Patent ID: 8562757

Claim:
A Mg-based alloy plated steel material characterized by being provided with a hot dip Mg-based alloy plating layer containing Zn: 15 atm % or more, Mg: over 35 atm %, and further containing Ca and optionally one or more elements selected from the group of elements B: Al, and Y in a total of 0.03 to 15 atm %, wherein said hot dip Mg-based alloy plating layer comprises only crystal phase, and contains an intermetallic compound Zn 3 Mg 7 , wherein an X-ray intensity ratio of diffraction peak intensity of Zn 3 Mg 7 relative to the sum of all diffraction peak intensities appearing at diffraction plane spacing of 0.1089 to 1.766 nm is 10% or more, wherein diffraction peak of diffraction plane spacing of 0.233 nm is excluded from determining said X-ray intensity ratio.