| 摘要 |
PURPOSE:To improve moldability of curved surface and prevent deformation thereof by specifying weight ratio of Mn included in the shadow mask which is provided with many pinholes and mainly consisting of Fe-Ni. CONSTITUTION:The shadow mask provided with many pinholes used for color picture tube is composed of a thin plate mainly consisting of the Fe-Ni system alloy, Mn included in such thin plate of shadow mask is 0.1% or less in wt%, growth of crystal grains of surface is accelerated as in the case of inside of shadow mask, and thereby strength of yielding point is lowered. Accordingly, the moldability of curved surface of shadow mask mainly consisting of the Fe-Ni system alloy can be improved assuring high precision and high quality surface grade preventing deformation, and a color picture tube without deterioration of color purity can be obtained. |
