金型鋳造された球状黒鉛鋳鉄のチル化傾向に及ぼす球状化剤含有マグネシウム量の影響

抄録

  Effect of magnesium contents alloyed in the spheroidizing additives on chilling tendency of spheroidal graphite cast iron were studied with the metal molds of 20, 25 and 30mm in diameter. Chilling tendency was moderated when magnesium contents alloyed in additives was reduced with reducing the treatment temperature from 1500°C to 1400°C. However, in the case of the additives of less than 5% Mg, chilling tendency treated at 1350°C was greater than treated at 1400°C.
  The chilling tendency increased with increasing magnesium vapour pressure calculated with equation of P. K. Trojan, and remarkable chill formation occurred in case of 1500°C treatment with Mg vapour pressure of more than 2 atm. The least chilling tendency was, on the other hand, observed at 1400°C treatment with Mg vapour pressure of 0.3-0.5 atm.