METHOD FOR MANUFACTURING TENSILE STRENGTH 590MPa CLASS COLD ROLLED DP STEEL WITH EXCELLENT WORKABILI

文件类型：PDF文档
文件大小：353K
PURPOSE : A method for manufacturing high-strength hot-rolled DP steel with a tensile strength of about 590MPa and low property deviation is provided to reduce energy consumption by excluding a re-heating process from the processes of the conventional mill. CONSTITUTION : A method for manufacturing high-strength hot-rolled DP steel comprises the steps of : continuously casting steel into a thin slab(a) 30-150mm thick, roughing, heating, finish rolling, cooling, and coiling the thin slab to obtain a hot-rolled strip(b), and picking, cold rolling, continuous annealing, and cooling the hot-rolled strip. In the finish rolling step, rolling speed deviation in a single strip is controlled to 15%% or less and the rolling temperature of the final rolling stand is controlled to ±20°C of a target temperature. In the cooling step, the annealed strip is continuously cooled at a cooling speed of 10-150°C/s to a temperature of 200-400°C. COPYRIGHT KIPO 2012