HIGH STRENGTH LIGHTWEIGHT TRIPLE CLAD STEEL SHEET HAVING EXCELLENT DENT RESISTANCE AND FORMABILITY PROPERTIES

摘要

The present invention relates to a high-strength lightweight triplicated clad steel sheet with excellent dent resistance and machinability, and a manufacturing method thereof. An embodiment of the present invention provides a high-strength lightweight triplicated clad steel sheet with excellent dent resistance and machinability including two high-manganese steel sheets comprising: 0.01-1.0 wt% of C; 8-30 wt% of Mn; 0.01-3.0 wt% of Al; 0.01-3.0 wt% of Si; 0.1 wt% or less of P; 0.02 wt% or less of S; 0.1 wt% or less of N; and the remainder consisting of Fe and inevitable impurities, an aluminum-based plate interposing the two high-manganese steel sheets, and a manufacturing method thereof. The thickness of the high-manganese steel sheet is 0.1-1.0 mm, and the thickness of the aluminum-based plate is 0.1-1.5 mm. The total thickness of the high-strength lightweight triplicated clad steel sheet is 0.8-2.5 mm, and the strength of the high-strength lightweight triplicated clad steel sheet is 40 GPa·mm^3 or higher. The lightweight clad steel sheet of the present invention is capable of remarkably reducing product weight when compared with an existing clad material by obtaining light, and obtains excellent strength and ductility; thereby being desirably applied to components of a vehicle and the like where lightening of a weight is required. In addition, the lightweight clad steel sheet of the present invention is capable of remarkably improve mechanical properties of a vehicle exterior panel such as a door, hood, and a trunk cover exterior material currently manufactured of aluminum.