Material for hot stamping and method of manufacturing the same

Abstract

Provided are a material for hot stamping, and the material includes: a steel sheet including carbon (C) in an amount of 0.28 wt% to 0.50 wt%, silicon (Si) in an amount of 0.15 wt% to 0.70 wt%, manganese (Mn) in an amount of 0.5 wt% to 2.0 wt%, phosphorus (P) in an amount less than or equal to 0.05 wt%, sulfur (S) in an amount less than or equal to 0.01 wt%, chromium (Cr) in an amount of 0.1 wt% to 0.5 wt%, boron (B) in an amount of 0.001 wt% to 0.005 wt%, an additive in an amount less than or equal to 0.1 wt%, balance iron (Fe), and other inevitable impurities; and fine precipitates distributed within the steel sheet. The additive includes at least one of titanium (Ti), niobium (Nb), and vanadium (V), and the fine precipitates include nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V) and trap hydrogen.

What is claimed is: 
     
         1 . A material for hot stamping, the material comprising:
 a steel sheet comprising carbon (C) in an amount of 0.28 wt% to 0.50 wt%, silicon (Si) in an amount of 0.15 wt% to 0.70 wt%, manganese (Mn) in an amount of 0.5 wt% to 2.0 wt%, phosphorus (P) in an amount less than or equal to 0.05 wt%, sulfur (S) in an amount less than or equal to 0.01 wt%, chromium (Cr) in an amount of 0.1 wt% to 0.5 wt%, boron (B) in an amount of 0.001 wt% to 0.005 wt%, an additive in an amount less than or equal to 0.1 wt%, balance iron (Fe), and other inevitable impurities; and   fine precipitates distributed within the steel sheet,   wherein the additive comprises at least one of titanium (Ti), niobium (Nb), and vanadium (V), and   the fine precipitates comprise nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V) and trap hydrogen.   
     
     
         2 . The material of  claim 1 , wherein the fine precipitates are formed in an amount greater than or equal to 25,000 pieces and less than or equal to 30,000 pieces per unit area 100 µm 2 . 
     
     
         3 . The material of  claim 1 , wherein an amount greater than or equal to 90% of the fine precipitates are formed to have a diameter less than or equal to 0.01 µm. 
     
     
         4 . The material of  claim 3 , wherein a number of fine precipitates having the diameter less than or equal to 0.01 µm from among the fine precipitates is greater than or equal to 23,000 and less than or equal to 29,000 per unit area 100 µm 2 . 
     
     
         5 . The material of  claim 3 , wherein an amount greater than or equal to 60% of the fine precipitates are formed to have a diameter less than or equal to 0.005 µm. 
     
     
         6 . The material of  claim 1 , wherein a mean distance between the fine precipitates is greater than or equal to 0.15 µm and less than or equal to 0.4 µm. 
     
     
         7 . A method of manufacturing a material for hot stamping, the method comprising:
 reheating a slab within a slab reheating temperature range of 1,180° C. to 1,280° C.;   manufacturing a steel sheet by hot rolling the reheated slab within a finishing delivery temperature range of 830° C. to 930° C.; and   coiling the steel sheet within a coiling temperature range of 700° C. to 780° C. and forming fine precipitates within the steel sheet,   wherein the slab comprises carbon (C) in an amount of 0.28 wt% to 0.50 wt%, silicon (Si) in an amount of 0.15 wt% to 0.70 wt%, manganese (Mn) in an amount of 0.5 wt% to 2.0 wt%, phosphorus (P) in an amount less than or equal to 0.05 wt%, sulfur (S) in an amount less than or equal to 0.01 wt%, chromium (Cr) in an amount of 0.1 wt% to 0.5 wt%, boron (B) in an amount of 0.001 wt% to 0.005 wt%, an additive in an amount less than or equal to 0.1 wt%, balance iron (Fe), and other inevitable impurities,   the additive comprises at least one of titanium (Ti), niobium (Nb), and vanadium (V), and   the fine precipitates comprise nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V) and trap hydrogen.   
     
     
         8 . The method of  claim 7 , wherein the fine precipitates are formed in an amount greater than or equal to 25,000 pieces and less than or equal to 30,000 pieces per unit area 100 µm 2 . 
     
     
         9 . The method of  claim 7 , wherein an amount greater than or equal to 90% of the fine precipitates are formed to have a diameter less than or equal to 0.01 µm. 
     
     
         10 . The method of  claim 9 , wherein a number of fine precipitates having the diameter less than or equal to 0.01 µm from among the fine precipitates is greater than or equal to 23,000 and less than or equal to 29,000 per unit area 100 µm 2 . 
     
     
         11 . The method of  claim 9 , wherein an amount greater than or equal to 60% of the fine precipitates are formed to have a diameter less than or equal to 0.005 µm. 
     
     
         12 . The method of  claim 7 , wherein a mean distance between the fine precipitates is greater than or equal to 0.15 µm and less than or equal to 0.4 µm.