| abstract |
The present invention provides a surface-treated hot-dip galvanized steel material that has a good appearance without white defects due to white rust resistance, scratch resistance, and contamination resistance of a processed part, and without appearance defects caused by a plating layer. In the surface-treated hot-dip galvanized steel material of the present invention, an aluminum / zinc alloy plating layer (α) is plated on the surface of the steel material, and an alkylene group, a siloxane bond and a general formula —SiR 1 R 2 R 3 are formed on the upper layer. (R 1 , R 2 and R 3 in the formula are as described in the text) are coated with a coating film (β) having an organosilicon compound (A) having a crosslinkable functional group as a film-forming component. The surface-treated hot-dip galvanized steel material, wherein the aluminum / zinc alloy plating layer contains Al, Zn, Si and Mg as constituent elements, and the Al content is 25 to 75% by mass, and the Mg content is 0.1 to 10 The aluminum / zinc alloy plating layer contains 0.2 to 15% by volume of Si—Mg phase, and the mass ratio of Mg in the Si—Mg phase to the total amount of Mg in the plating layer is 3% or more. It is characterized by being. [Selection figure] None |