Effect of Grain Size on Mechanical Properties of Ni-Fe Base Superalloy for Advanced USC Turbine Rotor Materials Free

The effect of grain size after solution treatment on the mechanical properties of FENIX-700, including its cooling rate, was investigated. In addition, the dependance of precipitation observed at grain boundaries on the heat treatment conditions was also discussed on the basis of the results of microstructure observations. It was confirmed that the tensile ductility, the creep rupture ductility, and the absorbed energy decreased as the grain size increased. The creep rupture strength, in contrast, increased remarkably as the grain size increased. The tensile strength increased as the cooling rate increased. Experimental results showed that satisfactory mechanical properties would be obtained for a grain size of ASTM G.S.No. 1.0-3.0.