Toyo Kohan Co., Ltd.

Susumu Shigemasa

Tsuneyuki Ide

Yasuo Tahara

Hironao Okayama

Taizo Sato

Akira Ikeda

Takahiko Miyazaki

Hiroaki Ikenaga

An aperture grill material for a color picture tube having excellent tensile strength and high-temperature creep characteristics and magnetic characteristics superior to existing materials, a production method therefor, an aperture grill and a color picture tube. The aperture grill material for a color picture tube is characterized by being consisting of a low-carbon alloy steel sheet containing 0.05 to 2.5% by weight of Cu and 0.001 to 0.4% by weight of P, and containing 0.01 to 0.5% by weight of at least one of at least one of Cr and Mo. A production method for the aperture grill material for a color picture is characterized by comprising the steps of cold-rolling a low-carbon alloy hot-rolled steel strip containing 0.05 to 2.5% by weight of Cu, 0.001 to 0.4% by weight of P, and 0.01 to 0.5% by weight of at least one of Cr and Mo, and then precipitating the steel strip within a temperature range 300 to 800&deg; C.

Method for manufacturing an aperture grill material for color picture tube

An invar alloy steel sheet for shadow masks is provided which has improved etchability, an economical production method, a shadow mask made of the invar alloy steel sheet, and a color picture tube which incorporates the shadow mask. The invar alloy steel sheet is produced by hot working an alloy slab consisting of 33 top 40 wt % nickel with the balance being iron, and then subjecting the slab to a primary cold rolling at a rolling reduction ratio of not more than 80%, annealing at a temperature of at least 550&deg; C., and subjecting the slab to a secondary cold rolling at a rolling reduction ratio of not more than 50%. The invar alloy steel sheet has a percentage of &lcub;100&rcub; texture of 60 to 80%.

Method for production of invar alloy steel sheet material for shadow mask

Growing community of inventors

Yamaguchi-ken, Japan

Susumu Shigemasa