複合脱酸処理による球状黒鉛鋳鉄の薄肉化に及ぼす酸素及び硫黄の影響

抄録

  It has been reported in present paper that 2mm thick section can be made without chill structures in vacuum depressurization processing. This paper describes a method to shorten the decompression processing time. Holding time in vacuum was decreased within five minutes with a addition of CaC₂ into molten iron in vacuum in this study. Total oxygen, dissolved oxygen and sulfur content in melt were decreased rapidly at a time. The greatest nodule count of 2mm thickness specimen was obtained with a addition of 1%CaC₂ and 2mm thickness specimen was produced without chill. When 2%CaC₂ was added into the melt, chill structure was observed in 2mm thickness specimen. The results demonstrated that there is an appropriate amount of CaC₂ addition.