| 摘要 |
<p>PURPOSE: A steel sheet having an excellent yield strength and elongation and a manufacturing method thereof are provided to include below 0.005% of C, 0.003 to 0.015% of B, below 0.03% of Si, below 0.015% of S, below 0.01% of P, and below 0.005% of N, thereby preventing the generation of secondary working brittleness and surface defects. CONSTITUTION: A steel sheet having an excellent yield strength and elongation includes below 0.005 wt% of C(excluding 0 wt%), 0.003 to 0.015 wt% of B, below 0.03 wt% of Si(excluding 0 wt%), below 0.015 wt% of S(excluding 0 wt%), below 0.01 wt% of P(excluding 0 wt%), below 0.005 wt% of N(excluding 0 wt%), remnant Fe, and other inevitable impurities. The work-hardening exponent of the steel sheet is over 0.25. The steel sheet is one selected from a group of a cold rolled steel sheet, a galvanized steel, and an alloyed galvanized steel.</p> |
