Spark plug, metal shell for spark plug, and method of manufacturing spark plug
US8421324B2 · kind B2 · utility
2Cited by
2References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 16, 2010 |
| Grant date | Apr 16, 2013 |
| Priority date | — |
| Expiry date | Sep 16, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12611
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Provided is a spark plug that is excellent not only in salt resistance but also in stress corrosion cracking resistance. The spark plug includes a metal shell covered by a composite layer including a nickel plating layer and a chromate layer formed on the nickel plating layer. The chromate layer has a film thickness of 2 to 45 nm and Cr element concentration of not more than 60 at % and contains Ni in addition to Cr.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.