Materials Science Forum, Vol.426-4, 761-766, 2003
The effect of cold rolling on the grain boundary character and creep rupture properties of INCONEL alloy 718
In order to evaluate the effects of sheet processing on the grain boundary character distribution (GBCD) of INCONEL(R) alloy 718 (IN 718), electron backscattered diffraction (EBSD) mapping was performed on samples cold rolled between 0-40%. Increased cold rolling increased the fraction of low-angle boundaries at the expense of. the coincident site lattice boundaries. The tensile-creep rupture life (T-r) and elongation-to-failure (epsilon(f)) were evaluated at 649degreesC and 758MPa, and the data indicated that increased cold rolling significantly increased both the T-r and epsilon(f) values. In addition the GBCD and room-temperature (RT) tensile properties were evaluated for superplastically formed INCONEL(R) alloy 718 (IN 718SPF). The tensile results indicated the exceptional strength of the fine-grained IN 718SPF material, however the GBCD parameters were intermediate to those of the 10% and 20% cold rolled IN 718 materials.