Ni-15Cr-8Fe-6Nb合金におけるδ相の析出と成長
1992 年 78 巻 11 号 p. 1745-1752
詳細
1992 年 78 巻 11 号 p. 1745-1752
The precipitation and growth behaviors of δ phase in Ni-base superalloy, modified Inconel X-750 type alloy ( X-750 M), have been investigated mainly by opticaland transmission electron microscopy.
The morphology, the crystallography and equilibrium transformation temperatures of the cellular and the Widmanstätten precipitation of γ phase to δ+ γ phases have been discussed.
The obtained results are as follows:
(1) The hardness of X-750 M aged in various conditions closely related to the size and the quantity of γ" and δ precipitates.
(2)The orientation relationship between γ and δ phase in the cellular and the Widmanstätten precipitates was:
{111}γ//{010}δ <110>γ//<100>δ.
(3) The interlamellar spacing in each precipitation mode was inversely proportional to the degree of undercooling below the equilibrium transformation temperature of γ phase to δ+ γ phases.
(4) According to the theory of diffusion controlled eutectoidal growth, the equilibrium transformation temperatures of the cellular and the Widmanstätten precipitation were estimated to be 1279 and 1313 K, respectively. These temperatures were consistent with the experimental tendency.
