Cast iron and piston ring
AssigneeRiken
InventorTetsuya Miwa
Life of this patent
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Abstract
There is provided a piston ring, which has improved wear resistance and seizure resistance, and which does not abrade the cylinder liner made of flaky-graphite cast iron having a hardness of from HRB 85-95. The composition: C: 3.0-3.5%; Si: 2.2-3.2%; Mn: 0.4-1.0%; P: not more than 0.2%; S: not more than 0.12%; Cr: 0.1-0.3%; V: 0.05-0.2%; Ni: 0.8-1.2%; Mo: 0.5-1.2%; Cu: 0.5-1.2%; and B: 0.05-0.1% are contained in the cast iron. The structure: from 2 to 20% by area of the undissolved carbides and fine graphite are dispersed in a matrix consisting of either tempered martensite or bainite or both. The hardness: HRC 32-45.
Claims4
A cast iron, which has a composition containing C:
- 3.0-3.5%;
- Si:
- 2.2-3.2%;
- Mn:
- 0.4-1.0%;
- P:
- not more than 0.2%;
- S:
- not more than 0.12%;
- Cr:
- 0.1-0.3%;
- V:
- 0.05-0.2%;
- Ni:
- 0.8-1.2%;
- Mo:
- 0.5-1.2%;
- Cu:
- 0.5-1.2%;
- and B:
- 0.05-0.1%, by weight ratio, the balance being essentially Fe and unavoidable impurities, in which cast iron from 2 to 20% by area of the undissolved carbides and fine graphite are dispersed in a matrix consisting of either tempered martensite or bainite or both, and which cast iron has a hardness of from HRC 32-45.
Dependencies are inferred from the claim text.