Zn-Mg alloy plated steel material having excellent corrosion resistance and plating adhesion
Provided is a Zn—Mg alloy plated steel material comprising: a base steel material; and first to third Zn—Mg alloy layers sequentially formed on the base steel material, wherein the first to third Zn—Mg alloy layers have a Zn single phase, a Mg single phase, a MgZn 2 alloy phase, and a Mg 2 Zn 11 alloy phase, an area rate of the MgZn 2 alloy phase included in the first to third Zn—Mg alloy layers is larger than an area rate of the Mg 2 Zn 11 alloy phase included in the first to third Zn—Mg alloy layers, and an area rate of a MgZn 2 alloy phase included in each of the first to third Zn—Mg alloy layers is larger than an area rate of a MgZn 2 alloy phase included in the second Zn—Mg alloy layer.
1. A Zn—Mg alloy plated steel material comprising:
a base steel material; and
first to third Zn—Mg alloy layers sequentially disposed on the base steel material,
wherein the first to third Zn—Mg alloy layers have a Zn single phase, a Mg single phase, a MgZn 2 alloy phase, and a Mg 2 Zn 11 alloy phase,
an area ratio of the MgZn 2 alloy phase, comprised in the first to third Zn—Mg alloy layers, is greater than an area ratio of the Mg 2 Zn 11 alloy phase comprised in the first to third Zn—Mg alloy layers, and
an area ratio of a MgZn 2 alloy phase, comprised in each of the first and third Zn—Mg alloy layers, is greater than an area ratio of the MgZn 2 alloy phase comprised in the second Zn—Mg alloy layer.
2. The Zn—Mg alloy plated steel material of claim 1 , wherein an area ratio of the Mg 2 Zn 11 alloy phase, comprised in each of the first and third Zn—Mg alloy layers, is smaller than an area ratio of the Mg 2 Zn 11 alloy phase included in the second Zn—Mg alloy layer.
3. The n-Mg alloy plated steel material of claim 1 , wherein the first to third Zn—Mg alloy layers comprise, by an area ratio, more than 45% to 80% or less of a MgZn 2 alloy phase and an Mg 2 Zn 11 alloy phase.
4. The Zn—Mg alloy plated steel material of claim 1 , wherein an average content of Mg, comprised in the first and third Zn—Mg alloy layers, is 8 to 12% by weight.