飞机起落架镀镉4130钢在甲酸钾溶液薄液膜下腐蚀电化学行为研究  

Corrosion Electrochemical Behavior Beneath Thin Electrolyte Layer of Potassium Formate Solution of Cd-plated 4130 Steel Used for Aircraft Landing Gear

作　　者：林修洲[1,2] 杨丽 梅拥军 郑兴文 罗淑文[3] 崔学军 

机构地区：[1]四川理工学院材料腐蚀与防护四川省重点实验室,自贡643000 [2]四川理工学院材料科学与工程学院,自贡643000 [3]中国民航局第二研究所,成都610041

出　　处：《中国腐蚀与防护学报》2017年第6期567-574,共8页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(U1333103和U1633118);四川省青年科技创新研究团队项目(2016TD0024);四川理工学院人才引进项目(2016RCL12)~~

摘　　要：采用自制薄液膜腐蚀试验装置,研究了飞机起落架镀镉AISI 4130钢在低温除冰液(主要成分甲酸钾)薄液膜下的腐蚀电化学行为。结果表明:镀镉4130钢在甲酸钾溶液中的腐蚀过程主要受氧扩散控制,薄液膜下腐蚀产物沉积对腐蚀过程产生较大影响。液膜较厚(≥240μm)时,液膜厚度变化对阴极极限扩散电流密度和溶液电阻影响不大;液膜较薄时,阴极极限扩散电流密度和溶液电阻随液膜厚度减小而增大。在相同液膜厚度下,镀镉4130钢腐蚀电位随溶液浓度增大而降低。在低浓度甲酸钾溶液中,镀镉4130钢腐蚀速率较低,腐蚀电位和腐蚀速率受液膜厚度影响不大。在高浓度甲酸钾溶液中,镀镉4130钢腐蚀电位随液膜厚度减小而正移;薄液膜下腐蚀速率明显高于全浸,且随液膜厚度减小先增大后减小,在液膜厚度约为150μm时出现极大值。The Cd-plated AISI 4130 steel is being widely used for aircraft landing gear and potassium formate is the main composition of the common deicing fluid.Therefore,it is worthy to investigate the corrosion electrochemical behavior of Cd plated AISI 4130 steel beneath thin electrolyte layer of potassium formate solution at low temperature.Results showed that the corrosion process of the Cd-plated AISI 4130 steel in potassium formate solution is mainly controlled by the diffusion of dissolved oxygen,and influenced by the deposition of corrosion product beneath the thin electrolyte layer.When the thickness of the electrolyte layer is higher（240 μm or more）,there is little influence of the thickness of the electrolyte layer on the cathodic limited diffusion current density and solution resistance.When the thickness of the electrolyte layer is thinner,the cathodic limited diffusion current density and solution resistance are increased with the decrease of the thickness of the electrolyte layer.For the same thickness of the electrolyte layer,the corrosion potential of the Cd-plated AISI 4130 steel decreases with the increase of solution concentration.For the dilute solutions,the corrosion rate of the Cd-plated AISI 4130 steel is lower,and the corrosion potential and corrosion rate are less affected by the thickness of the electrolyte layer.When the concentration of potassium formate solution is higher,the corrosion potential of the Cd-plated AISI4130 steel is positively shifted with the decrease of the thickness of the electrolyte layer.The corrosion rate of the Cd-plated AISI 4130 steel beneath thin electrolyte layer is obviously higher than that of full immersion test,and the corrosion rate for the former case increased first and then decreased with the decreasing thickness of the electrolyte layer,and reached the maximum value when the thickness of the electrolyte layer is about 150 μm.

关 键 词：镀镉4130钢 甲酸钾溶液 除冰液 薄液膜 腐蚀电化学 

分 类 号：TG172[金属学及工艺—金属表面处理]