Zinc alloy-plated steel having excellent corrosion resistance and surface smoothness
Provided is a plated steel to be used for automobiles, electric home appliances, building materials and the like and, more specifically, to a zinc alloy-plated steel having excellent corrosion resistance and surface smoothness, and a method for manufacturing the same.
1. A zinc alloy-plated steel having excellent corrosion resistance and surface smoothness, the zinc alloy-plated steel comprising:
a base steel and a zinc alloy-plated layer formed on the base steel,
wherein the zinc alloy-plated layer comprises, by weight percentage (wt %), 10 to 25% of aluminum (Al), 5 to 20% of magnesium (Mg), and a remainder of zinc (Zn) and unavoidable impurities,
the zinc alloy-plated layer comprises: at least one of an MgZn 2 alloy phase and an Mg 2 Zn 11 alloy phase; an Al solid-solution phase; an Al-Zn-Mg eutectic phase; and a remainder of a Zn solid solution phase,
a total area fraction of the at least one of the MgZn 2 alloy phase and the Mg 2 Zn 11 alloy phase is 20 to 50%,
a total area fraction of the Al solid-solution phase and Al-Zn-Mg eutectic phase is 46% or less, and
an area fraction of the Al solid-solution phase is 12 to 25%.
2. The zinc alloy-plated steel of claim 1 , wherein the zinc alloy-plated layer further comprises, by weight percentage (wt %), at least one of strontium (Sr), beryllium (Be), calcium (Ca), and lithium (Li) in a total amount of 0.0005 to 0.009%.