STOCK FOR COLD ROLLED STEEL SHEET FOR DEEP DRAWING EXCELLENT IN RIDGING RESISTANCE AFTER COLD ROLLING-ANNEALING

摘要

PROBLEM TO BE SOLVED: To develop a hot rolled steel sheet as the stock for a cold rolled steel sheet for deep drawing excellent in ridging resistance after cold rolling- annealing by specifying the orientative concentrating degree in the colonies in a hot rolled steel sheet of a low carbon steel having a specified compsn. ;SOLUTION: A steel contg., by weight, 0.01% C, 2.0% Si, 3.0% Mn, 0.15% P, 0.05% S, 0.01 to 0.20% Al and 0.01% N or furthermore contg. one or two kinds of 0.001 to 0.2% Ti and 0.001 to 0.2% Nb or 0.0001 to 0.008% B is subjected to hot rolling and cold rolling and is successively subjected to recrystallization annealing. In this case, the orientative concentrating degree in the colonies in the hot rolled steel sheet S=X₂₀°/X₃₀° is prescribed to ≤0.8 (where X₃₀° denotes the area of the colony in which the difference in the orientation between the adjacent crystal grains is regulated to ≤30°, and X₂₀° denotes the area of the colony in which the difference in the orientation between the adjacent crystal grains in the X₃₀°). The hot rolled steel sheet as the stock for a cold rolled steel sheet having ridging resistance and deep drawability remarkably more excellent than those of the conventional one can be obtd.;COPYRIGHT: (C)1998,JPO