| 摘要 |
PURPOSE:To improve the weldability of a galvanized steel plate, by specifying the thickness of an Fe-Zn alloy layer in each layer to be formed by galvanizing. CONSTITUTION:In the manufacture of a galvanized steel plate, the thickness of an Fe-Zn alloy layer 5 in a layer 7 to be formed on each surface of steel plate 2 by galvanizing is made two-thirds of the thickness of the layer 7 by regulating the temp. of a galvanizing bath, the Al content of the bath, the dipping time of the plate 2 in the bath and the temp. of the plate 2 to be dipped in the bath and by carrying out heat treatment such as heating and cooling after galvanizing. The remainder of the layer 7 is a Zn layer 6. When such both-side galvanized steel plates 1, 2 are welded with welding tips 3, 3', the plates show higher weldability than conventional galvanized steel plates. |
