Method of manufacturing a high-strength steel plate for cathode-ray tube frame

摘要

PROBLEM TO BE SOLVED: To provide a high strength steel sheet for a cathode-ray tube frame which has excellent cold strength, high temperature strength and blackening treatability, and in which the reduction of expanded tension after blackening treatment is suppressed.;SOLUTION: The high strength steel sheet for a cathode-ray tube frame is produced by subjecting a slab having a composition containing, by mass, 0.03 to 0.3% C, 0.02 to 1.0% Si, 0.1 to 2.5% Mn, ≤0.15% P, ≤0.03% S, ≤0.1% Al, 0.03 to 0.2% Cu and 0.01 to 0.4% of one or more kinds of elements selected from Nb, V and Ti, and, if required, containing one or more kinds of elements selected from ≤1.5% Cr, 0.01 to 1% Mo, ≤0.5% W and ≤0.1% Ni, and the balance substantially Fe to hot rolling at a finishing temperature of 800 to 950°C and a coiling temperature of 400 to 600°C, and, before or after pickling, performing skinpass rolling at a rolling ratio of 0.3 to 7.0%.;COPYRIGHT: (C)2003,JPO