Verfahren zum Beizen und Passivieren von rostfreiem Stahl ohne Salpetersäure

摘要

Process for stainless steel pickling consisting in placing the material to be treated in a bath kept at a temperature ranging from 30 DEG C to 70 DEG C and containing: a) HCl b) Fe<3+> c) HF d) emulsifiers, wetting agents, polishing agents, acid attack inhibitors; the bath being fed continuously with: an air flow equal to at least 3 m<3>/h per m<3> bath min. and an oxidizer quantity adjusted to the bath redox potential to be kept at 250 mV min.