U.S. patent application number 15/679868 was filed with the patent office on 2018-03-08 for non-magnetic metal alloy compositions and applications.
The applicant listed for this patent is Scoperta, Inc.. Invention is credited to Justin Lee Cheney, John Hamilton Madok, Kyle Walter Rafa.
Application Number | 20180066345 15/679868 |
Document ID | / |
Family ID | 50475474 |
Filed Date | 2018-03-08 |
United States Patent
Application |
20180066345 |
Kind Code |
A1 |
Cheney; Justin Lee ; et
al. |
March 8, 2018 |
NON-MAGNETIC METAL ALLOY COMPOSITIONS AND APPLICATIONS
Abstract
Disclosed are non-magnetic metal alloy compositions and
applications that relate to non-magnetic metal alloys with
excellent wear properties for use in dynamic three-body
tribological wear environments where an absence of magnetic
interference is required. In one aspect, the disclosure can relate
to a drilling component for use in directional drilling
applications capable of withstanding service abrasion. In a second
aspect, a hardbanding for protecting a drilling component for use
in directional drilling can be provided. In a third aspect, a
method for prolonging service life of a drilling component for use
in directional drilling can be provided.
Inventors: |
Cheney; Justin Lee;
(Encinitas, CA) ; Madok; John Hamilton; (San
Diego, CA) ; Rafa; Kyle Walter; (Fremont,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Scoperta, Inc. |
San Diego |
CA |
US |
|
|
Family ID: |
50475474 |
Appl. No.: |
15/679868 |
Filed: |
August 17, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14051150 |
Oct 10, 2013 |
9738959 |
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15679868 |
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61712716 |
Oct 11, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C22C 32/0052 20130101;
C22C 38/04 20130101; C22C 38/58 20130101; C22C 38/54 20130101; C22C
38/28 20130101; C22C 37/10 20130101; C22C 38/14 20130101; C22C
38/50 20130101; C22C 37/08 20130101; C22C 38/02 20130101; C09D 1/00
20130101; C22C 38/18 20130101; C22C 38/002 20130101; C23C 30/00
20130101; C22C 29/14 20130101; C22C 32/0073 20130101; C22C 38/56
20130101; C22C 38/36 20130101; C22C 38/08 20130101; C22C 38/44
20130101; B23K 35/004 20130101; C22C 29/06 20130101; C22C 38/48
20130101; C22C 38/24 20130101; C22C 38/46 20130101; C22C 38/32
20130101; C09D 5/00 20130101; C22C 38/26 20130101; C22C 38/38
20130101; C22C 38/22 20130101; B23K 35/308 20130101; C22C 38/12
20130101 |
International
Class: |
C22C 38/58 20060101
C22C038/58; B23K 35/00 20060101 B23K035/00; B23K 35/30 20060101
B23K035/30; C22C 38/18 20060101 C22C038/18; C22C 38/26 20060101
C22C038/26; C22C 38/28 20060101 C22C038/28; C09D 1/00 20060101
C09D001/00; C22C 38/12 20060101 C22C038/12; C22C 38/22 20060101
C22C038/22; C23C 30/00 20060101 C23C030/00; C22C 38/48 20060101
C22C038/48; C22C 38/44 20060101 C22C038/44; C22C 38/38 20060101
C22C038/38; C22C 38/36 20060101 C22C038/36; C22C 38/32 20060101
C22C038/32; C22C 38/24 20060101 C22C038/24; C22C 38/14 20060101
C22C038/14; C22C 38/08 20060101 C22C038/08; C22C 38/02 20060101
C22C038/02; C22C 38/00 20060101 C22C038/00; C22C 37/10 20060101
C22C037/10; C22C 37/08 20060101 C22C037/08; C22C 38/56 20060101
C22C038/56; C22C 38/54 20060101 C22C038/54; C22C 38/50 20060101
C22C038/50; C22C 38/46 20060101 C22C038/46 |
Claims
1.-20. (canceled)
21. A hardbanding layer comprising: a composition, in wt. %,
comprising Fe and: Mn: 8-20; Nb: 2-8; V: 0-3; C: 1-6; B: 0-1.5; W:
0-10; and Ti: 0-0.5; hard particles having an average particle size
of 100 nm to 20 .mu.m in an amount up to 50 vol. %; a
macro-hardness of 40 HRC or greater; and a relative magnetic
permeability of less than 1.02.
22. The hardbanding layer of claim 21, wherein the hardbanding
layer comprises an austenitic matrix.
23. The hardbanding layer of claim 21, wherein the hard particles
have an average size of between 1-5 .mu.m in an amount up to 30
vol. %.
24. The hardbanding layer of claim 21, wherein the composition
further comprises chromium.
25. The hardbanding layer of claim 24, wherein the composition
further comprises, in wt. %, Cr: 15-18.
26. The hardbanding layer of claim 21, wherein the composition
contains no boron.
27. The hardbanding layer of claim 21, wherein the composition is
characterized as having a magnetic permeability of less than
1.01.
28. The hardbanding layer of claim 21, wherein the composition is
characterized as having a magnetic permeability of less than
1.005.
29. The hardbanding layer of claim 21, wherein the composition is
characterized as having no magnetic permeability.
30. The hardbanding layer of claim 21, wherein the hardbanding
layer is formed by metal inert gas welding.
31. The hardbanding layer of claim 21, wherein the macro-hardness
of the hardbanding layer is greater than 50 HRC.
32. A wire configured for welding, the wire comprising: a
composition, in wt. %, comprising Fe and: Mn: 8-20; Nb: 2-8; V:
0-3; C: 1-6; B: 0-15; W: 0-10; and Ti: 0-0.5; wherein the wire is
configured to form a welded hardbanding layer comprising: hard
particles having an average particle size of 100 nm to 20 .mu.m in
an amount up to 50 vol. %; a macro-hardness of 40 HRC or greater;
and a relative magnetic permeability of less than 1.02.
33. The wire of claim 32, wherein the wire further comprises an
austenitic matrix.
34. The wire of claim 32, wherein the composition further comprises
chromium.
35. The wire of claim 34, wherein the composition further comprises
in wt. % Cr: 15-18.
36. The wire of claim 32, wherein the composition contains no
boron.
37. The wire of claim 32, wherein the composition is characterized
as having a magnetic permeability of less than 1.01.
38. The wire of claim 32, wherein the composition is characterized
as having a magnetic permeability of less than 1.005.
39. The wire of claim 32, wherein the composition is characterized
as having no magnetic permeability.
40. The wire of claim 32, wherein the welded hardbanding layer is
formed by metal inert gas welding.
Description
INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS
[0001] Any and all applications for which a foreign or domestic
priority claim is identified in the Application Data Sheet as filed
with the present application are hereby incorporated by reference
under 37 CFR 1.57.
BACKGROUND
Field
[0002] The disclosure relates to non-magnetic metal alloys with
excellent wear properties for use in dynamic three-body
tribological wear environments where an absence of magnetic
interference is required.
Description of the Related Art
[0003] Conditions of abrasive wear can be damaging as they often
involve sand, rock particles, or other extremely hard media wearing
away against a surface. Applications which see severe abrasive wear
in the prior art typically utilize materials of high hardness, 40
R.sub.c+, encompassing hard metals or carbides.
[0004] In certain wear applications, e.g., exploration wells in
crude oil or natural gas fields such as directional bores and the
like, it is advantageous for drilling string components including
drill stems to be made of materials with magnetic permeability
values below about 1.02 or possibly even less than 1.01 (API
Specification 7 regarding drill string components), in order to be
able to follow the exact position of the bore hole and to ascertain
and correct deviations from its projected course.
[0005] A number of other disclosures are directed to non-magnetic
alloys for use in forming drilling components including U.S. Pat.
No. 4,919,728 which details a method for manufacturing non-magnetic
drilling string components. US Patent Publication No. 2005/0047952
describes a non-magnetic corrosion resistant high strength steel.
Although both patents describe magnetic permeability of less than
1.01, the compositions described have a maximum of 0.15 wt %
carbon, 1 wt % silicon and no boron. The low levels and absence of
the above mentioned hard particle forming elements suggests that
the alloys would not precipitate sufficient, if any, hard
particles. It can be further expected that inadequate wear
resistance and hardness for high wear environments would be
provided. U.S. Pat. No. 4,919,728 describes alloys which contain
carbon levels below 0.25 wt % while US Patent Publication No.
2005/0047952 details carbon levels below 0.1 wt %, significantly
below the alloys discussed in this disclosure. With these levels of
carbon in conjunction with the absence of boron, few hard particles
can form which impart wear resistance to a hardband. Also in U.S.
Pat. No. 4,919,728, a method for cold working at various
temperatures is used to achieve the desired properties. Cold
working is not possible in coating applications such as hardfacing.
The size and geometry of the parts would require excessive
deformations loads as well as currently unknown methods to
uniformly cold work specialized parts such as tool joints.
[0006] US Patent Publication No. 2010/0009089 details a
non-magnetic for coatings adapted for high wear applications where
non-magnetic properties are required. The alloys listed in this
publication are nickel-based with preformed tungsten carbide hard
spherical particles poured into the molten weld material during
welding in the amount of 30-60 wt %.
[0007] Disclosures offering alloying solutions for competing wear
mechanisms in oil & gas drilling hardfacing applications
include but are not limited to U.S. Pat. Nos. 4,277,108; 4,666,797;
6,117,493; 6,326,582; 6,582,126; 7,219,727; and US Patent
Publication No. 2002/0054972. US Publication Nos. 2011/0220415 and
2011/0042069 disclose an ultra-low friction coating for drill stem
assemblies. U.S. Pat. Nos. 6,375,895, 7,361,411, 7,569,286,
20040206726, 20080241584, and 2011/0100720 disclose the use of hard
alloys for the competing wear mechanisms.
[0008] There is still a need for non-magnetic alloy compositions
for hardbanding components for use in directional drilling
applications that have resistance to abrasion. There is also a need
for an improved method to protect drill collars from heavy abrasion
during drilling operations.
[0009] The austenite phase described as a component of this
disclosure is naturally paramagnetic while ferrite which composes
typical hardbanding is ferromagnetic. When a magnet is brought into
close proximity or contact with a ferromagnetic hardband, it
exhibits attractive forces. A magnet exhibits no detectable
attraction to an entirely austenitic material.
[0010] Magnetic permeability is the measure of how well a material
can support a magnetic field within it. The relative magnetic
permeability of a vacuum is 1. The definition of a non-magnetic
material suitable for use on a drill collar is <1.01 according
to API Specification 7. Even slight amounts of ferrite or
martensite in a mainly austenitic material can cause the magnetic
permeability to exceed 1.01. Ferrite and martensite have a magnetic
permeability greater than 50 depending on the alloy composition.
The magnetic permeability of magnetic hardbanding materials is not
readily available because it is generally not of concern in
applications where they are used. However, it can be inferred that
the magnetic permeability will be similar to that of traditional
magnetic materials such as alloy steels.
[0011] According to API Specification 7, a non-magnetic material
for use on drill collars must maintain a magnetic field gradient of
.+-.0.05. The magnetic field gradient is a measure of the
uniformity of the magnetic field.
SUMMARY
[0012] In one aspect, the disclosure relates to a drilling
component for use in directional drilling applications capable of
withstanding service abrasion. The drilling component has at least
a surface protected by a welded layer comprising an alloy
composition containing in wt. %: Mn: 8-20, Cr: 0-6, Nb: 2-8, V:
0-3, C: 1-6, B: 0-1.5, W: 0-10, Ti: 0-0.5, balance Fe and
impurities as trace elements. The welded layer exhibits a hardness
of at least 40 R.sub.c, the as-welded condition, a wear rate of
less than 0.6 grams of mass loss as measured according to ASTM
G65-04, Procedure A, and a magnetic permeability value of less than
1.01.
[0013] In a second aspect, a hardbanding for protecting a drilling
component for use in directional drilling is provided. The
hardbanding comprises: a layer comprising an alloy composition
having in wt. %: Mn: 8-16, Cr: 3-6, Nb: 3-6, V: 0-1, C: 1.5-5, B:
0-1.5, W: 3-6, Ti: 0-0.5, balance Fe and impurities as trace
elements. The layer forms an austenitic microstructure containing
embedded hard particles in an amount of less than 50 vol. %.
[0014] In a third aspect, a method for prolonging service life of a
drilling component for use in directional drilling is provided. The
method comprises: welding onto at least a surface of the drilling
component an alloy composition containing in wt. %: Mn: 8-20, Cr:
0-6, Nb: 2-8, V: 0-3, C: 1-6, B: 0-1.5, W: 0-10, Ti: 0-0.5, balance
Fe and impurities as trace elements. The welding is by any of laser
welding, shielded metal arc welding (SMAW), stick welding, plasma
transfer arc welding (PTAW), gas metal arc-welding (GMAW), metal
inert gas welding (MIG), submerged arc welding (SAW), open arc
welding (OAW), and combinations thereof. The welded layer exhibits
a hardness of at least 40 R.sub.c, a wear rate of less than 0.6
grams of mass loss as measured according to ASTM G65-04, Procedure
A, and a magnetic permeability value of less than 1.01.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1A is a Scanning Electron micrograph of an austenitic
alloy demonstrating large, interconnected carbides providing paths
for crack propagation.
[0016] FIG. 1B is an optical micrograph of one embodiment of the
alloy in this patent which demonstrates finely distributed hard
particles in a soft austenitic matrix.
[0017] FIG. 2 is a magnetic permeability survey done at an
independent testing facility showing the permeability of one
embodiment of the present disclosure.
[0018] FIG. 3 is a magnetic field gradient survey done at an
independent testing facility showing the uniformity of the magnetic
field of one embodiment of the present disclosure.
[0019] FIG. 4 is a Stainless Steel tool joint welded with an
embodiment of the present disclosure with 3 parallel beads.
[0020] FIG. 5 is the weld bead examined with optical
micrographs.
DETAILED DESCRIPTION
[0021] The following terms will be used throughout the
specification and will have the following meanings unless otherwise
indicated.
[0022] "Casing" is defined as a metal pipe or tube used as a lining
for water, oil, or gas well.
[0023] "Coating" is comprised of one or more adjacent layers and
any included interfaces. Coating also refers to a layer placed
directly on the substrate of a base body assembly to be protected,
or the hardbanding placed on a base substrate material. In another
embodiment, "coating" refers to the top protective layer.
[0024] A "layer" is a thickness of a material that may serve a
specific functional purpose such as reduced coefficient of
friction, high stiffness, or mechanical support for overlying
layers or protection of underlying layers.
[0025] "Hardband" (or "hardface") refers to a process to deposit a
layer of a special material, e.g., super hard metal, onto drill
pipe tool joints, collars and heavy weight pipe in order to protect
both the casing and drill string components from wear associated
with drilling practices.
[0026] "Hardbanding" (or "hardband" or "hardfacing") refers to a
layer of superhard material to protect at least a portion of the
underlying equipment or work piece, e.g., tool joint, from wear
such as casing wear. Hardbanding can be applied as an outermost
protective layer, or an intermediate layer interposed between the
outer surface of the body assembly substrate material and the
buttering layer(s), buffer layer, or a coating.
[0027] "Coating" may be used interchangeably with "hardbanding,"
referring to the layer of superhard material to protect the
underlying equipment.
[0028] "Hard particles" refer to any single or combination of hard
boride, carbide, borocarbide particles.
[0029] "As-welded" refers to the condition of a weld without work
hardening, heat treating, etc. or any other process which alter the
properties or microstructure through post-welding processing.
[0030] The disclosure relates to a non-magnetic metal alloy for use
in single or multi-stage tribological processes involving multiple
bodies of varying hardness, and applications employing the metal
alloy, e.g., hardbanding (or hardfacing) applications.
Metal Alloy Composition
[0031] The metal alloy for hardfacing is characterized as having an
austenitic microstructure (face centered cubic gamma phase) and
consisting essentially of: Mn: 8-20, Cr: 0-6, Nb: 2-8, V: 0-3, C:
1-6, B: 0-1.5, W: 0-10, Ti: 0-0.5, balance Fe and impurities as
trace elements, for a non-magnetic composition with desirable
effects including minimal, if any, cracking in the coating and a
high resistance to abrasive wear.
[0032] In one embodiment, the alloy is any of the followings in wt.
%:
[0033] A33: Fe: bal, Mn: 10, Cr: 5, Nb: 4, V: 0.5, C: 4, W: 5, Ti:
0.25
[0034] A34: Fe: bal, Mn: 10, Cr: 5, Nb: 4, V: 0.5, C: 3.5, W: 5,
Ti: 0.20
[0035] A36: Fe: bal, Mn: 16, Cr: 5, Nb: 4, V: 0.5, C: 3.25, W: 5,
Ti: 0.20
[0036] A35: Fe: bal, Mn: 10, Cr: 5, Nb: 4, V: 0.5, C: 3, W: 5, Ti:
0.20
[0037] The alloy incorporates the above elemental constituents a
total of 100 wt. %. In some embodiment, the alloy may include, may
be limited to, or may consist essentially of the above named
elements. In one embodiment, the alloy may include 2% or less of
impurities. Impurities may be understood as elements or
compositions that may be included in the alloys due to inclusion in
the feedstock components, through introduction in the manufacturing
process. In another embodiment, the feedstock contains silicon in
the amount such that the final alloy contains 0.15 wt % although
the ingot form did not contain any.
[0038] In all embodiments of the present disclosure, the hard
particles are precipitated from the molten metal during
solidification of the alloy. The soft austenite matrix provides
toughness and ductility to the alloy while the hard particles
impart the wear resistance. The soft matrix prevents spalling of
the hard particles. The fine distribution of hard particles also
allows for uniform wear and prevents selective wear of the soft
matrix.
[0039] Other alloys such as those listed in US Patent Publication
Nos. 2010/0009089 use preformed carbides or borides which are
poured into the solidifying metal during welding. These carbides
and borides are larger where the particle size ranges from 50-180
.mu.m. Particles this large often spall due to poor adhesion with
the matrix and break leading to reduced wear resistance
[0040] Using preformed carbides requires a large hopper directly
above the welding arc in order to feed the particles into the
molten weld. In this process, feeding the carbides into the weld
too quickly or too slowly can be detrimental to the performance of
the weld. Also, not only does the welding wire need to be
purchased, but preformed carbides as well increasing the overall
cost of applying the hardface. The alloys described in the present
disclosure can be deposited using standard welding process without
feeding preformed carbides into the weld. This simplifies the
application process allowing for more uniform and repeatable
hardfaced layers both on a single part and between multiple
parts.
[0041] In one embodiment, the metal alloy is applied as a coating
of Fe-based (austenitic) matrix containing fine-scaled hard boride,
carbide, and complex carbide, e.g., borocarbide particles (e.g.,
M.sub.2B or MC, where M is a transition metal) having average
particle sizes of 100 nm-20 .mu.m, in an amount of less than 50
vol. %. In another embodiment, the hard particles are present in an
amount of less than 30 vol. %. In one embodiment, the carbide
particles have an average particle size of 1-5 .mu.m.
[0042] In one embodiment, the boride phase is represented as
M.sub.2B, wherein M is a transition metal. In another embodiment,
the embedded hard particles in the austenitic Fe-based matrix
contain Nb, Cr, and W with both carbon and/or boron. In yet another
embodiment, the particles are in the form of embedded Nb carbide
and Fe--W-boro carbide precipitates. In another embodiment, the Nb
carbide precipitates are less than 5 .mu.m in size. In every
embodiments, the Nb carbide precipitates first at higher
temperatures, acting as a site for lower temperature forming
carbides to nucleate.
Method for Designing Hardbanding
[0043] In one embodiment, the alloy may be formed by blending
various feedstock materials together, which may then be melted in a
hearth or furnace and formed into ingots. The ingots can be
re-melted and flipped one or more times, which may increase
homogeneity of the ingots.
[0044] Each ingot produced was evaluated examining its
microstructure, hardness and magnetic permeability. Incremental
changes in composition were made in each successive ingot, leading
to the final alloys. The compositions of the ingots made are listed
in Table I.
TABLE-US-00001 TABLE I Ingot Compositions amounts in weight percent
Alloy Name Fe Mn Cr Nb V C B W Si Ti Ni A1 54.5 2 18 4 2 1.25 0.85
7 0.15 0.25 10 A2 60.5 2 15 4 2 1.25 0.85 7 0.15 0.25 7 A3 60.25 2
15 4 2 1.5 0.85 7 0.15 0.25 7 A4 60.5 2 15 4 2 1 1.1 7 0.15 0.25 7
A5 60.25 2 15 4 2 1 1.35 7 0.15 0.25 7 A6 60 2 15 4 2 1 1.6 7 0.15
0.25 7 A7 59.2 2 15 4.3 2 1.5 1.6 7 0.15 0.25 7 A8 79.1 1.5 5 4 0.5
1.5 1 5 0.15 0.25 2 A9 78.31 2.50 4.95 3.96 0.50 1.49 1.00 4.95
0.15 0.25 2.00 A10 76.74 2.45 4.85 3.88 0.49 1.46 0.98 4.85 0.15
0.24 4 A11 75.21 2.40 4.75 3.80 0.48 1.43 0.96 4.75 0.14 0.24 6.00
A12 72.58 6.00 4.59 3.67 0.46 1.38 0.93 4.59 0.14 0.23 5.79 A13
65.25 10.00 5 4 0.5 1.5 1 5 1.5 0.25 6.00 A14 72.75 10 5 4 0.5 1.5
1 5 0 0.25 0 A15 72.25 10 5 4 0.5 1 1 5 1 0.25 0 A16 72.00 10 5 4
0.5 1.25 1 5 1 0.25 0 A17 71.28 11.00 4.95 3.96 0.50 1.24 0.99 4.95
0.99 0.25 0.00 A18 69.85 13.00 4.85 3.88 0.49 1.21 0.97 4.85 0.97
0.24 0.00 A19 69.25 12 5 4 0.5 1.5 1 5 1.5 0.25 0 A20 68.75 12 5 4
0.5 1.5 1.5 5 1.5 0.25 0 A21 70.25 12 5 4 0.5 2 1 5 0 0.25 0 A22
68.8 14.0 4.9 3.9 0.5 2.0 1.0 4.9 0.0 0.2 0.0 A23 67.00 16.00 4.80
3.84 0.48 1.92 0.96 4.80 0.00 0.24 0.00 A24 67.80 16.00 5.00 4.00
0.50 1.50 0.00 5.00 0.00 0.20 0.00 A25 66.80 16.00 5.00 4.00 0.50
2.50 0.00 5.00 0.00 0.20 0.00 A26 66.30 16.00 5.00 4.00 0.50 3.00
0.00 5.00 0.00 0.20 0.00 A27 72.80 10.00 5.00 4.00 0.50 2.50 0.00
5.00 0.00 0.20 0.00 A28 72.30 10.00 5.00 4.00 0.50 2.50 0.50 5.00
0.00 0.20 0.00 A29 69.41 9.60 4.80 3.84 0.48 2.40 0.48 9.00 0.00
0.19 0.00 A30 72.80 10.00 5.00 4.00 0.50 0.50 2.00 5.00 0.00 0.20
0.00 A31 68.23 16.00 4.60 3.66 0.47 0.47 1.88 4.70 0.00 0.19 0.00
A32 65.30 16.00 5.00 4.00 0.50 4.00 0.00 5.00 0.00 0.20 0.00 A33
71.30 10 5.00 4.00 0.50 4.00 0.00 5.00 0.00 0.20 0.00 A34 71.80 10
5.00 4.00 0.50 3.50 0.00 5.00 0.00 0.20 0.00 A35 72.30 10 5.00 4.00
0.50 3.00 0.00 5.00 0.00 0.20 0.00 A36 72.05 10 5.00 4.00 0.50 3.25
0.00 5.00 0.00 0.20 0.00 A37 65.80 10.00 12.00 4.00 0.50 2.50 0.00
5.00 0.00 0.20 0.00
[0045] Each composition after melting into ingot form is sectioned
on a wet abrasive saw as to avoid heating the ingot and
subsequently altering the microstructure. The magnetic permeability
is measured using a Low-Mu Magnetic Permeability Tester
manufactured by Severn Engineering. A reference standard with a
known magnetic permeability is placed in the tester. The tester is
comprised of the reference standard and a pivoting magnet. The
magnet extends from the side of the tester opposite the reference
standard. The magnet tip is brought into contact with the surface
of the ingot. If the magnet is not attracted to the ingot, then the
magnetic permeability is less than that of the reference standard
being used. The magnetic permeability of each ingot composition is
listed in Table II.
TABLE-US-00002 TABLE II Alloy Magnetic Hardness Name Permeability
(HRc) A1 no 24 A2 no 29 A3 no 33 A4 yes 27.5 A5 no 31 A6 no 32 A7
no 35 A8 Yes NA A9 Yes NA A10 Yes NA A11 Yes NA A12 >1.04 NA A13
<1.03 34 A14 <1.02 53.5 A15 >1.04 47 A16 >1.04 NA A17
>1.04 43 A18 <1.02 38 A19 >1.04 46.5 A20 >1.04 NA A21
>1.04 56 A22 <1.03 57.5 A23 >1.04 60 A24 <1.01 29 A25
<1.01 37 A26 <1.01 40 A27 <1.01 35 A28 <1.01 48 A29
<1.01 36 A30 >1.04 54 A31 >1.04 35 A32 <1.01 50 A33
<1.01 52 A34 <1.02 41 A35 <1.01 41.5 A36 <1.01 46 A37
<1.01 39
[0046] Each ingot composition after magnetic permeability testing
is measured, the hardness is determined using a Rockwell C hardness
tester. An average of 5 hardness measurements is recorded as the
hardness of that ingot. The hardness of each ingot composition is
detailed in Table II.
[0047] Achieving both a sufficiently low magnetic permeability and
high as-welded hardness is difficult. The non-magnetic austenite is
softer than the magnetic ferrite. Examining a magnetic and a
non-magnetic alloy with the same volume percentage of hard
particles, the non-magnetic alloy will be significantly softer.
[0048] For ingots A1-A11, they were made prior to having a magnetic
permeability test method. They were evaluated using a hand-magnet
as either magnetic or non-magnetic. Only those alloys showing no
magnetism using the hand magnet were hardness tested.
[0049] The microstructure of each ingot is evaluated by optical
microscopy. The desired microstructure contains a sufficient amount
of the ductile austenite matrix along with embedded hard particles.
Furthermore, a large volume fraction of finely distributed hard
particles is desired. Large interconnected hard particles are
undesirable due to increasing the brittleness of the ingot as shown
in FIG. 1A. Fine disconnected hard particles as shown in FIG. 1B
reduce or eliminate paths for crack propagation, decreasing the
likelihood of cracking during the welding process or in
service.
[0050] Combinations of powders may be contained in conventional
steel sheaths, which when melted may provide the targeted alloy
composition. The steel sheaths may include plain carbon steel, low,
medium, or high carbon steel, low alloy steel, or stainless steel
sheaths.
[0051] The ingots may then be melted and atomized or otherwise
formed into an intermediate or final product. The forming process
may occur in a relatively inert environment, including an inert
gas. Inert gasses may include, for example, argon or helium. If
atomized, the alloy may be atomized by centrifugal, gas, or water
atomization to produce powders of various sizes, which may be
applied to a surface to provide a hard surface.
[0052] The alloys may be provided in the form of stick, wire,
powder, cored wire, billet, bar, rod, plate, sheet, and strip. In
one embodiment, the alloys are formed into a stick electrode, e.g.,
a wire, of various diameters, e.g., 1-5 mm. In some embodiments,
the cored wire may contain flux, which may allow for welding
without a cover gas without porosity-forming in the weld
deposit.
[0053] In one embodiment, the metal alloys are applied onto a
surface using techniques including but not limited to thermal spray
coating, laser welding, weld-overlay, laser cladding, vacuum arc
spraying, plasma spraying, and combinations thereof. In another
embodiment, the alloys are deposited as wire feedstock employing
hardfacing known in the art, e.g., weld overlay. The alloys can be
applied with mobile or fixed, semi or automatic welding equipment.
In one embodiment, the alloys are applied using any of laser
welding, shielded metal arc welding (SMAW), stick welding, plasma
transfer arc welding (PTAW), gas metal arc-welding (GMAW), metal
inert gas welding (MIG), submerged arc welding (SAW), or open arc
welding (OAW).
[0054] In one embodiment, the alloy is deposited onto a machined
surface or alternatively, a surface blast cleaned to white metal
(e.g., ISO 8501-1). The depth of the machined surface is grooved
for flush type application depends on the welding applicator. In
one embodiment for application on a used pipe, the existing
hardbanding is first completely removed by gouging, grinding, or
using other suitable techniques.
[0055] In one embodiment, the surfaces for deposition are first
preheated at a temperature of 200.degree. C. or greater, e.g.,
275-500.degree. C., for 0.01 hours to 100 hours. In one embodiment,
the preheat may reduce or prevent cracking of the deposited
welds.
[0056] The alloy may be applied to a surface in one or more layers
as an overlay. In one embodiment, each layer having an individual
thickness of 1 mm to 10 mm. In one embodiment, the overlay has a
total thickness of 1 to 30 mm. In one embodiment, the width of the
individual hard-band ranges from 5 mm to 40 mm. In another
embodiment, the width of the total weld overlay ranges from 5 mm to
20 feet.
[0057] After deposition on a substrate, the alloy is allowed to
cool to form a protective coating. In one embodiment, the cooling
rate ranges from 100 to 5000 K/s, a rate sufficient for the alloy
to produce iron rich phases containing embedded hard particles
(e.g., carbides, borides, and/or borocarbides). After weld
deposition, cooling in open air can cause a cooling rate which is
too rapid, leading to cracking of the weld. In most cases, wrapping
of the welded part with a thermally insulating blanket is
sufficient to reduce the cooling rate to an acceptable level.
[0058] Properties
[0059] A work piece having at least a portion of its surface coated
or having a welded layer of the austenitic alloy composition, e.g.,
a hardbanding layer, is characterized as having an as-welded
macro-hardness as measured via standard Rockwell C test of greater
40 R.sub.c in one embodiment; 45 R.sub.c in a second embodiment;
and at least 50 R.sub.c in a third embodiment.
[0060] The alloy composition as deposited on the surface of a work
piece is characterized as being crack-free, as inspected by any of
magnetic particle inspection, eddy current inspection, etching,
visual inspection, hardness checking, dye penetration inspection,
or ultrasound inspection. The absence of cracks in the coating
protects the underlying part from exposure to any corrosive media
present.
[0061] The alloy composition in one embodiment is further
characterized has having magnetic permeability values (using a
Low-Mu Permeability Tester) of less than 1.02 in one embodiment,
less than 1.01 in a second embodiment, and less than 1.005 in a
third embodiment. The alloy when applied as hardbanding on drill
stem components provides the necessary paramagnetic behavior for
the operator to be able to monitor the progress of the bore hole
required in directional drillings. In one embodiment, the magnetic
permeability was measured at a commercial testing facility and FIG.
2 shows the material survey. The entire survey stayed below the
1.01 maximum.
[0062] In one embodiment, the commercially measured magnetic field
gradient was <0.05 microtesla. No hot spots exceeding the 0.05
microtesla range were found. This indicates a uniform magnetic
field as shown in FIG. 3.
[0063] When applied as coatings, e.g., hardbanding, for protection
of work pieces, the fine-grained microstructural features in the
alloy provide durability and prevent wear on secondary "softer"
bodies which come into contact with the work piece protected by the
coatings. The component protected by the alloy is characterized as
having elevated wear resistance with a dry sand abrasion mass loss
(ASTM G65-04 procedure A) of less than 0.6 grams in one embodiment;
and less than 0.35 grams in a second embodiment.
Applications
[0064] The alloy in one embodiment is suitable for use as
hardbanding in hard bodies wear applications. In these
applications, the material loss in coatings is typically caused by
abrasive wear of the harder abrading particles. To reduce the
material loss in this process, one should increase the hardness of
the coating and/or increasing the amount of comparably hard
particles (comparable as related to the abradable particles) or
phases within the coating. The alloys contain a sufficient amount
of hard particles and display a sufficient hardness property for
the protected equipment under these conditions.
[0065] The alloys are particularly useful for oil & gas
applications, e.g., for work pieces employed in directional
drilling operations as coating for drill stem assemblies, exposed
outer surface of a bottom hole assembly, coatings for tubing
coupled to a bottom hole assembly, coatings for casings,
hardbanding on at least a portion of the exposed outer surface of
the body, and as coatings for oil and gas well production devices
as disclosed in US Patent Publication No. 2011/0042069A1, the
disclosure is included herein by reference in its entirety.
Examples include devices for use in drilling rig equipment, marine
riser systems, tubular goods, wellhead, formation and sandface
completions, lift equipment, etc. Specific examples include
drillpipe tool joints, drill collars, casings, risers, and drill
strings. The coating can be on a least a portion of the inner
surface of the work piece, at least a portion of the outer surface,
or combinations thereof, preventing wear on the drill collar.). The
coatings provide protection in operations with wear from vibration
(stick-slip and torsional) and abrasion during straight hole or
directional drilling, allowing for improved rates of penetration
and enable ultra-extended reach drilling with existing
equipment.
[0066] The coating can be applied as raised ("proud") or flush
("recessed") coating. The coating can be applied on used equipment,
e.g., pipe with no previous hardbanding, or to be hardbanded on new
work pieces. The coating can be deposited over pre-existing weld
deposits and many other previous hard-facing and hard-banding
deposits. In one embodiment, the old hardbanding on the equipment
is first removed before the application of the alloy.
[0067] Besides the use as protective coatings, the alloy lends
itself to use in the fabrication of articles of manufacture,
including drill collars and housings for containing
measurement-while-drilling equipment used in the directional
drilling of oil and gas wells. A drill collar is made from a bar,
which is trepanned to form an internal bore to desired dimensions.
Following trepanning, at least the interior surface is treated so
as to place it into compression, for example as by burnishing or
peening.
[0068] Outside the oil & gas industry, the alloys can also be
used as coatings or forming work pieces in many other applications,
including but not limited to coatings for fuel cell components,
cryogenic applications, and the like, for equipment operating in
corrosive environments with non-magnetic requirements.
EXAMPLES
[0069] The following examples are intended to be non-limiting.
Example 1
[0070] An alloy composition of Alloy 1 (Mn: 10%, Cr: 5%, Nb: 4%, V:
0.5%, C: 3.5%, W: 5%, Ti: 0.25%, Fe: balance) was produced in the
form of a 1/16'' cored wire. The alloy was arc-welded onto a 65/8''
outer diameter box Stainless Steel tool joint pre-heated to
450.degree. F. The joint was rotated at a rotation rate of one full
rotation every 2 min and 30 sec. The welding parameters are 290
amps, 29.5 volts and a 1'' wire stickout. The welding head was
moved through the action of an oscillator at a rate of 58
cycle/min, resulting in a weld bead approximately 1'' wide and
4/32'' thick. Three consecutive beads were made, one next to
another to produce three adjacent 1'' beads for a total width of
roughly 3''. The joint was wrapped in insulation to reduce the
cooling rate and allowed to cool to room temperature. The as-welded
tool joint can be seen in FIG. 4
[0071] The microstructure of the weld bead was examined with
optical micrographs as shown in FIG. 5. A section of a weld was
taken and wear tested producing an ASTM G65 wear loss of 0.35 g.
Relative magnetic permeability was measured with a probe and
provided a value of less than 1.01. Rockwell C hardness was
measured at 43.
[0072] For the purposes of this specification and appended claims,
unless otherwise indicated, all numbers expressing quantities,
percentages or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about." Accordingly, unless indicated to
the contrary, the numerical parameters set forth in the following
specification and attached claims are approximations that may vary
depending upon the desired properties sought to be obtained by the
present disclosure. It is noted that, as used in this specification
and the appended claims, the singular forms "a," "an," and "the,"
include plural references unless expressly and unequivocally
limited to one referent. As used herein, the term "include" and its
grammatical variants are intended to be non-limiting, such that
recitation of items in a list is not to the exclusion of other like
items that can be substituted or added to the listed items.
[0073] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to make and use the disclosure. The patentable
scope is defined by the claims, and may include other examples that
occur to those skilled in the art. Such other examples are intended
to be within the scope of the claims if they have structural
elements that do not differ from the literal language of the
claims, or if they include equivalent structural elements with
insubstantial differences from the literal languages of the claims.
All citations referred herein are expressly incorporated herein by
reference.
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