Zinc-Plated Steel Sheet for Hot Pressing Having Outstanding Surface Characteristics, Hot-Pressed Moulded Parts Obtained Using the Same, and a Production Method for the Same

Abstract

Provided is a zinc-plated steel sheet for hot pressing having outstanding surface characteristics, comprising: a steel foundation plate comprising a metal surface diffusion layer of which the Gibbs free energy reduction per mole of oxygen during oxidation is less than that of Cr, an aluminium-rich layer containing at least 30 wt. % of aluminium formed on the surface diffusion layer, and a zinc plating layer formed on the aluminium-rich layer. In this way, a metal having a low affinity for oxygen is coated to an effective thickness prior to annealing and thus the creation of annealing oxides at the surface of the steel sheet is suppressed and a uniform zinc plating layer is formed, and alloying of the zinc plating layer is promoted during press-processing heat treatment. Cracking in the steel foundation plate during hot press molding is prevented.

Dependencies are inferred from the claim text.