23–25 May 2022 Hybrid conference
voestalpine Stahlwelt
Europe/Vienna timezone

Comparative studies of passive layers of CrMnN and CrNi austenitic steel stainless grades highlighting the effect of manganese

24 May 2022, 10:50
25m
Room 1

Room 1

Invited Lecture Corrosion properties High Mn Stainless Steels

Speaker

Rainer Fluch (voestalpine BÖHLER Edelstahl GmbH& CoKG)

Description

It is state of the art, that the corrosion resistance of stainless steels is mainly controlled by the alloying elements Cr, Mo and N. Derived from that, the widely applied pitting resistance equivalent number (PREN), is used to estimate and compare the pitting corrosion resistance of such steels. -
In this work, the focus was laid on the role of the Mn influence on the passive layer. Therefore, a CrMnN and a CrNi austenitic stainless steel were chosen and examined by high resolution imaging methods like GDOES and TEM, in combination with electrochemical methods like cyclic voltametry and Mott-Schottky analysis.
The results of the analysis indicated that additionally to the varying Mn content, in the CrMnN alloy the Mn-enrichment was found to be shifted towards the surface in relation to the predominant Cr-enrichment of the passive layer. Thus implies that Mn can react with the corrosive medium.
This findings are put in context to the electrochemical results and subsequently a possible explanation for the differing behaviour of both alloying concepts and therefore passive layers is formulated.

Speaker Country Österreich

Authors

Rainer Fluch (voestalpine BÖHLER Edelstahl GmbH& CoKG) Stephan Trattner (CEST, Competence Centre for Electrochemical Surface Technologies) Jürgen Schodl (CEST, Competence Centre for Electrochemical Surface Technologies) Günter Fafilek (Technical University of Vienna, Department of Chemical Technologies and Analytics)

Presentation materials