US4903888A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbine system having more failure resistant rotors and repair welding of low alloy ferrous turbine components by controlled weld build-up
Assignee: Siemens Energy Inc
•
Filing: 1988-05-05
•
Granted: 1990-02-27
•
Expires: 2008-05-05
Abstract
Abstract Novel methods for repairing worn surfaces of turbine rotors, are disclosed. These methods include depositing a first layer of weld metal on a worn surface of the component, whereby a heat-affected zone is created. A second layer of weld metal is then deposited over the first layer using a greater amount of heat to temper at least a portion of the heat-affected zone produced by the first layer. The preferred embodiments include the use of gas tungsten arc welding for producing fine-grain size and more creep resistance, especially in the weld and heat-affected zone. The resulting build-up can be machined, for example into a blade fastening to produce a component having properties equal to or better than the base-metal alloy. The invention also provides a longer lasting turbine system, including rotors which have serrated steeples that are more resistant to failure.
Inventors
- 👤 Robert E. Clark
- 👤 Dennis R. Amos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:23
CPC Classifications
B; B23; B23P; B23P6/00; B23P6/002; B23P6/007; B23K; B23K9/00; B23K9/04; B23K15/00; B23K15/0046; B23K15/0086; B23K26/00; B23K26/20; B23K26/32; B23K26/34; B23K26/342; B23K35/00; B23K35/02; B23K35/0255; B23K35/0261; B23K35/0272; B23K35/22; B23K35/24; B23K35/30; B23K35/3053; B23K35/308; B23K9/044; B23K9/046; B23K9/23; C; C22; C22C; C22C38/00; C22C38/12; C22C38/18; C22C38/22; C22C38/24; F; F01; F01D; F01D5/00; F01D5/005; B23K2101/00; B23K2101/001; B23K2103/00; B23K2103/50; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49316; Y10T29/49318; Y10T29/49718; Y10T29/49746
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
120 words
A method of repairing a worn surface of a low alloy ferrous steam turbine component comprising: (a) providing a steam turbine component having a worn surface thereon, said component comprising about 1,05% to about 1.35% by weight Cr, about 1.00% to about 1.30% by weight Mo, about 0.21% to about 0.29% by weight V and about 0.27% to about 0.34% by weight C; (b) depositing a first layer of weld metal on said worn surface, said depositing step producing a heat-affected-zone in said component; and (c) depositing a second layer of weld metal on said first layer with higher heat than that used to apply said first layer to temper at least a portion of said heat-affected-zone in said component.
Claim 2
Independent Claim
120 words
A method of repairing a worn surface of a low alloy ferrous steam turbine component comprising: (a) providing a steam turbine component having a worn surface thereon, said component comprising about 1,05% to about 1.35% by weight Cr, about 1.00% to about 1.30% by weight Mo, about 0.21% to about 0.29% by weight V and about 0.27% to about 0.34% by weight C; (b) depositing a first layer of weld metal on said worn surface, said depositing step producing a heat-affected-zone in said component; and (c) depositing a second layer of weld metal on said first layer with higher heat than that used to apply said first layer to temper at least a portion of said heat-affected-zone in said component.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said depositing steps (b) and (c) comprise any one of gas tungsten arc welding, plasma-arc welding, electron beam welding, laser-beam welding and gas metal arc welding
Claim 4
Dependent Claim
23 words
The method of claim 2 further comprising preheating said steam turbine component to at least about 177° C. prior to said welding step.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said depositing step (b) comprises gas metal arc welding.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said depositing step (c) comprises gas metal arc welding.
Claim 7
Dependent Claim
17 words
The method of claim 4 wherein said welding step comprises welding at about 40 to 160 amperes.
Claim 8
Dependent Claim
17 words
The method of claim 4 wherein said welding step comprises welding at about 60 to 140 amperes.
Claim 9
Dependent Claim
20 words
The method of claim 4 wherein said welding step comprises welding at about 80 to 120 amperes of direct current.
Claim 10
Dependent Claim
17 words
The method of claim 5 wherein said welding step comprises welding at about 50 to 200 amperes.
Claim 11
Dependent Claim
17 words
The method of claim 5 wherein said welding step comprises welding at about 75 to 175 amperes.
Claim 12
Dependent Claim
20 words
The method of claim 5 wherein said welding step comprises welding at about 100 to 150 amperes of direct current.
Claim 13
Dependent Claim
24 words
The method of claim 5 wherein said providing step comprises selecting a turbine component comprising a rotor having at least one worn steeple thereon.
Claim 14
Dependent Claim
24 words
The method of claim 9 wherein said providing step further comprises mechanically removing said worn steeple of said rotor to produce a prepared surface.
Claim 15
Dependent Claim
23 words
The method of claim 13 wherein said depositing step (b) comprises welding a first bead transversely across said rotor on said prepared surface.
Claim 16
Dependent Claim
30 words
The method of claim 14 wherein said welding step further comprises welding a second bead on said prepared surface, transversely across said rotor and spaced apart from said first bead.
Claim 17
Dependent Claim
38 words
The method of claim 15 wherein said welding step further comprises positioning a first run off tab along at least a first longitudinal edge of said rotor for at least providing a starting surface for said welding step.
Claim 18
Dependent Claim
43 words
The method of claim 16 wherein said welding step further comprises positioning a second run off tab on a second longitudinal edge of said rotor, transversely opposed from said first longitudinal edge, for at least providing a surface for stopping said welding step.
Claim 19
Dependent Claim
25 words
The method of claim 17 wherein said positioning steps comprise welding said first and second run off tabs to said rotor with a buttering layer.
Claim 20
Dependent Claim
13 words
The method of claim 18 further comprising selecting a buttering layer comprising chrome.
Claim 21
Dependent Claim
17 words
The method of claim 19 further comprising dispensing said buttering layer in at least two overlapping weldments.
Claim 22
Dependent Claim
25 words
The method of claim 3 wherein said depositing steps (b) and (c) further comprise maintaining the interpass temperature of the base metal below 300° C.
Claim 23
Dependent Claim
25 words
The method of claim 3 wherein said depositing steps (b) and (c) further comprise maintaining the temperature of said turbine component below about 250° C.
Claim 24
Dependent Claim
26 words
The method of claim 3 wherein said depositing steps (b) and (C) further comprise maintaining the interpass temperature of said turbine component below about 204° C.
Claim 25
Dependent Claim
41 words
The method of claim 21 wherein said maintaining step comprises maintaining said turbine component and said first and second layers of weld metal at a temperature of about 149° C. to about 260° C. after said depositing steps (b) and (c).
Claim 26
Dependent Claim
39 words
The method of claim 21 wherein said maintaining step comprises maintaining said turbine component and said first and second layers of said weld metal at about 176° C. to about 204° C. after said depositing steps (b) and (c).
Claim 27
Dependent Claim
29 words
The method of claim 22 wherein said maintaining step further comprises heating said turbine component and said first and second layers of said weld metal above about 500° C.
Claim 28
Dependent Claim
29 words
The method of claim 22 wherein said maintaining step further comprises heating said turbine component and said first and second layers of said weld metal above about 600° C.
Claim 29
Dependent Claim
29 words
The method of claim 22 wherein said maintaining step further comprises heating said turbine component and said first and second layers of said weld metal above about 663° C.
Claim 30
Dependent Claim
24 words
The method of claim 1 wherein said depositing steps (b) and (c) comprise disposing a side plate on said turbine component for withdrawing heat.
Claim 31
Dependent Claim
19 words
The method of claim 29 wherein said disposing a side plate step comprises selecting a side plate comprising copper.
Claim 32
Dependent Claim
12 words
The method of claim 29 further comprising water cooling said side plate.
Claim 33
Dependent Claim
34 words
The method of claim 31 wherein said disposing step disposes said water cooled side plate along the edge of said worn surface, whereby said first layer is deposited against said water cooled side plate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |