2024铝合金在中国西部盐湖大气环境中的局部腐蚀行为  

LOCALIZED CORROSION OF ALUMINUM ALLOY 2024 EXPOSED TO SALT LAKE ATMOSPHERIC ENVIRONMENT IN WESTERN CHINA

作　　者：王彬彬[1] 王振尧[1] 曹公望 刘艳洁[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：《金属学报》2014年第1期49-56,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金重点项目51131007;国防技术基础项目H102011B002资助~~

摘　　要：通过4 a的现场大气暴露实验,利用SEM/EDS,OM,XRD技术和电化学测试技术,研究了包/不包铝的2024铝合金在中国西部盐湖大气环境中的局部腐蚀行为.结果表明,包/不包铝的2024铝合金在盐湖大气环境中发生了严重的点蚀,暴露2 a后,包铝层已被腐蚀穿透;不包铝的2024铝合金最大点蚀深度已达约320μm个别位置发生穿孔.包/不包铝的2024铝合金的主要腐蚀产物都是层状双金属氢氧化物—[Mg_(1-x)Al_x(OH)_2]^(x+)(Cl^-,CO^(2-))_x·mH_2O.电化学测试分析结果表明,随Cl^-浓度的升高,2024铝合金的开路电位不断降低,耐蚀性变差.Localized corrosion behavior of aluminum alloy 2024 with/without cladding exposed to salt lakes atmospheric environment in western china for 4 a was investigated. The depth of pitting, corrosion products, morphology of surface and cross-section, and corrosion potential were analyzed by SEM/EDS, OM, XRD and elec- trochemical analysis system. The results showed that 2024 suffered severe pitting corrosion. The cladding layer of aluminum alloy 2024 exposed for 2 a had been penetrated. Depth of pitting of aluminum alloy 2024 without clad- ding after 2 a exposure had reached 320 ~tm; meanwhile, few pitting that penetrated the whole substrate of alumi- num alloy 2024 without cladding had been observed. A main corrosion product of aluminum alloy 2024 with/with- out cladding-[Mg1-xAlx（OH）2]x＋ （CI, CO2）x· mH2O （layered double hydroxides, LDH） was determined. Also, the re- suits of electrochemistry indicated that the corrosion potential of aluminum alloy 2024 decreased gradually with the concentration of CI increasing. The effects of factors of salt lake atmospheric environments, corrosion product and C1- concentration on the corrosion behavior of 2024 with/without cladding were discussed.

关 键 词：2024铝合金 盐湖 大气腐蚀 点蚀 腐蚀产物 

分 类 号：TG178[金属学及工艺—金属表面处理]