| 摘要 |
PURPOSE:To obtain a steel sheet for a titled can having excellent openability by regulating the secondary cold rolling rate after hot rolling, primary cold rolling and annealing which are intermediate stages for producing a steel sheet for an ordinary can in a specific range from the relation among the hardness, content of C and cleanliness after annealing. CONSTITUTION:The above-described secondary cold rolling rate R is regulated by the equation and is made into the range of R<45 then hot rolling, primary cold rolling, annealing and secondary cold rolling which are intermediate stages for the steel sheet for the can are successively accomplished. Hardness H in this case varies with an annealing method (box annealing, continuous annealing, etc.), annealing conditions (temp. and heating and cooling conditions) and steel components and is generally in a 40-65 range in HR30T hardness. The content of C can be adjusted in a <=1,300ppm range with the steel plate for the can according to the decarburized state of the molten steel or the presence of absence of decarburization annealing in the intermediate stage. The resulting steel sheet for the easy-to-open can has good openability even if the residual thickness of a score is the same and further the reduction in the residual thickness of the score is made possible. |
