INVAR ALLOY STEEL SHEET MATERIAL FOR SHADOW MASK, METHOD OF PRODUCTION THEREOF, SHADOW MASK, AND COLOR PICTURE TUBE

摘要

An invar alloy steel sheet for a shadow mask having improved etching characteristics, an economical method of production thereof, a shadow mask made from the invar alloy steel sheet, and a color picture tube incorporating the shadow mask. The production method is characterized by hot working a slab of an alloy consisting of 33 to 40 wt.% of Ni and the balance of Fe, applying primary cold rolling at a rolling reduction of not higher than 80 %, annealing the sheet at a temperature not lower than 550 DEG C, and applying further secondary cold rolling at a rolling reduction of not higher than 50 %, so that a planar integration of the {100} plane of the rolled surface is 60 to 80 %.