| 摘要 |
<p>PURPOSE: A cold rolled steel sheet and a manufacturing method thereof are provided to manufacture a complex product with high strength by increasing elongation ratio. CONSTITUTION: A manufacturing method of a cold rolled steel sheet comprises the next step. The slab, including at least one of titanium, niobium and aluminum and at least, one of manganese, phosphorus, and silicon, is cooled in a first rate after heat rolling. The slab is kept in 700~800°C temperature range after cooling. The slab is cooled in a second rate which is higher than the first rate after the sustain step. The slab is wound and cool rolled after cooling.</p> |
