| 摘要 |
Provided is a galvanized steel sheet having a tensile strength of 770 MPa or more including a steel sheet portion, and a plated layer formed on the surface of the steel sheet portion, in which the plated layer is a galvanized plated layer or an galvannealed plated layer, the steel sheet portion has a soft layer that directly adjoins the interface with the plated layer and an inside layer that is other than the soft layer, the thickness D of soft layer is 0.001% to 5% of thickness t of the steel sheet portion, and, when the hardness of the soft layer measured by nano-indentation method is indicated by H1, and the representative hardness of the steel sheet portion measured by the nano-indentation method is indicated by Ha in cross section that goes along the thickness direction of the steel sheet portion, H1 is 5% to 75% of Ha. |
| 主权项 |
1. A galvanized steel sheet having a tensile strength of 770 MPa or more, comprising;
a steel sheet portion containing, by mass %,
C: 0.05% to 0.50%,Si: 0.005% to 2.5%,Mn: 0.01% to 3.0%,Al: 0% to 0.5%,Ni: 0% to 2.0%,Cu: 0% to 7.0%,Cr: 0% to 2.0%,Mo: 0% to 2.0%,B: 0% to 0.002%,Ti: 0% to 0.1%,Nb: 0% to 0.1%,V: 0% to 0.1%,REM: 0% to 0.1%,Ca: 0% to 0.1%,P: limited to 0.03% or less,S: limited to 0.02% or less,N: limited to 0.0060% or less, anda remainder of Fe and inevitable impurities; and a plated layer formed on a surface of the steel sheet portion,wherein:
the plated layer is a galvanized plated layer or a galvannealed plated layer, the galvanized plated layer containing Al: 0.01% to 1.5% and one or more selected from Pb, Sb, Si, Sn, Mg, Mn, Ni, Cr, Co, Ca, Cu, Li, Ti, Be, Bi, and REM in a total of 0% to 3.5% with a remainder composed of Zn and inevitable impurities, and the galvannealed plated layer containing Fe: 5% to 15% Al: 0.01% to 1% and one or more selected from Pb, Sb, Si, Sn, Mg, Mn, Ni, Cr, Co, Ca, Cu, Li, Ti, Be, Bi, and REM in total of 0% to 3.5% with a remainder of Zn and inevitable impurities, the steel sheet portion has a soft layer in a direction of the steel sheet surface that directly adjoins an interface with the plated layer on one side and directly adjoins an inside layer that is other than the soft layer on an opposite side, the soft layer is closer to the interface with the plated layer in a thickness direction than the inside layer, a thickness D of the soft layer is 0.001% to 5% of a thickness t of the steel sheet portion, and, when a hardness of the soft layer measured by a nano-indentation method is indicated by H1, and a representative hardness of the steel sheet portion measured by the nano-indentation method is indicated by Ha in a cross section that goes along the thickness direction of the steel sheet portion, H1 is 5% to 75% of Ha. |
