Plated steel sheet for hot press forming having excellent surface properties and method for manufacturing same

Abstract

The present invention relates to a plated steel sheet for hot press forming, having excellent surface properties, and a method for manufacturing same, and more specifically relates to a plated steel sheet for hot press forming, which has excellent production properties and corrosion resistance, and has excellent surface quality as the plating layer does not separate from the base material even after hot press forming, and a method for manufacturing same.

1 . A plated steel sheet for hot press forming, comprising:
 a base steel; and   a plating layer on at least one surface of the base steel;   wherein the plating layer comprises by weight %: 21 to 34% of Zn, 6.3 to 15% of Si, 3 to 13% of Fe, with a balance of Al and other inevitable impurities, and   wherein the following Relational expressions 1 and 2 are satisfied,   
       
         
           
             
               
                 
                   
                     0.09 
                     ≤ 
                     
                       
                         [ 
                         Zn 
                         ] 
                       
                       ⁢ 
                       
                         / 
                         [ 
                         Si 
                         ] 
                       
                     
                     ≤ 
                     4.8 
                   
                 
                 
                   
                     [ 
                     
                       Relational 
                       ⁢ 
                           
                       expression 
                       ⁢ 
                           
                       1 
                     
                     ] 
                   
                 
               
             
           
         
         
           
             
               
                 
                   
                     3.6 
                     ≤ 
                     
                       
                         [ 
                         Al 
                         ] 
                       
                       ⁢ 
                       
                         / 
                         [ 
                         Si 
                         ] 
                       
                     
                     ≤ 
                     8.5 
                   
                 
                 
                   
                     [ 
                     
                       Relational 
                       ⁢ 
                           
                       expression 
                       ⁢ 
                           
                       2 
                     
                     ] 
                   
                 
               
             
           
         
         in Relational expressions 1 and 2, where [Zn] represents an average content, weight %, of Zn in the plating layer, [Si] represents an average content, weight %, of Si in the plating layer, and [Al] represents an average content, weight %, of Al in the plating layer. 
       
     
     
         2 . The plated steel sheet for hot press forming of  claim 1 , wherein the plating layer comprises by weight %, 25 to 34% of Zn. 
     
     
         3 . The plated steel sheet for hot press forming of  claim 1 , wherein the plating layer comprises
 an Al—Zn-based plating layer; and   a Fe—Al-based interfacial alloy layer between the Al—Zn-based plating layer and the base steel.   
     
     
         4 . The plated steel sheet for hot press forming of  claim 3 , wherein a weight ratio (Sb/Sa) of an average Si content (Sb) in the Fe—Al-based alloy layer and an average Si content (Sa) in the Al—Zn-based plating layer is 1 to 3.1. 
     
     
         5 . The plated steel sheet for hot press forming of  claim 3 , wherein, based on a cross-section of the Al—Zn-based plating layer in a thickness direction, the plating layer comprises a region in which the Si content is concentrated at 40% or more as compared to the average Si content of the Al—Zn-based plating layer per unit area of 100 μm 2  of the plating layer. 
     
     
         6 . The plated steel sheet for hot press forming of  claim 3 , wherein, based on the cross-section of the Al—Zn-based plating layer in the thickness direction, the plating layer comprises by area fraction, a Si phase in an amount of 3 to 30%. 
     
     
         7 . The plated steel sheet for hot press forming of  claim 6 , wherein the Si phase comprises by weight %, 40 to 99.9% of Si. 
     
     
         8 - 14 . (canceled)