| Applications: The excellent corrosion protection and high surface quality offered by Galvannealed coatings make these products well suited for numerous automotive applications involving both visible and non-visible parts. The presence of iron in the coating improves resistance spot welding behavior, so that Galvannealed products are especially recommended when joining proves difficult with other coatings. Technical characteristics: Surface appearance: The high surface quality of Galvannealed coatings leads to a finished paint appearance meeting the most stringent requirements of the automotive sector for visible bodywork parts. Hardness: Galvannealed coatings are hardened by the presence of iron. Hardness depends on the proportions of the different alloy phases, which can be controlled via the galvannealing parameters. This hardness can lead to a certain risk of powdering during severe deep drawing operations, particularly for higher coating weights. For this reason, we recommend thinner coatings than in the case of Extragal®. The coating hardness also leads to a reduction in the Lankford ratio r, as measured during tensile tests, resulting in reduced deep-drawability Information provided by ArcelorMittal |
