Steel sheet plated by hot dipping with alloyed zinc with excellent adhesion and process for producing the same

摘要

The present invention provides a galvannealed steel sheet excellent in the adhesion with a base steel sheet and a manufacturing method thereof. The galvannealed steel sheet according to the invention has, in an interface between a galvannealed layer and the base steel sheet thereon the galvannealed layer is formed, an irregularity that has a depth of 10 nm or more at a pitch of 0.5 mum or less at least one per 5 mum of a length of the interface.