Steam turbine rotor having graded weldments

摘要

This invention provides stream turbine components, such as rotor disc, which include a ring member comprising a low alloy ferrous base metal having less than about 6 wt. % alloy ingredients and a ferrous graded layer disposed on the ring member which includes a plurality of layered weldments having an increasing weight percentage of a layering metal containing Cr. Disposed on the graded layer of this invention is a Cr-containing steeple alloy disposed on the graded layer for optimizing a life extending property of the steeple region of the turbine component.