12th International Conference on Zinc & Zinc Alloy Coated Steel Sheet - GALVATECH 2021

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Houssem Eddine CHAIEB a,*, Vincent MAUREL a, Samuel FOREST a, Kais AMMAR a, Alain KÖSTER a, Franck NOZAHIC b, Joost DE STRYCKER b, Jean-Michel MATAIGNE c

a Le Centre des Matériaux, MINES ParisTech, 63-65 Rue Henri Auguste Desbruères, 91100 Corbeil-Essonnes, France

b ArcelorMittal Global R&D; Gent, J.F. Kennedylaan 3, B-9060 Zelzate, Belgium

c ArcelorMittal Global R&D; Maizières, Voie Romaine, Maizières-lès-Metz, France

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Zinc based coatings deposited on steel by hot-dip galvanizing are well known to present a strong basal orientation. This has been highlighted in several previous works [1, 2]. This orientation tendency is less pronounced in Zn-5Al coating and orientation heterogeneities are witnessed. Understanding the origin of such heterogeneities and linking them to the solidification process requires the development of new guidelines.

Figure 1. SEM image of Zn-5Al coating

Figure 2. EBSD of Zn-5Al coating

An epitaxial relationship between certain zinc dendrites and binary eutectic appears to be present. In this study, we aim at describing the microstructure and the texture of the near-eutectic Zn-5Al hot-dip galvanized coating. Several experimental techniques (SEM, EBSD, Optical Microscopy) and preparation methods are applied in order to investigate the consequences of the solidification process of this grade of coatings and to link it to the observed crystallographic orientations.

The microstructure analysis was done both on the surface and the cross-section of the sample. A link between the microstructure and orientations’ heterogeneity is to be established. The observed complex morphologies of different phases yield a multiscale aspect of the coating microstructure that will be discussed.

[ 1 ] R. Parisot, S. Forest, A. Pineau, F. Grillon, X. Demonet, J.-M. Mataigne, Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part I. Deformation modes, Metall. Mater. Trans. A. 35 (2004) 797–811. doi:10.1007/s11661-004-0007-x.

[ 2 ] R. Parisot, S. Forest, A. Pineau, F. Grillon, X. Demonet, J.-M. Mataigne, Deformation and damage mechanisms of zinc coatings on hot-dip galvanized steel sheets: Part II. Damage modes, Metall. Mater. Trans. A. 35 (2004) 813–823. doi:10.1007/s11661-004-0008-9.