| 摘要 |
PROBLEM TO BE SOLVED: To provide a relatively inexpensive steel sheet having various characteristics required for a mask frame holding a tension-system color CRT shadow mask under tension such as surface quality, formability, weldability, room temperature and high temperature strength, low creep strain at high temperature and the adhesion of a blackened film. SOLUTION: This steel sheet has a steel composition containing, by mass, 0.03 to 0.30% C, <=0.30% Si, 0.05 to 1.5% Mn, <=0.05% P, <=0.02% S, 0.02 to 0.50% Mo, 0.02 to 0.20% V, <=0.10% Al and 0.0040 to 0.0200% N, containing one or more kinds selected from <=1.0% Cu, <=1.0% Ni, <=2.0% Cr, <=1.0% W,<= 0.003% B, <=0.030% Ti and <=0.030% Nb according to circumstances, and the balance substantially iron with inevitable impurities and satisfying Al <=7.0N and also has a metallic structure in which the ferrite grain size is <=15μm, and the ferrite volume ratio is <=90%.
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