公开(公告)号：US12227851B2

公开(公告)日：2025-02-18

申请号：US16615955

申请日：2017-09-01

Applicant: NIPPON STEEL NISSHIN CO., LTD.

Inventor： Susumu Fujiwara ,  Shinya Uesugi ,  Tomoharu Shigetomi

IPC: C23C2/06 ,  C21D3/06 ,  C21D8/02 ,  C22C18/04 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/32 ,  C23C2/02 ,  C23C2/26 ,  C23C2/28

Abstract: A high-strength surface-coated steel sheet includes a base steel sheet having a composition by mass of C: 0.01 to 0.20%, Si: 0.01 to 0.50%, Mn: 0.10 to 2.50%, P: 0.005 to 0.050%, B: 0.0005 to 0.010%, Ti: 0.01 to 0.20%, Nb: 0 to 0.10%, Mo: 0 to 0.50%, Cr: 0 to 0.50%, Al: 0.01 to 0.10%, and the balance of Fe and inevitable impurities; and a Zn—Al—Mg-based coating layer disposed on a surface of the base steel sheet, The steel sheet has a diffusible hydrogen concentration in the base steel sheet of 0.30 ppm or less and having a time until occurrence of red rust of 7000 hours or more as measured by a salt spray test. The high-strength hot-dip Zn—Al—Mg-based-plated steel sheet has a significantly lowered in-steel concentration of hydrogen which has entered the steel in a plating line and exhibits excellent corrosion resistance.

公开(公告)号：US10351925B2

公开(公告)日：2019-07-16

申请号：US15127820

申请日：2015-03-26

Applicant: NIPPON STEEL NISSHIN CO., LTD.

Inventor： Yukio Katagiri ,  Akito Kawamoto ,  Susumu Fujiwara

IPC: C22C38/02 ,  C22C38/04 ,  C22C38/16 ,  C22C38/20 ,  C22C38/22 ,  C22C38/42 ,  C22C38/44 ,  C22C38/12 ,  C21D9/46 ,  C21D8/02 ,  C22C38/00 ,  C22C38/60 ,  C22C38/06 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  B22D11/00

Abstract: A steel plate excellent in acid dew point corrosion resistance has a composition, in mass percent, from 0.001 to 0.15% of C, 0.80% or less of Si, 1.50% or less of Mn, 0.025% or less of P, 0.030% or less of S, from 0.10 to 1.00% of Cu, 0.50% or less of Ni, from 0.05 to 0.25% of Cr, 0.01 to 0.08% of Mo, 0.100% or less of Al, from 0 to 0.20% in total of Ti, Nb, and V, from 0 to 0.010% of B, from 0 to 0.10% in total of Sb and Sn, and a balance of Fe and unavoidable impurities, having a ferrite single phase structure, or a structure containing 30% by volume or less in total of one or more of cementite, pearlite, bainite, and martensite, with the balance ferrite phase. Ferrite crystal grains have an average crystal grain diameter of 12.0 mm or less.