High Temperature Creep, Fatigue and Creep/Fatigue Interaction Behavior of γ' Strengthened Austenitic Iron-Base Superalloy

Abstract

A new modified Nb-containing A-286 γ' strengthened austenitic Fe-base superalloy (14Cr- 28Ni-1.5Mo-1W-2Ti-Nb-Al) designated as GH871 in China characterizes with high level of tensile, stress rupture and low cycle fatigue properties at 650°C. However, the stress rupture ductility is low and the crack propagation rates at 650°C creep or creep/fatigue interaction conditions are high. For ductility and crack propagation behavior improvement vacuum melted GH871 can still keep its high strength level, also raise stress rupture ductility and simultaneously to decrease crack propagation rates at 650°C. Our results support GH871 to be used as a disk material in high temperature industry.