High temperature steam oxidation behaviors of Ni-base single crystal alloy CMSX-4 for gas turbine rotor blades

摘要

As one of the elemental tests for the development of 1700℃ class hydrogen fueled combustion turbine system under the World Energy Network (WE-NET) program, high temperature oxidation behaviors of single crystal (SC) alloy CMSXA and thermal barrier coating (TBC) were conducted at the temperature of 600℃ -1000℃ in the air and steam environments. Comparable weight gains due to the oxidation in the air and steam were observed at boot, but below this temperature maximum weight gain was observed at 800℃ in the steam whereas that in the air continuously decreased as the test temperature decreased. The scale model SC rotor blade with TBC which was tested in the hydrogen-oxygen combustion wind tunnel with practical steam condition of 1700℃ (max.) and 2.44 MPa for 186 mm were destructively evaluated, the result of which showed no symptom of steam oxidation due to increase of metal temperature over the designed one.