| 摘要 |
PURPOSE:To obtain a surface treated steel sheet having superior corrosion and shock resistances and adhesion by forming a high Ni-Zn alloy layer contg. Co and having an alpha-phase as a lower layer and a Zn-Ni alloy layer contg. Co and having a single gamma-phase as an upper layer by plating on a steel sheet for an automobile body. CONSTITUTION:An Ni-Zn alloy layer contg. 0.1-1wt% Co and 52-100wt%, preferably 60-95wt% Ni and having an alpha-phase as a lower layer and an Ni-Zn alloy layer contg. 0.1-1wt% Co and having a single gamma-phase as an upper layer are formed by plating on a steel sheet used as the inner or outer sheet of an automobile body. The thickness of the lower layer is 0.005-0.5mum and that of the upper layer is 2-5mum. A steel sheet having superior corrosion and shock resistances and adhesion is obtd.
|
