Patent US4221832A successfully refreshed from Google Patents.
US4221832A
Expired / Lapsed
US
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Surface treatment of metal strip
Assignee: Centre de Recherches Metallurgiques CRM ASBL
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Filing: 1979-03-13
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Granted: 1980-09-09
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Expires: 1999-03-13
Abstract
Abstract Metal strip, particularly steel strip, is heated above 300° C. and immersed in a coating bath whose temperature is at least 80° C. and which contains at least one metal salt, the strip being coated with a metal layer, e.g. Ni-based or Cr-based, by the coating bath.
Inventors
- 👤 Paulus Philippe
- 👤 Leroy Vincent
- 👤 Henri Graas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:42
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/38; C21; C21D; C21D1/00; C21D1/56; C21D1/60; C21D9/00; C21D9/46; C21D9/48; C23; C23C; C23C18/00; C23C18/16; C23C18/1601; C23C18/1633; C23C18/1646; C23C18/165; C23C18/1689; C23C18/1692; C23C18/31; C23C18/32; C23C18/34; C23C18/36; C23C18/54
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
65 words
A process for surface-treating a metal strip and coating it with a metal layer, comprising the following steps; (a) heating the strip to a temperature above 300° C.; and (b) immersing the strip in an aqueous coating bath having a temperature of at least 80° C. and containing at least one metal salt, the strip being coated with a metal layer by the coating bath.
Claim 2
Dependent Claim
65 words
A process for surface-treating a metal strip and coating it with a metal layer, comprising the following steps; (a) heating the strip to a temperature above 300° C.; and (b) immersing the strip in an aqueous coating bath having a temperature of at least 80° C. and containing at least one metal salt, the strip being coated with a metal layer by the coating bath.
Claim 3
Dependent Claim
14 words
A process as claimed in claim 1, in which the metal layer is nickel-based.
Claim 4
Dependent Claim
112 words
A process as claimed in claim 2, in which the coating bath contains: at least one nickel salt in a concentration within a range from 5 to 50 g/l; a reducing agent in a concentration greater than 0.1 mole/liter; a buffer component comprising at least one substance selected from the group consisting of an alkali salt of a dibasic organic acid having the general formula CO 2 H--(CH 2 ) n --CO 2 H, in which n=1 to 4, sodium hydroxyacetate (NaC 2 H 3 O 3 ), sodium acetate (CH 3 CO 3 Na.3H 2 O), alkali salts of glycolic acid (HOCH 2 COOH), citric acid, lactic acid, and propionic acid.
Claim 5
Dependent Claim
32 words
A process as claimed in claim 2, in which the coating bath comprises a solution for displacement-nickelling, containing a nickel salt and an acid and having a pH of 2 to 5.
Claim 6
Dependent Claim
15 words
A process as claimed in claim 2, in which the strip is a steel strip.
Claim 7
Dependent Claim
71 words
A process as claimed in claim 2, the process being carried out in the course of a thermal treatment in which the strip is introduced into a hot aqueous solution to cool it rapidly after recrystallization treatment and in which it is optionally introduced subsequently into another hot aqueous solution to effect final cooling, after thermal ageing treatment, at least one of the said solutions being used as a nickelling bath.
Claim 8
Dependent Claim
44 words
A process as claimed in claim 2, for forming a layer of low thickness and high nickel content, in which a single immersion lasting from 0.5 to 40 seconds is effected, counted from the instant when the temperature of the sheet reaches 150° C.
Claim 9
Dependent Claim
41 words
A process as claimed in claim 2, the process being carried out in the course of a thermal treatment comprising quenching in a hot aqueous solution followed by ageing, the process being effected after ageing to avoid diffusion of the nickel.
Claim 10
Dependent Claim
43 words
A process as claimed in claim 2, the process being carried out in the course of a thermal treatment comprising quenching which follows the heating for recrystallization, but without tempering, the quenching comprising the immersion of the strip in the said coating bath.
Claim 11
Dependent Claim
34 words
A process as claimed in claim 2, for forming a precipitation-hardened metal based layer, in which the immersion in the coating bath is followed by reheating to a temperature of 300° to 500° C.
Claim 12
Dependent Claim
101 words
A process as claimed in claim 2, in which the metal strip is steel strip for deep drawing, the process comprising the following steps: (a) heating to a temperature above the recrystallization temperature and holding at this temperature, under a protective atmosphere; (b) quenching in the said coating bath, the bath being at a temperature of at least 80° C., with a residence time of 0.5 to 40 seconds at a temperature below 150° C.; (c) rinsing of the strip after it leaves the bath; and (d) ageing the strip by heating it to a temperature of 300° to 500° C.
Claim 13
Dependent Claim
21 words
A process as claimed in claim 2, further comprising forming a layer of copper which enhances adhesion of a subsequent coating.
Claim 14
Dependent Claim
21 words
A process as claimed in claim 12, in which the copper layer is formed following the formation of a nickel-based layer.
Claim 15
Dependent Claim
65 words
A process as claimed in claim 1, further comprising effecting a chromatizing treatment in a solution containing Na 2 Cr 2 O 7 or CrO 3 in a concentration of 10 to 100 g/l, in the presence of SO 4 ions in a concentration substantially 100 times lower, and with a current density of the order of 10 A/dm 2 , the strip being cathodic.
Claim 16
Dependent Claim
25 words
A process as claimed in claim 14, in which the chromatizing treatment is effected during first cooling and/or during second cooling or following the latter.
Claim 17
Dependent Claim
14 words
A process as claimed in claim 1, in which the metal layer is chromium-based.
Claim 18
Dependent Claim
17 words
A process as claimed in claim 16, in which the coating bath contains chromic acid in solution.
Claim 19
Dependent Claim
19 words
A process as claimed in claim 17, in which the coating bath also contains at least one reducing agent.
Claim 20
Dependent Claim
18 words
A process as claimed in claim 18, in which the chromic acid concentration is 10 to 100 g/l.
Claim 21
Dependent Claim
27 words
A process as claimed in claim 17, in which the metal strip immersed in the bath is subjected to cathodic electrolysis, in the presence of sulphuric acid.
Claim 22
Dependent Claim
49 words
A process as claimed in claim 20, in which the immersion is carried out in two phases, the first of which comprises immersion in a CrO 3 medium titrating 50 to 500 g/l and the second of which comprises immersion in a solution of hexavalent chromium under cathodic polarization.
Claim 23
Dependent Claim
47 words
A process as claimed in claim 20, in which the immersion is carried out in a single phase by immersing the strip under cathodic polarization at low concentration with addition of at least one substance selected from the group consisting of sulphates, silicon fluoride, and boron fluoride.
Claim 24
Dependent Claim
37 words
A process as claimed in claim 17, further comprising subjecting the strip to ageing treatment under a reducing atmosphere whose dewpoint is from -10° C. to -40° C. in order to avoid oxidation of the metal layer.
Claim 25
Dependent Claim
71 words
A process as claimed in claim 16, the process being carried out in the course of thermal treatment during which the strip is introduced into a hot aqueous solution in order to cool it rapidly following recrystallization treatment and wherein it is optionally introduced subsequently into another hot aqueous solution to effect final cooling, following thermal ageing treatment, at least one of the said solutions being used as a chromatization bath.
Claim 26
Dependent Claim
42 words
A process as claimed in claim 16, the process being carried out in the course of thermal treatment comprising quenching in hot aqueous solution followed by ageing, the chromatization being effected after the ageing operation in order to avoid diffusion of chromium.
Claim 27
Dependent Claim
35 words
A process as claimed in claim 16, the process being carried out in the course of thermal treatment comprising quenching which follows recrystallization heating, but without tempering the chromatization being effected during the said quenching.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-09 | 1984-03-10 | 1984-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-09 | 1988-03-10 | 1988-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-09 | 1992-03-10 | 1992-09-09 | $7700.00 | Window Closed / Lapsed |