| 摘要 |
PURPOSE:To secure an extremely high alloying speed equal to or faster than the speed in the case of a low Al bath even if a high Al bath with Al concn. of 0.14% or more is used by imparting a newly formed surface to the surface of a steel plate after softening and annealing by mechanical processing in a stage before the steel plate is completely passed through a zinc bath. CONSTITUTION:A steel plate 1 is supplied from a pay-off reel 2 and introduced into a recrystallizing zone 4 through an oxidizing furnace (or a non-oxidizing furnace) 3 and, after introduced into a plating bath 6 through a low temp. keeping zone 5, passed through an alloying treatment furnace 7. In this case, it is necessary to provide a stage for carrying out the aforementioned mechanical processing by a wire brush roll 8 either after the steel plate is completely passed through the zone 4 or before it is completely passed through the bath 6. When this processing is carried out prior to annealing, processing effect is lost by annealing. On the other hand, in a plating method not passing through a flux method and an annealing method out of a plating line or in a plating line, the steel plate is passed through a degreasing, a pickling and a flux tanks 9-11 and a preheating and drying furnace 12. In this case, even if mechanical processing by a belt polishing machine 13 or the wire brush 8 is applied in either stages of pretreating processes 9-12 or the bath 6, entirely same effect can be expected. |
