(1. 北京科技大學(xué) 國家材料腐蝕與防護(hù)科學(xué)數(shù)據(jù)中心，北京 100083；
2. 北京科技大學(xué) 新材料技術(shù)研究院，北京 100083)
摘 要: 隨著材料服役環(huán)境的惡化，Zn-Al-Mg (ZAM) 鍍層因其具有優(yōu)良的耐蝕性而受到廣泛關(guān)注。本文從合金元素入手，探討了其對ZAM中合金相的形成乃至鍍層耐蝕性能的影響及作用機(jī)制；同時通過對ZAM在大氣環(huán)境中的腐蝕行為特征的歸納，從腐蝕產(chǎn)物的角度闡述了鍍層的腐蝕機(jī)理。一般認(rèn)為，MgZn2作為陽極優(yōu)先被腐蝕，從而產(chǎn)生Mg2+和Zn2+。Mg2+可以抑制腐蝕環(huán)境pH值的升高，從而防止在高pH值條件下保護(hù)性腐蝕產(chǎn)物Zn5(OH)8Cl2·H2O向非保護(hù)性腐蝕產(chǎn)物ZnO轉(zhuǎn)變。Zn2+的產(chǎn)生更有利于形成保護(hù)性腐蝕產(chǎn)物L(fēng)DH(雙層氫氧化物)。但目前的研究仍存在不足，特別是對高鋁含量的ZAM鍍層中復(fù)雜的相結(jié)構(gòu)所帶來的腐蝕機(jī)理仍不明晰。這些都是未來ZAM鍍層的研究重點。
關(guān)鍵字: 鋅鋁鎂合金鍍層；合金相；耐蝕性；大氣腐蝕；腐蝕產(chǎn)物
（1. National Material Corrosion and Protection Data Center, University of Science and Technology Beijing, Beijing 100083, China;
2. Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:With the deterioration of the service environment of materials, Zn-Al-Mg (ZAM) coatings have been received widespread attention due to their excellent corrosion resistance. From the perspective of alloying elements, this article discussed its influence on the formation of alloy phases in ZAM and even the corrosion resistance of the coating and its mechanism of action. At the same time, through the summary of the corrosion behavior of ZAM in the atmosphere, the corrosion mechanism of the coating was explained from the perspective of corrosion products. It was generally believed that MgZn2 was preferentially corroded as an anode, thereby generating Mg2+ and Zn2+. Mg2+ can inhibit the pH increase of the corrosive environment, thereby preventing the protective corrosion product (Zn5(OH)8Cl2·H2O) from transforming to the non-protective corrosion product (ZnO) at high pH scale. The production of Zn2+ is more conducive to the formation of protective corrosion products (LDH; double-layer hydroxide). However, the current research still has certain shortcomings. Especially, the corrosion mechanism caused by the complex phase structure in the ZAM coating with high aluminum content is still unclear. These are the focus of future research on ZAM coatings.
Key words: Al-Zn-Mg alloy coating; alloy phase; corrosion resistance; atmospheric corrosion; corrosion products
