Hot-stamped part and manufacturing method therefor

A method for manufacturing a hot-stamped part, the method comprising steps of:

• (a) preparing a blank;
• (b) heating the blank;
• (c) forming a molded body by hot-stamping the heated blank in a press mold;
• and
• (d) forming a hot-stamped part by cooling the molded body,
• wherein step (b) comprises:
• when a thickness of the blank is 1.2 mm, heating the blank in a preheated furnace for a time and to a temperature defined by one point within a first diagram having heating time-temperature coordinates of I (175 sec, 880° C.), II (210 sec, 820° C.), III (745 sec, 820° C.) and IV (455 sec, 880° C.) as apexes,
• wherein the heating time per changed thickness is constantly changed depending on a change in thickness of the blank with the temperature of the first diagram fixed, and
• the blank in step (a) comprises 0.28 to 0.38 wt % of carbon (C), 0.1 to 0.4 wt % of silicon (Si), 1.2 to 2.0 wt % of manganese (Mn), more than 0 but not more than 0.020 wt % of phosphorus (P), more than 0 but not more than 0.003 wt % of sulfur (S), 0.1 to 0.5 wt % of chromium (Cr), 0.0015 to 0.0040 wt % of boron (B), 0.025 to 0.05 wt % of titanium (Ti), and the balance of iron (Fe) and unavoidable impurities, the hot-stamped part formed after step (d) comprises a base layer, a microstructure of the base layer is full martensite, and the hot-stamped part further comprises an Al—Si coating layer on the base layer, wherein a fraction of a Fe—Al—Si-based intermetallic compound layer in the coating layer is less than 40%, and a final part obtained through the hot-stamping process has an average prior-austenite grain size (PAGS) of 25 μm or less, a tensile strength (TS) of 1,700 MPa or more, a yield strength (YS) of 1,100 MPa or more, and an elongation (El) of 5% or more.