Steel coated with zinc and zinc alloys is widely utilized for home appliances, construction, automobiles, and other applications due to its high corrosion resistance. In this work, the corrosion behavior at cut edges of Zn–11%Al–3%Mg–0.2%Si-alloy-coated steel sheets (SD) was investigated with a cyclic wet–dry corrosion test. The results showed that SD has anticorrosive property superior to that of zinc-coated steel sheets (GI) during the early period of corrosion. GI produced red rust, whereas SD produced no red rust. After the cyclic wet–dry corrosion test, zinc-containing white rust was deposited on steel substrate. In the case of SD, magnesium reached the center of the cut edge, and a larger area on the steel was covered with white rust. Polarization measurements of steel substrate on which white rust was deposited clarified that the white rust of SD reduced both the anodic and cathodic current densities of the steel substrate more than GI. In the case of SD, the galvanic current between the steel substrate with white rust and the coating layer was small compared to that in the case of GI. It is suggested that this anticorrosive property of SD is caused by magnesium-containing white rust.

涂有锌和锌合金的钢由于其高耐腐蚀性而被广泛用于家用电器，建筑，汽车和其他应用。在这项工作中，通过循环湿-干腐蚀试验研究了Zn-11％Al-3％Mg-0.2％Si合金涂层钢板（SD）切边的腐蚀行为。结果表明，在腐蚀初期，SD的防腐性能优于镀锌钢板（GI）。GI产生红锈，而SD没有产生红锈。经过干湿循环腐蚀试验后，含锌的白锈沉积在钢基底上。在SD的情况下，镁到达切削刃的中心，并且钢上较大的区域被白锈覆盖。对其上沉积有白锈的钢基材进行极化测量可知，SD的白锈比GI减少的钢基材的阳极和阴极电流密度都更大。在SD的情况下，与GI的情况相比，具有白锈的钢基材与涂层之间的电流较小。建议SD的这种防腐蚀性能是由含镁的白锈引起的。