Corrosion behavior of WE54 magnesium alloy in 3.5%NaCl solution
(1.Environmental Corrosion Center, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China
2.辽宁省沈阳市科学院金属研究所金属腐蚀与防护国家重点实验室)
2.辽宁省沈阳市科学院金属研究所金属腐蚀与防护国家重点实验室)
Abstract: The corrosion behavior of WE54 magnesium alloy was investigated in 3.5%NaCl aqueous solution. The electrochemical study shows that the value of corrosion potential of WE54 magnesium was ？1.8V(vs SCE). In the initial stage of immersion, a kind of visible thin film, which has the appearance of artificial conversion coating by microscopy observation, formed on the surface of WE54 alloy. Through the comparison of corrosion behavior between WE54 and AZ91D, it is shown that the value of corrosion potential of WE54 is approximately 200 mV lower than that of AZ91D, and the corrosion rate of WE54 was one order smaller than that of AZ91D. After 72 h constant immersion and corrosion products removal, deeper grooves along grain boundaries was revealed but lighter corrosion was apparent on the matrix of WE54 alloy. As far as AZ91D alloy was concerned, severe localized corrosion was dominant and network-bone-like structure was remained.
Key words: magnesium alloys; WE54; corrosion; electrochemical behavior; microstructure