Microcrack-reduced, hot press-formed article, and method for manufacturing same

Abstract

Disclosed are a hot press-formed article and a method for manufacturing the same. The article is manufactured by hot press forming a galvanized steel sheet comprising a base steel plate and a zinc-based coat layer formed on a surface of the base steel plate, wherein the zinc-based coat layer contains at least one element selected from the group consisting of Sb, Sn, and Bi in a total amount of 0.05% to 2.0% by weight, and a balanced amount of Zn and inevitable impurities, at least 70% by weight of the at least one element selected from the group consisting of Sb, Sn, Bi being concentrated in a region 3 μm or less distant from the surface of an alloyed zinc-based coat layer, formed by alloying the zinc-based coat layer, of the hot press-formed article.

1 . A hot press-formed article comprising:
 a base steel sheet; and   an alloyed zinc-based plated layer formed on a surface of the base steel sheet,   wherein the alloyed zinc-based plated layer includes:   at least one element selected from the group consisting of Sb, Sn, and Bi in a total amount of 0.7 to 2.0 wt %, and a balance of Zn and inevitable impurities, and   at least 70 wt % of the at least one element is concentrated in a region within 3 μm or less from a surface of the alloyed zinc-based plated layer in a thickness direction thereof.   
     
     
         2 . The hot press-formed article of  claim 1 , wherein the total amount of the at least one element is 0.7 to 1.5 wt %. 
     
     
         3 . The hot press-formed article of  claim 1 , wherein the alloyed zinc-based plated layer further includes 0.1 to 7.5 wt % of Al and 0.1 to 5.0 wt % of Mg. 
     
     
         4 . The hot press-formed article of  claim 1 , wherein a degree of alloying of Fe of the alloyed zinc-based plated layer is 30% to 85%. 
     
     
         5 . The hot press-formed article of  claim 1 , wherein a degree of alloying of Fe of the alloyed zinc-based plated layer is 45% to 78%. 
     
     
         6 . The hot press-formed article of  claim 1 , wherein a degree of alloying of Fe of the alloyed zinc-based plated layer is 50% to 75%.