process for the manufacture of lochmasken for farbbildröhren

摘要

PURPOSE:To produce a shadow mask of superior photoetching characteristics and press formability for color televisions by decarburizing and annealing an extra low carbon Al killed steel strip of an extremely small solid solutionized N amount within the specific temperature range. CONSTITUTION:The slab of an Al killed steel contg. 0.01%C, 0.10-1.00% Mn, 0.025%S, 0.010-0.120% sol.Al, and 100ppmN and having the quantitative relation of (sol.Al/N)X14/27=1.5 is made to a steel strip of =0.2mm. thickness by hot rolling-cold rolling-annealing-skin pass rolling. After this steel strip is pierced by photoetching, it is subjected to final annealing for 1-10min at 650-850 deg.C temperatures in a decarburizing atmosphere to fix the solid solutionized N in the steel strip as AlN. The press formability is considerably improved and the product superior as a shadow mask for color television cathode-ray tubes is obtained.