Process for pickling a piece of steel and in particular a sheet strip of stainless steel
AssigneeUsinor Sacilor
InventorsHenri Giraud, Bernard Vialatte, Martine Lauvergne
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Abstract
The process comprises applying an aqueous pickling solution containing hydrochloric acid and ferric and ferrous pickling irons in solution, and, for the purpose of maintaining a constant pickling power of the aqueous solution of hydrochloric acid having a pH lower than 1, maintaining the concentration of Fe.sup.3+ ions at a value between 1 g/litre and 300 g/litre, by reoxidation by means of an oxygenation of the Fe.sup.2+ ions produced during the pickling, the REDOX potential being maintained at a value between 0 and 800 mV, the potential being measured between a platinum electrode and a reference AG/AGCl electrode which are placed in the solution.
Claims10
Process for pickling a piece of steel and in particular a strip of stainless steel, comprising:
- applying an aqueous pickling solution containing hydrochloric acid and ferric and ferrous pickling ions in solution, and, for the purpose of maintaining a constant pickling power of said aqueous solution of hydrochloric acid having a pH lower than 1, maintaining the concentration of Fe.sup.3+ ions at a value between 1 g/litre and 300 g/litre by reoxidation by means of an oxygenation of the Fe.sup.2+ ions produced during said pickling, the REDOX potential being maintained at a value between 400 and 600 mV, said potential being measured between a platinum electrode and a reference AG/AGCl electrode which are placed in said solution.
Process for effecting an accelerated pickling of a piece of steel and in particular a strip of stainless steel in a continuous production line producing said strip, comprising:
- applying an aqueous pickling solution containing hydrochloric acid and ferric and ferrous pickling ions in solution, and, for the purpose of maintaining a constant pickling power of said aqueous solution of hydrochloric acid having a pH lower than 1, maintaining the concentration of Fe.sup.3+ ions at a value between 1 g/litre and 300 g/litre by reoxidation by means of an oxygenation of the Fe.sup.2+ ions produced during said pickling, the REDOX potential being maintained at a value between 400 and 600 mV, said potential being measured between a platinum electrode and a reference AG/AGCl electrode which are placed in said solution.
Dependencies are inferred from the claim text.