| 摘要 |
PURPOSE:To obtain a surface-treated steel plate which is superior in a high speed mush welding and is suited for weight reduction of cans by an extremely simple and highly productive method by cold rolling a steel plate wherein a proper amount of a tin-plating layer is alloyed perfectly with iron. CONSTITUTION:Tin is plated umiformly at about 0.01-2.0g/m<2> (per one side surface in the case of both side plating) on the clean surface of a steel plate. Below this lower limit, the amount of tin is not enough for uniform coating, and the amounts above the upper limit are uneconomical and are undesirable in workability of final products and the like. Next, in order to turn this plating layer perfectly into an Sn-Fe alloy, the steel plate is heated ususlly for about 2-60 seconds at 300-800 deg.C in a nonoxidating atmosphere. Annealing is carried out simultaneously with this heating or annealing is carried out prior to the in plating. The alloying reaches the entire part of the plating layer, and the Fe/Sn atom ratio of the surface layer is kept at about 40-80% for the sake of the final surface characteristics having undergone subsequent cold rolling and working. Thence, this steel sheet is further cold-rolled at 5-40% drafts to a steel sheet of, for example, around 0.16mm. thickness. |
