二相ステンレス鋼の結晶粒成長(結晶粒成長)(<特集>再結晶・粒成長)

概要

論文の詳細を見る
Grain radii of α and γ phases in duplex stainless steels annealed at 1000-1200℃ have been measured, and the growth mode of α and γ grains has been investigated. The results obtained are as follows : (1) The grain size of duplex stainless steels is much finer than those of α and γ single phase stainless steels. This is caused by the facts that α and γ grains restrict the growth of partner's grains by the pinning effect, and the growth mode of both grains becomes similar to the Ostwald ripening. (2) In α-rich duplex stainless steels, the grain growth of both α and γ phases is controlled by volume diffusion in the α phase, and is described by the third power law (R^^-^3-R^^-^3_0=k_3t). (3) In γ-rich duplex stainless steels, the grain growth is controlled by the diffusion along grain boundary of γ phase, and is expressed by the fourth power law (R^^-^4-R^^-^4_0=k_4t). If the volume fraction of α phase is smaller than 0.1, however, α grains are mostly located within γ grains, and the grain growth is controlled by volume diffusion, obeying the third power law. (4) The grain radius of major phase, R^^- is related to the grain raius, γ^^- and the volume fraction of minor phase, f through the Zener's relation (R^^-=β γ^^-/f). The coefficient β is nearly 4/9, which has been proposed by HELLMAN and HILLERT.
社団法人日本鉄鋼協会の論文
1984-11-01