Patent ID: 11898252
Assignee: POSCO CO., LTD
Field: Surface technology, coating (Chemistry)
Classification: CPC C | IPC C

Claim 1:
2. 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.