Influence of austenitisation temperatures during hot stamping on the local electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si. (September 2021)

• Record Type: Journal Article
• Authors: Couto, Camila Pucci; Revilla, Reynier I.; Politano, Rodolfo; Costa, Isolda; Panossian, Zehbour; De Graeve, Iris; Rossi, Jesualdo Luiz; Terryn, Herman
• Is Part Of: Corrosion science. Volume 190(2021)
• Publication Date: 2021-09
• Subjects: Hot stamping -- Austenitisation temperature -- Hot-dip Al-Si -- Electrochemical behaviour -- Scanning kelvin probe force microscopy; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.109673
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Hot-stamping austenitisation temperature is critical to Al-Si coating's morphology. System's local electrochemical behaviour varies with austenitisation temperature. Iron enrichment through diffusion causes overall ennoblement of the Al-Si coating. The driving force for cathodic protection reduces with austenitisation temperature. The need for local investigations is highlighted by the complexity of the system. Abstract: Scanning Kelvin probe force microscopy was used to evaluate the effect of austenitisation temperatures during hot stamping on the local electrochemical behaviour of 22MnB5 steel coated with hot-dip Al-Si. A variation in the austenitisation temperature around 50 °C substantially altered the coating morphology as well as the local electrochemical behaviour of the system (coating/steel). Both coating layer and steel substrate became nobler as the austenitisation temperature increased. The former was due to the overall iron enrichment while the latter was related to the microstructural transformation during quenching. Therefore, the driving force for cathodic protection decreased as the austenitisation temperature increased.