フェイディング過程における球状黒鉛鋳鉄の黒鉛形状に及ぼすけい素接種の影響

抄録

  With a view to investigating the effect of silicon on the spheroidization of graphite in spheroidal graphite cast iron, graphite form was changed while holding molten iron at high temperature, i.e. fading process in both cast iron with or without post-inoculation at given holding time of molten iron, the variation in the graphite form was observed with an image analyzing computer, following which silicon segregation was studied by potentio-static electrolytic etching. The position of eutectic crystallization in boundaries.
  It has been clarified that the deterioration of graphite form appeared mainly on the primary graphite deposited at the matrix with high silicon content. It was also clarified that when sheroidity remained at a high level, the post-inoculation accelerated the spheroidization of graphite, but when it was at a low level C/V graphites formed. Moreover, it seems that fine graphites showing spheroidal form crystallize at eutectic cell boundaries with low silicon content, which are locations of the last stage of solidification. Subsequently, it has been concluded that the graphitization was accelerated by silicon inoculation, but the shape of graphite depended on both the difference of spheroidity and the difference of it being either primary or eutectic graphite.