Patent ID: 9068255
Filing Date: 2015-06-30
Classification: C22C,C23C,Y10T

Abstract:
1. A zinc-plated steel sheet for hot pressing having excellent surface characteristics comprising: a base steel sheet including a metal surface diffusion layer, in which a reduced amount of Gibbs free energy for one mole of oxygen during an oxidation reaction is smaller than that of Cr (chromium), to a depth of about 1 μm from a surface; an Al (aluminum)-rich layer containing about 30 wt % or more of Al formed on the surface diffusion layer of the metal in which a reduced amount of Gibbs free energy for one mole of oxygen during an oxidation reaction is smaller than that of Cr; and a zinc plating layer formed on the Al-rich layer, wherein an annealing oxide having an average thickness of about 150 nm or less is non-uniformly distributed between the surface diffusion layer and the Al-rich layer, and a content of the metal, in which a reduced amount of Gibbs free energy for one mole of oxygen during an oxidation reaction is smaller than that of Cr, to a depth of about 1 μm from the surface of the base steel sheet is about 0.1 wt % or more.