γ型 Fe-Co-Cr-Ni 基耐熱合金の時効組織および機械的性質との関連性 : γ型耐熱合金の焼戻過程に関する研究 V

概要

論文の詳細を見る
The as-aged structures of an Fe-Co-Cr-Ni base heat-resisting alloy LCN-155 were examined by metallographic methods-both optical and electronic. Mechanical properties at room temperature were then measured and correlated with the as-aged microstructure. The experimental results obtained were as follows : In a lower-temperature or shorter-time aging, first of all, M_<23>C_6 carbide precipitated at the grain boundaries, resulting in a marked decrease in ductility and there followed formation of very fine nuclei of M_<23>C_6 along the cleavage planes within matrix, resulting in a progressive increase of strength and hardness. But in a higher temperature or longer time aging, the dispersion state of the intragranular precipitates which correlated with the mechanical properties was affected with the transition of precipitates. With an alloy which only one-phase (M_<23>C_6) precipitated, the intragranular precipitates grew along the cleavage planes and it showed a continuous localized structure. However, with an alloy in which two more phases (M_<23>C_6 and X phase) precipitated and transfered from one phase to another (M_<23>C_6⇾X phase) during aging, the cleavage precipitates was redistributed due to the carbide reaction and it showed a continuous (homogeneous) structure. It was concluded that this redistribution of precipitates due to carbide reaction would cause excellent mechanical properties.
社団法人日本鉄鋼協会の論文
1962-04-01