Usinor

Ugine Sa

Ugine, Aciers De Chatillon Et Gueugnon

Paul Didier

Dominique Henriet

Bernard Vialatte

Process for the pickling of metallic materials

A method for pickling steel materials, in particular continuously on a treatment line, comprising a shot-blasting operation, a preparation operation, a pickling operation and a passivation operation, in which line the preparation operation is carried out by bringing the materials into contact with at least one 2 to 10N sulphuric acid solution, and in which line the pickling operation is carried out by bringing the materials into contact with at least one solution containing 1 to 10% by weight of hydrofluoric acid and Fe.sup.2+ and Fe.sup.3+ ions. No figure.

Method for continuous pickling of steel materials on a treatment line

Method for pickling or cleaning materials of steel, in particular stainless steel, comprising treating the materials with an aqueous solution containing ferrous ions and ferric ions and an organic acid which does not oxidize the iron in an amount sufficient to maintain the Fe.sup.2+ and Fe.sup.3+ ions in solution, the ferric and ferrous ions being present in the solution in a ration Fe.sup.2+ /Fe.sup.3+ between 10/90 and 40/60, and maintaining the ration Fe.sup.2+ /Fe.sup.3+ within the defined range by addition of hydrogen peroxide.

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Gueugnon, France

Paul Didier