EP 0505606 B2 20030226 - Process for pickling and passivating stainless steel without using nitric acid
Title (en)
Process for pickling and passivating stainless steel without using nitric acid
Title (de)
Verfahren zum Beizen und Passivieren von rostfreiem Stahl ohne Verwendung von Salpetersäure
Title (fr)
Procédé de décapage et de passivation de l'acier inoxydable sans utilisation de l'acide nitrique
Publication
Application
Priority
IT MI910879 A 19910329
Abstract (en)
[origin: EP0505606A1] A process for pickling and passivating stainless steel using a bath of the following initial composition: H2SO4 at least 150 g/l Fe<3><+> at least 15 g/l HF at least 40 g/l stabilized H2O2 1-20 g/l non-ionic surfactants and acid attack inhibitors 1 g/l, into which an air flow and an H2O2 quantity of between 0.3 and 1 g/l per hour, controlled to maintain the bath Redox potential at >/= 350 mV, are fed in continuously.
IPC 1-7
IPC 8 full level
C23C 22/34 (2006.01); C23G 1/04 (2006.01); C23G 1/08 (2006.01)
CPC (source: EP)
C23C 22/34 (2013.01); C23G 1/00 (2013.01); C23G 1/086 (2013.01)
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0505606 A1 19920930; EP 0505606 B1 19951102; EP 0505606 B2 20030226; AT E129753 T1 19951115; DE 505606 T1 19940203; DE 69114265 D1 19951207; DE 69114265 T2 19960418; DE 69114265 T3 20040805; DK 0505606 T3 19951204; ES 2082063 T3 19960316; ES 2082063 T5 20031101; FI 101234 B 19980515; FI 920580 A0 19920212; FI 920580 A 19920930; GR 3018681 T3 19960430; IT 1245594 B 19940929; IT MI910879 A0 19910329; IT MI910879 A1 19920929; JP 2655770 B2 19970924; JP H04304391 A 19921027
DOCDB simple family (application)
EP 91113628 A 19910814; AT 91113628 T 19910814; DE 69114265 T 19910814; DE 91113628 T 19910814; DK 91113628 T 19910814; ES 91113628 T 19910814; FI 920580 A 19920212; GR 960400082 T 19960117; IT MI910879 A 19910329; JP 28420691 A 19911004