Aluminum-based alloy-plated steel sheet having excellent workability and corrosion resistance, and manufacturing method therefor

An aluminum alloy-plated steel sheet comprising:

• a base steel sheet;
• and
• an alloy-plated layer formed on the base steel sheet,
• wherein the alloy-plated layer includes:
• a first alloy-plated layer that contains, by wt %, 35 to 50% of Fe, 1 to 20% of Zn, 5% or less of Mn, less than 0.1% of Si, and a balance of Al and unavoidable impurities;
• and
• a second alloy-plated layer that contains, by wt %, 30 to 40% of Fe, 1 to 22% of Zn, 2% or less of Mn, less than 0.1% of Si, and a balance of Al and unavoidable impurities, and
• a ratio of an area occupied by the base steel sheet in a region from a surface roughness center line of the alloy-plated layer to 3/4t is 30% or more, where t is a distance from the surface roughness center line of the alloy-plated layer to the lowest line of the alloy-plated layer.

A method for manufacturing an aluminum alloy-plated steel sheet used for hot press forming, the method comprising:

• preparing a base steel sheet;
• dipping the base steel sheet in an aluminum plating bath that contains, by wt %, 3 to 30% of Zn, less than 0.1% of Si, and a balance of Al and unavoidable impurities to obtain an aluminum-plated steel sheet;
• performing cooling by supplying air heated to 200 to 300° C. to the aluminum-plated steel sheet after the aluminum plating to form an oxide film on a surface of the aluminum-plated steel sheet;
• and
• obtaining an aluminum alloy-plated steel sheet by on-line alloying in which heat treatment is performed after the cooling while maintaining the aluminum-plated steel sheet in a heating temperature range of 650 to 750° C. for 1 to 20 seconds.