Carbon and Titanium Effect on Tensile Behavior of Aged A286 Nickel-Iron Based Superalloy

Abstract

A286 nickel-iron based superalloy used in high temperature applications. Age hardening is done to enhance the creep behavior which is much affected by TiC and eta (ⴄ (Ni3Ti)) phases. Effect of carbon and titanium (0.02C-2.46Ti, 0.04C-2.54Ti, 0.05C-2.58Ti, and 0.06C-2.62Ti) on tensile behavior of aged A286 superalloy is systematically investigated via TiC and ⴄ (Ni3Ti) phases. It has been revealed that carbon and titanium contents are in proportional to nucleation of TiC and eta phases in the austenitic matrix of this alloy. Precipitation of these phases enhanced yield strength from 354MPa to 501MPa and ultimate tensile strength (UTS) 543MPa to 651MPa. However, plasticity decreased nearly 4%. Fracture topography showed that the ductile transgranular fracture in low C-Ti alloys are due to TiC particles, whereas in high C-Ti alloys fracture nature is found brittle intergranular due to eta phases.