ZN-PLATED HIGH-MN STEEL SHEET FOR HOT PRESS FORMING HAVING EXCELLENT SURFACE PROPERTY AND HOT PRESSED PARTS USING THE SAME

摘要

PURPOSE: A Zn-plated high-Mn steel sheet for hot pressing having an excellent surface property and a hot pressed part using the same are provided to prevent deterioration in a plated layer since when pressing is made, the alloying of a Zn-plated layer is encouraged and the melting temperature of the Zn-plated layer quickly increases. CONSTITUTION: A Zn-plated high-Mn steel sheet for hot pressing having an excellent surface property comprises a steel sheet, an Al-enriched layer, and a Zn-plated layer. The steel sheet comprises a superficial diffusing layer of metal less than Cr in the absolute value of the reduced amount of Gibb's free energy per Oxygen 1M when oxidation is made within a 1μm depth from the surface. The Al-enriched layer contains Al of more than 30weight%, which is formed on the superficial diffusing layer of the metal less than Cr in the absolute value of the reduced amount of Gibb's free energy per Oxygen 1M when oxidation is made.