Claims
- 1. A steel sheet including a composite coating, the composite coating consisting of a metallic inner layer and an outer silicate layer,
- said metallic layer being an alloy of lead and tin,
- said silicate layer including a metal salt and a surface film of silane,
- said metal salt being from the group consisting of barium nitrate, calcium nitrate and strontium nitrate, and
- said silicate layer having a thickness of at least about 2 nm thereby minimizing rusting of the sheet.
- 2. A steel sheet including a composite coating, the composite coating consisting of a metallic inner layer and an outer silicate layer,
- said metallic layer being an alloy of lead and tin,
- said silicate layer including a metal salt and a surface film of silane,
- said metal salt being from the group consisting of barium nitrate, calcium nitrate and strontium nitrate,
- said silicate layer having a thickness of at least about 2 nm, and
- said silane film having a thickness of at least about 1 nm thereby minimizing rusting of the sheet.
Parent Case Info
This is a divisional of copending application Ser. No. 07/632,858 filed on Dec. 24, 1990, incorporated herein by reference, now U.S. Pat. No. 5,108,793.
US Referenced Citations (4)
Number |
Name |
Date |
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3415613 |
Ault et al. |
Dec 1968 |
|
4407899 |
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Oct 1983 |
|
4411964 |
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Oct 1983 |
|
4419137 |
Cayless et al. |
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|
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Country |
50-01937 |
Jan 1975 |
JPX |
52-50940 |
Apr 1977 |
JPX |
59-07079 |
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JPX |
Non-Patent Literature Citations (3)
Entry |
Harold Knight, "Lead Coatings on Steel", Nov. 1944, Reprint from Metals and Alloys. |
van Ooij and Sabata, "Development of an Inorganic Non-Chromate Post-Rinse Treatment for the Stabilization of Phosphate Conversion Coatings on Cold-Rolled and Electrogalvanized Steels", International Conference on Corrosion Control by Organic Coatings, Cambridge, UK, 11-14 Apr. 1989. |
van Ooij & Sabata, "A Research Look at the Effect of Pretreatment on the Corrosion Resistance of Automotive Sheet Steels", Pretreat '90, pp. 5-1 to 5-26, Cincinnati. Ohio, Nov. 6-8, 1990. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
632858 |
Dec 1990 |
|