Superalloy material with improved weldability
AssigneeSiemens Westinghouse Power Corporation
InventorsDavid B. Allen, Gregg P. Wagner, Brij B. Seth
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Abstract
A fusion weldable superalloy containing 0.005-0.5 wt. % scandium. In one embodiment, the superalloy may have a composition similar to IN-939 alloy, but having added scandium and having only 0.005-0.040 wt. % zirconium. A gas turbine component may be formed by an investment casting of such a scandium-containing superalloy, and may include a fusion weld repaired area. A scandium-containing nickel-based superalloy coated with an MCrAlY bond coat will have improved cyclic oxidation resistance due to the sulfur-gettering effect of the scandium.
Claims20
A nickel-based superalloy consisting essentially of the composition by weight percent of:
- chromium 22.0-22.8%;
- cobalt 18.5-19.5%;
- titanium 3.6-3.8%;
- aluminum 1.8-2.0%;
- tungsten 1.8-2.2%;
- niobium 0.9-1.1%;
- tantalum 1.3-1.5%;
- carbon 0.13-0.17%;
- zirconium 0.005-0.040%;
- boron 0.004-0.014%;
- iron 0.5% maximum;
- sulfur 0.005% maximum;
- silver 0.0005% maximum;
- bismuth 0.00005% maximum;
- silicon 0.2% maximum;
- manganese 0.2% maximum;
- lead 0.005% maximum;
- nitrogen 0.005% maximum;
- scandium 0.005-1.0%;
- and the balance nickel.
A fusion weldable alloy comprising:
- at least 45% by weight of at least one of the group of nickel and cobalt;
- 18-37% by weight chromium;
- at least 0.005% by weight scandium;
- and less than 0.04% by weight zirconium.
Dependencies are inferred from the claim text.