Chemical cleaning process for metall workpieces

摘要

The cleaning process is usable especially for washing the outer faces of steam generator tubes. The surface metal oxides are removed by a complexing operation (which may be preceded by a reduction) and then dissolving of the siliceous compounds is effected by a reaction with electrophilic compounds in aqueous insertion medium or a reaction with alcohols or amines in aqueous condensation medium, the reaction being intended to weaken the bonds, in a medium ensuring the complexing of Si(OH)4.