Ever increasing demands for lower gas turbine operating costs have led to the need for longer lasting components. This in turn, requires the availability of alloys which are reliable to such long lifetimes. In the mill produced condition, most alloys have desirable microstructures and mechanical properties. However, after exposure to the harsh temperatures found in gas turbine engines, the microstructures of most alloys will begin to change. The effects on the mechanical properties of such microstructural changes can range from mild deterioration to significant degradation. In this paper, the effects of thermal exposures at temperatures from 1200 to 1600°F for durations up to one year on the mechanical properties of three wrought gas turbine alloys will be reported. The alloys will include HAYNES® 188 alloy (Co-Ni-Cr-W), HAYNES 230® alloy (Ni-Cr-W), and HAYNES HR-120® alloy (Fe-Ni-Cr-Nb-N).
Surface layer quality in compressor titanium blades at multiaxes deep grinding