Process for acid pickling of stainless steel products
US5154774A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1991 |
| Grant date | Oct 13, 1992 |
| Priority date | — |
| Expiry date | Dec 31, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/086
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention relates to a process for pickling stainless steel products, in which a pickling bath is used having the initial composition: PA1 HF 10 to 50 g/l PA1 Dissolved ferric iron (Fe.sup.3+).gtoreq.15 g/l PA1 Water: as required at a temperature of between 15.degree. and 70.degree. C., characterized in that, during the pickling operation(s), the ferric iron content of the bath is maintained at at least 15 g/l by oxidation of the bath comprising at least one or several injections of air in a total quantity greater than or equal to 1 Nm.sup.3 per m.sup.2 of pickled stainless steel and per hour of pickling of each unit of surface area pickled. The process of the invention applies particularly to the industrial pickling of stainless steel sheets and strips, in which it is possible to avoid the use of nitric acid and the resulting pollution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.