Method for preparing corrosion-resistant zinc-cobalt surfaces
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jun 11, 1991
Grant Date -
N/A
app pub date -
Jul 31, 1989
filing date -
Jul 31, 1989
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
The present invention relates to compositions and methods for providing a corrosion-resistant coating on a zinc-cobalt alloy surface said surface with a hexavalent chromium-containing treatment solution. In a preferred embodiment, the solution comprises: (a) about 2 to about 30 g/l of CrO.sub.3 ; (b) 0 to about 25 g/1 of dichromate ion such that the total Cr.sup.+6 is about 1 to about 35 g/l; (c) about 0.5 to about 20 g/l of NH.sub.4.sup.+ ; and (d) about 5 to about 30 g/l of formate ion. The solution additionally comprises: (e) about 2 to about 25 g/l of Cl.sup.- ; and has a pH controlled by the addition of HCl or NaOH of about 0.8 to about 2.5. The solution is substantially-free of sulfate, chlorate and nitrate. In one embodiment, the formate is optional and low levels of Cr.sup.+6 are employed.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully