Mechanistic study on the cut-edge corrosion behaviors of Zn-Al-Mg alloy coated steel sheets in chloride containing environments

• DOI: 10.1016/j.corsci.2019.108170
• Publication Date: 2019-08-16T11:22:18Z
• Authors: Jae-Won Lee; Bo Ra Park; Se-Young Oh; Dae Won Yun; Joong Ki Hwang; Min-Suk Oh; Sung Jin Kim
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract To understand the cut-edge corrosion behaviors of Zn-Al-Mg alloy-coated steel better, mechanistic studies with a Zn-MgZn2 eutectic specimen fabricated by a hot-pressing process were conducted using various electrochemical methods, such as the scanning vibrating electrode technique and galvanic corrosion measurements. The results showed that the MgZn2 phase dissolved preferentially with the galvanic current flowing from the phase to Zn. Mg/Zn cations from the dissolving MgZn2 phase were reduced effectively, facilitating the co-precipitation of Mg(OH)2, Zn5(CO3)2(OH)6, and Zn5(OH)8Cl2·H2O, which was confirmed by X-ray photoelectron spectroscopy. Based on the results, a much longer-lasting corrosion inhibition mechanism of the alloy-coated steel was provided.