Hot stamping component and method of manufacturing the same
The present disclosure provides a method of manufacturing a hot stamping component, the method includes inserting a blank into a heating furnace, heating the blank, and transferring the heated blank from the heating furnace to a mold, wherein an air cooling time of the blank in the transferring of the blank satisfies Equation 1.
1. A method of manufacturing a hot stamping component, the method comprising:
inserting a blank into a heating furnace;
heating the blank; and
transferring the heated blank from the heating furnace to a mold;
wherein an air cooling time of the blank in the transferring of the blank satisfies Equation 1 below
λ t =( a t ×T t +b t )× t c t <Equation 1>
where λ t represents an air cooling time(s), a t represents a heating furnace discharge temperature and an atmospheric temperature correction coefficient, T t represents a heating temperature (° C.), b t represents a material component correction coefficient, t represents a material thickness (mm), and c t represents a high temperature material thickness sensitivity correction coefficient.
2. The method of claim 1 , wherein, in Equation 1, at is 0.0160 or greater and 0.0165 or less, T t is Ac3 or more and 1000° C. or less, b t is −10 or greater and 0.5 or less, t is 1 mm or greater and 2.6 mm or less, and c t is 0.7 or greater and 0.9 or less.
3. The method of claim 2 , wherein, in Equation 1, λ t is 5 s or more and 20 s or less.
4. The method of claim 3 , wherein, in the transferring of the blank, the heated blank is air-cooled at room temperature.
5. The method of claim 1 , wherein the heating of the blank comprises:
step-heating the blank in multiple stages; and
soaking the blank in a temperature range of about Ac3 to about 1,000° C.
6. The method of claim 5 , wherein, in the heating of the blank, the heating time of the blank satisfies equation (2) below
λ n =( a n ×T n +b n )× t c n <Equation 2>
where λ n represents a heating time(s), a n represents a heating furnace heat loss correction coefficient, T n represents a heating temperature (° C.), b n represents an Ac3 temperature correction coefficient, t represents a material thickness (mm), and c n represents a high temperature material thickness sensitivity coefficient.
7. The method of claim 6 , wherein, in Equation 2, an is −0.60 or greater and −0.55 or less, T n is Ac3 or greater and 1000° C. or less, b n is 700 or greater and 900 or less, t is 1 mm or greater and 2.6 mm or less, and c n is 0.7 or greater and 0.9 or less.
8. The method of claim 7 , wherein, in Equation 2, λ n is 100 s or more and 900 s or less.
9. The method of claim 5 , wherein the heating furnace comprises a plurality of sections having different temperature ranges.
10. The method of claim 9 , wherein a ratio of a length of sections for step-heating the blank to a length of a section for soaking the blank is about 1:1 to 4:1.
11. The method of claim 1 , further comprising:
after transferring the blank, forming a molded body by pressing the transferred blank with the mold; and
cooling the formed molded body.
12. The method of claim 11 , wherein, in the molding of the molded body, a molding start temperature of the blank is 500° C. or higher and 700° C. or less.
13. The method of claim 11 , wherein the cooling of the molded body is performed within the mold.
14. The method of claim 13 , wherein, in the cooling of the molded body, a mold cooling time during which the molded body is cooled in the mold satisfies Equation 3 below
λ q =( a q ×P+b q )× t c q <Equation 3>
where λ q represents a mold cooling time(s), a q represents a mold thermal conductivity correction coefficient, P represents a pressing force (MPa), b q represents a material hardenability correction coefficient, t represents a material thickness (mm), and c q represents a low temperature material thickness sensitivity coefficient.
15. The method of claim 14 , wherein, in Equation 3, a q is −1.0 or greater and −0.2 or less, P is 0.1 MPa or greater and 5 MPa or less, b q is 11 or greater and 15 or less, t is 1 mm or greater and 2.6 mm or less, and c q is 1.00 or greater and 1.05 or less.
16. The method of claim 15 , wherein, in Equation 3, λ q is 6 s or more and 40 s or less.
17. The method of claim 11 , wherein, in the cooling of the molded body, a cooling end temperature of the mold at which the cooling is terminated is above the room temperature and below about 200° C.
18. A hot stamping component manufactured according to the method of claim 1 , the hot stamping component having a tensile strength of 1,350 MPa or greater and less than 2,300 MPa.