HIGH DUCTILITY AND STRENGTH COLD ROLLED STEEL SHEET WITH REDUCED CRACKING IN HOT-ROLLING AND METHOD FOR MANUFACTURING THE SAME

摘要

The present invention relates to a cold rolled steel sheet appropriately used for a vehicle structure member, building materials, or the like. More specifically, the present invention relates to a high ductility and strength cold rolled steel sheet without cracking during hot-rolling, and a method to manufacture the same. According to an aspect of the present invention, provided is a high ductility and strength cold rolled steel sheet with reduced cracking during hot-rolling, comprising: 0.05-0.3 wt% of carbon (C); 3.0-8.0 wt% of manganese (Mn); 1.0-4.0 wt% of aluminum (Al); silicon (Si) in an amount equal to or less than 2.0 wt% (excluding 0 wt%); phosphorus (P) in an amount equal to or less than 0.03 wt% (excluding 0 wt%); sulfur (S) in an amount equal to or less than 0.015 wt% (excluding 0 wt%); nitrogen (N) in an amount equal to or less than 0.02 wt% (excluding 0 wt%); and the remainder consisting of Fe and inevitable impurities.