SURFACE TREATED STEEL SHEET FOR CAN MAKING

摘要

PURPOSE:To develop a steel sheet for can making having excellent weldability and corrosion resistance by plating Sn at different weights on both surfaces of the steel sheet having an Fe-Ni alloy layer and alloying part thereof to the Fe-Ni layer then forming a chromate layer thereon. CONSTITUTION:The Fe-Ni alloy contg. 2-50% Ni is coated to 10-5,000Angstrom thickness by a method such as plating on both surfaces of the steel sheet as a stock for can making. Sn is plated at 0.1-1.0g/m<2> on the surface of the steel sheet having such Fe-Ni alloy layer on the side where the inside surface of the can is formed and at 1.0-5.0g/m<2> on the side where the outside surface of the can is formed. The Sn plating surface is subjected to a tin melting treatment by an electrical resistance heating or other method to alloy part of the plated Sn to the Fe-Ni-Sn alloy layer. Such a chromate film at which the chromate is incorporated at 5-30mg/m<2> in terms of Cr is finally formed on such surface. The surface treated steel sheet for can making having excellent weldability as well as the excellent corrosion resistance after painting on the inside surface side of the can and rust resistance without painting on the outside surface side of the can is thus developed.