US 11,952,652 B2
Zinc-plated steel sheet for hot pressing having outstanding surface characteristics, hot-pressed moulded parts obtained using the same, and a production method for the same
Il-Ryoung Sohn, Gwangyang (KR); Jong-Sang Kim, Gwangyang (KR); Joong-Chul Park, Gwangyang (KR); Yeol-Rae Cho, Gwangyang (KR); Jin-Keun Oh, Gwangyang (KR); Han-Gu Cho, Gwangyang (KR); Bong-Hoon Chung, Gwangyang (KR); and Jong-Seog Lee, Gwangyang (KR)
Assigned to POSCO CO., LTD, Pohang-si (KR)
Filed by POSCO, Pohang-si (KR)
Filed on Mar. 7, 2018, as Appl. No. 15/914,389.
Application 15/914,389 is a division of application No. 14/703,065, filed on May 4, 2015, granted, now 9,945,020.
Application 14/703,065 is a division of application No. 13/518,904, granted, now 9,068,255, previously published as PCT/KR2010/009392, filed on Dec. 28, 2010.
Claims priority of application No. 10-2009-0132777 (KR), filed on Dec. 29, 2009; application No. 10-2010-0136211 (KR), filed on Dec. 28, 2010; application No. 10-2010-0136212 (KR), filed on Dec. 28, 2010; application No. 10-2010-0136213 (KR), filed on Dec. 28, 2010; and application No. 10-2010-0136214 (KR), filed on Dec. 28, 2010.
Prior Publication US 2018/0195159 A1, Jul. 12, 2018
Int. Cl. C23C 2/26 (2006.01); C22C 38/00 (2006.01); C22C 38/04 (2006.01); C23C 2/02 (2006.01); C23C 2/06 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01); C23C 8/10 (2006.01); B32B 15/04 (2006.01)
CPC C23C 2/06 (2013.01) [C22C 38/001 (2013.01); C22C 38/04 (2013.01); C23C 2/022 (2022.08); C23C 2/026 (2022.08); C23C 2/261 (2022.08); C23C 2/28 (2013.01); C23C 2/40 (2013.01); C23C 8/10 (2013.01); Y10T 428/12799 (2015.01); Y10T 428/12917 (2015.01); Y10T 428/12924 (2015.01); Y10T 428/12931 (2015.01); Y10T 428/12937 (2015.01); Y10T 428/12951 (2015.01); Y10T 428/12958 (2015.01)] 7 Claims
OG exemplary drawing
 
1. A method of manufacturing a hot-press part, the method comprising:
coating a metal on a steel sheet to form a metal coated steel sheet, wherein the metal is one or more selected from the group consisting of Ni, Co, Cu, Sn and Sb, and wherein the metal has a reduced amount of Gibbs free energy for one mole of oxygen during an oxidation reaction, the reduced amount of Gibbs free energy being smaller than that of Cr;
annealing the metal coated steel sheet to form an annealed steel sheet at a temperature range of 700° C. to 900° C. in a gas atmosphere of 3 to 5 vol % of hydrogen (H2) where a dew point temperature of the gas atmosphere is −10° C. or less;
forming a zinc plating layer on the annealed steel sheet to form a zinc-plated steel sheet by dipping the annealed steel sheet in a molten zinc plating bath;
heating the zinc-plated steel sheet within a temperature range of about 750° C. to about 950° C. at a heating rate ranging from about 2° C./sec to about 10° C./sec in an oxidizing atmosphere to form a heated zinc-plated steel sheet; and
press forming the heated zinc-plated steel sheet to form the hot-press part,
wherein the hot-press part comprises:
a base steel sheet;
a zinc plating layer including a Fe—Zn phase having a metal, in which a reduced amount of Gibbs free energy for one mole of oxygen during an oxidation reaction is smaller than that of Cr, dissolved in an amount of about 0.008 wt % or more formed on the base steel sheet; and
an oxide layer having an average thickness range of about 0.01 μm to about 5 μm formed on the zinc plating layer, and
wherein the oxide layer comprises a continuous coating layer having an average thickness range of about 10 nm to about 300 nm, the continuous coating layer comprising one or more oxides selected from the group consisting of SiO2 and Al2O3, and an oxide including ZnO and MnO is formed on the continuous coating layer.