Spheroidal graphite cast iron and method of producing spheroidal graphite cast iron, and vehicle undercarriage parts
AssigneeRiken
InventorTomoyuki TOBITA
Life of this patent
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Abstract
A spheroidal graphite cast iron having a chemical composition 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; and a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite. Part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.
Claims9
A spheroidal graphite cast iron comprising:
- a chemical composition 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;
- and
- a structure in which a ferrite layer encloses spheroidal graphite crystallized out in a matrix of pearlite,
- wherein in the structure, part of the pearlite is extended from the matrix side to the spheroidal graphite side to divide the ferrite layer at one or more areas.
A method of producing a spheroidal graphite cast iron, comprising:
- performing soaking on a cast material having a chemical composition 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%,
- Mn:
- 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.
Dependencies are inferred from the claim text.