A Method For Manufacturing Galvanized High Strength Steel Plate Having Electric and Magnetic Shielding Property by Cold Rolling Condition

PURPOSE: A method for manufacturing high strength hot dip galvanized steel plate having electromagnetic shielding property by controlling cold rolling condition is provided. CONSTITUTION: The method includes the steps of hot rolling a steel slab comprising 0.0150 wt.% or less of C+N+S, Mn 0.2 to 0.8 wt.%, 0.6 wt.% or less of Al, 0.4 wt.% or less of Si, 0.1 to 0.6 wt.% of at least one elements selected from Cu and Sn, a balance of Fe and incidental impurities; cold rolling the hot rolled steel sheet at a reduction ratio of 44 to 70 %, followed by annealing; hot dip galvanizing the annealed steel sheet; and rolling the hot dip galvanized steel sheet at a reduction ratio of 0.2 to 1.0 %. In the method, Mn+Cu+Sn+Si+Al is less than 1.0 wt.%; C and N are less than 0.0030 wt.%, respectively; S is less than 0.009 wt.%. 냉연조건 제어를 통한 전자파 차폐성이 유수한 고강도 용융도금강판 제조방법이 제공된다. 본 발명은, 중량%로, C+N+S: 0.0150%이하, Mn:0.2~0.8%, Al:0.6%이하, Si:0.4%이하, Cu와 Sn중 선택된 1종이상의 합:0.1~0.6%, 잔부 철 및 불가피한 불순물을 포함하여 조성되는 강 슬라브를 열간압연하는 단계; 상기 열연강판을 44~70%의 압하율로 냉간압연한 후 소둔하는 단계; 상기 소둔처리된 강판을 용융도금한 후 0.2~1.0%의 압하율로 경압하하는 단계;를 포함하는 전자파 차폐성이 우수한 고강도 용융도금강판 제조방법에 관한 것이다.