Shadow mask for cathode ray tubes used in color TV screens and computer screens consists of sheet metal made of an iron alloy containing nickel and cobalt

摘要

Shadow mask consists of sheet metal made of an iron alloy containing 31.0-38.0 wt.% nickel and 1.0-6.5 wt.% cobalt. The alloy has a crystal grain size fraction of 10 or more and 12 or more, a crystal grain size of 50 microns or less in a cross-section parallel and vertical to the rolling direction of the sheet and an average crystal grain size of 30 microns in a cross-section parallel to the rolling direction of the sheet. Preferred Features: The alloy has a heat expansion coefficient of approximately 4.0 x 10-6/ deg C.