GB2448109A - Enhanced erosion resistance for low pressure steam turbine bl ades - Google Patents

Enhanced erosion resistance for low pressure steam turbine bl ades Download PDF

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Publication number
GB2448109A
GB2448109A GB0706696A GB0706696A GB2448109A GB 2448109 A GB2448109 A GB 2448109A GB 0706696 A GB0706696 A GB 0706696A GB 0706696 A GB0706696 A GB 0706696A GB 2448109 A GB2448109 A GB 2448109A
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United Kingdom
Prior art keywords
blade
leading edge
edge region
ageing
temperature
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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GB0706696A
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GB0706696D0 (en
Inventor
Stuart Richard Holdsworth
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Technology GmbH
Original Assignee
Alstom Technology AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alstom Technology AG filed Critical Alstom Technology AG
Priority to GB0706696A priority Critical patent/GB2448109A/en
Publication of GB0706696D0 publication Critical patent/GB0706696D0/en
Priority to PCT/EP2008/053981 priority patent/WO2008122563A2/en
Publication of GB2448109A publication Critical patent/GB2448109A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
    • F01D5/286—Particular treatment of blades, e.g. to increase durability or resistance against corrosion or erosion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/0869—Devices involving movement of the laser head in at least one axial direction
    • B23K26/0876—Devices involving movement of the laser head in at least one axial direction in at least two axial directions
    • B23K26/0884—Devices involving movement of the laser head in at least one axial direction in at least two axial directions in at least in three axial directions, e.g. manipulators, robots
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D10/00—Modifying the physical properties by methods other than heat treatment or deformation
    • C21D10/005—Modifying the physical properties by methods other than heat treatment or deformation by laser shock processing
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/02—Hardening by precipitation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/006—Vehicles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2220/00—Application
    • F05D2220/30—Application in turbines
    • F05D2220/31—Application in turbines in steam turbines

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Optics & Photonics (AREA)
  • Materials Engineering (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Robotics (AREA)
  • Plasma & Fusion (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat Treatment Of Articles (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)

Abstract

The erosion resistance of a leading edge region 2 of a low pressure turbine blade 1 made from a precipitation hardening stainless steel is enhanced by applying a resolution treatment to the leading edge region, ageing the blade such that the material in the leading edge region has a higher erosion resistance than the remainder of the component, and laser-peening the leading edge region 2 sufficiently to generate a deep surface layer in which the stresses are highly compressive.

Description

ENHANCED EROSION RESISTANCE FOR LOW PRESSURE STEAM
TURBINE BLADES
Field of the Invention
The present invention relates to low pressure (LP) axial flow steam turbine blades made of precipitation hardened (PH) stainless steels, and in particular to a process whereby the erosion resistance of the blades can be enhanced.
Background of the Invention
A problem experienced by LP steam turbine rotor blades, and last stage LP steam turbine rotor blades in particular, is that of erosion by high-velocity water droplets that condense out of the steam and impact the leading edges of the blade aerofoils. A known way of dealing with this problem is to protect the leading edges of the blade aerofoils with a high hardness alloy sheath or deposited coating, since erosion resistance increases with increasing hardness. For example, US-A-S 351 395 discloses a method in which a steam turbine blade consisting of a martensitic steel is cast, the blade is subjected to solution annealing to make it suitable for welding, a metal alloy insert is tempered to a hardness less than that of the annealed component, the insert is welded to the leading edge of the blade, the component and insert are subjected to ageing heat treatment, the component and insert are machined, and then S...
**. 20 the insert is hardened through substantially its entire thickness. S...
* Additionally, it is already known to locally harden portions of general mechanical components made from PH stainless steels by means of certain heat treatment * *, regimes. For example, GB-A 1 074 576 discloses a method of locally hardening * : * 25 various types of components consisting of PH steel (such as gears and metalworking components, but not turbine blades), to give added resistance to erosion. One method described comprises over-ageing the whole component to give a desired (lower) hardness combined with reasonable ductility, and then selectively solution-heating the region which is to be hardened. Then the whole component is subjected to further ageing treatment to give higher hardness in the region which was solution-heated.
The patent explains that this method is applicable to austenitic-martensitic steels in which precipitation hardening of the austenite can cause a micro-structural phase change to martensite, which in turn can be further precipitation hardened. The patent also discloses that the normal method of hardening such steels involves an initial age hardening treatment at a comparatively high temperature followed by further age hardening at a lower temperature.
An extension of this approach of local hardening of PH steel components of a general mechanical type, to local hardening of steam turbine blade leading edges in particular, is of interest because it avoids the addition of extra material to the leading edge. Such addition of material adds mass to the blade, thereby increasing the rotational forces on it, and may also affect its aerodynamic performance. However, in high stress situations (e.g., last stage rotor blades in large steam turbines of the type used in power generation) there remains a problem of stress-corrosion cracking of the hardened area. The present invention was devised to eliminate or reduce this problem.
Summary of the Invention
According to the present invention, a method of enhancing the erosion resistance of a leading edge region of a low pressure turbine blade made from a precipitation : ... hardening stainless steel comprises the steps of hardening the leading edge region by * ... 20 applying a re-solution treatment thereto, ageing the blade such that the leading edge * : region has a higher erosion resistance than the remainder of the component, and laser- * peening the leading edge region sufficiently to generate a deep surface layer in which * the stresses are highly compressive. I. S * . * * S.
* .: 25 Before heat treatment begins, the blade manufacturing processes leave the blade with a smooth surface for aerodynamic efficiency and to avoid stress-raising features on the surface which could lead to stress-corrosion cracking. Use of the laser-peening process is advantageous because laser-peenirig, when properly applied to the leading edge region of the blade, will not significantly roughen its surface, unlike other types of peemng process. Furthermore, it is believed that the high compressive stress layer created by the laser peening process combats the tendency to stress-corrosion cracking that is induced by the age hardening process and increases the resistance of the treated area to erosion by water droplets.
In more detail, the method comprises the steps of: (a) applying a solution heat treatment to the blade; (b) holding the blade for a period of time and at a temperature sufficient to achieve transformation of the blade's metallurgical structure to martensite; (c) applying an intermediate heat treatment to the blade; (d) applying an ageing heat treatment to the blade; (e) applying a re-solution heat treatment to a leading edge region of the blade; (f) holding the blade for a period of time and at a temperature sufficient to achieve transformation of the metallurgical structure of the leading edge region of the blade to martensite; (g) applying an ageing heat treatment to the blade such that the leading edge region has a higher erosion resistance than the remainder of the blade; and (h) laser-peening the leading edge region to generate a high compressive stress state in a surface layer of the leading edge region.
We have found that the laser peening step can produce a surface layer of compressively stressed material at least 1mm thick and preferably up to 2mm thick in * the treated leading edge region, the value of the compressive stress produced being in I...
* the range of roughly 800-1000 MPa at the surface of the blade material, diminishing to zero at the boundary of the affected layer. U. S
S S * S.
: * 25 The invention also includes a steam turbine blade having a hardened erosion-resistant leading edge region that is unitary with, and consists of the same material as, the rest of the blade, the region having a smooth laser-peened surface layer exhibiting a value of compressive stress at the surface of 800 MPa.
Further aspects of the invention will be apparent from a perusal of the following
description and claims.
Brief Description of the Drawings
Exemplary embodiments of the invention will now be described, with reference to the accompanying drawings, in which: Figure 1 is a schematic side elevation of a turbine blade according to the present invention; and Figure 2 illustrates the laser peening step of the invention method by reference to a cross-section of a surface layer in the leading edge region of the turbine blade, taken within the area A of Figure 1.
Detailed Description of the Preferred Embodiments
Referring to Figure 1, the blade I illustrated is to be mounted in the last stage of a steam turbine. The blade 1 is forged from a low-carbon (PH) steel. The region of the blade most susceptible to erosion is the shaded region 2, in the leading edge portion 3 of the blade, adjacent to tip 4 of the blade, the end remote from the root 5.
The blade I may consist of a low-carbon steel containing Cr and Ni, having the designation PH-l5Cr-5Ni. In particular, this steel may have the following composition: up to 0.07 wt.% C, up to 1.0 wt% Si, up to 1.0 wt.% Mn, 13.0-15.5 wt% Cr, 3.5-6.00 wt.% Ni, 1.4-4.5 wt.% total Cu and Mo, the Mo being optional, and 0.15- 0.45 wt.% Nb, the balance being Fe and incidental impurities. Two examples of PH-I5Cr-5Ni steel are: 0sS* S..
(1) up to 0.07 wt% C, up to 0.7 wt.% Si, up to 1.0 wt% Mn, 13.0-15.0 wt.% Cr, 5.0-6.0 wt.% Ni, 1.2-2.0 wt.% Mo, 1.4-2.1 wt.% Cu, and 0.15-0.30 wt% Nb, the balance being Fe and incidental impurities; and (2) up to 0.07 wt.% C, up to 1.0 wt.% Si, up to 1.0 wt.% Mn, 14.0-15.5 wt.% Cr, 3.5-5.5 wt.% Ni, 2.5-4.5 wt.% Cu, and 0.15-0.45 wt.% Nb, the balance being Fe and incidental impurities.
For a steam turbine blade made of PH-I 5Cr-5Ni type of steel, a typical heat treatment procedure following blade forging would, for example, consist of the following sequence of treatments (the times and temperatures being approximate): solution treatment:-hold for lb at 1000 C, then air cool or quench and hold for 24h at =20 C; intermediate treatment:-hold for 3h at 800 C, then air cool; ageing treatment:-hold for 4h at 530 C; air cool or quench to ambient temperature.
Alternatively the blade I may be made of a low-carbon steel containing Cr, Ni, and Mo and having the designation PH-I3Cr-8Ni-2Mo. The composition of this steel is as follows: up to 0.05 wt.% C, up to 0.1 wt. % Si, up to 0.1 wt.% Mn, 12.25-13.25 wt.% Cr, 7.5-8.5 wt.% Ni, 2.0-2.5 wt.% Mo, and 0.90-1.35 wt.% Al, the balance being Fe and incidental impurities.
For a steam turbine blade made of PH-i 3Cr-8Ni-2Mo type of steel, a typical heat treatment procedure following blade forging would, for example, consist of the following sequence of treatments (the times and temperatures being approximate): solution treatment:-hold for Ih at 925 C, then air cool; ageing treatment:-hold for 4h at 540 C. * * * S.. *5S*
s..' 20 For a PH-l5Cr-5Ni type of steel a preferred process in accordance with the present invention starts with solution heat treatment of the forged blade 1, e.g. at a *0sS temperature of about 1000 C for about 1 hour. This may be followed by air cooling or quenching to ambient temperature and holding for 24h (at =20 C) prior to heating to an intermediale treatment temperature, e.g. about 800 C, at which the blade is held, *: 25 e.g. for about 3 hours, before air cooling or quenching again to ambient temperature.
Ageing heat treatment is then carried out at a temperature in the range from about 500 C to about 530 C, at which the blade is held, e.g. for about 4 hours, before air cooling to ambient temperature.
Subsequently the leading edge region 2 of the blade I is subjected to local re-solution heat treatment involving localised heating, preferably and conveniently using the technique of induction heating. The region 2 is held at a sufficiently high temperature, for a sufficient time, to dissolve precipitates in this region. The temperature may be in the range from about 1080 C to about 1100 C and the time less than 1 minute, for example. The temperature chosen will depend on other parameters such as the leading edge thickness, the speed of the induction coil, and the amount of back-face air cooling, and the combination of parameters chosen will depend on the desired profile of the heat-affected microstructure. The blade is then cooled to a temperature of =10 C and held for 24h.
After this re-solution heat treatment of the region 2, the blade I is subjected to an ageing heat treatment at a lower temperature than the previous ageing treatment. This causes re-ageing of the region 2 but has no significant effect on the already-aged material. The blade may be held at a temperature below 500 C, e.g. about 450 C, for a suitable time, e.g. about 2 hours. The temperature and time are chosen so as to maximise the hardness of the region 2 and thereby enhance its erosion resistance.
Suitable temperatures and times can be found empirically.
For a PH-i 3Cr-SNi-2Mo steel a preferred process according to the present invention again starts with solution heat treatment of the forged blade I, followed by ageing at a suitable temperature and for a suitable time to give the blade the required properties.
The temperature may be greater than 530 C, for example in the range from about 540 C to about 560 C. Subsequently the region 2 of the blade is subjected to local re-solution heat treatment. This temperature may, for example, be in the range from about 960 C to about 980 C. The blade is then re-aged at a lower temperature than the previous ageing treatment, which may be below 520 C, in particular about 500 C * 25 for example. Again the temperature and time to maximise the hardness (and therefore S*.
erosion resistance) of the region 2 can be determined empirically.
* The above hardening treatment for PH stainless steels achieves a satisfactory hardness * . and erosion resistance for the treated leading edge region of the blade, but * 30 unfortunately the treated region is more prone to stress-corrosion cracking, ***S..
* particularly in the high stress environment experienced by the last stage rotor blades of large steam turbines. 1-lowever, we have discovered that this tendency to stress-COITOSjOrI cracking can be effectively much reduced or eliminated by a laser peening process that puts a high degree of compressive stress into the surface layer of the hardened region. Unlike ball or shot peening processes, laser peening does not roughen the surface to which it is applied, and is therefore particularly suitable for application to turbine blades, where it is important to avoid roughening of the surface for aerodynamic reasons and to avoid stress-raising features.
As illustrated in Figure 2, the laser peening process used in the present invention involves firing a laser beam 8 at the surface of the trailing edge region 2 to be treated in short bursts or pulses to generate extremely high pressure pulses 9. This sends shock waves 10 from the point of impingement of the laser beam into the sub-surface layer of the part. The laser is pulsed and controlled so that the laser beam 8 hits in a pre-defined surface pattern to produce a desired surface layer of residual compressive stress. This surface layer is much deeper than that produced by ball or shot peening treatments, hence it provides greater resistance to fatigue and corrosion failure.
To obtain the desired extremely high pressure pulses that exert the peening action, it is necessary to cover the region 2 to be peened by a thin layer of water or other substance (called the "inertial tamping layer"). It is also usual to interpose a thin layer of paint or plastic tape 12 (called the "ablative layer") between the metal and the inertial tamping layer to protect the surface and mediate the pressure pulses to the metal surface.
:. Laser peening is available to order from the Metal Improvement Company at West *, 25 Craven Drive, West Craven Business Park, Earby, Lancashire, BBI8 6JZ United I.e.
Kingdom and at 7655 Longard Road Livermore, CA 94550, U.S.A., see also S...
hup:/fwww.metalimprovement.conijlaserpeen.php. I..
The above-mentioned web site mentions an exemplary laser peening process using a Neodymium: glass laser having a wavelength of Ijim with a power of 25 Joules and a S.....
* pulse duration of 25ns. The pulse pressures generated by the impingement of the laser beam on the inertial tamping layer are said to be of the order of 6900 MPa.
Furthermore, it is said that compared with a shot peened surface, laser peening produces only small amounts of cold working in the compressive layer and besides increasing the component's resistance to failure mechanisms such as fatigue and stress corrosion, also lessens thermal relaxation of residual stresses in the surface
EXAMPLE
Procedure: I) A blade consisting of a steel having the composition PH-l5Cr-5Ni (I) mentioned above is forged.
2) The blade is subjected to: solution treatment: lh, 1000 C, air cool, then holding at =20 C for >24h intermediate treatment: 3h, 800 C, air cool, then ageing treatment: 4h, 500-530 C.
3) A leading edge region of the blade is subjected to induction heating, with a peak temperature in the range 1080-1100 C, for less than 1 minute, and then held at =l0 C for 24h.
4) The blade is re-heated and held at a temperature of 450 C for 2h.
5) The leading edge region is then subjected to an all-over laser peening process to obtain the desired degree of compressive stress. The blade is precisely manipulated * 25 by a robotic arm during the laser peening process to ensure uniform coverage by the *: pattern of laser pulses, consistent depth of the compressive stress layer, and repeatability of the process. S..
ResuJts: :.: 30 The locally-performed re-solution treatment causes re-solution of original precipitates in the locally-heated zone. The locally solution-treated material responds to the low-temperature final ageing treatment to generate the peak hardness condition and provide a hard surface with good water droplet erosion resistance. The originally aged blade material is not influenced by the additional low-temperature ageing and retained its original mechanical properties. The subsequent laser peening process produces a compressive stress layer about 2mm deep and compressive stress at the S surface of the treated leading edge region is in the range 800-I000MPa. S. * S * *** I...
S S * .SS S... S... S..
I I. U I I * * *5
I
I -.10-

Claims (19)

1. A method of enhancing the esion resistance of a leading edge region
of a low pressure turbine blade made from a precipitation hardening stainless steel, including the steps of applying a re-solution treatment to the leading edge region, age ing the blade such that the material in the leading edge regioe has a higher eroskrn resistance than the remainder of the component, and laser-peening the leading edge region sufficiently to generate a deep surface layer in which the stresses e highly compressive.
2. The method of claim 1, comprising the steps of: (a) applying a solution heat treatment to the blade; (b) holding the blade for a period of time and at a tetnperatwe sufficient to achieve transfomiation of the blade's metallurgical structure to maitensite; (c) applying an intemiediate beat treatment to the blade; (d) applying an agcing heat trvatzneJt to the blade; (e) applying a re-solution heat ireatment to a leading edge region of the blade; (f) holding the blade for a period of time and at a temperature sufficient to achieve transformation of the metallurgical structure of the leading edge region of the blade to martensite (g) applying an ageing beat treatment to the blade such that the leading edge region has a higher erosion resistance than the remainder of the blade; and (ii) laser-peening the leading edge region to generate a high compressive stress layer in a deep surface layer of the leading edge region.
3. A method according to claim 1 or claim 2 in which the laser-peening step generates a compressive stress layer having a compressive stress of at least 800MPa at its surface.
4. A method according to any one ofclaiins Ito 3, in which Ihe depth of the compressive stress layer is about 2mm.
5. Amethodasclaimclaim2oraclaimedinclaims3or4asdePcfldeflt on claim 2, in which step (c) comprises induction heating of the leathig edge region of the blade.
6. Authucbimedinm2,oclaiinedinanyoneofclaiius3to5as dependent on claim 2, in which step (d) comprises holding the component at a first ageing temperature for a first ageing period, and step (g) comprises holding the component at a second ageing temperature for a second ageing period, the second agemg temperature being lower than the first ageing temperature. to
7. A method as claimed in claim 6. in which the second ageing period is shorter than the first ageing period
8. A method as claimed in any one of claims I to 7, in which the precipitation hardening steel is of the PH-l5Cr-5Ni type.
9. Amethodasclaimedinclaim8,usdcpcndentonclaiin6,inwhichthefirst agcing temperature is in the range from approximately 500 C to approximately 530 C and the second ageing temperature is approximately 450 C.
10. A method as claimed in claIm S as dependent on claim 5, in which step (e) comprises heating the trailing edge region to a tempersiure iu the range from approxiwately iogo c to approximately 1100 C.
11. A method as claimed in any one of claims I to 7, in which the precipitation haitlening steel is of the PH-i 3Cr-SNI-2Mo type. /
12. Awethod as med inclaimi as dependentonclaim 6, inwbichthe first ageing temperature is greater than 530 C aad the second ageing temperature is less than 520 C. -12.
13. A method as claimed in claini 12, in which the first ageing tcmpcrature is in the range from approximately 540 C to approximately 5W'C.
14. A method as claimed in claim 12 or claim tI, in which the second ageing tenipature is approximately 500 C.
IS. A method as claimed ni claim 12 as dependent on cLaim 5, in which step (e) comprises healing the leading edge region to a temperature in the ratge from uxiaiatCly 960 C to approximately 980 C.
16. A steam turbine blade produced by a method in accordance with any prece4ling claim.
17. A steam turbine blade having a hardened erosion-resistant leading edge region that is unitary with, and consists of the same material as, the rest of the blade, the region having a smooth laser-peened surface layer exhibiting a value of cOJJIprCSsiVC stess at the surface of ?SOO MPa.
18. A steam turbine blade according to claim 17, in which the laser peened surface layer is about 1mm to 2mm deep.
19. A method of locally enhancing the ension resistance of a steam turbine blade, substantially as described in the Example.
GB0706696A 2007-04-04 2007-04-04 Enhanced erosion resistance for low pressure steam turbine bl ades Withdrawn GB2448109A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0706696A GB2448109A (en) 2007-04-04 2007-04-04 Enhanced erosion resistance for low pressure steam turbine bl ades
PCT/EP2008/053981 WO2008122563A2 (en) 2007-04-04 2008-04-03 Enhanced erosion resistance for low pressure steam turbine blades

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Application Number Priority Date Filing Date Title
GB0706696A GB2448109A (en) 2007-04-04 2007-04-04 Enhanced erosion resistance for low pressure steam turbine bl ades

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GB2448109A true GB2448109A (en) 2008-10-08

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WO (1) WO2008122563A2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9291062B2 (en) 2012-09-07 2016-03-22 General Electric Company Methods of forming blades and method for rendering a blade resistant to erosion
CN110732779B (en) * 2019-10-18 2021-05-04 扬州镭奔激光科技有限公司 Fixed-axis rotation laser shot blasting method for blisk stable constraint layer

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2397307A (en) * 2003-01-20 2004-07-21 Rolls Royce Plc Abradable Coatings
US20050158460A1 (en) * 2004-01-21 2005-07-21 Williams Christopher C. Method for protecting new/used engine parts
JP2005265449A (en) * 2004-03-16 2005-09-29 Toshiba Corp Preventive maintenance method of structure
US20060048867A1 (en) * 2004-08-30 2006-03-09 Japan Atomic Energy Research Institute Method of an ultra-short femtosecond pulse and KW class high average-power laser for preventing cold-worked stress corrosion cracking in iron steels and alloyed steel including stainless steels

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5591009A (en) * 1995-01-17 1997-01-07 General Electric Company Laser shock peened gas turbine engine fan blade edges
GB2424422A (en) * 2005-03-23 2006-09-27 Alstom Technology Ltd Precipitation hardening of a steel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2397307A (en) * 2003-01-20 2004-07-21 Rolls Royce Plc Abradable Coatings
US20050158460A1 (en) * 2004-01-21 2005-07-21 Williams Christopher C. Method for protecting new/used engine parts
JP2005265449A (en) * 2004-03-16 2005-09-29 Toshiba Corp Preventive maintenance method of structure
US20060048867A1 (en) * 2004-08-30 2006-03-09 Japan Atomic Energy Research Institute Method of an ultra-short femtosecond pulse and KW class high average-power laser for preventing cold-worked stress corrosion cracking in iron steels and alloyed steel including stainless steels

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WO2008122563A2 (en) 2008-10-16
WO2008122563A3 (en) 2008-12-18

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