High modulus wear resistant gray cast iron for piston ring applications
AssigneeFederal-Mogul Corporation
InventorHeron Gekonde
Life of this patent
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Abstract
A piston ring formed of cast iron provides improved machinability and exceptional performance and minimum costs. The cast iron includes 2.2 to 2.9 wt. % carbon, 3.2 to 4.2 wt. % silicon, 0.75 to 1.25 wt. % copper, 1.0 to 1.5 wt. % manganese, 0.09 to 0.15 wt. % sulfur, not greater than 0.2 wt. % phosphorous, and an average carbon equivalent of 3.8. The cast iron preferably includes a matrix of martensite with MnS and carbides dispersed therein. The matrix is also preferably free of ferrite, austenite, and steadite. The cast iron is formed by casting, autenitizing, quenching, and tempering the alloy.
Claims14
A piston ring formed of a cast iron, comprising, in weight percent (wt. %) of said cast iron:
- 2.2 to 2.9 wt. % carbon,
- 3.2 to 4.2 wt. % silicon,
- 0.75 to 1.25 wt. % copper,
- 1.0 to 1.5 wt. % manganese,
- 0.09 to 0.15 wt. % sulfur, and
- not greater than 0.1 wt. % phosphorous, based on the total weight of said cast iron;
- and
- wherein said cast iron comprises a matrix including at least one of martensite and bainite, and including manganese sulfide (MnS) and carbides dispersed throughout said matrix.
Dependencies are inferred from the claim text.