Self-lubricating piston ring material for internal combustion engine and piston ring
US6527879B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2001 |
| Grant date | Mar 4, 2003 |
| Priority date | — |
| Expiry date | Jun 20, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16J9/26
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
There are disclosed a piston ring material and a piston ring both having such superior properties contradictory each other as the sliding property required in a piston ring and the mechanical properties of a steel wire material subjected to a manufacture process. The piston ring material or the piston ring consists essentially, by mass, of not less than 0.3% but less than 0.8% C, 0.1 to 3.0% Si, 0.1 to 3.0% Mn, 0.03 to 0.3% S, 0.3 to 6.0% Cr, preferably 3.0 to 6.0% or 0.3 to 1.0% Cr, 0 to 3.0% Cu, and the balance Fe, and the distribution state of sulfide inclusions with a maximum diameter/minimum size≧3 observed on structure parallel to the outer peripheral surface of the formed piston ring is such that an intersecting angle made between straight lines passing the maximum size of two of the sulfide inclusions is not more than 30 degrees. Further, the area ratio of nonmetallic inclusions occupying the structure is 2.0% or less, or in addition to the above-described composition, at least one selected from the group consisting of 0.01% or less of Ca, 0.5% or less in total of one or more of V, Nb, Ti, and 1.5% or less of Al is contained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.