Television picture tube inner shielding material having a blackened layer of superior adhesion and method of manufacturing the same

A method of fabricating inner shielding material comprising:

• preparing a slab of a composition of .ltoreq.0.005% C, .ltoreq.2.0% Si, .ltoreq.0.4% P, 0.1 to .ltoreq.1.0% Mn, 0.01% S, .ltoreq.0.1% sol.Al, .ltoreq.0.01% N and the balance Fe and residual impurities;
• fabricating a hot-rolled sheet from the slab;
• cold rolling the hot-rolled sheet to a thickness of 0.10 to 0.25 mm;
• continuously annealing the cold-rolled sheet;
• and
• first forming on the surface of the cold-rolled sheet an oxide film comprised of Fe.sub.3 O.sub.4 by employing an oxidizing gas atmosphere over part or all of the course of the continuous annealing in which the temperature rises from 300.degree. C. to 750.degree. C., and then switching to a non-oxidizing gas atmosphere to carry out soaking treatment, after which cooling is effected in a non-oxidizing atmosphere;
• whereby a blackened layer comprising FeO is formed.