公开(公告)号：US10793936B2

公开(公告)日：2020-10-06

申请号：US15539669

申请日：2015-12-23

Applicant: POSCO

Inventor： Myung-Soo Kim ,  Ki-Cheol Kang ,  Jong-Ho Kim

IPC: C22C38/58 ,  C21D8/02 ,  C23C2/06 ,  C22C38/44 ,  C22C38/04 ,  C22C38/60 ,  C22C38/00 ,  C22C38/48 ,  C22C38/54 ,  C21D8/04 ,  C23C2/02 ,  C23C2/40 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C22C38/50

Abstract: A high strength galvanized steel sheet having excellent surface qualities, plating adhesion, and formability is provided, wherein a galvanized layer is formed on a cold-rolled steel sheet comprising 0.1-0.3 wt % of C, 1-2.5 wt % of Si, 2.5-8 wt % of Mn, 0.001-0.5 wt % of sol. Al, at most 0.04 wt % of P, at most 0.015 wt % of S, at most 0.02 wt % of N (excluding 0 wt %), 0.1-0.7 wt % of Cr, at most 0.1 wt % of Mo, (48/14)*[N] to 0.1 wt % of Ti, 0.005-0.5 wt % of Ni, 0.01-0.07 wt % of Sb, at most 0.1 wt % of Nb, and at most 0.005 wt % of B, with the remainder being Fe and other inevitable impurities.

公开(公告)号：US20230024286A1

公开(公告)日：2023-01-26

申请号：US17785845

申请日：2020-10-13

Applicant: POSCO

Inventor： Rho-Bum Park ,  Jong-Ho Kim

IPC: C25D5/36 ,  C22C38/04 ,  C22C38/02 ,  C25D5/48 ,  C23C2/02 ,  C23C2/34

Abstract: The present invention relates to a steel sheet with improved yellowing resistance and phosphatability, wherein the steel sheet contains 0.5% by weight or more of Mn, and contains 0.01 to 10 mg/m2 of Ca+Mg, 0.01 to 10 mg/m2 of P, 0.01 to 20 mg/m2 of C, and 0.05 to 30 mg/m2 of O as components excluding a steel component on the surface of the steel sheet after pickling, water rinsing, and drying. According to the present invention, in a manufacturing process of the steel sheet, the surface of the steel sheet is subjected to a chemical conversion treatment for improving phosphatability and yellowing resistance in a water-cooling section or a water-washing section, thereby having an effect of improving the surface quality of products using same and various subsequently treated products.