Influence of intercritical annealing temperature on the micro-galvanic interactions between austenite and ferrite in medium-Mn steel. (November 2022)

• Record Type: Journal Article
• Authors: Pütz, René Daniel; Allam, Tarek; Wang, Junmiao; Nowak, Jakub; Haase, Christian; Sandlöbes-Haut, Stefanie; Krupp, Ulrich; Zander, Daniela
• Is Part Of: Corrosion science. Volume 208(2022)
• Publication Date: 2022-11
• Subjects: Advanced high strength steel -- Medium-Mn steel -- ICP-MS -- EIS -- Selective dissolution -- Micro-galvanic coupling; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110633
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: The micro-galvanic coupling between ferrite and austenite in X6MnAl12–3 was investigated depending on intercritical annealing (ICA) temperature and consequently different Mn contents in reverted austenite, phase fractions, and interface area combining microstructural changes, electrochemical testing and the solution's element concentration during immersion. Rising the ICA temperature from 550 °C to 600 °C led to an increase of the selective dissolution of reverted austenite due to an increased ferrite/austenite area, while a further increase to 700 °C led to a reduced dissolution tendency of austenite due to its decreased Mn content and expected decrease in the potential difference between both phases. Highlights: The reverted austenite fraction increased with increasing ICA temperature. The reverted austenite was selectively dissolved by micro-galvanic coupling. ICP-MS was additionally used to understand the dissolution of elements. The corrosion susceptibility increased with rising ICA temperature up to 600 °C. The corrosion susceptibility decreased again at an ICA temperature of 700 °C.