镁铝合金在模拟低温条件下大气腐蚀行为研究
Atmospheric Corrosion Behavior of Mg-alloys AZ31B and AZ91D in Simulated Low Temperature Environments
吴洋 1安易强 2王力伟 1崔中雨2
作者信息
- 1. 青岛大学机电工程学院 青岛 266071
- 2. 中国海洋大学材料科学与工程学院 青岛 266404
- 折叠
摘要
采用室内模拟方法研究了 AZ31B和AZ91D镁合金在低温交变条件下的大气腐蚀行为.采用失重法得到两种镁合金的腐蚀速率与温度呈正相关,形貌分析表明在低温条件下两种镁合金均发生了明显的局部腐蚀.结合腐蚀速率和形貌观察,相同温度条件下AZ31B镁合金比AZ91D镁合金腐蚀严重,但AZ91D镁合金具有十分明显的点蚀特征,表现为AZ91D镁合金的平均点蚀密度和深度高于AZ31B镁合金,但其平均点蚀体积相对较小.红外光谱和能谱分析表明,在15～25℃温度循环时,Mg(OH)2、MgO和碳酸盐是腐蚀产物的主要成分;而在低温循环(-5～-15℃和-5～-25℃)时,腐蚀产物中MgO的含量较高,EDS能谱检测到AZ91D镁合金点蚀严重的区域存在Al和Cl,Cl-对氧化膜的破坏作用对AZ91D镁合金的点蚀有重要影响.
Abstract
The atmospheric corrosion behavior of Mg-alloys AZ31B and AZ91D at alternating low temperatures was investigated via laboratory simulation i.e.a high/low temperature dry-humid alternating test chamber.The corrosion rate of the two alloys was positively correlated with temperature as the re-sults acquired by the mass loss measurement.The morphology analysis showed that the two alloys ex-hibited obvious localized corrosion in the low temperature environment.Combined with corrosion rate and morphology observation(SEM,CLSM),it was found that AZ31B Mg-alloy was more seriously corrod-ed than AZ91D Mg-alloy at the same temperature,but AZ91D Mg-alloy showed obvious pitting character-istics.The average pitting density and depth of AZ91D Mg-alloy were larger than that of AZ31B Mg-alloy,but the corresponding average pitting volume was smaller.FTIR and EDS analysis showed that Mg(OH)2,MgO and carbonates were the main components of the corrosion products formed at 15-25℃,while the content of MgO in the corrosion products was higher at lower alternating temperatures(from-5℃ to-15℃ and-5℃ to-25℃).EDS results suggested that Aland Cl were present in the area where AZ91D Mg-alloy pitting was serious.It was considered that the destruction of the oxide scale by Cl-had an important influ-ence on the pitting corrosion of AZ91D Mg-alloy.
关键词
镁合金/局部腐蚀/腐蚀形貌/腐蚀产物/低温腐蚀Key words
Mg-alloy/location corrosion/corrosion morphology/corrosion product/low temperature corrosion引用本文复制引用
基金项目
山东省优秀青年科学基金(ZR2022YQ44)
中央高校基本科研业务费(202241012)
中央高校基本科研业务费(202262011)
国家自然科学基金(52201098)
出版年
2024
NETL
NSTL
万方数据