Process for acid pickling of stainless and special steels using stabilized peroxide compounds based on saturated tertiary aliphatic alcohols as oxidants in the pickling solution

摘要

In a process for acid pickling of stainless and special steels using a pickling solution based on hydrofluoric acid and an oxidizing agent in the form of hydrogen peroxide or a similar peroxide compound, the addition of saturated tertiary aliphatic alcohols to the solution inhibits the decomposition of the hydrogen peroxide and/or other peroxide compound, limiting the excessive consumption thereof. In particular, tert. butyl and tert. amyl alcohols have large stabilizing capacity even in the presence of more than 50 g/l of Fe and of a high bath temperature and do not leave residues in the pickling solution since they generate volatile alkenes by acid dehydration. The pickling solution, separated from the sludges at the appropriate time and continuously replenished, can be used indefinitely. IMAGE