DISSIMILAR METAL WELDS AND ITS MANUFACTURING METHOD OF LARGE WELDED STRUCTURES SUCH AS THE TURBINE ROTOR

• US 20120301309A1
• Filed: 05/22/2012
• Published: 11/29/2012
• Est. Priority Date: 05/23/2011
• Status: Abandoned Application

• Current Assignee: mitsubishi hitachi power systems, ltd. (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: NISHIOKA, Eiji, SATO, Jun, IMANO, Shinya, KUDO, Takeshi, MURATA, Kenichi, HOSOKAWA, Kazutaka, ENDO, Kazuhiko
• Application Number:
  US13/477,289
• Publication Number:
  US 20120301309A1
• Time in Patent Office: Days
• US Class Current: 416/223.R
• CPC Class Codes: B23K 2101/001 Turbines
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 2103/18 Dissimilar materials
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 9/0026 specially adapted for particular articles or work
• CPC Class Codes: B23K 9/0282 for welding tube sections
• CPC Class Codes: B23K 9/046 on surfaces of revolution
• CPC Class Codes: B23K 9/173 and of a consumable electrode
• CPC Class Codes: B23K 9/232 of different metals
• CPC Class Codes: B23K 9/235 Preliminary treatment
• CPC Class Codes: F01D 5/063 Welded rotors welding per se B23K
• CPC Class Codes: F05D 2230/232 by welding
• CPC Class Codes: F05D 2300/50212 dissimilar
• CPC Class Codes: Y10T 29/4932 Turbomachine making

Abstract

Dissimilar metal welds including a buttering portion with a small variation in strength distribution in a plate thickness direction are formed by welding two parent materials having at least one of different compositions and different refining conditions through a buttering for alleviating mismatch between one of the different compositions and the different refining conditions of the two members and through a welded metal for joining one of the parent materials and the buttering. The buttering is formed of welding metals laminated in a plate thickness direction, and a dilution ratio of the buttering with the parent materials is 50% or less. The manufacturing method includes performing butt welding on a dummy material formed by increasing a groove depth by providing a member on a bottom side of a welding groove and on parent materials by using the buttering; and processing a groove within a welding metal formed of the buttering.

Claims

1. Dissimilar metal welds formed by welding two parent materials having at least one of different compositions and different refining conditions, through a buttering for alleviating mismatch between one of the different compositions and the different refining conditions of the two members and through a welded metal for joining one of the parent materials and the buttering,

wherein the buttering is formed of welding metals laminated in a plate thickness direction, and a dilution ratio of the buttering with the parent materials is equal to or less than 50%.

2. The dissimilar metal welds according to claim 1, wherein the buttering includes 30 ppm or less of oxygen.

3. A steam turbine rotor comprising dissimilar metal welds according to claim 1.

4. The turbine rotor according to claim 3, wherein

at least one of the two parent materials comprises a nickel (Ni)-base alloy including, by weight, 5 to 15% of cobalt (Co), 13 to 15.5% of chromium (Cr), 4.0 to 5.5% of aluminum (Al), 0.1 to 2.0% of titanium (Ti), 0.1 to 1.0% of niobium (Nb), 0.1 to 3.0% of tantalum (Ta), 0.1 to 2.0% of molybdenum (Mo), 4.5 to 10% of tungsten (W), 0.1 to 2.0% of hafnium (Hf), 0.05 to 0.20% of carbon (C), 0.001 to 0.03% of boron (B), 0.01 to 0.1% of zirconium (Zr), and a remainder including nickel (Ni) except for inevitable impurities.

5. The turbine rotor according to claim 3, wherein at least one of the parent materials comprises a nickel (Ni)-ferrum (Fe)-base alloy including, by weight, 30 to 40% of ferrum (Fe), 14 to 16% of chromium (Cr), 1.2 to 1.7% of titanium (Ti), 1.1 to 1.5% of aluminum (Al), 1.9 to 2.7% of niobium (Nb), 0.05% or less of carbon (C), and a remainder including nickel (Ni) except for inevitable impurities.

6. The turbine rotor according to claim 3, wherein at least one of the parent materials comprises 12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co).

7. The turbine rotor according to claim 3, wherein at least one of the parent materials comprises 1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

8. The turbine rotor according to claim 3, wherein at least one of the parent materials comprises 3-4%-nickel (Ni)-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.17 to 0.32% of carbon (C), 0.2 to 0.4% of manganese (Mn), 3 to 4% of nickel (Ni), 1.25 to 2.0% of chromium (Cr), 0.25 to 0.60% of molybdenum (Mo), and 0.05 to 0.15% of vanadium (V).

9. The turbine rotor according to claim 3, wherein

in at least one of a rotor for a high-pressure steam turbine, a rotor for an intermediate-pressure steam turbine, and a rotor for high-pressure and intermediate-pressure steam turbines,

the parent material on a high-temperature side where a steam temperature is high comprises one of:

a nickel (Ni)-base alloy including, by weight, 5 to 15% of cobalt (Co), 13 to 15.5% of chromium (Cr), 4.0 to 5.5% of aluminum (Al), 0.1 to 2.0% of titanium (Ti), 0.1 to 1.0% of niobium (Nb), 0.1 to 3.0% of tantalum (Ta), 0.1 to 2.0% of molybdenum (Mo), 4.5 to 10% of tungsten (W), 0.1 to 2.0% of hafnium (Hf), 0.05 to 0.20% of carbon (C), 0.001 to 0.03% of boron (B), 0.01 to 0.1% of zirconium (Zr), and a remainder including nickel (Ni) except for inevitable impurities; and

a nickel (Ni)-ferrum (Fe)-base alloy including, by weight, 30 to 40% of ferrum (Fe), 14 to 16% of chromium (Cr), 1.2 to 1.7% of titanium (Ti), 1.1 to 1.5% of aluminum (Al), 1.9 to 2.7% of niobium (Nb), 0.05% or less of carbon (C), and a remainder including nickel (Ni) except for inevitable impurities, and

the parent material on a low-temperature side where the steam temperature is low comprises one of;

12%-chromium (Cr)-based steel having a wholly tempered bainite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co); and

1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

10. The turbine rotor according to claim 3, wherein

in one of a rotor for a high-pressure steam turbine, a rotor for an intermediate-pressure steam turbine, and a rotor for high-pressure and intermediate-pressure steam turbines,

the parent material on a high-temperature side where a steam temperature is high comprises 12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co), and

the parent material on a low-temperature side where the steam temperature is low comprises 1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

11. The turbine rotor according to claim 3, wherein

the turbine rotor is one of a rotor for a high-pressure and low-pressure integrated steam turbine and a rotor for an intermediate-pressure and low-pressure integrated steam turbine, the rotors being formed by connecting one of a high-pressure rotor and an intermediate-pressure rotor, with a low-temperature rotor by butt welding,

the one of the high-pressure rotor and the intermediate-pressure rotor comprises one of:

1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V); and

12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co), and

the low-temperature rotor comprises 3-4%-nickel (Ni)-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.17 to 0.32% of carbon (C), 0.2 to 0.4% of manganese (Mn), 3 to 4% of nickel (Ni), 1.25 to 2.0% of chromium (Cr), 0.25 to 0.60% of molybdenum (Mo), and 0.05 to 0.15% of vanadium (V).

20. A steam turbine rotor comprising dissimilar metal welds according to claim 2.

21. The turbine rotor according to claim 20, wherein

at least one of the two parent materials comprises a nickel (Ni)-base alloy including, by weight, 5 to 15% of cobalt (Co), 13 to 15.5% of chromium (Cr), 4.0 to 5.5% of aluminum (Al), 0.1 to 2.0% of titanium (Ti), 0.1 to 1.0% of niobium (Nb), 0.1 to 3.0% of tantalum (Ta), 0.1 to 2.0% of molybdenum (Mo), 4.5 to 10% of tungsten (W), 0.1 to 2.0% of hafnium (Hf), 0.05 to 0.20% of carbon (C), 0.001 to 0.03% of boron (B), 0.01 to 0.1% of zirconium (Zr), and a remainder including nickel (Ni) except for inevitable impurities.

22. The turbine rotor according to claim 20, wherein at least one of the parent materials comprises a nickel (Ni)-ferrum (Fe)-base alloy including, by weight, 30 to 40% of ferrum (Fe), 14 to 16% of chromium (Cr), 1.2 to 1.7% of titanium (Ti), 1.1 to 1.5% of aluminum (Al), 1.9 to 2.7% of niobium (Nb), 0.05% or less of carbon (C), and a remainder including nickel (Ni) except for inevitable impurities.

23. The turbine rotor according to claim 20, wherein at least one of the parent materials comprises 12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co).

24. The turbine rotor according to claim 20, wherein at least one of the parent materials comprises 1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

25. The turbine rotor according to claim 20, wherein at least one of the parent materials comprises 3-4%-nickel (Ni)-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.17 to 0.32% of carbon (C), 0.2 to 0.4% of manganese (Mn), 3 to 4% of nickel (Ni), 1.25 to 2.0% of chromium (Cr), 0.25 to 0.60% of molybdenum (Mo), and 0.05 to 0.15% of vanadium (V).

26. The turbine rotor according to claim 20, wherein

in at least one of a rotor for a high-pressure steam turbine, a rotor for an intermediate-pressure steam turbine, and a rotor for high-pressure and intermediate-pressure steam turbines,

the parent material on a high-temperature side where a steam temperature is high comprises one of:

a nickel (Ni)-base alloy including, by weight, 5 to 15% of cobalt (Co), 13 to 15.5% of chromium (Cr), 4.0 to 5.5% of aluminum (Al), 0.1 to 2.0% of titanium (Ti), 0.1 to 1.0% of niobium (Nb), 0.1 to 3.0% of tantalum (Ta), 0.1 to 2.0% of molybdenum (Mo), 4.5 to 10% of tungsten (W), 0.1 to 2.0% of hafnium (Hf), 0.05 to 0.20% of carbon (C), 0.001 to 0.03% of boron (B), 0.01 to 0.1% of zirconium (Zr), and a remainder including nickel (Ni) except for inevitable impurities; and

a nickel (Ni)-ferrum (Fe)-base alloy including, by weight, 30 to 40% of ferrum (Fe), 14 to 16% of chromium (Cr), 1.2 to 1.7% of titanium (Ti), 1.1 to 1.5% of aluminum (Al), 1.9 to 2.7% of niobium (Nb), 0.05% or less of carbon (C), and a remainder including nickel (Ni) except for inevitable impurities, and

the parent material on a low-temperature side where the steam temperature is low comprises one of;

12%-chromium (Cr)-based steel having a wholly tempered bainite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co); and

1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

27. The turbine rotor according to claim 20, wherein

in one of a rotor for a high-pressure steam turbine, a rotor for an intermediate-pressure steam turbine, and a rotor for high-pressure and intermediate-pressure steam turbines,

the parent material on a high-temperature side where a steam temperature is high comprises 12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co), and

the parent material on a low-temperature side where the steam temperature is low comprises 1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V).

28. The turbine rotor according to claim 20, wherein

the turbine rotor is one of a rotor for a high-pressure and low-pressure integrated steam turbine and a rotor for an intermediate-pressure and low-pressure integrated steam turbine, the rotors being formed by connecting one of a high-pressure rotor and an intermediate-pressure rotor, with a low-temperature rotor by butt welding,

the one of the high-pressure rotor and the intermediate-pressure rotor comprises one of:

1%-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.25 to 0.35% of carbon (C), 0.5 to 1% of manganese (Mn), 1% or less of nickel (Ni), 0.8 to 1.5% of chromium (Cr), 1.0 to 1.5% of molybdenum (Mo), and 0.2 to 0.3% of vanadium (V); and

12%-chromium (Cr)-based steel having a wholly tempered martensite structure including, by weight, 0.1 to 0.2% of carbon (C), 0.3 to 1.0% of manganese (Mn), 1% or less of nickel (Ni), 9 to 13% of chromium (Cr), 0.1 to 1.5% of molybdenum (Mo), 0.2 to 5.0% of tungsten (W), 0.02 to 0.1% of niobium (Nb), and 3% or less of cobalt (Co), and

the low-temperature rotor comprises 3-4%-nickel (Ni)-chromium (Cr)-molybdenum (Mo)-vanadium (V)-based steel having a bainite structure including, by weight, 0.17 to 0.32% of carbon (C), 0.2 to 0.4% of manganese (Mn), 3 to 4% of nickel (Ni), 1.25 to 2.0% of chromium (Cr), 0.25 to 0.60% of molybdenum (Mo), and 0.05 to 0.15% of vanadium (V).

12. A method of manufacturing one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds, the dissimilar metal welds being formed by welding two parent materials having at least one of different compositions and different refining conditions, through a buttering for alleviating mismatch between one of the different compositions and the different refining conditions of the two members and through a welded metal for joining one of the parent materials and the buttering, the method comprising at least the steps of:

performing butt welding on a dummy material formed by increasing a groove depth by providing a member on a side of a bottom of a welding groove, and on the parent materials, by using the buttering; and

processing a groove within a welding metal formed of the buttering.

16. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to claim 12, wherein in the butt welding step, the dummy material has a bottom having a plate thickness of 3 mm or more, the bottom being butted to extend along a bottom surface of the parent materials from a groove center.

17. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to claim 16, wherein in the butt welding step, a bottom of the dummy material is butted to overlap in length within a range of 3 to 15 mm along a bottom surface of the parent materials from a groove center.

18. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to 12, wherein the step of processing a groove within a welding metal made of the buttering material comprising processing a butt portion of the buttering to have a dilution ratio of 50% or less.

19. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to 12, wherein the step of processing a groove within a welding metal made of the buttering material comprising processing a plate thickness of the weld to be smaller than a plate thickness of one of the parent materials and the dummy material.

29. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to claim 12, wherein the dummy material has a heat capacity of the same level as that of the parent material.

30. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to any one of claim 12, wherein the dummy material has the same chemical composition as that of the parent material.

31. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to claim 12, wherein in the butt welding step, a bottom of the dummy material is butted to overlap in length within a range of 3 to 15 mm along a bottom surface of the parent materials from a groove center.

13. A manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds, the dissimilar metal welds being formed by welding two parent materials having at least one of different compositions and different refining conditions, through a buttering for alleviating mismatch between one of the different compositions and the different refining conditions of the two members and through a welded metal for joining one of the parent materials and the buttering, the manufacturing method comprising at least the steps of:

performing butt welding on a dummy material formed by increasing a groove depth by providing a member on an opening side of a welding groove, and on the parent materials, by using the buttering; and

processing a groove within a welding metal formed of the buttering.

14. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to claim 13, wherein the dummy material has a heat capacity of the same level as that of the parent material.

15. The manufacturing method of one of dissimilar metal welds and a turbine rotor including the dissimilar metal welds according to of claim 13, wherein the dummy material has the same chemical composition as that of the parent material.