U.S. patent application number 13/912543 was filed with the patent office on 2013-10-10 for local heat treatment of ibr blade using infrared heating.
The applicant listed for this patent is United Technologies Corporation. Invention is credited to Herbert A. Chin, Thomas DeMichael, Wangen Lin, James J. Moor.
Application Number | 20130266298 13/912543 |
Document ID | / |
Family ID | 46125273 |
Filed Date | 2013-10-10 |
United States Patent
Application |
20130266298 |
Kind Code |
A1 |
Moor; James J. ; et
al. |
October 10, 2013 |
LOCAL HEAT TREATMENT OF IBR BLADE USING INFRARED HEATING
Abstract
A device and method for locally heat treating at least one
airfoil in an integrally bladed rotor device. A pair of IR heat
sources are positioned to direct IR heat rays in the direction
where local heat treatment is required. A pair of parabolic mirrors
are positioned to direct the IR heat rays on to the metal
component. The heat treating is useful after welding the airfoil on
to the rotor device.
Inventors: |
Moor; James J.; (New
Hartford, CT) ; DeMichael; Thomas; (Stafford Springs,
CT) ; Chin; Herbert A.; (Portland, CT) ; Lin;
Wangen; (S. Glastonbury, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Hartford |
CT |
US |
|
|
Family ID: |
46125273 |
Appl. No.: |
13/912543 |
Filed: |
June 7, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13184733 |
Jul 18, 2011 |
|
|
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13912543 |
|
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Current U.S.
Class: |
392/422 |
Current CPC
Class: |
C21D 1/34 20130101; F01D
5/286 20130101; C21D 9/32 20130101; C21D 1/00 20130101; Y10T
29/49336 20150115; F01D 5/34 20130101; C21D 1/04 20130101; F05D
2230/40 20130101; C21D 9/50 20130101 |
Class at
Publication: |
392/422 |
International
Class: |
C21D 1/00 20060101
C21D001/00 |
Claims
1. A device for heat treating a metal component, comprising: at
least one parabolic mirror formed in the axially extending cavity;
and at least one IR heat source for providing IR heat rays in a
direction toward the at least one parabolic mirror; such that the
at least one parabolic mirror is positioned to focus a band of the
IR heat rays onto the metal component.
2. The device of claim 1, wherein the metal part is at least one
airfoil in an integrally bladed rotor.
3. The device of claim 2, wherein the IR heat source and parabolic
mirror are sized to direct the IR heat rays along the junction
between the airfoil and the integrally bladed rotor device.
4. The device of claim 3, which includes a pair of housings on
opposite sides of the entire area of contact between the airfoil
and the integrally bladed rotor device, with each housing having an
IR heat source and a parabolic minor formed in the housing for each
IR heat source.
5. The device of claim 4, wherein each of the pair of IR heat
sources are mounted to its respective housing with a clip.
6. The device of claim 5 wherein the parabolic mirror directs the
IR heat rays to a region of the airfoil where it is joined to the
integrally bladed rotor device.
7. The device of claim 1, wherein the IR heat rays are focused into
an elongated band having a band width of from about 6 mm to about
18 mm.
8. The device of claim 2, which further includes a cooling element
for each IR heat source for maintaining a desired temperature for
the IR heat source.
9. The device of claim 8, wherein the cooling element is part of
the housing having an axial passage adapted to transfer cooling
liquid through the passage, and the housing extends along the
airfoil.
10. The device of claim 9, wherein the housing includes a cavity
forming a parabolic minor and the IR heat source is mounted in the
cavity to focus the IR heat rays on the junction of the airfoil
where it is joined to the integrally bladed rotor device.
11. A system for heat treating at least one airfoil in an
integrally bladed rotor device, the system comprising: at least one
IR heat source means mounted in a position for directing IR heat
rays in a direction; and at least one parabolic mirror means for
reflecting the IR rays on to the at least one portion of an
airfoil.
12. The system of claim 11, which includes a pair of housings each
having an axially extending cavity, the cavity forming the
parabolic minor, the housings further each positioning an IR heat
source, wherein the pair of IR heat sources are facing in opposite
directions and each IR heat source is aligned with the parabolic
minor.
13. The system of claim 12, wherein the parabolic minor directs the
IR heat rays radially inward to the airfoil where it is joined to
the integrally bladed rotor device.
14. The system of claim 13, which further includes a cooling
element for each IR heat source for maintaining a desired
temperature for the IR heat source.
15. The system of claim 14, wherein the cooling element is part of
a housing having an axial passage adapted to transfer cooling
liquid through the passage, and the housing extends along the width
of the airfoil.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a continuation of U.S. patent
application Ser. No. 13/184,733, filed Jul. 18, 2011.
BACKGROUND
[0002] The manufacture, service and/or repair of metal components,
such as gas turbine engines, often times require localized heating
of specific areas of the components. This is done, for example, to
allow for stress relief, metal forming and/or brazing applications.
Localized heating is preferred when processing the entire component
could adversely affect the metallurgical properties of the
component. Warping and other forms of deformation are also to be
avoided.
[0003] Integrally bladed rotors are used in some gas turbine
engines and are expected to be used even more as engine designs
continue to evolve. Upon original manufacture, all integrally
bladed rotor material is heat treated to obtain the desired
mechanical properties prior to finish dimension machining.
[0004] During blade repair operations, it may be necessary to
locally heat treat the repaired areas of the integrally bladed
rotors that have been exposed to elevated temperatures. In the
finished machine condition, conventional heat treatment is not
always possible due to concerns with distortion. Additionally,
conventional heat treatment of a finished machined integrally
bladed rotor may create unnecessary risk due to the potential for
surface contamination throughout the entire part. Because of these
concerns, local heat treatment has been considered to be a
desirable option.
SUMMARY
[0005] The present invention comprises the use of focused infrared
heat lamps to locally heat treat and/or stress relieve portions of
integrally bladed rotors without adversely impacting other critical
areas of the integrally bladed rotors. This is done by the use of
infrared heat sources on the individual integral blades in an inert
environment which in one form uses parabolic mirrors to focus heat
only onto the desired area. A fixture is provided that locates the
device at the precise location where heat is to be applied to a
localized area, such as after a replacement blade has been attached
by welding to a rotor. The present invention may also be used in
the initial manufacture of integrally bladed rotors to locally heat
treat areas after details have been attached to the rotor, such as
by welding or to locally create alternate material properties.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view showing the device of this
invention.
[0007] FIG. 2 is a plan view showing the device of this invention
focused on a single integrally bladed rotor.
[0008] FIG. 3 is a section view taken along line 2-2 of FIG. 2.
DETAILED DESCRIPTION
[0009] Device 10 is positioned proximate an integrally bladed rotor
(IBR) airfoil 11 for heating a portion of the IBR airfoil 11 and
thereby eliminate overall part exposure to heat. Device 10 includes
a pair of infrared (IR) lamp housings 13 and 15, each with an IR
lamp generating IR rays that are reflected off parabolic minors 17
and 19, respectively, to contact IBR 11 and heat treat that blade
without exposing any other part of IBR airfoil 11 to unwanted
heat.
[0010] FIG. 1 illustrates a complete integrally bladed rotor with
rotor hub 21 supporting a plurality of other airfoils 23. Device 10
is positioned on airfoil 11 and includes electrical contacts 25
connected to a power source, not shown, for actuation of IR lamps
27 that are held in place by clips 29. Rays from IR lamps 27 are
focused by mirrors 17 and 19 as an elongated band of IR radiation
on a specific portion of airfoil 11, in this instance the portion
of airfoil 11 attached to rotor hub 21. The width of the band of
focused IR radiation may be any width that permits complete heat
treatment of the desired portions of the component. Band widths may
range from about 6 mm to about 18 mm, and may be about a 12 mm band
width. Other widths may also be accommodated depending on, for
example, the size of the parts, the material being heat treated
[0011] Device 10 also includes tubes or passages 33, shown more
clearly in FIG. 3, that are connected to a source of water or other
cooling medium, not shown, to cool portions of device 10 to prevent
distortion and a resulting uneven heating. Other cooling devices
such as fans and refrigerants may also be used.
[0012] Also shown in FIG. 3 are dotted lines 37 that represent the
extent of unfocused IR rays from lamps 27, and dashed lines 39
represent the extent of IR rays focused by minors 17 and 19 onto
the portion of airfoil 11 that is to be heat treated, such as to
relieve stress in the metal after welding airfoil 11 to rotor hub
21.
[0013] It is known that heat treatment in the presence of oxygen
can cause titanium alloys to become embrittled if the temperature
exceeds 1,000.degree. F. (538.degree. C.). In addition to
embrittlement, the material properties of titanium alloys changes
if it is exposed to a temperature exceeding 800.degree. F.
(427.degree. C.), but as will be understood the actual temperature
depends on the specific alloy. Oxygen contamination at referenced
temperatures can be avoided by proper protection such as the use of
inert shielding gas. The present invention ensures that the
portion(s) of the product being treated will receive desired
thermal treatment but generally remain below 1,000.degree. F.
(538.degree. C.) and even below 800.degree. F. (427.degree.
C.).
[0014] The present invention was used to heat treat and stress
relieve a plurality of IBR blades without adversely heating other
critical areas of the IBR. In addition, replacement blades have
been attached to an IBR by focusing the heat only at the desired
location, e.g., where the replacement blade is attached to the IBR.
A complete blade replacement for an IBR using the present invention
produced no stress or distortion on the rest of the assembly. The
device of this invention is suitable for OEM manufacture and for
repair of existing IBR systems.
[0015] 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.
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