Hot ductility behavior of Incoloy901 superalloy in the cast and wrought conditions

Abstract

Abstract Hot ductility was investigated in Incoloy901 using hot tensile testing over a temperature range of 900 to 1 200 °C and at strain rates of 0.01 to 1 s−1, in the cast and wrought conditions. Maximum ductility was detected in the cast and wrought conditions at temperature ranges of 1 000 to 1 050 °C and 1 000 to 1 100 °C, respectively. More voids were seen at the fracture surface of the wrought specimens compared to the cast ones. At 950 °C, the formation of large and non-homogeneous voids at the fracture surface, as well as the appearance of transgranular and intergranular cracks in the wrought specimen, support moderate ductility of the alloy. Microstructural analysis does not support the occurrence of dynamic recrystallization in the cast specimens. In contrast, dynamic recrystallization in the wrought specimens at the region of maximum hot ductility promoted diffusion, leading to ductile fracture. At temperatures higher than the maximum ductility range, the formation of intergranular cracks resulted in a remarkable decline in ductility.