Hot stamping component and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2023150008-A1
Application number	US-202218076967-A
Country	US
Kind code	A1
Filing date	Dec 7, 2022
Priority date	Oct 29, 2021
Publication date	May 18, 2023
Grant date	—

Abstract

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.

First claim

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 where λ t represents an air cooling time (s), at represents a heating furnace discharge temperature and an atmospheric temperature correction coefficient, Tt represents a heating temperature (°C), bt 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, bt 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 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, a n 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 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.

Assignees

• Hyundai Steel Co

Inventors

• Park Jae Myoung
• Kong Je Youl
• Park Kye Jeong
• Yoon Seung Chae

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C21D1/18

  Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62) · CPC title

• C22C38/54

  with boron · CPC title

• C22C38/58

  with more than 1.5% by weight of manganese · CPC title

• C22C38/50

  with titanium or zirconium · CPC title