HETEROGENEOUS COATED STEEL SHEET HAVING EXCELLENT WORKABILITY AND CORROSION RESISTANCE, AND METHOD FOR MANUFACTURING SAME
Provided is a coated steel sheet which can be used in vehicles, home appliances, construction materials, and the like, and more specifically, to a heterogeneous coated steel sheet having a zinc coating layer formed on one surface thereof and a zinc-magnesium coating layer formed on the other surface thereof. The heterogeneous coated steel sheet includes: a steel sheet; a zinc coating layer attached to one side of the steel sheet; and a zinc-magnesium alloy coating layer attached to the other side of the steel sheet, wherein a coating adhesion amount of the zinc coating layer is 5 to 60 g/m 2 , a coating adhesion amount of the zinc-magnesium alloy coating layer is 10 to 40 g/m 2 , and a magnesium content of the zinc-magnesium alloy coating layer is 8 to 30 wt %.
1 . A heterogeneous coated steel sheet having excellent workability and corrosion resistance, comprising:
a steel sheet;
a zinc coating layer attached to one side of the steel sheet; and
a zinc-magnesium alloy coating layer attached to the other side of the steel sheet,
wherein a coating adhesion amount of the zinc coating layer is 5 to 60 g/m 2 ,
a coating adhesion amount of the zinc-magnesium alloy coating layer is 10 to 40 g/m 2 , and
a magnesium content of the zinc-magnesium alloy coating layer is 8 to 30 wt %.
2 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 1 , wherein the zinc-magnesium alloy coating layer has a multilayer structure of two or more layers.
3 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 1 , further comprising a zinc layer between the steel sheet and the zinc-magnesium alloy coating layer.
4 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 3 , wherein a coating adhesion amount of the zinc layer is 3 g/m 2 or more.
5 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 1 , further comprising a zinc layer on the zinc-magnesium alloy coating layer.
6 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 5 , wherein a coating adhesion amount of the zinc layer is 10 g/m 2 or more and 20 g/m 2 or less.
7 . The heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 1 , wherein a corrosion potential of the zinc-magnesium alloy coating layer is −1.07 to −1.13 V(SCE).
8 . A method of manufacturing a heterogeneous coated steel sheet having excellent workability and corrosion resistance, the method comprising:
preparing a steel sheet;
levitating a coating material by electromagnetic force in a vacuum chamber to generate zinc deposition vapor, and forming a zinc coating layer having an adhesion amount of 5 to 60 g/m 2 on one surface of the steel sheet by inducing and ejecting the zinc deposition vapor; and
generating zinc-magnesium alloy deposition vapor by levitating a coating material by electromagnetic force in a vacuum chamber, and forming a zinc-magnesium alloy coating layer having an adhesion amount of 10 to 40 g/m 2 on the other surface of the steel sheet by inducing and ejecting the zinc-magnesium alloy deposition vapor,
wherein a Mg content contained in the zinc-magnesium alloy deposition vapor is 8 to 30 weight %.
9 . The method of manufacturing a heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 8 , wherein the forming of the zinc coating layer and the forming of the zinc-magnesium alloy coating layer are sequentially performed regardless of an order, or are simultaneously performed.
10 . The method of manufacturing a heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 8 , further comprising forming a zinc layer before and/or after forming the zinc-magnesium alloy coating layer.
11 . The method of manufacturing a heterogeneous coated steel sheet having excellent workability and corrosion resistance of claim 10 , wherein the zinc layer is formed by generating zinc deposition vapor by levitating a coating material by electromagnetic force in a vacuum chamber and by inducing and ejecting the zinc deposition vapor.