U.S. patent application number 16/369849 was filed with the patent office on 2019-10-03 for tubular wires made from copper coated strip.
The applicant listed for this patent is Hobart Brothers Company. Invention is credited to Mario A. Amata, Steven E. Barhorst, Joseph C. Bundy.
Application Number | 20190299339 16/369849 |
Document ID | / |
Family ID | 66641449 |
Filed Date | 2019-10-03 |
United States Patent
Application |
20190299339 |
Kind Code |
A1 |
Barhorst; Steven E. ; et
al. |
October 3, 2019 |
TUBULAR WIRES MADE FROM COPPER COATED STRIP
Abstract
The present disclosure relates to a method for producing a
tubular welding electrode comprising the steps of providing a strip
of copper-coated steel material having a length and first and
second surfaces, wherein at least the first surface of the strip is
at least substantially coated with a copper alloy, forming the
strip into a "U" shape along the length, filling the "U" shape of
the strip with a granular powder flux, and mechanically closing the
"U" shape to form a sheath of copper-coated steel material that
substantially encases the granular powder flux, thus forming a
tubular welding electrode.
Inventors: |
Barhorst; Steven E.;
(Sidney, OH) ; Amata; Mario A.; (Dublin, OH)
; Bundy; Joseph C.; (Piqua, OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hobart Brothers Company |
Troy |
OH |
US |
|
|
Family ID: |
66641449 |
Appl. No.: |
16/369849 |
Filed: |
March 29, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62650475 |
Mar 30, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C25D 5/48 20130101; B23K
35/0266 20130101; B23K 35/0272 20130101; H01M 2/00 20130101; B23K
35/0261 20130101; B23K 35/3053 20130101; B23K 35/406 20130101; C25D
7/0614 20130101; B23K 35/404 20130101; B23K 2035/408 20130101 |
International
Class: |
B23K 35/30 20060101
B23K035/30; B23K 35/40 20060101 B23K035/40 |
Claims
1. A tubular welding electrode having a length comprising: a
granular core extending substantially along the length of the
electrode; and a steel sheath extending substantially along the
length of the electrode and substantially encasing the granular
core; wherein the steel sheath has an inner and an outer surface;
wherein the steel sheath has and opposing radial ends that extend
substantially along the length of the electrode; wherein the
opposing radial ends of the steel sheath are joined via a seam
extending substantially along the length of the electrode; and
wherein the outer surface of the steel sheath is at least
substantially coated with copper or a copper alloy prior to joining
the opposing radial ends of the steel sheath.
2. The tubular welding electrode of claim 1, wherein the seam is a
butt or overlap seam.
3. The tubular welding electrode of claim 1, wherein the granular
core is a granular powder flux fill core.
4. The tubular welding electrode of claim 1, wherein the granular
core is a granular metal core.
5. The tubular welding electrode of claim 1, wherein the copper or
copper alloy is plated onto the outer surface of the steel
sheath.
6. The tubular welding electrode of claim 1, wherein both the inner
and outer surfaces of the steel sheath are at least substantially
coated with copper or a copper alloy.
7. A tubular welding electrode having a length comprising: a
granular core extending substantially along the length of the
electrode; and a steel sheath extending substantially along the
length of the electrode and substantially encasing the granular
core; wherein the steel sheath has an inner and an outer surface,
and wherein the inner surface of the steel sheath is at least
substantially coated with copper or a copper alloy.
8. The tubular welding electrode of claim 7, wherein the granular
core is a granular powder flux fill core.
9. The tubular welding electrode of claim 7, wherein the granular
core is a granular metal core.
10. The tubular welding electrode of claim 7, wherein the copper or
copper alloy is plated onto the inner surface of the steel
sheath.
11. The tubular welding electrode of claim 7, wherein both the
inner and outer surfaces of the steel sheath are at least
substantially coated with copper or a copper alloy.
12. A method for producing a tubular welding electrode comprising:
a. providing a strip of copper-coated steel material having a
length and first and second surfaces, wherein at least the first
surface of the strip is at least substantially coated with copper
or a copper alloy; b. forming the strip into a "U" shape along the
length; c. filling the "U" shape of the strip with a granular flux;
and d. mechanically closing the "U" shape to form a sheath of
copper-coated steel material that substantially encases the
granular flux, thus forming a tubular welding electrode.
13. The method of claim 12, wherein the mechanical closing involves
forming a butt or overlap seam.
14. The method of claim 12, wherein the copper or copper alloy is
plated onto the strip of steel material.
15. The method of claim 12, further comprising a step e) of drawing
the tubular welding electrode to a desired diameter.
16. The method of claim 12, wherein the second surface is not
coated with copper or a copper alloy and during step b) the first
surface of the strip is located on the inside of the "U" shape.
17. The method of claim 12, wherein the second surface is not
coated with copper or a copper alloy and during step b) the first
surface of the strip is located on the outside of the "U"
shape.
18. The method of claim 12, wherein the second surface of the strip
is at least substantially coated with copper or a copper alloy.
19-24. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit of priority from U.S.
Provisional Patent Application No. 62/650,475, filed Mar. 30, 2018,
which is hereby incorporated by reference in its entirety
herein.
FIELD
[0002] The present disclosure generally relates to welding wire
and, more particularly, to tubular wires made from copper coated
strip.
BACKGROUND
[0003] Existing processes used to manufacture tubular welding
electrodes use uncoated steel strips. The uncoated steel strips are
filled with a granular flux fill, which becomes the core of the
tubular welding electrodes. The uncoated steel strips are then
mechanically closed, for example with a butt or overlap seam. This
seam is mechanical and not sealed. Because the seam is not sealed,
coatings are not applied to the surface of these tubular welding
electrodes. If coatings were to be applied, undesired plating
chemicals and acids could get inside into the granular flux fill
core, which will adversely affect welding performance.
[0004] Another process method used to manufacture tubular welding
electrodes is sometimes known as the "seamless" process. The
seamless process involves using a strip that is formed into a
relatively large (approx. 5/8 inch diameter) fully circumferential
round tube shape. The adjacent longitudinal edges of the strip are
then welded together (e.g., to remove the seam) to form a tube. The
flux is added to the tube in an offline vibratory filling process.
This process can take upwards of 24 hours to complete. The filled
tube is drawn in a series of annealing and drawing reduction steps
to a final desired wire diameter. After drawing is completed, the
seamless tubular electrode may be copper plated. Here, there is no
exposed seam that can trap or allow through to the core undesired
acids or other chemicals associated with the plating process.
Although such "seamless" wire electrodes allow for the electrodes
to have a copper coating (thus improving electrical conductivity
and reducing contact tip wear for welding), they are relatively
expensive to manufacture--the manufacturing process comprises
multiple process steps that are difficult or impossible to conduct
as an in-line process and that require large amounts of work in
progress (WIP).
[0005] Thus, there exists a need for a copper coated tubular wire
electrode that can be manufactured by a relatively efficient and
less expensive route than the typical seamless process but that
does not allow acids or other undesired chemicals to react with the
granular flux fill core.
SUMMARY
[0006] According to one aspect of the present disclosure, a tubular
welding electrode having a length comprises a granular core
extending substantially along the length of the electrode and a
steel sheath extending substantially along the length of the
electrode and substantially encasing the granular core. The
granular core may be a granular powder flux fill core or a metal
core. As used in the present disclosure, "extending substantially
along the length" means extending along at least the majority of
the length, including (but not necessarily) the entire length. As
used in the present disclosure, "substantially encasing" means at
least mostly encasing, including (but not necessarily) fully
encasing.
[0007] The steel sheath has an inner and an outer surface. The
steel sheath has and opposing radial ends that extend substantially
along the length of the electrode. At least one of the inner or
outer surfaces of the steel sheath is at least substantially coated
with copper or a copper alloy. The inner or outer surfaces are at
least substantially coated with copper or a copper alloy prior to
joining the opposing radial ends of the steel sheath. As used in
the present disclosure, an "at least substantially coated" surface
is one that is at least 90% coated (and may be fully coated or
fully coated except for inadvertent defects in the coating). The
copper or copper alloy may be applied to the steel sheath by
plating. Either the inner or the outer surface, or both, may be
coated with the copper alloy. The opposing radial ends of the steel
sheath may be joined via a seam that extends substantially along
the length of the electrode. The seam may be a butt or overlap
seam.
[0008] According to another aspect of the present disclosure, a
method for producing a tubular welding electrode comprises the
steps of (a) providing a strip of copper-coated steel material
having a length and first and second surfaces, wherein at least the
first surface of the strip is at least substantially coated with a
copper alloy; (b) forming the strip into a "U" shape along the
length; (c) filling the "U" shape of the strip with a granular
flux; and (d) mechanically closing the "U" shape to form a sheath
of copper-coated steel material that substantially encases the
granular flux, thus forming a tubular welding electrode. The
mechanical closing may involve forming a butt or overlap seam. The
copper alloy may be plated onto the strip of steel material. The
method may comprise a further step (e) of drawing the tubular
welding electrode to a desired diameter. During step (b), the
copper-coated surface may be located on either the inside or the
outside, or both, of the "U" shape.
[0009] According to another aspect of the present disclosure, a
method for producing a tubular welding electrode comprises the
steps of (a) providing a strip of copper-coated steel material
having a length and first and second surfaces, wherein the first
surface of the strip is at least substantially coated with a copper
alloy; (b) forming the strip into a substantially circular shape
along the length; (c) welding the strip to form a tube sealed along
the length; and (d) filling the sealed tube with a granular flux to
form a tubular welding electrode. The copper alloy may be plated
onto the strip of steel material. The method may comprise a further
step (e) of drawing the tubular welding electrode to a desired
diameter. During step (b), the copper-coated surface may be located
on either the inside or the outside, or both, of the circular
shape.
[0010] It is to be understood that both the foregoing general
description and the following detailed description describe various
embodiments and are intended to provide an overview or framework
for understanding the nature and character of the claimed subject
matter. The accompanying drawings are included to provide a further
understanding of the various embodiments, and are incorporated into
and constitute a part of this specification. The drawings
illustrate the various embodiments described herein, and together
with the description serve to explain the principles and operations
of the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The following is a description of the examples depicted in
the accompanying drawings. The figures are not necessarily to
scale, and certain features and certain views of the figures may be
shown exaggerated in scale or in schematic in the interest of
clarity or conciseness.
[0012] FIG. 1 is a drawing showing a strip of material;
[0013] FIG. 2 is a drawing showing a strip of material that has
been formed into a "U" shape;
[0014] FIG. 3 is a drawing showing the "U" shaped strip filled with
a granular flux;
[0015] FIG. 4 is a drawing showing the strip formed into a sheath
filled with a granular flux and closed with a butt seam;
[0016] FIG. 5 is a drawing showing the strip formed into a sheath
filled with a granular flux and closed with an overlap seam;
and
[0017] FIG. 6 is a flow chart showing manufacturing methods
according to the present disclosure.
[0018] The foregoing summary, as well as the following detailed
description, will be better understood when read in conjunction
with the figures. It should be understood that the claims are not
limited to the arrangements and instrumentality shown in the
figures. Furthermore, the appearance shown in the figures is one of
many ornamental appearances that can be employed to achieve the
stated functions of the apparatus.
DETAILED DESCRIPTION
[0019] In the following detailed description, specific details may
be set forth in order to provide a thorough understanding of
embodiments of the present disclosure. However, it will be clear to
one skilled in the art when disclosed examples may be practiced
without some or all of these specific details. For the sake of
brevity, well-known features or processes may not be described in
detail. In addition, like or identical reference numerals may be
used to identify identical or similar elements.
[0020] The following example relates to copper coated tubular
welding electrodes. Example tubular welding electrodes are
manufactured by first providing a coated steel strip 100 having a
length and opposing planar surfaces (one planar surface 110 is
shown in FIG. 1. The material of the steel strip may be a carbon
steel. Alternatively, where feasible, other metals may be used in
lieu of a steel strip. The coating on the steel strip may be copper
or a copper alloy. Instead of copper or a copper alloy, the coating
may be formed from another metal, such as nickel or a nickel alloy,
chromium or a chromium alloy, zinc or a zinc alloy, tin or a tin
alloy, or aluminum or an aluminum alloy. For example, the coating
may be an aluminum-silicon alloy (aluminum containing 5-11 wt. %
silicon), which will result in aluminized steel when the alloy is
coated onto the steel. These metals or alloys may be applied to the
surface of the steel strip by plating. Plating may be
electroplating or electroless plating (chemical plating).
Alternatively, the coating metals or coating alloys may be applied
to the surface of the steel strip by spraying. The coating is
applied to either or both of the planar surfaces of the steel
strip.
[0021] Multiple layers of metals or alloys may be built up upon the
surface of a steel strip. For example, a steel strip may be coated
with a layer of a nickel or nickel alloy. The nickel-based layer
may then be coated with a layer of copper or copper alloy. The
nickel-based layer may be easier to plate on to the steel strip
than copper, and may improve the bonding of the layers. The
nickel-based layer may improve the wear resistance and corrosion
resistance of the coating.
[0022] Among the advantages of applying a copper or copper alloy
coating to the steel strip is that, during welding of the tubular
wire electrode, the copper-based coating provides improved
electrical conductivity, reduced tip wear, better feeding, and/or
fewer arcing issues.
[0023] The example strip 200 is formed into a "U" shape along the
length of the strip, as shown in FIG. 2. A "U" shape may also be
referred to as a "C" shape or a semicircular shape. Once in a "U"
shape, the strip 300 is filled with a granular flux 310, as shown
in FIG. 3. The granular flux may be a granular powder flux or a
granular metal flux. After filling, the "U" shape is mechanically
closed--for example, via a butt seam 420 or overlap 520 seam--to
form a sheath 400, 500 of copper-coated steel material that at
least substantially (if not fully) encases the granular powder flux
410, 510, thus forming a tubular welding electrode, as shown in
FIGS. 4 and 5. This production method provides an efficient and
less expensive route than the conventional seamless process, while
still reducing (e.g., preventing) the ability of acids and/or other
undesired chemicals from reacting with the granular flux fill core.
Seams may be formed by other methods--for example, by laser
welding.
[0024] Example production methods 600 are shown in the flow chart
in FIG. 6. A strip of copper-coated steel material is provided 602.
Seamed or seamless production is selected 604. For seamed
production, the coated strip is formed 610 into a "U" shape along
the length of the strip. Once in a "U" shape, the strip is filled
612 with a granular flux. After filling, the "U" shape is
mechanically closed 614 to form a sheath of copper-coated steel
material that encases the granular powder flux, thus forming a
tubular welding electrode. If desired 630, the tubular welding
electrode may be drawn 632 to reduce the diameter to a desired
diameter 634.
[0025] Alternatively, instead of forming the strip into a "U"
shape, the strip may be formed into a substantially circular shape
along its length 620. Once in a circular shape, the strip may be
welded 622 along its length to form a sealed tube. The sealed tube
can then be filled 624--for example, by a vibratory filling
process--with a granular flux to form a tubular welding electrode.
If desired 630, the tubular welding electrode may be drawn 632 to
reduce the diameter to a desired diameter 634. For example, a
sealed tube or tubular welding electrode with a 5/8 inch diameter
may be drawn to a 3/8 inch diameter, or further to a 3/32 inch
diameter, or further to a 0.045 inch diameter.
[0026] Some of the elements described herein are identified
explicitly as being optional, while other elements are not
identified in this way. Even if not identified as such, it will be
noted that, in some examples, some of these other elements are not
intended to be interpreted as being necessary, and would be
understood by one skilled in the art as being optional.
[0027] While the present disclosure has been described with
reference to certain implementations, it will be understood by
those skilled in the art that various changes may be made and
equivalents may be substituted without departing from the scope of
the present method and/or system. In addition, many modifications
may be made to adapt a particular situation or material to the
teachings of the present disclosure without departing from its
scope. For example, systems, blocks, and/or other components of
disclosed examples may be combined, divided, re-arranged, and/or
otherwise modified. Therefore, the present disclosure is not
limited to the particular implementations disclosed. Instead, the
present disclosure will include all implementations falling within
the scope of the appended claims, both literally and under the
doctrine of equivalents.
* * * * *