Patent ID: 7614849

Claim:
A steam turbine component assembly, comprising: an inner housing having a surface exposed to a high temperature operating environment and an opposite surface exposed to a lower temperature operating environment where the temperature difference between the higher and lower temperature environments is at least 200° C.; an outer housing that surrounds the inner housing; and a thermal barrier coating having a pre selected porosity, thickness or material composition applied to the higher temperature surface effective to control thermal deformation of the inner and outer housings relative to each other, wherein the thermal barrier coating is applied to a valve housing, wherein the thermal barrier coating is applied to a housing comprising a substrate comprising an iron-base, nickel-base or cobalt-base alloy, wherein the thermal barrier coating comprises zirconium oxide or titanium oxide, wherein the thermal barrier coating is applied to a housing having an intermediate protective layer arranged between the housing and the thermal barrier coating, the intermediate protective layer comprising the composition of MCrAlX where M is at least one element selected from the group consisting of nickel, cobalt or iron and X is yttrium or silicon or at least one rare earth element wherein the intermediate protective layer consists of: 11.5 wt %-20 wt %, chromium, 0.3 wt %-1.5 wt %, silicon, 0.0 wt %-1.0 wt %, aluminum, and remainder iron.