Patent ID: 6489711
Filing Date: 2002-12-03
Classification: C23F,H01J

Abstract:
A shadow mask for a color picture tube that is made of an iron-base alloy material containing nickel and has a low coefficient of thermal expansion, wherein a grain size number of said iron-base alloy material measured by a grain size measuring method defined by ASTM E112 (JIS G0551) is not more than 7.5,wherein said iron-base alloy material is press-formed without carrying out annealing after it has been provided with apertures in a predetermined pattern, wherein said iron-base alloy material has a 0.2% proof stress in a range of from 220 to 300 N/mm2, and wherein a degree of texture in each plane of said iron-base alloy material measured by X-ray diffraction method is not more than 20%, and a difference between the degree of texture in each plane and that in any other plane is not more than 20%.