Porcelain-enameled steel sheets and frits for enameling

摘要

A porcelain enameled steel sheet comprises an aluminum/zinc alloy-plated steel sheet and a porcelain enamel coating layer as the upper most layer of the steel sheet, wherein an interstitial layer having good adhesion to the plating layer and the enamel coating layer is sandwiched between these two layers. The intermediate layer is preferably a member selected from the group consisting of: (1) the surface layer on the aluminum/zinc alloy-plating layer, whose aluminum content is not less than 96% by weight; (2) the surface layer on the aluminum-zinc alloy-plating layer, which comprises aluminum, nickel and not more than 1% by weight of zinc; (3) a coating layer comprising at least one member selected from the group consisting of Ni, Co, Mo, Mn, Ni-P, Ni-Co-P and Co-P; (4) a chromate layer; and (5) a coating layer comprising at least one member selected from the group consisting of zinc phosphate, manganese phosphate and aluminum phosphate. The porcelain enameled steel sheet is excellent in both corrosion resistance and enamel-adhesive properties and can thus be used in various fields, in particular, in the field wherein it is post-processed through bending.