Produce mirror-shining surface of electrogalvanized steel with significantly elevated scratch resistance through combined nanoelectrodeposition and passivation treatment

This article reports a study on production of mirror-shining surface of electrogalvanized steel with significantly elevated scratch resistance, achieved by combined nano-electrodeposition and passivation treatment. Roughness, indentation deformation, elastic modulus and micro-scratch resistance of the treated electrogalvanized steel surface were investigated. Through in situ property mapping using a multi-mode atomic force microscope, surface properties of passivation films on coarse-grained and nanocrystalline zinc coatings were evaluated. It was demonstrated that the combination of nano-electrodeposition and passivation treatment greatly improved the passive film on the zinc coating with mirror brightness and significantly raised resistance to scratch, which is about two orders of magnitude higher than that of oxide film on conventional electrogalvanized steel.