More creep resistant turbine rotor, and procedures for repair welding of low alloy ferrous turbine components
AssigneeWestinghouse Electric Corp.
InventorsRobert E. Clark, Dennis R. Amos
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Abstract
A more creep resistant turbine rotor and novel methods for repairing worn surfaces of Cr-Mo-V steam turbine components are disclosed. These methods include specified alloy compositions and welding procedures that minimize weld stresses and cracking. These alloys exhibit improved creep and fatigue properties and are preferably deposited using a gas tungsten arc welding procedure. Bead sequencing, cooling side plates and the use of run-off tabs are also disclosed for minimizing welding defects in turbine rotors and discs.
Claims5
In a steam turbine system having a rotor comprising a Cr-Mo-V alloy having less than about 6 wt. % alloying ingredients for securing blades, the improvement comprising:
- a plurality of layered weldments, including at least two spaced apart weldments, disposed on said rotor, each of said weldments consisting essentially of a ferrous alloy comprising about 7.0 to 11.0 wt. % Cr and about 0.1 to 3.0 wt. % Mo said weldments forming a build-up on said rotor which can be machined into a blade-retaining device, said rotor being relatively free of cracking resulting from the welding process.
Dependencies are inferred from the claim text.