Metal member with chromate coat, spark plug with chromate coat and manufacturing methods thereof
US6538365B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2001 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Feb 26, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C2222/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A metal member 55 (with a zinc plating layer 56 for prevention of corrosion) having a sliding expected surface that is expected to slide with the other member is immersed into a chromating bath containing a mixture of trivalent chromium salt and a complexing agent for trivalent chromium. And a chromate coat 57 having a film thickness of 0.2 to 0.5 &mgr;m and composed of trivalent chromium at 95 mass % or more of chromium component contained is formed at least on the sliding expected surface. Thereinafter, its chromate coat 57 is subjected to the heat treatment at temperatures from 85 to 255° C., thereby enhancing the sliding property of the chromate coat 57. As a result, the metal member 55 with chromate coat can be easily slid with the other member.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.