| 摘要 |
PURPOSE:To obtain easily an alloyed hot-galvanized steel sheet by coating the surfaces of a steel sheet with Ni, hot-galvanizing the sheet, and heat treating it to cause rapidly an alloying reaction. CONSTITUTION:The surfaces of a steel sheet are degreased, pickled, and coated with Ni or an Ni alloy by about 0.05-20g/m<2> (expressed in terms of Ni). The coated steel sheet is hot-galvanized by dipping in a molten zinc bath, and it is heat treated with an infrared heater or the like to alloy each zinc layer. By this method, an alloyed hot-galvanized steel sheet can be manufactured in a short time by on-line operation. |
