Patent ID: 11946109
Assignee: RIKEN
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 3:
4. A method of producing the spheroidal graphite cast iron of claim 1, comprising:
performing soaking on a cast material having a chemical composition consisting of:
C: 3.0% to 4.0%,
Si: 2.0% to 2.4%,
Cu: 0.20% to 0.50%,
Mn: 0.15% to 0.35%,
S: 0.005% to 0.030%,
Mg: 0.03% to 0.06%, each by mass, and
the balance being Fe and inevitable impurities,
where Mn and Cu are contained at 0.45% to 0.75% in total,

by retaining the cast material at temperatures of 800° C. or more and 850° C. or less for a time of more than 30 min and 240 min or less; and
cooling the cast material after the soaking.