Cold rolled steel sheet with excellent workability and manufacturing method (COLD-ROLLED STEEL SHEET HAVING EXCELLENT WORKABILITY AND PROCESS PRODUCING THE SAME)

摘要

The present invention aims to obtain a cold rolled steel sheet having excellent cold workability regardless of high N content in order to reuse scrap steel recycled from scrap, satisfying C 0.1%, N 60-150ppm, relation Mn / S≥7. Mn 0.4% or less, S 0.0030% or less, Al 0.196 or less, and Ti satisfying the relationship N (%)-Ti / 3.42 (%) ≤0.007 or less, and 0.08% or less, wherein at least 1/2 weight of the total TiN weight To obtain a steel sheet having a TiN size of 0.05-10 μm. When manufactured by continuous annealing, Ti is added so as to satisfy the relation N (%)-Ti / 3.42 (%) ≦ 0.004, and further, high temperature winding is applied. Perform in hot rolling or add B.;When manufactured by box annealing, the Ti content is adjusted to satisfy the relation 0.002% ≤N (%)-Ti / 3.42 (%) ≤0.007, the slab heating temperature is set to a higher temperature and the coiling temperature of the hot rolled sheet Set to a lower temperature.