Hot-stamped part

Abstract

Provided is a hot-stamped part including a base steel sheet, the base steel sheet including an amount of about 0.19 to about 0.25 wt % of carbon (C), an amount of about 0.1 to about 0.6 wt % of silicon (Si), an amount of about 0.8 to about 1.6 wt % of manganese (Mn), an amount of about 0.03 wt % or less of phosphorus (P), an amount of about 0.015 wt % or less of sulfur (S), an amount of about 0.1 to about 0.6 wt % of chromium (Cr), an amount of about 0.001 to about 0.005 wt % of boron (B), an amount of about 0.1 wt % or less of an additive, remaining iron (Fe), and other unavoidable impurities. In an indentation strain rate with respect to an indentation depth of about 200 nm to about 600 nm is observed in a nano indentation test, a number of indentation dynamic strain aging (DSA) is about 26 to about 40.

1 . A hot-stamped part comprising a base steel sheet, the base steel sheet comprising an amount of about 0.19 to about 0.25 wt % of carbon (C), an amount of about 0.1 to about 0.6 wt % of silicon (Si), an amount of about 0.8 to about 1.6 wt % of manganese (Mn), an amount of about 0.03 wt % or less of phosphorus (P), an amount of about 0.015 wt % or less of sulfur (S), an amount of about 0.1 to about 0.6 wt % of chromium (Cr), an amount of about 0.001 to about 0.005 wt % of boron (B), an amount of about 0.1 wt % or less of an additive, remaining iron (Fe), and other unavoidable impurities, wherein in an indentation strain rate with respect to an indentation depth of about 200 nm to about 600 nm observed in a nano indentation test, a number of indentation dynamic strain aging (DSA) is about 26 to about 40. 
     
     
         2 . The hot-stamped part of  claim 1 , wherein the base steel sheet comprises a martensite structure in which a plurality of lath structures are distributed. 
     
     
         3 . The hot-stamped part of  claim 2 , wherein an average interval between a plurality of laths is about 140 nm to about 300 nm. 
     
     
         4 . The hot-stamped part of  claim 1 , further comprising fine precipitates distributed in the base steel sheet,
 wherein the fine precipitates comprise a nitride or a carbide of at least any one of titanium (Ti), niobium (Nb), and vanadium (V).   
     
     
         5 . The hot-stamped part of  claim 4 , wherein a number of the fine precipitates distributed per unit area (100 μm 2 ) is about 7,500 to about 18,000. 
     
     
         6 . The hot-stamped part of  claim 4 , wherein an average diameter of the fine precipitates is about 0.0068 μm or less. 
     
     
         7 . The hot-stamped part of  claim 4 , wherein a rate of fine precipitates having a diameter of about 0.01 μm or less among the fine precipitates is about 63% or greater. 
     
     
         8 . The hot-stamped part of  claim 4 , wherein a rate of fine precipitates having a diameter of about 0.005 μm or less among the fine precipitates is about 28% or greater. 
     
     
         9 . The hot-stamped part of  claim 1 , wherein a V-bending angle of the hot-stamped part is equal to or greater than about 50°. 
     
     
         10 . The hot-stamped part of  claim 1 , wherein a tensile strength of the hot-stamped part is equal to or greater than about 1350 MPa. 
     
     
         11 . The hot-stamped part of  claim 1 , wherein an amount of activation hydrogen of the hot-stamped part is about 0.8 wppm or less.