Influence of annealing oxide structure and composition on pickling of the duplex stainless steel 1.4462
2011 (English)In: 7th European Stainless Steel Conference: Science and Market, Proceedings, Associazione Italiana di Metallurgia , 2011Conference paper, Published paper (Refereed)
Abstract [en]
In this work, correlation between the oxide formation and pickling behaviour of a conventional duplex material - 1.4462 is reported. The materials investigated are the duplex grade 1.4462 and two single phase alloys with compositions corresponding to the respective phases of the duplex material. Annealing was conducted at 1070 °C for 8 minutes. Topography and composition of the oxide layer were analysed with GDOES, FIB, XRD, SEM-EDS and CLSM. The ferritic steel formed a thick chromium-enriched oxide with a silica-rich sublayer. On the austenitic steel, ironenriched nodules were observed in the centre of the grains, together with oxide ridges on the top of the grain boundaries. The oxide on the duplex grade differed depending on the phase; nodule formation was observed on the austenitic grains while a more homogenous oxide formed on the ferritic grains. Pickling was performed in a mixed nitric/hydrofluoric acid bath. The fastest removal was observed for the austenitic sample, followed by the duplex and the ferritic samples. The oxide on the austenitic sample spalled from the surface while the oxide on the ferritic grade was removed by dissolution rather than by spallation. A mixed behaviour was observed on the duplex grade where some zones pickled faster than others.
Place, publisher, year, edition, pages
Associazione Italiana di Metallurgia , 2011.
Keywords [en]
Annealing, Austenitic stainless steel, Duplex stainless steel, EN 1.4462, Ferritic stainless steel, Nodules, Oxide, Pickling, Stainless steel
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:ri:diva-12962ISBN: 9788885298842 (print)OAI: oai:DiVA.org:ri-12962DiVA, id: diva2:973155
Conference
7th European Stainless Steel Conference: Science and Market, 21 September 2011 through 23 September 2011, 114650
2016-09-222016-09-22Bibliographically approved