| 摘要 |
PURPOSE:To improve the productivity of steel sheets having required hardness by continuously annealing the steel sheets having specific components according to the hardness of the steel sheets to be produced and then selectively using the kinds of temper rolling. CONSTITUTION:The steel sheets respectively contg., by weight, <=0.005% C and 0.001%<=(Nb or Ti)<=0.01% are continuously annealed and are then subjected to the wet process temper rolling at the time of producing the steel sheets having 46 to 60 hardness (HR30T). The steel sheets which contain, by weight, 0.01%<C<0.1% and does not contain carbonitride forming elements are subjected to the continuous annealing then to the dry process temper rolling at the time of producing the steel sheets having 61 to 72 hardness (HR30T). |
