Sollac

Arcelormittal

Usinor

Jacques Petitjean

Christian Allely

Alain Bello

Pierre C Lacaze

Isabelle Marolleau

Salah Aeiyach

Sylviane Wajda

Hedayatullah Mir

Armand Rossi

Geneviève Klam

Genevieve Klam

Christian ALLÉLY

A steel sheet is provided with a coating providing sacrificial cathodic protection. The coating includes between 1 and 40% by weight zinc, between 0.01 and 0.4% by weight lanthanum, optionally up to 10% by weight magnesium, optionally up to 15% by weight silicon, and optionally up to 0.3% by weight, in cumulative amounts, of additional components, the remainder includes aluminum and unavoidable impurities or residual elements. A method of producing parts by hot or cold swaging and the parts which can be obtained in this way are also provided.

Steel sheet provided with a coating providing sacrificial cathodic protection comprising lanthane

A method for forming a zinc oxalate coating on the surface of a strip or sheet of metal covered with a zinc or zinc alloy coating other than zinc/iron coatings, with the aid of an aqueous solution consisting of oxalic acid having a concentration of between 5.10and 0.1 mole/l, and at least one compound and/or ion of an oxidant zinc metal having a concentration of between 10and 10mole/l, and possibly a wetting agent. The inventive method enables sheet metal to be treated at very high speeds without using large amounts of oxidant. It facilitates management of treatment baths. The invention can be used in the lubrication of sheet metal, especially for die stamping.

Method for oxalating the galvanized surface of sheet metal

The invention concerns a steel plate coated with a metal layer based on zinc and a zinc hydroxysulphate layer, whereof the surface density of sulphur is more than 0.5 mg/m . The invention also concerns a method for obtaining said plate by treating a zinc coated sheet metal: either in a highly alkaline sulphate solution under polarization; or in a sulphate solution containing Zn ions without polarization. The hydroxysulphate deposit brings about a pre-lubricating effect applicable to operations for forming sheet metal.

Zinc coated steel plates coated with a pre-lubricating hydroxysulphate layer and methods for obtaining same

A bath of pH higher than 4 containing more than 1 mole/liter of Zn.sup.++ ions and at least one polyethylene glycol polymer of the general formula R.sup.1 --O(CH.sub.2 --CH.sub.2 --O).sub.n --R.sup.2, in which n.ltoreq.13 and in which the concentration of polymer in the bath is adapted to incorporate in the coat an organic compound having a content by weight greater than 0.1%, expressed as weight of carbon per unit weight of the coat. The bath is adapted to high current densities, and the coat applied on the steel sheet imparts both a leveling effect and an improvement of corrosion resistance.

Aqueous electrodeposition bath based on chlorides for preparation of a

The invention relates to a process for depositing a thin adhesive coating of polypyrrole on the surface of an article made of oxidizable metal, by electropolymerization of an aqueous or aqueous-alcoholic electrolytic solution of pyrrole and/or of one or more substituted pyrroles, in which the anode of the electropolymerization device consists of the article made of oxidizable metal, in which the solution contains ions selected from the ions of formula: ##STR1## in which X is selected from O, S and NH,

Process and bath for the electrolytic deposition of polypyrrole on an

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Thionville, France

Jacques Petitjean