| 摘要 |
Provided are an austenitic high strength, high manganese molten aluminized steel sheet having excellent hot dip aluminum coatability, and a manufacturing method thereof. According to one aspect of the present invention, the austenitic high strength, high manganese molten aluminized steel sheet having excellent hot dip aluminum coatability comprises: 0.3-0.9 wt% of C, 12-25 wt% of Mn, 0.3-3.0 wt% of Al, 0.6-2.5 wt% of Si, 0.01-0.5 wt% of Ti, 0.05-0.5 wt% of V, 0.5 wt% or less of Bi (excluding 0 wt%), 0.0005-0.005 wt% of B, and the remainder consisting of Fe and inevitable impurities. According to another aspect of the present invention, the manufacturing method comprises: a step of heating a matrix steel sheet having the aforementioned composition at a heating speed of 1.6-4.1 °C/s in a reducing atmosphere controlled at a dew point of -30°C or less; a cracking step in which the heated steel sheet is maintained in a reducing atmosphere of 700-850°C; a step of cooling the steel sheet after the cracking step; and a step of forming an aluminum coating layer on the cooled steel sheet. Accordingly, the present invention provides an austenitic high strength, high manganese molten aluminized steel sheet having excellent hot dip aluminum coatability having a yield strength of 700 MPa or greater, and a product of a yield strength and elongation (YSxEL) being 30,000 MPa% or greater. |
