Hot-dipped aluminum coated steel sheet having excellent corrosion resistance and heat resistance, and production method thereof

摘要

A hot-dipped aluminum coated steel sheet including, on the surface thereof, a coating layer consisting of 2 to 15 wt% of Si, not greater than 1.2 wt% of Fe, 0.005 to 0.6 wt% of Mn, 0.002 to 0.05 wt% of Cr and the balance of A l and unavoidable impurities, and an alloy layer disposed between the coating layer and the steel sheet, having a thickness of not greater than 7 mu m and having a mean composition consisting of 20 to 50 wt% of Fe, 3 to 20 wt% of Si, 0.1 to 10 wt% of Mn, 0.05 to 1.0 wt% of Cr and the balance substantially consisting of A l . This steel sheet can be produced by conducting coating in a coating bath consisting of 3 to 15 wt% of Si, 0.5 to 3.5 wt% of Fe, 0.05 to 1.5 wt% of Mn, 0.01 to 0.2 wt% of Cr and the balance substantially consisting of A l , or by adjusting the sum of the concentrations of Zn and Sn in the impurities in the coating layer to not greater than 1 wt%.