Patent · US Expired

Process for inhibiting the corrosion of a metal installation in contact with an acid bath

US4402759A · kind A · utility

2Cited by
2References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 4, 1980
Grant dateSep 6, 1983
Priority date
Expiry dateSep 4, 2000

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC23G1/04
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

The invention relates to a process for inhibiting the corrosion of an installation, made of a material chosen from amongst the metals which are less noble than hydrogen, and their alloys, in contact with an acid bath containing an alkylpyridinium chloride. A soluble cyanide complex, which is capable of forming an insoluble compound by reacting with ferric ions in the bath, is added to the bath so as to limit the concentration of the ferric ions in the bath to a maximum of 30 mg/kg. The content of ferric ions in the bath is controlled by means of a potentiometric measurement so as to bring the potential of the bath into the region of a predetermined value. The invention applies in particular to the treatment of baths for cleaning or descaling steel installations.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.