| 摘要 |
PROBLEM TO BE SOLVED: To attain a sheet metal for a shadow mask excellent in low thermal expansion characteristics at low cost, and to provide a shadow mask, a shadow mask assembled body and a cathode-ray tube. SOLUTION: As for the sheet metal for a shadow mask composed of an Fe-Ni alloy containing, by mass, 34 to 38% Ni, and the balance substantially Fe or an Fe-Ni-Co alloy containing 2 to 7% Co and 35 to 39% (Ni+Co), and the balance substantially Fe, the shadow mask and shadow mask assembled body and cathode-ray tube to be mounted with the same, the time of the heat history in the temperature range of 400 to 550 deg.C applied in the cooling stage at the time of a heat treating stage (final annealing, press forming preannealing, blackening treatment, baking treatment and glass sealing treatment) in the producing process therefor is <=30 min (inclusive of 0 min). The same is preferably controlled to <=20 min, and more preferably to <=10 min.
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