Gas turbine nozzle, power generation gas turbine, co-base alloy and welding material

• US 6,077,615 A
• Filed: 12/16/1997
• Issued: 06/20/2000
• Est. Priority Date: 10/20/1997
• Status: Expired due to Term

• Current Assignee: mitsubishi hitachi power systems, ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Kumata, Kazuhiko, Nakazaki, Takamitsu, Yada, Masami, Iizuka, Nobuyuki, Yokoba, Norio, Kobayashi, Kei, Funamoto, Takao
• Primary Examiner(s): Jones, Deborah
• Assistant Examiner(s): Koehler, Robert R.
• Application Number:
  US08/991,610
• Time in Patent Office: 917 Days
• Field of Search: 428/544, 428/576, 428/636, 428/637, 428/668, 420/436, 420/437, 420/438, 420/439, 420/440, 420/588, 148/408, 148/425, 148/442, 60/39.75, 415/191, 415/200
• US Class Current: 428/544
• CPC Class Codes: B23K 35/3046 Co as the principal constituent
• CPC Class Codes: B23P 6/007 using only additive methods, e.g. build-up welding
• CPC Class Codes: B23P 6/045 of turbine components, e.g. moving or stationary blades, rotors, etc.
• CPC Class Codes: F01D 5/005 Repairing methods or devices
• CPC Class Codes: Y10T 428/12 All metal or with adjacent metals
• CPC Class Codes: Y10T 428/12222 Shaped configuration for melting [e.g., package, etc.]
• CPC Class Codes: Y10T 428/12639 Adjacent, identical composition, components
• CPC Class Codes: Y10T 428/12646 Group VIII or IB metal-base
• CPC Class Codes: Y10T 428/12861 Group VIII or IB metal-base component

Abstract

A Co-base alloy including, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 3-10% W, 5-10% Ta and 0.05-0.7% Zr, is used as a welding material. A gas turbine nozzle has a crack repaired with a multi-layer weld using the Co-base alloy and a gas turbine for power generation employs the nozzle.

Claims

1. A nozzle for a gas turbine, formed by vanes and side walls provided at both ends of said vanes, and made of a Co-base casting alloy comprising, by weight, 0.20-0.30% C, not more than 1.0% Si, not more than 1.0% Mn, 20-32% Cr, 9-12% Ni, 5-10% W, not more than 5% Fe and 0.0005-0.015% B, wherein said nozzle has at least a crack repaired with a multi-layer weld formed by welding, said multi-layer weld being made of a Co-base alloy comprising, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 3-10% W, 5-15% Ta and 0.05-0.7% Zr.

2. A nozzle for a gas turbine according to claim 1, wherein said multi-layer weld is formed by welding 3 passes or more in a width direction perpendicular to a welding direction, said multi-layer weld having an outer surface ground to the same height as that of a surface of an adjacent portion to the repaired portion.

3. A nozzle for a gas turbine according to claim 1, wherein said multi-layer weld is formed in a length of 10 mm or more.

4. A nozzle for a gas turbine according to claim 1, wherein said nozzle has at least two vanes and said multi-layer weld is made of said Co-based alloy in which Cr and W each are less in weight % than said Co-base casting alloy.

5. A nozzle for a gas turbine according to claim 1, wherein said multi-layer weld is made of said Co-base alloy which has a C content of 0.10-0.40 times as much as the C content of said Co-base casting alloy.

6. A nozzle for a gas turbine according to claim 2, wherein said multi-layer weld is formed in a length of 10 mm or more.

7. A nozzle for a gas turbine according to claim 1, wherein said crack is repaired with a multi-layer weld formed by welding 3 passes or more in the width direction perpendicular to a welding direction and said multi-layer weld having an outer surface ground to the same height as that of a surface of an adjacent portion to the repaired portion.

8. A nozzle for a gas turbine according to claim 1,

wherein said nozzle is formed with at least two vanes and said nozzle has at least a crack repaired with a multi-layer weld formed by welding, said multi-layer weld being made of a Co-base alloy which has C of content of 0.10-0.40 times as much as the C content of said Co-base casting alloy.

9. A nozzle for a gas turbine according to claim 1,

wherein said multi-layer weld is made of said Co-base alloy which has a C content of 0.10-0.40 times as much as the C content of said Co-base casting alloy and

in which Cr and W each are less in weight % than said Co-base casting alloy.

10. A nozzle for a gas turbine according to claim 1,

wherein said multi-layer weld is formed by welding 3 passes or more in the welding width direction perpendicular to a welding direction, said multi-layer weld having an outer surface ground to the same height as that of a surface of an adjacent portion to the repaired portion and

said multi-layer weld is formed in a length of 10 mm or more.

11. A gas turbine for power generation, provided with said gas turbine nozzles according to claim 1.

17. A gas turbine for power generation comprising an air compressor, a combustor, turbine blades fixed to a turbine disc and turbine nozzles provided corresponding to said turbine blades, wherein an inlet temperature of combustion gas to a first stage of said turbine nozzle is 1,250-1,600°

C., and said gas turbine nozzles each are as defined in claim 1.

12. A welding material made of a Co-base alloy comprising, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 3-10% W, 5-15% Ta and 0.05-0.7% Zr.

13. A Co-base alloy according to claim 12, further comprising, by weight, at least one element selected from not more than 1% Al and not more than 2% Fe.

14. A welding material according to claim 12, wherein said Co-based alloy further comprises, by weight, at least one element selected from 0.05-1.0% Ti, 0.05-0.5% Nb and 0.05-0.5% Hf.

15. A welding material according to claim 12, wherein said Co-based alloy further comprises, by weight, 0.005-0.02% B.

16. A welding material according to claim 12, wherein said welding material is constructed in the form of a wire, rod or a compound wire from metal powder which is filled into a steel tube of small diameter.

18. A welding material made of a Co-base alloy comprising, by weight, 0.03-0.10% C, not more than 1.0% Si, not more than 1.0% Mn, 20-30% Cr, 15-23% Ni, 4-7% W, 5-15% Ta and 0.05-0.7% Zr.