| 摘要 |
PURPOSE:To produce a zero spangle zinc plated steel plate of uniform surface appearance by charging an inert gas of controlled concn. of O2 into a sealed box provided on a zinc hot dipping bath contg. prescribed components, and controlling the zinc adhesion of a steel plate passing in the box. CONSTITUTION:First, a steel strip 1 is subjected sufficiently to pretreatments such as cleaning of the surfaces to be plated and the like in order to suit for plating. Next, the strip 1 is plated by using a zinc hot dipping bath consisting of <=0.04% Pb, 0.1-0.3% Al, and the balance unavoidable impurities and Zn. Following to this, the strip 1 is conducted into a sealed box 5 charged with N2 at ordinary temp. and kept at <=2.0% concn. of O2. The zinc adhesion weight is controlled in the box 5. The resultant zinc plated steel plate has no spangles (zero spangle) and has smooth specular gloss. |
