| 摘要 |
PURPOSE: A method for producing cold rolled steel sheets is provided to have excellent stretching property while having non-aged characteristic by improving ductility. CONSTITUTION: A steel slab is composed of 0.0005-0.002wt% of C, 0.05-0.3wt% of Mn, under 0.015wt% of S, under 0.015wt% of P, 0.01-0.08wt% of Al, 0.001-0.005wt% of N, under 0.025wt% of C+N+S+P, and the remnant wt% of Fe and impurities. Then, the steel slab is hot rolled at a temperature of over the deformation temperature of Ar3 for being wound up at the temperature of under 750°C. The steel slab is cold rolled at a reduction ratio of 50-90% for being annealed at the temperature of 650-850°C for 10 seconds. Thus, non-aged cold rolled steel sheets are produced.
|
