EP 0291493 B1 19940817 - Process for electrolytic pickling of chrome containing stainless steel.
Title (en)
Process for electrolytic pickling of chrome containing stainless steel.
Title (de)
Verfahren zum elektrolytischen Beizen von chromhältigem Edelstahl.
Title (fr)
Procédé de découpage électrolytique d'acier inoxydable contenant du chrome.
Publication
Application
Priority
AT 114787 A 19870507
Abstract (en)
[origin: US4851092A] In a process for the electrolytic pickling of chromium-containing stainless steel, pickling proceeds initially in an aqueous Na2SO4 solution and subsequently in acid, preferably mixed acid. The CrO42- formed is converted by the addition of reducing agent and acid as a function of the pH value and the redox potential to Cr2(SO3)3 or Cr2(SO4)3. H2SO4 serves as the acid and a substance is used as a reducing agent selected from the group Nax Hy Sz Ov, wherein x=0 to 2, y=0 to 2, y=1 to 6 and v=2 to 6. The pH value is adjusted to less than three by the addition of acid.
IPC 1-7
IPC 8 full level
C01G 37/14 (2006.01); C25F 1/06 (2006.01)
CPC (source: EP KR US)
Citation (examination)
A.ARANEO -"CHIMICA ANALITICA QUALITATIVA" LIBRERIA ED., p.112
Designated contracting state (EPC)
BE DE ES FR GB IT SE
DOCDB simple family (publication)
EP 0291493 A1 19881117; EP 0291493 B1 19940817; AT 387406 B 19890125; AT A114787 A 19880615; DE 3851086 D1 19940922; ES 2058340 T3 19941101; FI 86649 B 19920615; FI 86649 C 19920925; FI 882098 A0 19880505; FI 882098 A 19881108; JP 2649380 B2 19970903; JP S63286600 A 19881124; KR 880014141 A 19881223; KR 960001599 B1 19960202; US 4851092 A 19890725
DOCDB simple family (application)
EP 88890097 A 19880420; AT 114787 A 19870507; DE 3851086 T 19880420; ES 88890097 T 19880420; FI 882098 A 19880505; JP 11137988 A 19880507; KR 880004602 A 19880422; US 18980588 A 19880503