Patent ID: 9302449
Filing Date: 2016-04-05
CPC Classification: B32B,C23C,Y10T

Claim Text:
1. A high corrosion resistant hot dip zinc (Zn) alloy plated steel sheet comprising: an underlying steel sheet; and a hot dip Zn alloy plating layer, wherein a composition of the hot dip Zn alloy plating layer includes about 2.3 wt. % to about 3 wt. % of aluminum (Al), about 1.5 wt. % to about 3.3 wt. % of magnesium (Mg), and Zn and unavoidable impurities as a remainder, in which Al+Mg is in a range of about 3.8 wt. % to about 6.3 wt. % and Al/(Al+Mg) is a weight ratio in a range of about 0.41 to about 0.48, wherein the hot dip Zn alloy plated steel sheet is subjected to skin pass rolling, and wherein a surface roughness (Ra) of the hot dip Zn alloy plated steel sheet is about 2 μm or less before performing the skin pass rolling, and wherein the hot dip Zn alloy plating layer comprises a plated structure, in which a Zn—MgZn