U.S. patent application number 12/925200 was filed with the patent office on 2011-02-10 for tempered plated wire.
This patent application is currently assigned to Industrial Door Co., Inc.. Invention is credited to Jodi Boldenow, Steven Galloway, Karl Lundahl, Jeremy Sizer.
Application Number | 20110033729 12/925200 |
Document ID | / |
Family ID | 36205110 |
Filed Date | 2011-02-10 |
United States Patent
Application |
20110033729 |
Kind Code |
A1 |
Galloway; Steven ; et
al. |
February 10, 2011 |
Tempered plated wire
Abstract
The present invention is a method of manufacturing plated wire.
The method includes drawing a feed stock to form drawn wire,
tempering the drawn wire to form tempered wire and plating the
tempered wire to form the plated wire. The plated wire exhibits a
tensile strength that substantially meets ASTM A229-99.
Inventors: |
Galloway; Steven; (Fridley,
MN) ; Lundahl; Karl; (Stanchfield, MN) ;
Sizer; Jeremy; (Ramsey, MN) ; Boldenow; Jodi;
(Ramsey, MN) |
Correspondence
Address: |
KINNEY & LANGE, P.A.
THE KINNEY & LANGE BUILDING, 312 SOUTH THIRD STREET
MINNEAPOLIS
MN
55415-1002
US
|
Assignee: |
Industrial Door Co., Inc.
Coon Rapids
MN
|
Family ID: |
36205110 |
Appl. No.: |
12/925200 |
Filed: |
October 15, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11115624 |
Apr 27, 2005 |
7824533 |
|
|
12925200 |
|
|
|
|
60621847 |
Oct 25, 2004 |
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Current U.S.
Class: |
428/659 ;
428/658; 428/684; 428/686 |
Current CPC
Class: |
Y10T 428/12792 20150115;
C25D 7/0607 20130101; Y10T 428/12986 20150115; Y02P 10/253
20151101; C23C 30/00 20130101; C25D 5/36 20130101; C21D 9/60
20130101; Y10T 428/12799 20150115; Y10T 428/12972 20150115; Y02P
10/25 20151101; C21D 8/06 20130101 |
Class at
Publication: |
428/659 ;
428/686; 428/684; 428/658 |
International
Class: |
B32B 15/01 20060101
B32B015/01; B32B 15/02 20060101 B32B015/02 |
Claims
1. An article comprising: a tempered wire; and a finished surface
disposed on the tempered wire, wherein the finished surface
comprises a plating material, and wherein the article exhibits a
tensile strength that substantially meets ASTM A229-99 and exhibits
a hydrogen concentration of about two parts-per-million, or less,
per weight.
2. The article of claim 1, wherein the tempered wire comprises a
heat induction tempered wire.
3. The article of claim 1, wherein the finished surface is an
electroplated finished surface.
4. The article of claim 1, wherein the article exhibits a hydrogen
concentration of about one part-per-million, or less, by
weight.
5. The article of claim 1, wherein the finished surface has a
thickness ranging from about one micron to about six microns.
6. The article of claim 1, wherein the tempered wire comprises a
metal having a composition, by weight, of carbon 0.55 to 0.85
percent, manganese 0.30 to 1.20 percent, phosphorous up to 0.04
percent, sulfur up to 0.05 percent, silicon 0.15 to 0.35 percent,
and balance steel.
7. The article of claim 1, wherein the article further exhibits
properties that substantially meet a standard that is selected from
a group consisting of ASTM A230-99, ASTM A231-04, ASTM A232-99,
ASTM A401-03, ASTM A877-99, ASTM A878-00, and ASTM A1000-05.
8. The article of claim 1, wherein the plating material comprises
zinc.
9. The article of claim 1, wherein the tempered wire has a wire
diameter of about 0.5 mm to about 16.0 mm.
10. A plated wire comprising: a tempered steel wire; and a zinc
plated layer on the tempered steel wire, wherein the plated wire
exhibits a tensile strength that substantially meets ASTM A229-99
and exhibits a hydrogen concentration of about two
parts-per-million, or less, per weight.
11. The plated wire of claim 10, wherein the tempered steel wire
comprises a heat induction tempered steel wire.
12. The plated wire of claim 10, wherein the zinc plated layer is
an electroplated zinc layer.
13. The plated wire of claim 10, wherein the plated wire exhibits a
hydrogen concentration of about one part-per-million, or less, by
weight.
14. The plated wire of claim 10, wherein the zinc plated layer has
a thickness ranging from about one micron to about six microns.
15. The plated wire of claim 10, wherein the tempered wire
comprises a metal having a composition, by weight, of carbon 0.55
to 0.85 percent, manganese 0.30 to 1.20 percent, phosphorous up to
0.04 percent, sulfur up to 0.05 percent, silicon 0.15 to 0.35
percent, and balance steel.
16. The plated wire of claim 10, wherein the plated wire further
exhibits properties that substantially meet a standard that is
selected from a group consisting of ASTM A230-99, ASTM A231-04,
ASTM A232-99, ASTM A401-03, ASTM A877-99, ASTM A878-00, and ASTM
A1000-05.
17. The plated wire of claim 10, wherein the tempered wire has a
wire diameter of about 0.5 mm to about 16.0 mm.
18. The plated wire of claim 17, wherein the zinc plated layer has
a thickness ranging from about one micron to about six microns.
19. The plated wire of claim 18, wherein the tempered wire
comprises a metal having a composition, by weight, of carbon 0.55
to 0.85 percent, manganese 0.30 to 1.20 percent, phosphorous up to
0.04 percent, sulfur up to 0.05 percent, silicon 0.15 to 0.35
percent, and balance steel.
20. The plated wire of claim 19, wherein the plated wire further
exhibits properties that substantially meet a standard that is
selected from a group consisting of ASTM A230-99, ASTM A231-04,
ASTM A232-99, ASTM A401-03, ASTM A877-99, ASTM A878-00, and ASTM
A1000-05.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a division of U.S. patent application
Ser. No. 11/115,624, filed on Apr. 27, 2005, and claims benefit of
U.S. Provisional Patent Application No. 60/621,847, entitled
"Tempered Plated Wire and Methods of Manufacture", filed on Oct.
25, 2004, which is incorporated herein by reference in its
entirety.
BACKGROUND
[0002] The present invention relates to wire articles and methods
of manufacturing wire articles. In particular, the present
invention relates to wire articles manufactured by processes that
include a combination of tempering and plating.
[0003] Wire is used to form a variety of industrial products, such
as springs, wire screens, and cable. Accordingly, different types
of wire are manufactured through different processes, each of which
affect the physical properties of the wire (e.g., tensile strength,
surface qualities, and other metallurgic properties). For example,
wire may be tempered, which involves a series of heating and
cooling steps to obtain desired martensitic properties of the wire
(e.g., hardness, ductility, and tensile strengths).
[0004] Oil tempering is the most common tempering technique used to
manufacture wire. Oil tempering involves cold drawing the wire down
to a desired size, and then heat tempering the wire in a furnace
with lead. While this process provides wire with acceptable
martensitic properties, the resulting wire is also oily, which
reduces the aesthetic qualities of the wire.
[0005] A common drawback with tempered wire is that the resulting
wire exhibits an unfinished surface. This reduces the aesthetic
qualities of the wire and leaves the wire exposed to rusting, which
may decrease the life of the wire. Nonetheless, tempered wire
currently used in the industry is not plated with a finished
surface. Accordingly, there is a need for a process to manufacture
wire that combines the martensitic properties of tempering and the
finished surfaces obtained by plating.
SUMMARY
[0006] The present invention is further directed to an article that
exhibits a tensile strength that substantially meets ASTM A229-99.
The article includes a tempered wire and a finished surface
disposed on the tempered wire, where the finished surface includes
a plating compound.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a block diagram illustration of a method of the
present invention.
[0008] FIG. 2 is a sectional view of a wire of the present
invention.
[0009] FIG. 3 is a block diagram illustration of a preferred method
of the present invention.
[0010] While the above-identified drawings set forth an embodiment
of the invention, other embodiments are also contemplated, as noted
in the discussion. In all cases, this disclosure presents the
invention by way of representation and not limitation. It should be
understood that numerous other modifications and embodiments may be
devised by those skilled in the art, which fall within the scope
and spirit of the principles of the invention. The figures may not
be drawn to scale. Like reference numbers have been used throughout
the figures to denote like parts.
DETAILED DESCRIPTION
[0011] The present invention is directed to wire that is
manufactured by (1) tempering, to provide desired physical
strengths for the wire, and (2) plating, to provide a finished
surface on the wire. The wire manufactured pursuant to the present
invention exhibits good physical strengths (e.g., good martensitic
properties), good aesthetic qualities, and rust resistance, for use
as a variety of industrial products. In one embodiment, the wire
manufactured pursuant to the present invention has a finished
surface and exhibits a tensile strength that substantially meets
ASTM A229-99. The term "finished surface" is defined herein as a
thin layer of a plating compound that extends substantially around
the exterior surface of tempered wire.
[0012] FIG. 1 is a block diagram illustration of a method used to
manufacture wire, pursuant to the present invention. As depicted at
block 10, a feed stock is drawn to form wire having a desired wire
diameter. For example, the wire may be cold drawn from a stock
steel rod to obtain the desired wire diameter. Examples of suitable
wire diameters range from about 0.5 millimeters (mm) to about 16.0
mm.
[0013] After drawing, the wire is then tempered (block 12) to
obtain the desired martensitic properties. Examples of suitable
tempering techniques include conventional tempering techniques,
such as oil tempering and heat induction tempering. In one
embodiment, the wire is tempered via heat induction tempering. Heat
induction tempering involves running the wire through an
alternating-current magnetic field. The alternating-current
magnetic field induces a current within the wire, which
correspondingly heats the wire in a non-contact manner. Examples of
suitable heat induction systems for use with the present invention
include heat induction systems commercially available from Radyne
Corporation, England, United Kingdom. Such systems generally use a
series of coil assemblies to provide the alternating-current
magnetic field.
[0014] An example of a suitable method for heat induction tempering
the wire includes initially passing the wire through a first coil
assembly to heat the wire by induction to a temperature of up to
about 700.degree. C. The wire then passes through a second coil
assembly to heat the wire by induction to a temperature of up to
about 1100.degree. C. After the initial heating, the wire passes
through a third coil assembly to hold the temperature of the wire
by induction at a holding temperature of up to about 1100.degree.
C.
[0015] After heating, the wire is then quenched in a water bath
maintained at about 32.degree. C. to about 38.degree. C. to rapidly
cool the wire, and increase the hardness of the wire. The quenching
may involve immersing the wire in the bath, spraying the wire with
the bath water, and combinations thereof. After the quenching, the
wire then passes through a fourth coil assembly to heat the wire by
induction to a temperature of up to about 600.degree. C. for
tempering the wire. Finally, the wire is quenched in a controlled
manner through a series of water baths ranging in temperature from
about 28.degree. C. to about 32.degree. C. to provide the desired
properties of the wire. The controlled quenching may also involve
immersing the wire in the baths, spraying the wire with the bath
water, and combinations thereof.
[0016] The size and power requirements of the coil assemblies
required to heat the wire up to the above-listed temperatures will
vary based on the wire sizes, the line speeds of the wire, the wire
compositions, and the efficiencies of the coil assemblies. Examples
of particularly suitable heat induction temperatures provided by
the coil assemblies include an initial temperature of up to about
600.degree. C., a subsequent temperature and a temper hold
temperature each up to about 1100.degree. C., and a post-initial
quench tempering temperature up to about 600.degree. C.
[0017] After tempering, the wire is plated (block 14) with a
plating compound to provide a finished surface on the tempered
wire. Examples of suitable plating compounds include zinc, tin,
nickel, copper, other plating mediums, derivatives thereof, salts
thereof (e.g., zinc sulfate and zinc chloride), and combinations
thereof. Examples of suitable plating techniques include extrusion
coating, dip coating, knife coating, deposition coating,
electroplating, thermal diffusion galvanization, and combinations
thereof.
[0018] In one embodiment, the wire is plated by an electroplating
technique, such as electrodeposition (i.e., electrogalvanization).
Examples of suitable electroplating systems for use with the
present invention include systems commercially available from
Otomec srl, Olignate, Italy. An example of suitable processing
conditions for electroplating the wire includes feeding the wire
through a plating solution that contains a dissolved plating
compound and is charged with an electrical current. Examples of
suitable electrical currents range from about 2,000 amps to about
4,000 amps. The electrical current breaks down the plating
compound, which then adheres to the outer surface of the wire as a
finished surface.
[0019] As with the heat induction system, the size and power
requirements of the electroplating systems required to plate the
wire will vary based on the wire sizes, the line speeds of the
wire, the wire compositions, and the efficiencies of the
electroplating systems.
[0020] The above-discussed method of manufacturing wire pursuant to
the present invention may also include additional manufacturing
steps. For example, the method may also include a post-draw
cleaning to clean the wire before heat induction tempering.
Additionally, a descaling step may be used to remove iron oxide
prior to plating.
[0021] FIG. 2 is a sectional view of a manufactured wire 16 that
has been drawn, tempered, and plated pursuant to the present
invention. As shown, the manufactured wire 16 includes a tempered
wire 18, which is coated with a finished surface 20. The tempered
wire 18 may be drawn from a feed stock of any suitable metal
material to obtain a wire diameter 22 and an outer surface 24.
Examples of suitable wire diameters 22 range from about 0.5 mm to
about 16.0 mm, as previously discussed. In one embodiment, the
metal material is an electrically conductive material (e.g., steel)
for heat induction tempering. Table 1 provides an example of a
suitable composition for the tempered wire 18, where the weight
percents of the components are based on the entire weight of the
tempered wire 18.
TABLE-US-00001 TABLE 1 Percent by Composition Weight Carbon
0.55-0.85 Manganese 0.30-1.20 Phosphorous 0.04, max Sulfur 0.05,
max Silicon 0.15-0.35 Steel Balance
[0022] The finished surface 20 is a layer disposed on the outer
surface 24 of the tempered wire 18, and contains the plating
compounds that adhere to the outer surface 24. After plating, the
finished surface 20 exhibits a thickness 26. Examples of suitable
thicknesses 26 range from about one micron to about six microns.
The finished surface 20 protects the tempered wire 18 from external
conditions (e.g., rusting) and provides aesthetic qualities to the
manufactured wire 16. In addition, the tempering allows the
manufactured wire 16 to obtain desired martensitic properties.
Examples of suitable martensitic properties of the manufactured
wire 16 include properties that substantially meet one or more of
ASTM A229-99, ASTM A230-99, ASTM A231-04, ASTM A232-99, ASTM
A401-03, ASTM A877-99, ASTM A878-00, and ASTM A1000-05. Examples of
particularly suitable martensitic properties of the manufactured
wire 16 include tensile strengths that substantially meet ASTM
A229-99. These above-listed martensitic properties allows the
manufactured wire 16 to be used in industrial applications, such as
in the formation of torsion springs and extension springs.
[0023] FIG. 3 is a block diagram illustration of another embodiment
of the present invention, referred to herein as an in-line process
28. The in-line process 28 is similar to the method of the present
invention disclosed in FIG. 1, and includes cold drawing (block
30), heat induction tempering (block 32), and electroplating (block
34), and further includes moving the wire at a line speed in a
continuous process. The wire may be moved via a conventional
mechanism, such as a pulley system with drive wheels. As shown in
FIG. 3, a supply of feed stock 36 is drawn to a desired diameter at
block 30 to obtain a pre-tempered wire 38. The pre-tempered wire 38
is then heat induction tempered at block 32 to obtain the tempered
wire 18. After tempering, the tempered wire 18 is electroplated at
block 34 to obtain the manufactured wire 16, which contains the
finished surface 20 on the tempered wire 18. The heat induction
tempering and the electroplating may be performed with the systems
and processing conditions discussed above in FIG. 1.
[0024] Examples of suitable lines speeds for the wire (e.g., the
pre-tempered wire 38, the tempered wire 18, and the manufactured
wire 16) range from about 50 meters-per-minute to about 250
meters-per-minute. As depicted in FIG. 3, the pre-tempered wire 38
and the tempered wire 18 are preferably drawn through blocks 32 and
34 (e.g., tempering and plating) in a single continuous process at
the given line speed. More preferably, the feed stock 36 is also
fed to the cold drawing block 30 in the same continuous process, as
well. With these preferred embodiments, the in-line process 28
provides several advantages that overcome conventional problems of
tempering and plating wire.
[0025] First, the in-line process 28 minimizes the presence of
oxide scale. An oxide scale (e.g., an iron oxide scale) is
generally produced when iron is heated. As such, wire that has been
heat treated, quenched, and tempered contains iron oxide scale. The
amount of oxide scale present on the wire depends upon time of
exposure to air. Generally, the longer exposure time to the air,
the more oxide scale is created on the surface of the wire. A
drawback to having oxide scale on the wire is that the oxide scale
reduces adhesion. As such, the oxide scale must be removed before
plating processes will adhere, which would require a descaling step
prior to the plating process. Conventional plating techniques use
an acid wash to remove oxide scale prior to the application of the
plating. However, acid wash increases hydrogen embrittlement
(discussed below), is expensive, and is environmentally
undesirable.
[0026] The in-line process 28, however, minimizes the presence of
oxide scale, which substantially reduces or eliminates the need for
a descaling process prior to the plating. Because the tempered wire
18 is fed between blocks 32 and 34 in a continuous process at a
rapid line speed, the tempered wire 18 is minimally exposed to
ambient air. This reduces or results in a negligible amount of
oxide scale accumulation on the tempered wire 18. As such, the
tempered wire 18 may be plated at block 34 after minimal wire
preparation to remove the oxide scale, or alternatively, without
requiring an intermediate step to remove the oxide scale.
[0027] In addition to the descaling issues, subjecting the tempered
wire 18 to secondary heating would negate the original tempering of
the tempered wire 18. As used herein, the term "secondary heating"
refers to any post-tempering heating of wire to a temperature
greater than about 100.degree. C., and is intended to include
heating that occurs during the plating step. For example, one
common method of plating steel is with a molten zinc bath at about
540.degree. C. This type of plating, however, is undesirable for
the tempered wire 18. If the tempered wire 18 is subjected to the
molten zinc bath, the temperature of the tempered wire 18 would
increase. This increase in temperature would substantially reduce
the original temper obtained at block 32. As a result, the
manufactured wire 16, after plating, would lose the desired
martensitic properties.
[0028] The in-line process 28, however, substantially avoids the
need for secondary heating because the electroplating step at block
34 does not use a heated bath. The plating solution is electrically
charged to adhere the plating compounds to the tempered wire 18 to
form the finished surface 20. As such, the desired martensitic
properties obtained by tempering are not lost during the
plating.
[0029] Conventional electroplating techniques often require a
post-plating heat treatment. This is because hydrogen is generated
in the electroplating process, which does not immediately come to
equilibrium. As such, conventional electroplating techniques
require further time and temperature to stabilize the hydrogen. The
post-plating heat treatment may substantially reduce the original
temper from the wire production process, as discussed above. Also,
secondary heat treatments higher than about 200.degree. C. cause
the hydrogen to react with carbon to form methane
embrittlement.
[0030] Hydrogen embrittlement is another issue that is common with
conventional plating techniques. Hydrogen embrittlement may cause
grain structures of the steel material of wire to fracture. This is
due to the cubic structure of iron. When wire is tempered, the
tempered steel exhibits elongated cubes that form rhombahedrions.
Monatomic hydrogen molecules are capable of passing through all
metals and set in the steel. This causes iron carbide to break down
into iron compounds and carbide compounds, and forces hydrogen
atoms out and in between metal structures. Eventually, the
monatomic hydrogen molecules are forced together to form hydrogen
compounds (H.sub.2), which correspondingly forms gas bubbles.
Because of the stress in the structure of the steel, the generated
hydrogen is squeezed and causes the grain structures in the steel
to fracture.
[0031] During plating processes, hydrogen is generated and picked
up into the steel. Generally, two to three parts-per-million (ppm)
is the maximum allowable standard content of hydrogen in the
chemistry of steel. Higher concentrations of hydrogen in the steel
will cause grain structures to fracture. Keeping an allowable
minimum amount of hydrogen in the steel product produced is a
direct result of time, speed, temperature, and amount of current in
the plating process.
[0032] With the in-line process 28 of the present invention, the
tempered wire 18 moves through the plating solution at a rapid line
speed at block 34. This minimizes the exposure time of the tempered
wire 18 in the plating solution. As such, the amount of hydrogen
generated is substantially reduced, precluding the need for a
post-plating heat treatment to stabilize the hydrogen. This also
substantially reduces the amount of hydrogen that is picked up in
the steel (preferably less than about two ppm, by weight), which
correspondingly reduces the effects of methane and hydrogen
embrittlement.
[0033] Because of the rapid line speed, the temperature, and the
amount of current applied, the in-line process 28 creates a window
in which the martensitic properties of the tempered wire 18 can be
achieved, the desired tensile maintained, and wherein the plating
will not compromise them. In particular, the in-line process 28 may
eliminate or be substantially free of a descaling step, may be
eliminate or be substantially free of a secondary heating step, and
may provide a hydrogen content in the manufactured wire 16 of under
about one ppm by weight (based on the entire weight of the
manufactured wire 16), thereby avoiding hydrogen embrittlement.
[0034] The finished article (e.g., the manufactured wire 16) is
wire with a finished surface and that exhibits good martensitic
properties. As discussed above, examples of suitable martensitic
properties of the manufactured wire 16 include properties that
substantially meet ASTM A229-99, ASTM A230-99, ASTM A231-04, ASTM
A232-99, ASTM A401-03, ASTM A877-99, ASTM A878-00, and ASTM
A1000-05. Examples of particularly suitable martensitic properties
of the manufactured wire 16 include tensile strengths that
substantially meet ASTM A229-99. Such a manufactured wire 16 is
useful in the formation of torsion springs and extension
springs.
[0035] While the invention has been described with reference to an
exemplary embodiment(s), it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment(s) disclosed, but that the invention will
include all embodiments falling within the scope of the appended
claims.
* * * * *