Iron-nickel alloy shadow mask for a color cathode-ray tube

A shadow mask having a plurality of apertures therethrough for use in a color cathode-ray tube, said shadow mask comprising an improved iron-nickel alloy sheet consisting essentially of the following composition limits in weight percent:

• C.ltoreq.0.04, Mn.ltoreq.0.1, Si.ltoreq.0.04, P.ltoreq.0.012, S.ltoreq.0.012, Ni 34.5-37.5, Al.ltoreq.0.08, Y.ltoreq.0.5 and the balance being Fe and impurities unavoidably coming into said alloy during the course of production thereof, and
• an oxide layer formed on said alloy sheet, said oxide layer being stabilized and bound to said alloy sheet by Y.sub.2 O.sub.3 dispersed at interstitial sites throughout the lattice said alloy sheet.

A shadow mask having a plurality of apertures therethrough for use in a color cathode-ray tube, said shadow mask comprising an improved iron-nickel alloy sheet consisting essentially of the following composition limits in weight percent:

• C.ltoreq.0.04, Mn.ltoreq.0.1, Si.ltoreq.0.04, P.ltoreq.0.012, S.ltoreq.0.012, Ni 34.5-37.5, Al.ltoreq.0.08, Y 0.1-0.2 and the balance being Fe and impurities coming into said alloy during the course of production thereof, and
• an oxide layer formed on said alloy sheet, said oxide layer comprising a major proportion of maghemite (.gamma.-Fe.sub.2 O.sub.3) and magnetite (Fe.sub.3 O.sub.4), and a minor proportion of hematite (.alpha.-Fe.sub.2 O.sub.3) and yttria (Y.sub.2 O.sub.3), said oxide layer being stabilized and bound to said alloy sheet by Y.sub.2 O.sub.3 dispersed at interstitial sites throughout the lattice of said alloy sheet.