Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
20 words
A method as claimed in claim 1 in which the heat treatment is in the range 502* - 575* C.
Claim 2
Dependent Claim
20 words
A method as claimed in claim 1 in which the heat treatment is in the range 502* - 525* C.
Claim 3
Dependent Claim
20 words
A method as claimed in claim 3 in which the thickness of the iron layer is at least 1.5 microns.
Claim 4
Dependent Claim
22 words
A method as claimed in claim 1 in which the compacted steel substrate is heat treated for about 15 - 20 hours.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 1 in which the aluminum powder particles are applied to the wetted iron layer in an electrostatically charged condition.
Claim 6
Dependent Claim
27 words
A method as claimed in claim 1 in which the substrate is a moving steel strip each of whose opposite sides is provided with an aluminum coating.
Claim 7
Dependent Claim
39 words
A method as claimed in claim 1 in which the surface of the steel substrate is subjected to pickling in an acid, the electrolyte employed during the said electrolytic coating being derived from liquor resulting from the said pickling.
Claim 8
Dependent Claim
37 words
A method as claimed in claim 8 in which any remaining acid in the pickle liquor is neutralised with scrap iron, and the pickle liquor is diluted with water prior to its being used as the electrolyte.
Claim 9
Dependent Claim
14 words
A method as claimed in claim 8 in which the acid is hydrochloric acid.
Claim 10
Dependent Claim
57 words
A method as claimed in claim 1 in which the steel substrate, immediately after receiving the electrolytic coating, is dried so as to solidify any electrolyte on the steel substrate, the solidifed electrolyte being thereafter removed by washing with water, and the steel substrate being then wetted with the said aqueous solution of an alkali metal silicate.
Claim 11
Dependent Claim
20 words
A method as claimed in claim 11 in which the drying is effected by directing air onto the steel substrate.
Claim 12
Dependent Claim
123 words
A method as claimed in claim 7 in which the steel strip is passed, with a predetermined surface thereof lowermost, through at least one first plating bath, and is then passed, with the opposite surface thereof lowermost, through at least one second plating bath, each of the first and second plating baths being provided with an iron anode above which the steel strip is passed and the said at least one second plating bath being provided with an auxiliary anode disposed above the steel strip, the auxiliary anode being insoluble in the electrolyte in the second plating bath and being operated at a low voltage which cathodically polarises the steel strip and ensures that the latter is not pickled by the said electrolyte.
Claim 13
Dependent Claim
30 words
A method as claimed in claim 13 in which the auxiliary anode is a titanium anode and is operated at a current density of about 5 amperes per square foot.
Claim 14
Dependent Claim
28 words
A method as claimed in claim 1 in which the electrolyte employed in the electrolytic coating has a ferrous iron content of at least 70 grams per litre.
Claim 15
Dependent Claim
24 words
A method as claimed in claim 1 in which the temperature of the electrolyte employed in the electrolytic coating is at least 70* C.
Claim 16
Dependent Claim
39 words
A method as claimed in claim 1 in which, immediately prior to the electrolytic coating, the steel substrate is wetted with a liquid whose pH is substantially the same as that of the electrolyte employed in the electrolytic coating.
Claim 17
Dependent Claim
18 words
A method as claimed in claim 17 in which the electrolyte itself is employed as the said liquid.
Claim 18
Dependent Claim
30 words
A method as claimed in claim 1 in which the aluminum coated steel substrate is cold reduced and then annealed at a temperature within the range 500* - 525* C.