Shadow mask for a color picture tube

摘要

A shadow mask for a color picture tube, which has a plurality of regularly aligned apertures, an oxide film having good adhesion and anticorrosion characteristics which is made of a metal alloy consisting of as the major constituents, iron and nickel, wherein an iron content of at least a surface layer of a portion of the shadow mask which has the apertures is higher than that of the substrate of the metal alloy.