027] The diameter of the steel wire 2 is not particularly
limited. It is preferred that the diameter of the steel wire 2 is
appropriately controlled in accordance with uses of the hot-dip
aluminum-coated steel wire 3. For example, when the hot-dip
aluminum-coated steel wire 3 is used in a wire harness of an
automobile and the like, it is preferred that the diameter of the
steel wire 2 is usually 0.05 to 0.5 mm or so.
[0028] The steel wire 2 can be previously degreased before carrying
out hot-dip aluminum plating of the steel wire 2. The degreasing of
the steel wire 2 can be carried out by, for example, a method which
includes dipping the steel wire 2 in an alkaline degreasing liquid,
taking out the steel wire 2 from the alkaline degreasing liquid,
neutralizing the alkaline degreasing liquid deposited on the steel
wire 2, and washing the steel wire 2 with water; a method which
includes carrying out electrolytic degreasing of the steel wire 2
by passing electricity through the steel wire 2 under a condition
such that the steel wire 2 is dipped in an alkaline degreasing
liquid; and the like. Incidentally, the above-mentioned alkaline
degreasing liquid may contain a surfactant from the viewpoint of
improvement in degreasing property.
[0029] A plating film (not shown in the figure) made of aluminum or
an aluminum alloy has been formed on the surface of the hot-dip
aluminum-coated steel wire 3. In the present invention, since the
plating film made of aluminum or an aluminum alloy has been formed
on the surface of the hot-dip aluminum-coated steel wire 3 as
mentioned above, the hot-dip aluminum-coated steel wire 3 is
excellent in adhesiveness to an aluminum wire when a wire harness
is produced by bundling the hot-dip aluminum-coated steel wire 3
with the aluminum wire, and tensile strength and temporal stability
of electric resistance.
[0030] In FIG. 1, the steel wire 2 is provided from a delivery
device 4 of the steel wire 2. Thereafter, the steel wire 2 is
continuously transferred in the direction of arrow A, and dipped in
the molten aluminum 1 charged in a plating bath 5.
[0031] Incidentally, when the steel wire 2 is made of carbon steel,
it is preferred that degreasing of the steel wire 2 is carried out
between the delivery device 4 and the molten aluminum 1, because
there is a possibility that rust is generated on the surface of the
steel wire 2 due to degreasing of the steel wire 2 until hot-dip
aluminum plating of the steel wire 2 is carried out. The degreasing
of the steel wire 2 made of carbon steel can be carried out in the
same manner as the above-mentioned method for degreasing the steel
wire 2.
[0032] The molten aluminum 1 may contain only aluminum.
Alternatively, the molten aluminum 1 may contain an element other
than aluminum as occasion demands within a scope which would not
hinder an object of the present invention. Examples of the element
other than aluminum include, for example, nickel, chromium, zinc,
silicon, copper, iron and the like, and the present invention is
not limited only to those exemplified ones. When the element other
than aluminum is contained in aluminum, mechanical strength of a
plating film can be increased, and moreover, tensile strength of
the hot-dip aluminum-coated steel wire 3 can be increased. Among
the elements other than aluminum, although the kind of the element
depends on the kind of the steel wire 2, silicon is preferred from
the viewpoint of suppression of generation of a brittle
iron-aluminum alloy layer between iron contained in the steel wire
2 and aluminum contained in the plating film, increase in
mechanical strength of the plating film and lowering in melting
point of the molten aluminum 1, thereby increase in efficiency of
plating of the steel wire 2.
[0033] The lower limit of the content of the above-mentioned
element other than aluminum in the plating film is 0% by mass. From
the viewpoint of sufficient exhibition of properties based on the
element other than aluminum, the lower limit thereof is preferably
0.3% by mass or more, more preferably 0.5% by mass or more, and
furthermore preferably 1% by mass or more. From the viewpoint of
suppression of galvanic corrosion caused by contacting with an
aluminum wire, the upper limit thereof is preferably 50% by mass or
less, more preferably 20% by mass or less, and furthermore
preferably 15% by mass or less.
[0034] Incidentally, an element such as nickel, chrome, zinc,
copper or iron is possibly inevitably incorporated in the molten
aluminum 1.
[0035] According to the present invention, the steel wire 2 is
passed through the steel wire-introducing device 7 which is
provided at a dipping area 6 for dipping the steel wire 2 in the
molten aluminum 1, and then dipped in the molten aluminum 1. Since
the present invention employs the process which includes passing
the steel wire 2 through the steel wire-introducing device 7 which
is provided at a dipping area 6 for dipping the steel wire 2 in the
molten aluminum 1, and then dipping the steel wire 2 in the molten
aluminum 1, a hot-dip aluminum-coated steel wire 3 having a plating
film over the whole surface can be efficiently produced.
[0036] The steel wire-introducing device 7 according to the present
invention will be described hereinafter with reference to FIG. 2.
FIG. 2 is a schematic cross-sectional view showing one embodiment
of the steel wire-introducing device 7 for hot-dip aluminum plating
according to the present invention shown in FIG. 1 and FIG. 3.
[0037] As described above, the steel wire-introducing device 7
illustrated in FIG. 2 is used in the dipping area 6 for dipping the
steel wire 2 in the molten aluminum 1 when the steel wire 2 is
dipped in the molten aluminum 1, and continuously drawing up the
steel wire 2 from the molten aluminum 1, to produce a hot-dip
aluminum-coated steel wire 3.
[0038] As shown in FIG. 2, the steel wire-introducing device 7 has
a through hole 8 for passing the steel wire 2 through the steel
wire-introducing device 7 in the direction of arrow B, and a
tubular body 9 having a total length L of 10 mm to 1000 mm. The
total length L of the steel wire-introducing device 7 is 10 mm or
more, preferably 30 mm or more, more preferably 40 mm or more, and
furthermore preferably 50 mm or more, from the viewpoint of
prevention of intrusion of the plating liquid of the molten
aluminum 1 into an introducing port 9b for introducing the steel
wire 2 when the dipping region 9a for dipping the steel wire 2 in
the molten aluminum 1 is dipped in the molten aluminum 1, or
prevention of intrusion of an oxide film which is generated on the
surface of the molten aluminum 1 into the through hole 8 of the
tubular body 9. The total length L of the steel wire-introducing
device 7 is 1000 mm or less, preferably 800 mm or less, more
preferably 500 mm or less, furthermore preferably 300 mm or less,
and still furthermore preferably 100 mm or less, from the viewpoint
of miniaturization of the tubular body 9, improvement in
workability and efficient production of the hot-dip aluminum-coated
steel wire 3 having a plating film over the whole surface.
[0039] The steel wire-introducing device 7 has the tubular body 9.
The tubular body 9 has a dipping region 9a for dipping the tubular
body 9 in the molten aluminum 1 from one end part of the tubular
body 9, which is dipped in the molten aluminum 1 up to a virtual
line P as shown in FIG. 2 within a length of 2 mm to 400 mm in a
longitudinal direction of the tubular body 9. The length of the
dipping region 9a is 2 mm or more, preferably 5 mm or more, and
more preferably 10 mm or more, from the viewpoint of avoidance of
affection of swaying of the surface of the molten aluminum 1, and
efficient production of the hot-dip aluminum-coated steel wire 3
having a plating film over the whole surface. The length of the
dipping region 9a is 400 mm or less, preferably 100 mm or less,
more preferably 50 mm or less, and furthermore preferably 30 mm or
less, from the viewpoint of improvement in workability and
efficient production of the hot-dip aluminum-coated steel wire 3
having a plating film over the whole surface.
[0040] The length of the tubular body 9 in the longitudinal
direction of the tubular body 9 where the tubular body 9 is not
dipped in the molten aluminum 1 is preferably 5 mm or more, and
more preferably 10 mm or more, from the viewpoint of prevention of
intrusion of the plating liquid of the molten aluminum 1 into the
introducing port 9b of the tubular body 9, or prevention of
intrusion of an oxide film which is generated on the surface of the
molten aluminum 1 into the through hole 8 of the tubular body
9.
[0041] A value of a ratio of an area of the opening part of the
through hole 8 of the tubular body 9 to an area of the cross
section of the steel wire 2 used in hot-dip aluminum plating, which
is a so-called cross-section of the steel wire 2 [area of the
opening part of the through hole 8 of the tubular body 9/area of
the cross section of the steel wire 2] is 3 or more from the
viewpoint of smooth introduction of the steel wire 2 into the
through hole 8 of the tubular body 9 and efficient production of
the hot-dip aluminum-coated steel wire 3 having a plating film over
the whole surface. The above value of the ratio is 4000 or less,
preferably 3000 or less, more preferably 2000 or less, and
furthermore preferably 1000 or less, from the viewpoint of
efficient production of the hot-dip aluminum-coated steel wire 3
having a plating film over the whole surface.
[0042] The shape of the opening part of the through hole 8 of the
tubular body 9 can be circular, oval, or polygon such as square or
rectangle, and the present invention is not limited by the shape
thereof. The gap (clearance) between the opening part of the
through-hole 8 of the tubular body 9 and the steel wire 2 is
preferably 10 .mu.m or more, more preferably 20 .mu.m or more,
furthermore preferably 50 .mu.m or more, and still more preferably
100 .mu.m or more, from the viewpoint of avoidance of sliding of an
inner wall of the through-hole 8 of the tubular body 9 and the
steel wire 2.
[0043] Incidentally, the opening parts of the through hole 8
provided in the tubular body 9 are an opening part 9c provided at
the introducing port 9b for introducing the steel wire 2 from one
end of the tubular body 9, and an opening part 9e provided at a
discharge port 9d for discharging the steel wire 2 from another end
of the tubular body 9 as shown in FIG. 2. The area and shape of the
opening part 9c can be the same as those of the opening part 9e.
Alternatively, the area and shape of the opening part 9c can be
different from those of the opening part 9e. However, it is
preferred that the area and shape of the opening part 9c are the
same as those of the opening part 9e, respectively, as shown in
FIG. 2 from the viewpoint that the steel wire 2 is smoothly passed
through the through hole 8 of the tubular body 9, that sliding of
the inner wall of the through hole 8 of the tubular body 9 and the
steel wire 2 is avoided, and that the hot-dip aluminum-coated steel
wire 3 having a plating film over the whole surface is efficiently
produced.
[0044] It is preferred that the steel wire 2 is preheated from the
viewpoint of efficient production of the hot-dip aluminum-coated
steel wire 3 having a plating film over the whole surface. As a
method for preheating the steel wire 2, there can be cited, for
example, a method which includes passing the steel wire 2 through a
heating device 17 before the steel wire 2 is passed through the
steel wire-introducing device 7 as shown in FIG. 3, and the like,
and the present invention is not limited only to the exemplified
one. Incidentally, FIG. 3 is a schematic explanatory view showing
another embodiment of the method for producing hot-dip
aluminum-coated steel wire 3 according to the present invention.
The heating device 17 includes, for example, a heating device as
described in the following working examples.
[0045] A heating gas which is introduced into the heating device 17
includes, for example, air, inert gases such as nitrogen gas, argon
gas and helium gas, and the like, and the present invention is not
limited only to those exemplified ones. Among them, the inert gases
are preferred from the viewpoint of prevention of oxidization of
the molten aluminum 1 existing in the steel wire-introducing device
7 by ventilating a heating gas exhausted from the lower end of the
heating device 17 to an introducing port equipped at the upper end
of the steel wire-introducing device 7 which is provided below the
heating device 17, to make the inside of the steel wire-introducing
device 7 an inert gas atmosphere. The temperature of the heating
gas cannot be absolutely determined because the temperature of the
heating gas differs depending on the kind and diameter steel wire 2
being used, conditions such as a line speed of the steel wire 2 and
a flow rate of the heating gas, and the like. Accordingly, it is
preferred that the temperature of the heating gas is controlled so
that the steel wire 2 is appropriately heated under the above
conditions.
[0046] The preheating temperature of the steel wire 2 cannot be
absolutely determined because the preheating temperature differs
depending on the kind of the steel wire 2 and the like. The
preheating temperature is preferably 50.degree. C. or higher, more
preferably 60.degree. C. or higher, and furthermore preferably
70.degree. C. or higher, from the viewpoint of efficient production
of the hot-dip aluminum-coated steel wire 3 having a plating film
over the whole surface. The upper limit of the preheating
temperature cannot be absolutely determined because the upper limit
of the preheating temperature differs depending on the kind of the
steel wire 2 and the like. It is preferred that the upper limit of
the preheating temperature is usually 800.degree. C. or lower in
consideration of energy efficiency. Incidentally, the
above-mentioned preheating temperature is a temperature determined
in accordance with a method as described in the following working
examples.
[0047] Next, as shown in FIG. 1 and FIG. 3, the steel wire 2 dipped
in the molten aluminum 1 is drawn up upward from the surface 10 of
the molten aluminum 1, to form a plating film made of the molten
aluminum 1 on the surface of the steel wire 2, and thereby the
hot-dip aluminum-coated steel wire 3 is obtained.
[0048] When the steel wire 2 is drawn up from the molten aluminum 1
in the direction of arrow C (upward) as illustrated in FIG. 4, it
is preferred that a stabilization member 11 is contacted with the
steel wire 2 at a boundary between the steel wire 2 and the surface
10 of the molten aluminum 1.
[0049] Incidentally, FIG. 4 is a schematic explanatory view showing
a boundary portion between the steel wire 2 and the surface 10 of
the molten aluminum 1 when the steel wire 2 is drawn up from the
molten aluminum 1 in the method for producing a hot-dip
aluminum-coated steel wire according to the present invention.
[0050] The stabilization member 11 includes, for example, a square
rod made of stainless steel, in which a heat-resistant cloth 11a is
wound around the surface of the square rod, and the like. The
heat-resistant cloth 11a wound around the surface of the square rod
includes, for example, woven fabric and non-woven fabric,
containing a heat-resistant fiber such as a ceramic fiber, a carbon
fiber, an aramid fiber or an imide fiber, and the present invention
is not limited only to those exemplified ones. It is preferred that
a virgin surface (new surface) of the heat-resistant cloth 11a of
the stabilization member 11 is contacted with the steel wire 2 from
the viewpoint of suppression of deposition of an aluminum lump on
the surface of the hot-dip aluminum-coated steel wire 3.
[0051] It is preferred that the stabilization member 11 is
contacted with both of the surface 10 of the molten aluminum 1 and
the steel wire 2 at the same time. When the stabilization member 11
is contacted with both of the surface 10 of the molten aluminum 1
and the steel wire 2 at the same time as mentioned above, pulsation
of the surface 10 of the molten aluminum 1 can be suppressed, and
minute vibration of the steel wire 2 can be suppressed by the
stabilization member 11 during drawing up the steel wire 2 in
contact of the steel wire 2 with the stabilization member 11.
Thereby a plating film 18 of the molten aluminum 1 can be uniformly
formed on the surface of the steel wire 2. Incidentally, when the
stabilization member 11 is contacted with the steel wire 2, it is
preferred that the stabilization member 11 is slightly pressed
toward the steel wire 2 in order to apply tension to the steel wire
2 as occasion demands from the viewpoint of suppression of minute
vibration of the steel wire 2.
[0052] In the embodiments illustrated in FIG. 1 and FIG. 3, a
nozzle 12 for blowing an inert gas to the boundary between the
steel wire 2 and the surface 10 of the molten aluminum 1 is
provided. In the embodiment illustrated in FIG. 4, a tip end 12a of
a nozzle 12 is provided so that an inert gas is blown from the tip
end 12a to the boundary between the steel wire 2 and the surface 10
of the molten aluminum 1.
[0053] According to the present invention, the hot-dip
aluminum-coated steel wire 3 having a uniform outer diameter and
little aluminum lump on its surface can be efficiently produced by
appropriately controlling the distance (the shortest distance) from
the steel wire 2 to a tip end 12a of the nozzle 12, the temperature
of the inert gas discharged from the tip end 12a of the nozzle 12,
an inner diameter of the tip end 12a of the nozzle 12, and a volume
flow rate of the inert gas discharged from the nozzle 12.
[0054] The distance (the shortest distance) from the steel wire 2
to the tip end 12a of the nozzle 12 is preferably 1 mm or more from
the viewpoint of avoidance of a contact of the tip end 12a with the
steel wire 2, and efficient production of the hot-dip
aluminum-coated steel wire 3. The distance (the shortest distance)
from the steel wire 2 to the tip end 12a of the nozzle 12 is
preferably 50 mm or less, more preferably 40 mm or less,
furthermore preferably 30 mm or less, and still further preferably
10 mm or less, from the viewpoint of production of a hot-dip
aluminum-coated steel wire 3 having a uniform outer diameter and
little aluminum lump on its surface.
[0055] The inner diameter of the tip end 12a of the nozzle 12 is
preferably 1 mm or more, and more preferably 2 mm or more, from the
viewpoint of efficient production of a hot-dip aluminum-coated
steel wire 3 by accurately blowing an inert gas from the tip end
12a of the nozzle 12 to the boundary between the steel wire 2 and
the surface 10 of the molten aluminum 1. The inner diameter of the
tip end 12a of the nozzle 12 is preferably 15 mm or less, more
preferably 10 mm or less, and furthermore preferably 5 mm or less,
from the viewpoint of production of a hot-dip aluminum-coated steel
wire 3 having a uniform outer diameter and little aluminum lump on
its surface.
[0056] The inert gas can be provided, for example, from an inert
gas providing apparatus 13 through a pipe 14 to the nozzle 12 as
shown in FIG. 1 and FIG. 3. Incidentally, a flow controller such as
a valve (not shown in the figure) can be provided in the inert gas
providing apparatus 13 or the pipe 14 in order to control the flow
rate of the inert gas.
[0057] The inert gas means a gas which is inert to molten aluminum.
Examples of the inert gas include, for example, nitrogen gas, argon
gas, helium gas and the like, and the present invention is not
limited only to those exemplified ones. Among the inert gases,
nitrogen gas is preferable. The inert gas may contain, for example,
oxygen gas, carbon dioxide gas and the like within a scope which
would not hinder an object of the present invention.
[0058] In FIG. 4, the volume flow rate of the inert gas discharged
from the tip end 12a of the nozzle 12 is preferably 2 L (liter)/min
or more, more preferably 5 L/min or more, and furthermore
preferably 10 L/min or more, from the viewpoint of production of a
hot-dip aluminum-coated steel wire 3 having a uniform outer
diameter and little aluminum lump on its surface. The volume flow
rate of the inert gas thereof is preferably 200 L/min or less, more
preferably 150 L/min or less, and furthermore preferably 100 L/min
or less, from the viewpoint of suppression of deposition of an
aluminum lump on the surface of the hot-dip aluminum-coated steel
wire 3 due to scattering of the molten aluminum 1.
[0059] The temperature of the inert gas discharged from the tip end
12a of the nozzle 12 is preferably 200.degree. C. or higher, more
preferably 300.degree. C. or higher, and furthermore preferably
400.degree. C. or higher, from the viewpoint of production of a
hot-dip aluminum-coated steel wire 3 having a uniform outer
diameter and little aluminum lump on its surface. The temperature
of the inert gas thereof is preferably 800.degree. C. or lower,
more preferably 780.degree. C. or lower, and furthermore preferably
750.degree. C. or lower, from the viewpoint of increase in thermal
efficiency. Incidentally, the temperature of the inert gas
discharged from the tip end 12a of the nozzle 12 is a temperature
as determined by inserting a thermocouple for measuring a
temperature, such as a sheath thermocouple having a diameter of 1.6
mm into the inert gas apart from the tip end 12a of the nozzle 12
in a distance of 2 mm.
[0060] The speed for drawing up the hot-dip aluminum-coated steel
wire 3 from the surface 10 of the molten aluminum 1 is not
particularly limited. It is preferred that the speed is
appropriately controlled in accordance with the average thickness
of a plating film formed on the surface of the hot-dip
aluminum-coated steel wire 3. The average thickness of the plating
film formed on the surface of the hot-dip aluminum-coated steel
wire 3 can be appropriately controlled by adjusting the speed for
drawing up the hot-dip aluminum-coated steel wire 3.
[0061] In the present invention, even when the speed for drawing up
the hot-dip aluminum-coated steel wire 3 is controlled to a high
speed such as 200 m/min or more, the hot-dip aluminum-coated steel
wire 3 having a uniform outer diameter and a plating film 18 formed
over the whole surface can be produced. Accordingly, the method for
producing a hot-dip aluminum-coated steel wire 3 according to the
present invention is excellent in industrial productivity of the
hot-dip aluminum-coated steel wire 3, because the hot-dip
aluminum-coated steel wire 3 having a plating film 18 formed over
the whole surface can be efficiently produced. Incidentally, the
speed for drawing up the hot-dip aluminum-coated steel wire 3 is
not particularly limited. The speed for drawing up the hot-dip
aluminum-coated steel wire 3 is preferably 200 m/min or less, more
preferably 100 m/min or more, and furthermore preferably 50 m/min
or less, from the viewpoint of efficient production of the hot-dip
aluminum-coated steel wire 3 having a plating film over the whole
surface.
[0062] Incidentally, a cooling device 15 can be provided above the
nozzle 12 as occasion demands as illustrated in FIG. 1 and FIG. 3
in order to cool the hot-dip aluminum-coated steel wire 3 in the
course of drawing up of the hot-dip aluminum-coated steel wire 3,
and efficiently solidify the plating film 18 formed on the surface
of the hot-dip aluminum-coated steel wire 3. The hot-dip
aluminum-coated steel wire 3 can be cooled by blowing, for example,
gas, liquid mist or the like to the hot-dip aluminum-coated steel
wire 3 in the cooling device 15.
[0063] The hot-dip aluminum-coated steel wire 3 produced in the
above can be collected by means of, for example, a winding device
16 or the like.
[0064] The average thickness of the plating film formed on the
surface of the hot-dip aluminum-coated steel wire 3 is preferably 2
.mu.m to 20 .mu.m or so, more preferably 4 .mu.m to 15 .mu.m or so,
from the viewpoint of suppression of exposure of the steel wire 2
included in the hot-dip aluminum-coated steel wire 3 to the air in
carrying out a process such as a wire stranding process or a
crimpling process, and increase in mechanical strength per unit
outer diameter of the hot-dip aluminum-coated steel wire 3.
[0065] The hot-dip aluminum-coated steel wire 3 obtained in the
above can be subjected to a drawing process using dies and the like
as occasion demands so that the hot-dip aluminum-coated steel wire
3 has an appropriate diameter.
[0066] The hot-dip aluminum-coated steel wire 3 obtained by the
method for producing a hot-dip aluminum-coated steel wire according
to the present invention can be suitably used, for example, in a
wire harness of an automobile, and the like.
EXAMPLES
[0067] Next, the present invention will be more specifically
described based on working examples. However, the present invention
is not limited only to those working examples.
Examples 1 to 39 and Comparative Examples 1 to 3
[0068] A hot-dip aluminum-coated steel wire was produced based on
the embodiment as illustrated in FIG. 1.
[0069] As a steel wire, a steel wire having a diameter shown in
Tables 1 to 3 and made of steel shown in Tables 1 to 3 was used.
The term "37A" listed in the column of "kind" of "steel wire" in
Table 3 means a steel wire made of high carbon steel containing
0.37% by mass of carbon.
[0070] Incidentally, the steel wire was subjected to degreasing by
dipping the steel wire in a degreasing liquid containing sodium
orthosilicate and a surfactant, before the steel wire was dipped in
the hot-dip aluminum.
[0071] In addition, as a device for introducing a steel wire, a
device 7 for introducing a steel wire shown in FIG. 2, which was
produced by assembling blocks or square bars made of stainless
steel, was used. The device 7 for introducing a steel wire had a
total length L of 300 mm, and the shape, size and area of the
opening part 9c of the introducing port 9b of the through hole 8
were the same as those of the opening part 9e of the discharge port
9d of the through hole 8. The shape, size and area of the opening
part of the through hole 8 of the device 7 for introducing a steel
wire, and the ratio of the area of the opening part to the area of
the cross-section of the steel wire (hereinafter, referred to as
"value of area ratio") are shown in Tables 1 to 3. The dipping
region 9a of 30 mm from the lower end of the steel wire-introducing
device 7 was dipped in the molten aluminum, and the steel wire
being introduced into the steel wire-introducing device 7 was
dipped in the molten aluminum as it was.
[0072] As the molten aluminum, molten aluminum having an aluminum
purity of 99.7% or more (referred to as "Al" in the column "kind"
of "hot-dip Al" in Tables 1 to 3), molten aluminum containing 4% by
mass of silicon (referred to as "4% Si" in the column "kind" of
"hot-dip Al" in Tables 1 to 3), molten aluminum containing 8% by
mass of silicon (referred to as "8% Si" in the column "kind" of
"hot-dip Al" in Tables 1 to 3), molten aluminum containing 11% by
mass of silicon (referred to as "11% Si" in the column "kind" of
"hot-dip Al" in Tables 1 to 3) or molten aluminum containing 13% by
mass of silicon (referred to as "13% Si" in the column "kind" of
"hot-dip Al" in Tables 1 to 3) was used. The steel wire was dipped
in the molten aluminum at a temperature of the molten aluminum
shown in Tables 1 to 3 at a line speed (speed of drawing up of the
steel wire) shown in Tables 1 to 3, and then the steel wire was
drawn up from the molten aluminum.
[0073] A nozzle having an inner diameter of 3 mm at its tip was
provided so that the tip of the nozzle was positioned at a place
apart from the steel wire in a distance of 2 mm. An inert gas
(nitrogen gas) of which temperature was controlled to 600.degree.
C. was discharged from the tip of the nozzle at a volume flow rate
of 10 L/min, and was blown to the boundary between the steel wire
and the surface of the molten aluminum.
[0074] The above operations were carried out, to obtain a hot-dip
aluminum-coated steel wire having a plating film of an average
thickness shown in Tables 1 to 3. Incidentally, a method for
determining the average thickness of the plating film is as
follows:
[0075] [Method for Determining Average Thickness of Plating
Film]
[0076] The average thickness of a plating film of a hot-dip
aluminum-coated steel wire obtained in each of working examples and
comparative examples was determined on the basis of an embodiment
shown in FIG. 5. FIG. 5 is a schematic explanatory view showing one
embodiment of a method for determining an average thickness of a
plating film of a hot-dip aluminum-coated steel wire obtained in
each of working examples and comparative examples.
[0077] As a device 19 for measuring a diameter of a steel wire by
passing through the steel wire, a device for measuring a diameter
having two optical micrometers each of which was commercially
available from KEYENCE CORPORATION under the product number of
LS-7000 was used as shown in FIG. 5. The device 19 for measuring a
diameter had a pair of a pulley 19c and a pulley 19d which were
positioned in a vertical direction against the steel wire, and a
pair of a light emitting unit 19a and a light receiving unit 19b
which were arranged in a horizontal direction at a central position
between the pulley 19c and the pulley 19d. The light emitting unit
19a and the light receiving unit 19b were arranged so that the
light emitting unit 19a and the light receiving unit 19b were
opposed to each other. The light emitting unit 19a and the light
receiving unit 19b adjacent each other were arranged so that an
angle between the light emitting unit 19a and the light receiving
unit 19b was 90.degree. as shown in FIG. 5.
[0078] While the hot-dip aluminum-coated steel wire 3 having a
length of 100 m obtained in each working example or each
comparative example was being run at a line speed of 100 m/min in a
direction of arrow D between the pulley 19c and the pulley 19d, the
outer diameter of the hot-dip aluminum-coated steel wire 3 was
measured at an interval of a length of about 1.4 mm in the
longitudinal direction of the aluminum-plated steel wire 3 by means
of the device 19 for measuring a diameter. The number of
measurement points of the outer diameter was adjusted to about
71000 points.
[0079] Next, an average value of the outer diameters of the hot-dip
aluminum-coated steel wire as measured in the above was calculated.
The value of the diameter of the steel wire before forming a
plating film (diameter of steel wire shown in the following Tables
1 to 3) was subtracted from the average value, and an obtained
value was divided by 2, to give an average thickness of a plating
film. The results are shown in Tables 1 to 3.
[0080] [Stability of Plating Film]
[0081] As a property of the hot-dip aluminum-coated steel wire
obtained in each working example or each comparative example,
stability of a plating film was examined in accordance with the
following method. The results are shown in Tables 1 to 3.
[0082] The surface of the hot-dip aluminum-coated steel wire having
a length of 100 m, obtained in each working example or each
comparative example was observed over the entire length with a
naked eye by using a microscope. When a portion where a plating
film was not formed on the surface of the steel wire was observed,
the length of the portion where a plating film was not formed was
measured by pulling out the steel wire within a range from 250 mm
before the portion where a plating film was not formed to 250 mm
after the portion where a plating film was not formed [hereinafter
referred to as observed length (500 mm)]. The length of the portion
where a plating film was not formed in the longitudinal direction
(hereinafter referred to as non-plated length) was measured, and
non-plated rate was determined in accordance with the following
equation:
[Non-plated rate]={[Non-plated length (mm)]/[Observed length
(mm)]}.times.100.
The stability of the plating film was evaluated in accordance with
the following evaluation criteria.
[0083] (Evaluation Criteria of Stability of Plating Film)
5: Non-plated rate is less than 1% (pass). 4: Non-plated rate is 1%
or more and less than 5% (pass). 3: Non-plating rate is 5% or more
and less than 30% (pass). 2: Non-plated rate is 30% or more and
less than 60% (failure). 1: Non-plated rate is 60% or more
(failure).
TABLE-US-00001 TABLE 1 Opening part of through hole of Average
Steel wire Hot-dip Al device for introducing a steel wire Value of
thickness of Stability Diameter Temp. Line speed Size Area area
plating film of plating Ex. No. (mm) Kind Kind (.degree. C.)
(m/min) Shape (mm) (mm.sup.2) ratio (.mu.m) film Ex. 1 0.20 SUS304
8% Si 700 25 Rectangle 0.25 .times. 3.0 0.75 24 4.0 5 Ex. 2 0.20
SUS304 8% Si 700 50 Rectangle 0.25 .times. 3.0 0.75 24 4.6 5 Ex. 3
0.20 SUS304 8% Si 700 100 Rectangle 0.25 .times. 3.0 0.75 24 4.8 4
Ex. 4 0.20 SUS304 8% Si 700 25 Rectangle 5.0 .times. 5.0 25 800 4.0
5 Ex. 5 0.20 SUS304 8% Si 700 50 Rectangle 5.0 .times. 5.0 25 800
4.6 5 Ex. 6 0.20 SUS304 8% Si 700 100 Rectangle 5.0 .times. 5.0 25
800 4.7 4 Ex. 7 0.20 SUS304 8% Si 700 25 Rectangle 7.0 .times. 7.0
49 1560 3.9 3 Ex. 8 0.20 SUS304 8% Si 700 50 Rectangle 7.0 .times.
7.0 49 1560 4.5 3 Ex. 9 0.20 SUS304 8% Si 700 100 Rectangle 7.0
.times. 7.0 49 1560 4.7 3 Ex. 10 0.20 SUS304 8% Si 700 25 Rectangle
10 .times. 10 100 3180 3.9 3 Ex. 11 0.20 SUS304 8% Si 700 50
Rectangle 10 .times. 10 100 3180 4.2 3 Ex. 12 0.20 SUS304 8% Si 700
100 Rectangle 10 .times. 10 100 3180 4.6 3 Ex. 13 0.20 SUS304 8% Si
700 50 Rectangle 0.31 .times. 0.31 0.096 3.1 4.5 5 Ex. 14 0.20
SUS304 8% Si 700 50 Round .phi.0.35 0.096 3.1 4.4 5 Ex. 15 0.20
SUS304 8% Si 700 50 Round .phi.2.0 3.14 100 4.6 5 Ex. 16 0.20
SUS304 8% Si 700 50 Round .phi.5.0 20 640 4.4 5 Ex. 17 0.20 SUS304
8% Si 700 50 Round .phi.8.0 50 1600 4.3 3 Ex. 18 0.20 SUS304 8% Si
700 50 Round .phi.12.0 113 3600 4.7 3 (Note) "Value of area ratio"
means a value of area ratio [area of opening part of through
hole/area of cross section of steel wire].
TABLE-US-00002 TABLE 2 Opening part of through hole of device for
Value Average Steel wire Hot-dip Al Line introducing a steel wire
of thickness of Diameter Temp. speed Size Area area plating film
Stability of Ex. No. (mm) Kind Kind (.degree. C.) (m/min) Shape
(mm) (mm.sup.2) ratio (.mu.m) plating film Ex. 19 0.20 SUS304 8% Si
685 50 Rectangle 1.0 .times. 2.0 2.0 64 4.2 5 Ex. 20 0.20 SUS304 8%
Si 720 50 Rectangle 1.0 .times. 2.0 2.0 64 4.5 5 Ex. 21 0.20 SUS304
4% Si 685 50 Rectangle 1.0 .times. 2.0 2.0 64 4.6 5 Ex. 22 0.20
SUS304 11% Si 685 50 Rectangle 1.0 .times. 2.0 2.0 64 4.3 5 Ex. 23
0.07 SUS304 8% Si 700 50 Rectangle 1.0 .times. 2.0 2.0 520 4.0 5
Ex. 24 0.10 SUS304 8% Si 700 50 Rectangle 1.0 .times. 2.0 2.0 255
4.5 5 Ex. 25 0.15 SUS304 8% Si 700 50 Rectangle 1.0 .times. 2.0 2.0
113 4.6 5 Ex. 26 0.30 SUS304 8% Si 700 50 Rectangle 2.0 .times. 3.0
6.0 85 4.5 5 Ex. 27 0.60 SUS304 8% Si 700 50 Rectangle 2.0 .times.
3.0 6.0 21 4.4 5 Ex. 28 1.00 SUS304 8% Si 700 50 Rectangle 2.0
.times. 3.0 6.0 8 4.6 5 Ex. 29 0.20 SUS430 8% Si 700 25 Rectangle
0.8 .times. 3.0 2.4 76 3.8 5 Ex. 30 0.20 SUS430 8% Si 700 50
Rectangle 0.8 .times. 3.0 2.4 76 4.3 5 Ex. 31 0.20 SUS430 8% Si 700
100 Rectangle 0.8 .times. 3.0 2.4 76 4.4 4 Ex. 32 0.20 SUS304 13%
Si 685 50 Rectangle 1.0 .times. 2.0 2.0 64 4.6 5 Ex. 33 0.20 SUS304
Al 700 50 Rectangle 1.0 .times. 2.0 2.0 64 4.2 5 Comp. Ex. 1 0.20
SUS304 8% Si 700 25 No installation -- 3.4 2 Comp. Ex. 2 0.20
SUS304 8% Si 700 50 No installation -- 3.6 1 Comp. Ex. 3 0.20
SUS304 8% Si 700 100 No installation -- 3.7 1 (Note) "Value of area
ratio" means a value of area ratio [area of opening part of through
hole/area of cross section of steel wire].
TABLE-US-00003 TABLE 3 Opening part of through hole of Average
Steel wire Hot-dip Al Line device for introducing a steel wire
thickness of Stability Diameter Temp. speed Size Area Value of
plating film of plating Ex. No. (mm) Kind Kind (.degree. C.)
(m/min) Shape (mm) (mm.sup.2) area ratio (.mu.m) film Ex. 34 0.20
37A 8% Si 700 50 Rectangle 0.25 .times. 3.0 0.75 24 4.3 5 Ex. 35
0.20 37A 8% Si 700 50 Rectangle 1.0 .times. 2.0 2.0 64 4.4 5 Ex. 36
0.20 37A 8% Si 700 50 Rectangle 5.0 .times. 5.0 25 800 4.4 5 Ex. 37
0.20 37A 8% Si 700 50 Rectangle 7.0 .times. 7.0 49 1560 4.5 3 Ex.
38 0.20 37A 8% Si 700 50 Rectangle 10 .times. 10 100 3180 4.2 3 Ex.
39 0.20 37A 8% Si 700 50 Round .phi.2.0 3.14 100 4.2 5 (Note)
"Value of area ratio" means a value of area ratio [area of opening
part of through hole/area of cross section of steel wire].
Examples 40 to 67 and Comparative Example 4
[0084] A hot-dip aluminum-coated steel wire was produced based on
the embodiment as illustrated in FIG. 3. As a steel wire, a steel
wire having a diameter shown in Tables 4 and 5, and made of steel
shown in Tables 4 and 5 was used. The term "37A" listed in Table 5
means a steel wire made of high carbon steel containing 0.37% by
mass of carbon.
[0085] Incidentally, the steel wire was subjected to degreasing by
dipping the steel wire in a degreasing liquid containing sodium
orthosilicate and a surfactant, before the steel wire was dipped in
the hot-dip aluminum.
[0086] In addition, the steel wire was preheated at a preheating
temperature shown in Tables 4 and 5 by introducing the steel wire
into a heating device, before the steel wire was introduced into a
steel wire-introducing device. As the heating device, a tubular
heater (not shown in the figure) was provided just before the steel
wire-introducing device. A Kanthal.RTM. wire wound in a coil shape
was built in the heater. The heater was connected with a
gas-introducing system for providing nitrogen gas (not shown in the
figure), and heated nitrogen gas was introduced into the heating
device, to preheat the steel wire in nitrogen gas atmosphere.
Incidentally, a steel wire connected with a thermocouple was
prepared, and the thermocouple was passed through the heating
device together with the steel wire, to determine the preheating
temperature.
[0087] As a device for introducing a steel wire, a device 7 for
introducing a steel wire shown in FIG. 2, which was produced by
assembling blocks or square bars made of stainless steel, was used.
The device 7 for introducing a steel wire had a total length L of
100 mm, and the shape, size and area of the opening part 9c of the
introducing port 9b of the through hole 8 were the same as those of
the opening part 9e of the discharge port 9d of the through hole 8.
The shape, size and area of the opening part of the through hole 8
of the device 7 for introducing a steel wire, and the value of area
ratio are shown in Tables 4 and 5. The dipping region 9a of 10 mm
from the lower end of the steel wire-introducing device 7 was
dipped in the molten aluminum, and the steel wire being introduced
into the steel wire-introducing device 7 was dipped in the molten
aluminum as it was.
[0088] As the molten aluminum, molten aluminum containing 8% by
mass of silicon (referred to as "8% Si" in the column "kind" of
"hot-dip Al" in Tables 4 and 5) was used. The steel wire was dipped
in the molten aluminum at a temperature of the molten aluminum
shown in Tables 4 and 5 at a line speed (speed of drawing up of
steel wire) shown in Tables 4 and 5, and then the steel wire was
drawn up from the molten aluminum.
[0089] In addition, a nozzle having an inner diameter of 3 mm at
its tip was provided so that the tip of the nozzle was positioned
at a place apart from the steel wire in a distance of 2 mm. An
inert gas (nitrogen gas) of which temperature was controlled to
600.degree. C. was discharged from the tip of the nozzle at a
volume flow rate of 10 L/min, and was blown to the boundary between
the steel wire and the surface of the molten aluminum.
[0090] The above operations were carried out, to obtain a hot-dip
aluminum-coated steel wire having a plating film of an average
thickness shown in Tables 4 and 5.
[0091] Next, the average thickness of a plating film and stability
of a plating film of the hot-dip aluminum-coated steel wire
obtained in the above were examined in the same manner as mentioned
above. Its results are shown in
TABLE-US-00004 TABLE 4 Average Opening part of through hole of
Value thickness Stability Steel wire Hot-dip Al Line Heating device
device for introducing a steel wire of of plating of Ex. Diameter
Temp. speed Preheating Introduced Size Area area film plating No.
(mm) Kind Kind (.degree. C.) (m/min) temp. (.degree. C.) gas Shape
(mm) (mm.sup.2) ratio (.mu.m) film Ex. 40 0.20 SUS304 8% Si 700 300
82 Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 5.9 3 Ex. 41 0.20
SUS304 8% Si 700 300 168 Nitrogen Rectangle 0.25 .times. 3.0 0.75
24 6.0 4 Ex. 42 0.20 SUS304 8% Si 700 300 250 Nitrogen Rectangle
0.25 .times. 3.0 0.75 24 5.8 4 Ex. 43 0.20 SUS304 8% Si 700 300 390
Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 5.7 5 Ex. 44 0.20
SUS304 8% Si 700 300 582 Nitrogen Rectangle 0.25 .times. 3.0 0.75
24 6.1 5 Ex. 45 0.20 SUS304 8% Si 700 300 710 Nitrogen Rectangle
0.25 .times. 3.0 0.75 24 5.8 5 Ex. 46 0.20 SUS304 8% Si 700 300 330
Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 6.4 5 Ex. 47 0.20
SUS304 8% Si 700 300 330 Nitrogen Round .phi.2.0 3.14 100 5.9 5 Ex.
48 0.20 SUS304 8% Si 685 300 390 Nitrogen Rectangle 0.8 .times. 3.0
2.4 76 6.2 5 Ex. 49 0.20 SUS304 8% Si 720 300 390 Nitrogen
Rectangle 0.8 .times. 3.0 2.4 76 5.6 5 Ex. 50 0.20 SUS304 8% Si 685
300 390 Nitrogen Ratangle 0.8 .times. 3.0 2.4 76 5.5 5 Ex. 51 0.20
SUS304 8% Si 700 300 390 Nitrogen Rectangle 0.31 .times. 0.31 0.096
3.1 4.4 5 Ex. 52 0.20 SUS304 8% Si 700 300 390 Nitrogen Round
.phi.0.35 0.096 3.1 4.5 5 Ex. 53 0.07 SUS304 8% Si 700 600 322
Nitrogen Rectangle 1.0 .times. 2.0 2.0 520 4.8 5 Ex. 54 0.10 SUS304
8% Si 700 600 333 Nitrogen Rectangle 1.0 .times. 2.0 2.0 255 5.2 5
(Note) "Value of area ratio" means a value of area ratio [area of
opening part of through hole/area of cross section of steel
wire].
TABLE-US-00005 TABLE 5 Opening part of Average Hot-dip Al Heating
device through hole of device for thickness Stability Steel wire
Preheating Line Preheating introducing a steel wire Value of
plating of Diameter temp. speed temp. Introduced Size Area of area
film plating Ex. No. (mm) Kind Kind (.degree. C.) (m/min) (.degree.
C.) gas Shape (mm) (mm.sup.2) ratio (.mu.m) film Ex. 55 0.15 SUS304
8% Si 700 200 315 Nitrogen Rectangle 1.0 .times. 2.0 2.0 1.13 5.3 5
Ex. 56 0.30 SUS304 8% Si 700 300 302 Nitrogen Rectangle 2.0 .times.
3.0 6.0 85 9.3 5 Ex. 57 0.60 SUS304 8% Si 700 300 282 Nitrogen
Rectangle 2.0 .times. 3.0 6.0 21 12.3 5 Ex. 58 1.00 SUS304 8% Si
700 300 240 Nitrogen Rectangle 2.0 .times. 3.0 6.0 8 14.9 5 Ex. 59
0.20 SUS430 8% Si 700 300 82 Nitrogen Rectangle 0.25 .times. 3.0
0.75 24 5.9 3 Ex. 60 0.20 SUS430 8% Si 700 300 168 Nitrogen
Rectangle 0.25 .times. 3.0 0.75 24 6.0 4 Ex. 61 0.20 SUS430 8% Si
700 300 390 Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 5.8 5 Ex.
62 0.20 37A 8% Si 700 300 82 Nitrogen Rectangle 0.25 .times. 3.0
0.75 24 5.9 3 Ex. 63 0.20 37A 8% Si 700 300 168 Nitrogen Rectangle
0.25 .times. 3.0 0.75 24 6.1 4 Ex. 64 0.20 37A 8% Si 700 300 390
Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 5.7 5 Ex. 65 0.20 37A
8% Si 700 300 710 Nitrogen Rectangle 0.25 .times. 3.0 0.75 24 6.2 5
Ex. 66 0.20 37A 8% Si 700 400 330 Nitrogen Rectangle 0.25 .times.
3.0 0.75 24 5.4 5 Ex. 67 0.20 37A 8% Si 700 300 390 Nitrogen Round
.phi.2.0 3.14 100 5.5 5 Comp. 0.20 SUS304 8% Si 700 300 260
Nitrogen No installation -- 3.8 1 Ex. 4 (Note) "Value of area
ratio" means a value of area ratio [area of opening part of through
hole/area of cross section of steel wire].
Examples 68 to 83
[0092] A hot-dip aluminum-coated steel wire was produced based on
the embodiment as illustrated in FIG. 1.
[0093] As a steel wire, a steel wire having a diameter shown in
Table 6, and made of steel shown in Table 6 was used. The term
"37A" listed in Table 6 means a steel wire made of high carbon
steel containing 0.37% by mass of carbon.
[0094] Incidentally, the steel wire was subjected to degreasing by
dipping the steel wire in a degreasing liquid containing sodium
orthosilicate and a surfactant, before the steel wire was dipped in
the hot-dip aluminum.
[0095] As a device for introducing a steel wire, a device 7 for
introducing a steel wire shown in FIG. 2, which was produced by
assembling blocks or square bars made of stainless steel, was used.
The device 7 for introducing a steel wire had a total length L of
800 mm, and the shape, size and area of the opening part 9c of the
introducing port 9b of the through hole 8 were the same as those of
the opening part 9e of the discharge port 9d of the through hole 8.
The shape, size and area of the opening part of the through hole 8
of the device 7 for introducing a steel wire, and the value of area
ratio are shown in Table 6. The dipping region 9a of 100 mm from
the lower end of the steel wire-introducing device 7 was dipped in
the molten aluminum, and the steel wire being introduced into the
steel wire-introducing device 7 was dipped in the molten aluminum
as it was.
[0096] As the molten aluminum, molten aluminum containing 8% by
mass of silicon (referred to as "8% Si" in the column "kind" of
"hot-dip Al" in Table 6), was used. The steel wire was dipped in
the molten aluminum at a temperature of the molten aluminum shown
in Table 6 at a line speed (speed of drawing up of steel wire)
shown in Table 6, and then the steel wire was drawn up from the
molten aluminum.
[0097] A nozzle having an inner diameter of 3 mm at its tip was
provided so that the tip of the nozzle was positioned at a place
apart from the steel wire in a distance of 2 mm. An inert gas
(nitrogen gas) of which temperature was controlled to 600.degree.
C. was discharged from the tip of the nozzle at a volume flow rate
of 10 L/min, and blown to the boundary between the steel wire and
the surface of the molten aluminum.
[0098] The above operations were carried out, to obtain a hot-dip
aluminum-coated steel wire having a plating film of an average
thickness shown in Table 6.
[0099] Next, the average thickness of a plating film and stability
of a plating film of the hot-dip aluminum-coated steel wire
obtained in the above were examined in the same manner as mentioned
above. Its results are shown in Table 6.
TABLE-US-00006 TABLE 6 Opening part of through hole of Average
Steel wire Hot-dip Al Line device for introducing a steel wire
thickness of Stability Diameter Preheating speed Size Area Value of
plating film of plating Ex. No. (mm) Kind Kind temp. (.degree. C.)
(m/min) Shape (mm) (mm.sup.2) area ratio (.mu.m) film Ex. 68 0.20
SUS304 8% Si 700 50 Rectangle 0.25 .times. 3.0 0.75 24 4.5 5 Ex. 69
0.20 SUS304 8% Si 700 50 Rectangle 5.0 .times. 3.0 15 480 4.4 5 Ex.
70 0.20 SUS304 8% Si 700 50 Rectangle 7.0 .times. 3.0 21 670 4.6 3
Ex. 71 0.20 SUS304 8% Si 700 50 Rectangle 10 .times. 10 100 3180
4.3 3 Ex. 72 0.20 SUS430 8% Si 700 50 Rectangle 0.31 .times. 0.31
0.096 3.1 4.3 5 Ex. 73 0.20 SUS430 8% Si 700 50 Round .phi.0.35
0.096 3.1 4.8 5 Ex. 74 0.20 SUS430 8% Si 700 50 Round .phi.2.0 3.14
100 4.6 5 Ex. 75 0.20 SUS430 8% Si 700 50 Round .phi.5.0 19.63 625
4.7 5 Ex. 76 0.20 SUS430 8% Si 700 50 Round .phi.8.0 50.24 1600 4.6
3 Ex. 77 0.20 SUS430 8% Si 700 50 Round .phi.12.0 113 3600 4.9 3
Ex. 78 0.20 37A 8% Si 700 50 Rectangle 0.25 .times. 3.0 0.75 24 4.5
5 Ex. 79 0.20 37A 8% Si 700 50 Rectangle 1.0 .times. 2.0 2.0 64 4.6
5 Ex. 80 0.20 37A 8% Si 700 50 Rectangle 5.0 .times. 5.0 25 800 4.8
5 Ex. 81 0.20 37A 8% Si 700 50 Rectangle 7.0 .times. 7.0 49 1560
4.7 3 Ex. 82 0.20 37A 8% Si 700 50 Rectangle 10 .times. 10 100 3180
4.7 3 Ex. 83 0.20 37A 8% Si 700 50 Round .phi.2.0 3.14 100 4.6 5
(Note) "Value of area ratio" means a value of area ratio [area of
opening part of through hole/area of cross section of steel
wire].
[0100] From the results shown in Tables 1 to 6, according to the
method for producing a hot-dip aluminum-coated steel wire of each
of the working examples, it can be seen that excellent effects such
that a hot-dip aluminum-coated steel wire having a plating film
over the whole surface can be efficiently produced.
[0101] In contrast, in Comparative Examples 1 to 4, a steel
wire-introducing device was not employed. Therefore, an oxide film
floating on the surface of the molten aluminum was included in the
molten aluminum when a steel wire was dipped in the molten
aluminum. Accordingly, a hot-dip aluminum-coated steel wire having
a lot of portions where plating films were not formed on its
surface was obtained. It can be seen from the fact that the hot-dip
aluminum-coated steel wire is wrong in stability of a plating
film.
INDUSTRIAL APPLICABILITY
[0102] The hot-dip aluminum-coated steel wire obtained by the
method for producing a hot-dip aluminum-coated steel wire according
to the present invention can be suitably used in, for example, a
wire harness of automobiles.
DESCRIPTION OF SYMBOLS
[0103] 1: molten aluminum [0104] 2: steel wire [0105] 3: hot-dip
aluminum-coated steel wire [0106] 4: delivery device [0107] 5:
plating bath [0108] 6: dipping area of a steel wire [0109] 7: steel
wire-introducing device [0110] 8: through hole [0111] 9: tubular
body [0112] 9a: dipping region of tubular body [0113] 9b:
introducing port of tubular body [0114] 9c: opening part of
introducing hole of tubular body [0115] 9d: discharge port of
tubular body [0116] 9e: opening part of discharge port of tubular
body [0117] 10: surface of molten aluminum [0118] 11: stabilizing
member [0119] 11a: heat-resistant cloth of stabilizing member
[0120] 12: nozzle [0121] 12a: tip end of nozzle [0122] 13: inert
gas providing apparatus [0123] 14: pipe [0124] 15: cooling device
[0125] 16: winding device [0126] 17: heating device [0127] 18:
plating film [0128] 19: device for measuring diameter [0129] 19a:
light emitting unit of device for measuring diameter [0130] 19b:
light receiving unit of a device for measuring a diameter [0131]
19c: pulley of a device for measuring a diameter [0132] 19d: pulley
of a device for measuring a diameter
* * * * *