U.S. patent application number 12/435297 was filed with the patent office on 2010-11-04 for system and method for applying a coating to a substrate.
This patent application is currently assigned to Vetco Gray Inc.. Invention is credited to Leonardo Ajdelsztajn, Fife B. Ellis, Dennis Gray, Joseph W. Pallini, JR..
Application Number | 20100279022 12/435297 |
Document ID | / |
Family ID | 42732810 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100279022 |
Kind Code |
A1 |
Ajdelsztajn; Leonardo ; et
al. |
November 4, 2010 |
System and Method For Applying A Coating To A Substrate
Abstract
A process for providing a protective layer to an article. The
process includes depositing a layer of material onto a surface of
the article with a thermal spray process. Examples of thermal spray
process include high velocity oxygen/air fuel, atmospheric plasma
spray, and chemical vapor deposition. Coating methods, such as cold
vapor deposition and physical vapor deposition, may also be used.
The layer can then be bonded to the article by heating material in
the layer adjacent its connection with the article. Bonding the
layer to the article can be performed by irradiating the layer with
a collimated light source, the layer irradiation can be applied
concurrently with the thermal spray process
Inventors: |
Ajdelsztajn; Leonardo;
(Niskayuna, NY) ; Gray; Dennis; (Delanson, NY)
; Ellis; Fife B.; (Houston, TX) ; Pallini, JR.;
Joseph W.; (Tomball, TX) |
Correspondence
Address: |
Patent Department;GE Oil & Gas
4424 West Sam Houston Parkway North, Suite 100
Houston
TX
77041
US
|
Assignee: |
Vetco Gray Inc.
Houston
TX
|
Family ID: |
42732810 |
Appl. No.: |
12/435297 |
Filed: |
May 4, 2009 |
Current U.S.
Class: |
427/451 ;
427/446; 427/452; 427/455; 427/456; 427/532; 427/554 |
Current CPC
Class: |
C23C 4/06 20130101; C23C
10/02 20130101; C23C 4/18 20130101; C23C 24/04 20130101; C23C 4/08
20130101 |
Class at
Publication: |
427/451 ;
427/532; 427/446; 427/554; 427/456; 427/452; 427/455 |
International
Class: |
C23C 4/06 20060101
C23C004/06; C23C 4/18 20060101 C23C004/18 |
Claims
1. A method of forming a bond comprising: (a) providing a body
having an external layer on a surface of the body; and (b) heating
the layer with collimated light so that particles in the layer are
diffusion bonded to the surface.
2. The method of claim 1, further comprising applying a thermal
spray to the surface to deposit the layer thereon.
3. The method of claim 2, wherein the thermal spray is applied by a
process selected from the list consisting of a high velocity oxygen
fuel process and high velocity air fuel process.
4. The method of claim 1, wherein step (b) includes directing a
laser at the metallic layer.
5. The method of claim 2, wherein the steps of heating the layer
with collimated light and depositing material onto the surface are
performed substantially in sequence.
6. The method of claim 2, further comprising applying a thermal
spray to the heated and bonded metallic layer to deposit a second
layer onto the surface, and heating the second metallic layer with
collimated light so that particles in the second layer are
bonded.
7. The method of claim 2, wherein the thermal spray includes a
cobalt alloy powder.
8. The method of claim 7, wherein the cobalt alloy powder includes
carbon; silicon; nickel; tantalum; nitrogen; manganese; chromium;
molybdenum, cobalt, tungsten; and iron.
9. The method of claim 1, wherein the body comprises a piston rod,
the method further comprising installing the piston rod into a
tensioning mechanism.
10. A method of sealing an article with a protective layer, the
method comprising: depositing a metal based layer of material onto
a surface of the article using a thermal spray process; and forming
a diffusion bond between the metal based layer and the surface by
heating the layer with collimated light.
11. The method of claim 10, further comprising regulating the metal
based layer thickness so that the heat applied from the collimated
light is transferrable through the layer to the interface between
the layer and the surface.
12. The method of claim 10, wherein the step of depositing a metal
based layer of material comprises using a process selected from the
list consisting of high velocity oxygen fuel, high velocity air
fuel, atmospheric plasma spray, cold spray, and physical vapor
deposition.
13. The method of claim 10, wherein the article comprises a portion
of a riser tensioning device, the method further comprising
installing the article in the tensioning device.
14. A method of protecting an article comprising: (a) depositing a
metal based layer of material onto a surface of the article using a
thermal spray process; and (b) simultaneously with step (a),
heating the layer with collimated light thereby forming a diffusion
bond between the metal based layer and the surface.
Description
BACKGROUND
[0001] 1. Field of Invention
[0002] The device described herein relates generally to a system
and method of applying a coating onto a substrate. More
specifically, the present disclosure relates to a system and method
for applying a coating to a substrate using a thermal spray to
deposit the coating and laser treatment of the deposited
coating.
[0003] 2. Description of Related Art
[0004] Structural materials subject to ambient conditions are
typically treated to prolong their useful life. Treatment methods
include forming the material from a corrosive resistant material,
such as stainless steel, coating the material, or cladding the
material. Coatings, such as paint or polymeric compounds, can
protect a material from moisture and corrosive elements that can
promote oxidation or galvanic action. However, most coatings wear
over time and require replacing and if the protected component is a
linkage member, the coating can be rubbed off with normal use.
Therefore, to protect such members, a cladding may be required that
is bonded to the member's outer surface and cannot be easily
removed or eroded.
SUMMARY OF INVENTION
[0005] Disclosed herein is method of forming a bond between a body
and an external layer. In an example the method includes providing
a body having an external layer on an outer surface of the body,
and heating the layer with collimated light so that particles in
the layer are diffusion bonded to the surface. The method can
include applying a thermal spray to the surface to deposit the
layer thereon. The thermal spray can be applied by a high velocity
oxygen fuel process or a high velocity air fuel process. Heating
with collimated light can include directing a laser at the metallic
layer. The steps of heating the layer with collimated light and
depositing material onto the surface can be performed substantially
in sequence. The method can further include applying a thermal
spray to the heated and bonded metallic layer to deposit a second
layer onto the surface, and heating the second metallic layer with
collimated light so that particles in the second layer are bonded.
The thermal spray can include a cobalt alloy powder. The cobalt
alloy powder may include carbon; silicon; nickel; tantalum;
nitrogen; manganese; chromium; molybdenum, cobalt, tungsten; iron,
and combinations. The body can be a piston rod, the method further
comprising installing the piston rod into a riser tensioning
mechanism.
[0006] Alternatively disclosed herein is a method of sealing an
article with a protective layer. In an example the method involves
depositing a metal based layer of material onto a surface of the
article using a thermal spray process and forming a diffusion bond
between the metal based layer and the surface by heating the layer
with collimated light. The method can also include regulating the
metal based layer thickness so that the heat applied from the
collimated light is transferrable through the layer to the
interface between the layer and the surface. The step of depositing
a metal based layer of material can implement a process such as
high velocity oxygen fuel, high velocity air fuel, atmospheric
plasma spray, cold spray, or physical vapor deposition. The article
can be a portion of a riser tensioning device or ram tensioning
device, where the method includes installing the article in the
tensioning device. The article can be a piston rod.
[0007] In another method disclosed herein for protecting an
article, the method can include depositing a metal based layer of
material onto a surface of the article using a thermal spray
process and simultaneously heating the layer with collimated light
thereby forming a diffusion bond between the metal based layer and
the surface.
BRIEF DESCRIPTION OF DRAWINGS
[0008] Some of the features and benefits of the present invention
having been stated, others will become apparent as the description
proceeds when taken in conjunction with the accompanying drawings,
in which:
[0009] FIG. 1 is a side sectional view of a layer being deposited
onto a substrate using a prior art thermal spray process;
[0010] FIG. 2 is a side cut-away view of a sample of a layer formed
using a thermal spray process as shown in FIG. 1;
[0011] FIG. 3 is a side sectional view of a collimated light source
heat treating a layer of deposited material, in accordance with an
exemplary embodiment of the present technique;
[0012] FIG. 4 is a side cut-away view of a sample of a layer of
deposited material treated as shown in FIG. 3;
[0013] FIG. 5 is a side sectional illustrating forming a layer
using a thermal spray system, and simultaneously treating the layer
using a collimated light source heat, in accordance with an
exemplary embodiment of the present technique;
[0014] FIG. 6 is a side cut-away view of a sample of a layer of
deposited and treated material treated as shown in FIG. 5;
[0015] FIG. 7 is a side cut-away view of a sample of a layer of
deposited and treated material treated as shown in FIG. 5;
[0016] FIG. 8 provides a graph charting elemental presence in the
sample with respect to distance from the layer surface;
[0017] FIG. 9 is an elevation view of a riser tensioner system, in
accordance with an exemplary embodiment of the present technique;
and
[0018] FIG. 10 is an elevation view of an exemplary embodiment of a
ram tensioner piston rod having a coating applied and treated in
accordance with the techniques described above.
[0019] While the invention will be described in connection with the
preferred embodiments, it will be understood that it is not
intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0020] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings in which
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the illustrated embodiments set forth
herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art. Like numbers
refer to like elements throughout.
[0021] Objects can be protected with a coating applied using a
thermal spray process; examples of which include, high velocity
oxygen fuel (HVOF), high velocity air fuel (HVAF), atmospheric
plasma spray, and plasma spray (in air or in low pressure
atmospheres). Other coating methods that may be employed include
cold spray and physical vapor deposition. In a side schematic view
in FIG. 1, a thermal spray depositor 10 is shown forming a metal
coating 12 onto a substrate 14. The spray depositor 10 includes a
combustion chamber 16 at its upper end having feeds for oxygen,
metal powder, and fuel. Oxygen connects to the combustion chamber
16 through an oxygen inlet 18, powder is provided to the chamber 16
through a powder inlet 20, and fuel through a fuel inlet 22.
Combusting the fuel and oxygen within the combustion chamber 16
forms a jet stream that exits the chamber 16 and travels through a
nozzle 24 attached to the combustion chamber 16. The jet stream
exits the spray depositor 10, shown as a spray stream 26, where it
is then deposited onto the substrate 14 for forming a coating 12
onto the substrate 14. The coating 12 can protect the substrate 14
from environmental conditions that can corrode, oxidize, erode, or
otherwise degrade the material forming the substrate 14.
[0022] One of the shortcomings of a protective coating applied with
a thermal spray process is that the coating 12 is not
metallurgically bonded with the substrate 14. Additionally, gaps or
porosities 28 may be present in the coating 12, which form an
inconsistent coating 12 and potential crack initiation sites. FIG.
2 provides an image of a sample body having a coating 12 formed
onto a substrate 14 by a thermal spray process; where porosities 28
are clearly present in the coating 12.
[0023] FIG. 3 illustrates a side sectional view of a coating 12
deposited on a substrate 14 with a thermal spray process being
treated with a collimated light source 30. In one example of use,
the collimated light source 30 is a laser. As shown, the light
source 30 directs a beam 32 to the coating 12 upper surface. The
energy in the beam 32 heats the coating 12 and provides a treating
effect onto the coating 12 when sufficient heat over time is
applied to the coating 12. Heat treating the coating 12 creates a
treated area 34 having an increased density over untreated areas.
Heat treating the layer can also form a diffusion bond 38 between a
portion of the coating 12 and substrate 14.
[0024] Irradiating the coating 12 with the collimated light beam 32
can sufficiently heat the coating 12 to form a metallurgical bond
to the substrate 14. The metallurgical bond can be an
interdiffusion of elements from the coating 12 and the substrate
14. This is known as a diffusion bond 38. A particle to particle
metallurgical bond can also be formed. Accordingly treating a
coating 12 with a collimated light beam 32 can treat and densify a
coating 12 and form a metallurgical bond 33 between the coating 12
and substrate 14. Creating a metallurgical bond between the coating
12 and substrate 14 ensures adhesion of the coating 12 to the
substrate 14 and enhances the protective qualities of the coating
12.
[0025] It has been discovered, however, that the presence of the
porosities 28 within a coating 12 being treated with a collimated
light source 30 can coalesce the porosities 28 into a void or
bubble space 36. The absence of material in a void or bubble space
36 reduces layer strength and therefore is not a desirable
condition. FIG. 4 is a sectional image of a sample treated with a
collimated light source. A treated zone 34 is shown extending along
the upper portion of the coating 12. Also illustrated is a bubble
zone 36 shown formed adjacent the treated area 34.
[0026] In FIG. 5, another example of forming a protective layer on
an article is depicted in a side schematic view. In this
embodiment, the collimated light source 30 is used to treat a layer
of coating 12 as it is deposited on the substrate 14 by the thermal
spray process device 10, or shortly thereafter while the coating 12
is still warm. As discussed above, irradiating the coating 12 with
the collimated light beam 32 can sufficiently heat the coating 12
to form a diffusion bond 38 to the substrate 14. Accordingly
treating the layer of the coating 12 with a collimated light beam
32 as the layer is applied can treat and densify the coating 12 to
form a diffusion bond 38 between the coating 12 and substrate 14.
As noted above, bonding the coating 12 and substrate 14 ensures
coating 12 adhesion to enhance protective qualities of the coating
12.
[0027] Alternatives of operation with both the spray deposition
device 10 and light source 30 exist wherein an entire area may
optionally be coated with a deposit of material and then at a later
time be treated with the beam 32 of the laser or light source 30.
Optionally, incremental segments of the coating 12 can be formed,
such as by the spray deposition device 10, and then treated with
the light source 30. It is within the capabilities of those skilled
in the art to determine the proper amount of heating in order to
form a dispersion bond between the coating 12 and substrate 14.
FIG. 6 illustrates a cutaway of a sample of a treated layer 34
having an increased density and wherein the layer 34 is fused to
its associated substrate 14.
[0028] FIG. 7 provides a cutaway of a sample and having distance
markers noted that identify a preset depth from the treated layer
34 upper surface and to a point beneath the substrate 14. In one
example of use, the layer is formed from a cobalt-based metallic
powdered mixture that includes chromium, nickel and cobalt. FIG. 8
depicts results of an elemental analysis of the layer 34 and
substrate 14 of FIG. 7. As shown on the abscissa, is a
representation of distance from the upper surface of the layer 34
and into the substrate 14. The ordinate represents an amount of the
particular elements described at that location in the sample. It
should also be pointed out that in the example the substrate 14
included an iron-based metal composition. Proximate to the depth
noted as X .mu.m, it is seen that the detection of chromium,
nickel, and cobalt drops in a substantially infinite slope. In
contrast, the detection of iron increases at a similarly but
oppositely directed slope at X .mu.m. This indicates the boundary
between the treating layer 34 and the substrate 14, but also
indicates that these elements within the grade deposition powder
material have diffused into the substrate 14 by virtue of the laser
treating process described above.
[0029] By creating a diffusion bond 38 between the treated layer 34
and the substrate 14, a protective barrier is provided onto the
substrate material that is essentially an extension of the material
itself. Therefore, the treated layer 34 is not likely to delaminate
as is the case in some other protective coatings. Accordingly, the
chances of caustic materials becoming imbedded between the layer
and substrate are essentially eliminated. The method described
herein can form a diffusion layer between the coating and the
substrate with a thickness of about 2-3 .mu.m. The diffusion layer
formed is thinner than one formed using a convention cladding
process, which can have a thickness in excess of 100 .mu.m. The
presence of a thin inter-diffusion layer also indicates low Fe
dissolution into the coating layer and consequently preventing
corrosion resistance deterioration due to high Fe content at the
coating surface.
[0030] In one example of use, a protective layer is deposited with
the thermal spray process onto a surface of a body to be protected.
The thermal spray process uses a powder having carbon from about
0.06% to about 0.15% by weight of the metal mixture, chromium from
about 26% to about 28% by weight of the metal mixture, cobalt from
about 20% to about 54% by weight of the metal mixture, iron from
about 2% to about 3% by weight of the metal mixture, manganese from
about 0.8% to about 1% by weight of the metal mixture, molybdenum
from about 5% to about 5.5% by weight of the metal mixture, nickel
from about 9% 10% by weight of the metal mixture, nitrogen from
about 0.15% to about 0.08% by weight of the metal mixture, silicon
from about 0.3% to about 1% by weight of the metal mixture, and
tungsten from about 2% to about 4.5% by weight of the metal
mixture.
[0031] The article being treated and/or protected may be a part of
a system used for producing hydrocarbons from a subsea wellhead. In
one example, the article is included in a riser tensioning device
used in a subsea well. The riser tensioning device can be what is
referred to in the art as a "pull-up" type of a "push-up" type.
With reference now to FIG. 9, an example of a tensioning mechanism
40 is shown in a side view. A riser 42 extends downwardly from a
platform 44 to a subsea wellhead (not shown). Riser 42 has a
longitudinal axis 46 and is surrounded by a plurality of hydraulic
cylinders 48. Each hydraulic cylinder 48 has a cylinder housing 50
having a chamber (not shown). A piston rod 52 has a rod end 54 that
extends downward from each cylinder housing 50 and hydraulic
cylinder 48. The piston ends of rods 52 opposite rod ends 54 are
disposed within the respective chambers (not shown) of cylinder
housings 50. Hydraulic fluid (not shown) is contained within the
housing 50 for pulling piston rods 52 upward. Each hydraulic
cylinder 48 also has accumulator 56 for accumulating hydraulic
fluid from hydraulic cylinder 48 and for maintaining high pressure
on the hydraulic fluid. A riser collar 58 rigidly connects to riser
42. The piston rods 52 attach to riser collar 58 at the rod ends
54. Cylinder shackles 60 rigidly connect cylinder housings 50 to
platform 44. In a specific example of use, the treating method
described herein is used to protect a piston rod, such as the
piston rod 52 of FIG. 9.
[0032] In another embodiment, a cladding method disclosed herein
can be applied to a ram tensioner piston rod. An example of a
hydro-pneumatic tensioner unit 128 is provided in a side view in
FIG. 10. On the tensioner unit 128 upper end is a rod end cap 146
used for connection to a top plate (not shown) to provide tension
to a riser system. The rod end cap 146 is shown as threadingly
attached to a shoulder or flange 148 formed of or attached to the
main body of a tensioner piston rod 132; bolts 150 are shown
coupling the cap 146 and rod 132. In an embodiment, the lower end
of the tension unit 128 is connected to the operational marine
platform (not shown). The tensioner piston rod 132 reciprocates in
a housing 130 in response to movement of the operational
platform.
[0033] It is to be understood that the invention is not limited to
the exact details of construction, operation, exact materials, or
embodiments shown and described, as modifications and equivalents
will be apparent to one skilled in the art. In the drawings and
specification, there have been disclosed illustrative embodiments
of the invention and, although specific terms are employed, they
are used in a generic and descriptive sense only and not for the
purpose of limitation. Accordingly, the invention is therefore to
be limited only by the scope of the appended claims.
* * * * *