Process for producing, by continuous annealing, soft blackplate for surface treatment

摘要

Steel blackplate for surface treatment, having a soft temper degree of T-3 or less, and improved fluting resistance is produced by the combination of a chemical composition of 0.01% to 0.08% carbon, 0.015% or less phosphorus, without titanium and niobium; steelmaking without vacuum-degassing; a low slab-heating temperature of 1240 DEG C. or less; a coiling temperature of 620 DEG C. to 710 DEG C.; continuous annealing having a heat pattern to decrease the solute carbon and nitrogen; and skin-pass rolling.