研究論文
ガラス処理による Fe‐C，Fe‐C‐Si 合金の過冷凝固
1990 年 62 巻 1 号 p. 31-36
詳細
1990 年 62 巻 1 号 p. 31-36
Glass encapsulated method is a well known technique for getting large undercooling of bulky melt. Experiments were carried out to clarify nucleous agents for solidification of cast iron. Pure Fe-C and Fe-C-Si alloys were prepared from electric iron, electrode graphite (5N-purity) and 5N-silicon. Alkali-free glass and sodalime glass were used for encasing the melt. After the experiments, the crystallization of glass were inspected by micro X-ray diffraction.
The following results were obtained.
(1) Silicon in the alloys increases the undercooling of primary γ-phase. Especially, in case of alkali-free glass treatment for Fe-C melt, the undercooling is not recognized completely.
(2) The crystallization of glass is evidently recognized at the treatments in which the undercooling were small or could not found. Silicon in melt decreases the crystallization of the glass.
(3) Cristbalite crystallized in the glass acts as a heterogeneous nuclei for γ-iron.
(4) The melt encased by alkali-free glass, the undercooling of graphite eutectic temperature becomes larger than that of sodalime glass, and the eutectic solidification transits more easily from Fe-graphite system to Fe-Fe3C system.
