STEEL SHEET WITH NICKEL - TIN AND LEAD - TIN LAYERS FOR FUEL TANK

摘要

A steel sheet plated with Pb-Sn alloy, suitable for use as the material of automobile fuel tanks for containing fuel having alcoholic content. The steel sheet has an NiSn alloy layer or a composite layer including a backing Ni layer and the NiSn alloy layer; the NiSn alloy layer or the composite layer being formed on the steel surface to have a thickness of 0.035 to 1 .mu.; and a plating layer of a Pb-Sn system alloy formed on the sole NiSn layer or the NiSn layer of the composite layer. The steel sheet plated with Pb-Sn alloy can be produced by plating the steel sheet with Ni backing, forming a Pb-Sn system alloy layer by a hot dip coating, and rapidly cooling the steel sheet. Alternatively, the steel sheet plated with Ni is subjected to successive electroplating with Sn and then with Pb, and is then treated at a specific temperature for melting and diffusing Sn into Ni to form the NiSn layer.