PREPARATION OF COLD ROLLED STEEL PLATE LOW IN ANISOTROPY AND EXCELLENT IN DEEP DRAWING PROPERTY DUE TO CONTINUOUS ANNEALING PROCESS

摘要

PURPOSE:To enable the preparation of a cold rolled steel plate low in anisotropy and excellent in deep drawing property, by a method wherein ultra-low carbon steel is processed into a steel plate by hot rolling and cold rolling under specific conditions and the obtained steel plate is continuously annealed. CONSTITUTION:A steel slab containing less than 0.0045% C, less than 0.30% Mn, 0.010-0.100% Al and 7.25XC% or less Nb when C is 0.0045-0.0020% or 0.0155% or less Nb when C is 0.0020% or less is hot rolled so as to adjust a hot rolling finish temp. to an Ar3 transformation point or less. This hot rolled steel plate is taken up at 700 deg.C or less to be cold rolled succeedingly and the obtained cold rolled steel plate is continuously annealed within a temp. range of recrystallizing temp. -910 deg.C. As the result, a cold rolled steel plate low in anisotropy and excellent in deep drawing property can be prepared at low cost by a continuous annealing process.