Ni-15Cr-8Fe-6Nb合金におけるγ''相の析出と成長
1992 年 78 巻 4 号 p. 650-657
詳細
1992 年 78 巻 4 号 p. 650-657
The nucleation and growth behavior of disc-shaped ordered γ''-phase and spherical ordered γ'-phase in Ni-base superalloys, modified Inconel X-750 type alloy (X-750M) and Inconel X-750 type alloy (X-750), has been investigated mainly by micro-Vickers hardness test and transmission electron microscopy. The hardness of X-750M aged in various conditions closely related to the size and the quantity of γ'' and δ-phases. Increasing the Nb content while decreasing the (Al+Ti) content in the alloys promoted the formations of γ'' and δ-phases. The growth kinetics of γ''precipitates in the region free of δ-phase followed the prediction of Lifshitz-Slyozov-Wagner theory of diffusion controlled growth at all aging temperatures. The activation energy of the growth of γ'' precipitates in X-750M was estimated to be 397 kJ/mol.
