Shadow mask of braun tube for color TV and process for manufacturing the same
AssigneesNisshin Steel Co., Ltd., Dai Nippon Printing Co., Ltd.
InventorsTakashi Matsukura, Norio Tsukiji, Yoshiaki Ishimoto, Masahiro Shimose, Yasuo Imamura
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Abstract
A shadow mask of a Braun tube for a color TV made of a steel alloy having the following compositions in weight percent: C.ltoreq.0.12, 0.2.ltoreq.Mn.ltoreq.1.5, 0.3.ltoreq.Si.ltoreq.1.5, 1.0.ltoreq.2Si+Mn, 0.005.ltoreq.Al.ltoreq.0.030, and the balance being Fe and unavoidable impurities. A cold rolled and annealed strip made from such a steel alloy has a Vickers hardness of at least 110 so that it can be easily and satisfactorily processed in the subsequent hole-formation step.
Claims7
A shadow mask of a Braun tube for a color TV made of a strip of low carbon steel, characterized in that said low carbon steel falls within the following composition limits in weight percent:
- C.ltoreq.0.12, 0.2<Mn<1.5, 0.3.ltoreq.Si.ltoreq.1.5, 1.0.ltoreq.2Si+Mn, 0.005.ltoreq.Al.ltoreq.0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof.
A process for manufacturing a shadow mask of a Braun tube for a color TV comprising the steps of subjecting a strip of low carbon steel to a cold rolling finish to provide a steel strip material of not more than 0.2 mm in thickness, annealing the so-rolled material, forming predetermined patterns of holes in the annealed strip material by a photoetching technique, cutting the material into individual flat masks of a predetermined dimension, and pressforming the flat mask into a desired shape, characterized in that said low carbon steel falls within the following composition limits in weight percent:
- C.ltoreq.0.12, 0.2.ltoreq.Mn.ltoreq.1.5, 0.3.ltoreq.Si.ltoreq.1.5, 1.0.ltoreq.2Si+Mn, 0.005.ltoreq.Al.ltoreq.0.030, and the balance being Fe and impurities unavoidably coming into said steel during the course of the production thereof, and that said annealed strip material has a Vickers hardness of at least 110.
Dependencies are inferred from the claim text.