摘要
为考察铝合金在含SO_(2)环境中的腐蚀行为规律,通过干/湿交替循环腐蚀试验,结合电化学分析、EDS能谱分析、FTIR分析等方法,研究了SO_(2)沉积速率对6061-T4铝合金在模拟海洋大气环境中腐蚀行为的影响。结果表明:在试验范围内,较低的SO_(2)沉积速率可显著促进腐蚀反应的进行,提高腐蚀速率。但是,随着沉积速率逐渐增大,SO_(2)对腐蚀反应的促进作用逐渐减弱,并在腐蚀后期出现抑制作用。当SO_(2)沉积速率增大至2000 mg/(m^(2)·d)时,SO_(2)对腐蚀反应只呈现抑制作用。SO_(2)发生氧化、水解反应,生成SO_4^(2-)与H^(+),导致基体表面液膜酸化,是SO_(2)促进铝合金腐蚀的主要原因。SO_(2)沉积量增大,导致基体与液膜界面处溶解氧的浓度梯度迅速降低,以及由Al_2(SO_4)_3与AlCl_(3)组成的腐蚀产物层阻碍腐蚀性介质接触基体表面,是SO_(2)对铝合金的腐蚀反应产生抑制作用的主要原因。
In order to investigate the corrosion behavior patterns of aluminum alloy in an environment containing SO_(2),the effect of the SO_(2)dep⁃osition rate on the corrosion behavior of 6061⁃T4 aluminum alloy in a simulated marine atmospheric environment was studied through dry/wet alternating cyclic corrosion tests,combined with methods such as electrochemical analysis,EDS analysis,and FTIR analysis.Results showed that within the test range,a relatively low SO_(2)deposition rate could dramatically promote the corrosion reaction and increase the corrosion rate.However,as the deposition rate gradually increased,the promoting effect of SO_(2)on the corrosion reaction gradually weakened,and an inhibito⁃ry effect appeared in the later stage of corrosion.When the SO_(2)deposition rate increased to 2000 mg/(m^(2)·d),SO_(2)only showed an inhibitory effect on the corrosion behavior.SO_(2)was oxidized and hydrolyzed,and generated SO_4^(2-)andH^(+),leading to the acidification of the liquid film on the substrate surface,which was the main reason why SO_(2)promoted the corrosion of the aluminum alloy.Besides,the increase of SO_(2)depo⁃sition caused the rapid decrease of the concentration gradient of dissolved oxygen at the interface between the substrate and the liquid film,and the corrosion product layer composed of Al_(2)(SO_(4))^(3)and AlCl_(3)prevented the corrosive medium from contacting the substrate surface,which was the main reason for the inhibition effect of SO_(2)on the corrosion reaction of aluminum alloy.
作者
刘伟
李洪林
吴海旭
石玲
LIU Wei;LI Honglin;WU Haixu;SHI Ling(School of Civil Engineering,Liaoning Petrochemical University,Fushun 113001,China;Institute of Metal Research Chinese Academy of Sciences,Shenyang 110016,China;Liaoning Zhongwang Group Co.,Ltd.,Liaoyang 111000,China)
出处
《材料保护》
2025年第2期83-91,共9页
Materials Protection
基金
辽宁省教育厅项目(L2020030)
中国石化催化剂有限公司攻关项目(KYC⁃WT⁃2022112201)
中国石化催化剂有限公司攻关项目(2021210403000299)。
