	US 12,312,652 B2
	Material for hot stamping and method of manufacturing the same
Nu Ri Shin, Incheon (KR); Hun Chul Kang, Incheon (KR); Ji Hee Son, Incheon (KR); and Byoung Hoon Kim, Incheon (KR)
Assigned to Hyundai Steel Company, Incheon (KR)
Filed by Hyundai Steel Company, Incheon (KR)
Filed on Feb. 28, 2023, as Appl. No. 18/115,459.
Application 18/115,459 is a continuation of application No. PCT/KR2021/007158, filed on Jun. 8, 2021.
Claims priority of application No. 10-2020-0111292 (KR), filed on Sep. 1, 2020; and application No. 10-2021-0042818 (KR), filed on Apr. 1, 2021.
Prior Publication US 2023/0227932 A1, Jul. 20, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C21D 9/46 (2006.01); B21B 3/02 (2006.01); B21D 22/02 (2006.01); C21D 6/00 (2006.01); C21D 6/02 (2006.01); C21D 8/02 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/32 (2006.01)

CPC C21D 9/46 (2013.01) [B21B 3/02 (2013.01); B21D 22/022 (2013.01); C21D 6/002 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 6/02 (2013.01); C21D 8/0205 (2013.01); C21D 8/0236 (2013.01); C21D 8/0263 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/32 (2013.01); C21D 2211/004 (2013.01); C21D 2211/008 (2013.01)]

9 Claims

1. A material for hot stamping, comprising:

a steel sheet comprising carbon (C) in an amount of 0.19 wt % to 0.25 wt %, silicon (Si) in an amount of 0.1 wt % to 0.6 wt %, manganese (Mn) in an amount of 0.8 wt % to 1.6 wt %, phosphorus (P) in an amount less than or equal to 0.03 wt %, sulfur(S) in an amount less than or equal to 0.015 wt %, chromium (Cr) in an amount of 0.1 wt % to 0.6 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),

wherein the fine precipitates comprise nitride or carbide of at least one of titanium (Ti), niobium (Nb), and vanadium (V) and trap hydrogen,

wherein an amount greater than or equal to 60% of the fine precipitates is formed to have a diameter less than or equal to 0.01 μm,

wherein the precipitates are formed in an amount greater than or equal to 7,000 pieces and less than or equal to 16,500 pieces per unit area 100 μm²,

wherein a tensile strength of the material after hot stamping is greater than or equal to 1,350 Mpa,

wherein a bendability of the material after hot stamping is greater than or equal to 50°, and

wherein an amount of activated hydrogen of the material for hot stamping is less than or equal to 0.8 wppm after hot stamping.