Massive white points outspreading along rolling direction on the surface of Sn-Fe alloy layer was discovered after removing tin coating of tinplates offered by some steel works.

• 脱去镀锡板的自由锡层后,在锡铁合金层的表面目视发现了大量沿轧制方向伸展的白点,并且合金层的耐蚀性随着白点数量与覆盖面积的增加而下降。