| 摘要 |
PURPOSE:To provide an electric iron sheet whose punchability and surface insulating characteristics are enhanced by carrying out zinc plating and then forming a zinc phosphate film of a specific thickness. CONSTITUTION:An electric iron sheet suitably contg. C, Si, Mn, P, S, Al, O and N is electroplated with 0.5-10g/m<2> of zinc. Next about 2g/m<2> of a zinc phosphate film is formed on the zinc plated film by chemical treatment. Thus, the punchability can be enhanced remarkably by the synergism of the lubricating effect of the zinc and the punching oil delivering effect of the phosphate, resulting in an electric iron sheet with superior surface insulating characteristics and punchability. |
