Effects of magnesium chloride-based multicomponent salts on atmospheric corrosion of aluminum alloy 2024  

以MgCl_2为主的混合盐对2024铝合金大气腐蚀的影响(英文)

作　　者：王彬彬[1] 王振尧[1] 韩薇[1] 汪川[1] 柯伟[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室,沈阳110016

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第4期1199-1208,共10页中国有色金属学报（英文版）

基　　金：Project(51131007) supported by the National Natural Science Foundation of China

摘　　要：Atmospheric corrosion of aluminum alloy 2024 （AA2024） with salt lake water was simulated through a laboratory- accelerated test of cyclic wet-dry and electrochemical techniques. Effects of the soluble magnesium salt contained in the salt water were investigated by scanning electron microscope （SEM）, transmission electron microscope （TEM）, energy dispersive spectrometer （EDS）, electron probe micro analyzer （EPMA）, X-ray diffraction （XRD）, infrared transmission spectroscope （IR）, and atmospheric corrosion monitor （ACM）. The results showed that, with the deposition, atmospheric corrosion of AA2024 could occur when the relative humidity （RH） was lower than 30%. A main crystalline component of corrosion products, layered double hydroxides （LDH）, [Mg1-xAlx（OH）2]^x＋ Clx-·mH2O （LDH-C1）, was determined, which meant that magnesium ion played an important role in the corrosion process. It not only facilitated the corrosion as a result of deliquescence, but also was involved in the corrosion process as a reactant.以盐湖水为腐蚀介质,通过实验室模拟循环干湿交替实验及电偶电流测量等电化学手段,利用扫描电镜(SEM)、透射电镜(TEM)、X射线能谱仪(EDS)、电子探针(EPMA)、X射线衍射(XRD)、红外光谱(IR)和大气腐蚀监测仪(ACM)等分析和测量技术,研究模拟盐湖大气环境下,可溶性镁盐(主要为MgCl_2)对2024铝合金大气腐蚀行为的影响。结果表明,在相对湿度低于30%的环境下,仍有腐蚀行为发生;腐蚀产物中出现了含氯的镁铝双金属氢氧化物——[Mg_(1-x)Al_x(OH)_2]^(x+)Cl_x^-·mH_2O(LDH-Cl),并作为主要腐蚀产物。分析表明,以MgCl_2为主的混合盐不仅在较低的相对湿度下为金属腐蚀的进行提供所需的液膜环境,同时也作为反应产物参与腐蚀反应。

关 键 词：aluminum alloy 2024 atmospheric corrosion magnesium chloride relative humidity corrosion products 

分 类 号：TG172.3[金属学及工艺—金属表面处理]