クロマイト正方晶化機構について

概要

論文の詳細を見る
In order to investigate the formation mechanism of the tetragonal chromite formed in molten Fe-Cr alloys, the authors have studied the influence of oxygen partial pressure and temperature on the axial ratio of the tetragonal chromite formed from the solid solutions between Fe_2O_3 and Cr_2O_3 in an atmospheres of various CO_2-H_2 mixtures or H_2 gas. The results obtained are summarized as follows : 1) The oxide coexisting with molten Fe-Cr alloy at 1600℃ varies from cubic, via tetragonal chromite, to Cr_2O_3 in accordance with oxygen partial pressure. When the mixing ratio of CO_2-H_2 is 1/(16) or 1/(18), the following three phases equilibrate. They are tetragonal chromite (c/a=0.95), sesquioxide and molten Fe-Cr alloy. 2) Single phase region of chromite becomes enlarged with temperature rise and the chromium ion in chromite increases. Tetragonal chromite having axial ratio c/a=0.90 was obtained with H_2 reduction at 1850℃. 3) The following equations were derived to lattice parameters of tetragonal chromite. α=α_0/γ・{(1+2γ^2)/3}^<1/2> and c=α_0{(1+2γ^2)/3}^<1/2> where γ is tetragonality (c/a) and a_0 is 8.37Å. 4) The determination of Cr^<2+> was tried with chemical means, but it was unadequate to confirm quantitatively.
社団法人日本鉄鋼協会の論文
1970-05-01