WAN Wen-juan
,
HAN Guang-wei
钢铁研究学报(英文版)
The influence of aging treatment on precipitation behavior of η phase in a new Ni-Co-Cr fastener superalloy, AEREX350, was investigated by means of optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The precipitation behavior of η phase with two kinds of morphologies in this material was found to be sensitive to the temperature and time of aging treatment. Time temperature transformation curves of these two η phase were both achieved. Furthermore, diffraction patterns revealed the semi-coherent orientation relationship between η phase and γ matrix. This approach may be used to optimize the microstructure of the alloy for excellent mechanical properties.
关键词:
precipitation;η phase;aging
WAN Wen-juan
,
HAN Guang-wei
钢铁研究学报(英文版)
The microstructure of hot-rolled AEREX350 alloy under various heat treatments was investigated by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that with increasing temperature, η phase precipitated firstly at grain boundaries in parallel at 800℃ and then began precipitating within grains at about 980℃. The η phase precipitating at grain boundaries played a role on preventing the migration of grain boundaries, and that precipitating within grains would develop as Widmanstätten structure with further increasing temperature. Both η phase dissolved at the temperature between 1085℃ and 1095℃, resulting in grain growth promptly due to release of pinning effect on grain boundaries. γ′ phase precipitated during the process of air cooling after hot-roll, and dissolved at temperature between 1010℃ and 1020℃.
关键词:
heat treatment;microstructure;precipitate;AEREX350
