Method for pickling mettalic surface, pickling solutions therefor, and process for regenerating spent pickling solutions
US6361613B1 · kind B1 · utility
3Cited by
6References
10Claims
0Family size
Inventor
Key dates
| Filing date | Dec 24, 1997 |
| Grant date | Mar 26, 2002 |
| Priority date | — |
| Expiry date | Dec 24, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23G1/086
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for removing scales formed on iron-based metal alloy containing Ni and/or Cr comprising contacting the metal alloy with a pickling solution containing nitrates and fluorides as essential components. The nitrates and fluorides used for the method are superior to the mixture of nitric acid and hydrofluoric acid in pickling efficiency, fundamental elimination of noxious gas; and optional abbreviation of pre-treatment before pickling. The pickling solution may also contain auxiliary component. A pickling composition containing nitrates and fluorides and a regenerating method of spent pickling solution is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.