Depth profiling approach to evaluate the influence of hot stamping on the local electrochemical behaviour and galvanic series of hot-dip Al-Si coating on 22MnB5 steel. (June 2021)

• Record Type: Journal Article
• Authors: Couto, Camila Pucci; Andreatta, Francesco; Lanzutti, Alex; Costa, Isolda; Panossian, Zehbour; De Graeve, Iris; Terryn, Herman; Rossi, Jesualdo Luiz; Revilla, Reynier I.
• Is Part Of: Corrosion science. Volume 185(2021)
• Publication Date: 2021-06
• Subjects: Hot-Stamping -- Al-Si coating -- Press-hardened steel -- GDOES -- Electrochemical micro-cell; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109435
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: A complex multi-layered system is formed in the Al-Si coating after hot stamping. Hot stamping increased the overall corrosion potential of the Al-Si coating. Si plays a crucial role on the passive electrochemical behaviour of the sublayers. Fe enrichment influenced the passive/active electrochemical behaviour of the coating. The active behaviour of the steel substrate was kept after hot stamping. Abstract: The influence of hot-stamping process on the corrosion properties of Al-Si coating on 22MnB5 steel was locally evaluated using a depth profiling approach combining GDOES and electrochemical micro cell. The results highlight the complexity of the system and the high dependence of the local galvanic series on the hot-stamping process. Due to iron diffusion from the steel substrate into the coating, the Al-rich layers presented active behaviour, whereas the initial coating condition showed a passive behaviour. Conversely, Fe/Si-rich sublayers acted as protective barrier for the steel substrate, as they show passive behaviour with nobler corrosion potentials and lower current densities.