摘要
研究发动机气缸盖用Al-Si合金在模拟海水和模拟乙二醇冷却液中的腐蚀行为,结合白光共焦技术及电化学拟合技术给出了合金在两种环境下的腐蚀动力学规律。结果表明:Al-Si合金在两种环境下都会发生坑腐蚀和晶间腐蚀。在3.5 wt.%NaCl溶液中,由于Cl^(-)的侵蚀性较强,Al基体发生电偶腐蚀,腐蚀速率较快。而50 wt.%乙二醇溶液中,由于乙二醇的吸附以及铝-醇膜的形成,防止溶液与合金接触,导致腐蚀速率极慢。由于腐蚀生成的产物堆积在腐蚀坑底部,阻止腐蚀坑底部与溶液的接触,导致两种环境下的腐蚀速率都随浸泡时间的延长逐渐下降,最终趋于稳定。最后比较了不同Cl^(-)浓度以及不同乙二醇浓度下的腐蚀动力学特征。发现海水环境中随着Cl^(-)浓度的提升,腐蚀抗性变化不大,但腐蚀速率有明显的升高;冷却液环境中随着乙二醇浓度的提升,腐蚀抗性不断增大,腐蚀速率逐渐降低。
The corrosion behavior of Al-Si alloy for engine cylinder heads in simulated seawater and simulated glycol coolants is studied,and the corrosion kinetics of the alloy in the two environments are given by combining white light confocal technology and electrochemical fitting technology.The results show that pitting corrosion and intergranular corrosion occur in Al-Si alloy in both environments.In 3.5 wt.%NaCl solution,the galvanic corrosion of the Al matrix occurs due to the strong aggressiveness of Cl^(-),and the corrosion rate is relatively fast.In the 50 wt.%ethylene glycol solution,the solution is prevented from contacting the alloy due to the adsorption of ethylene glycol and the formation of aluminum-alcohol film,resulting in extremely slow corrosion rate.Since the corrosion products accumulate at the bottom of the corrosion pit,which prevents the bottom of the corrosion pit from contacting the solution,the corrosion rate in both environments gradually decreases with the extension of the immersion time,and finally tends to be stable.Finally,the corrosion kinetic characteristics under different Cl^(-)concentrations and different ethylene glycol concentrations are compared.It is found that with the increase of Cl^(-)concentration in seawater environment,there is little change in corrosion resistance,but the corrosion rate increases significantly.In the coolant environment,with the increase of ethylene glycol concentration,the corrosion resistance continues to increase,and the corrosion rate Gradually decreases.
作者
水有富
刘金祥
黄渭清
左正兴
周海涛
白文君
SHUI Youfu;LIU Jinxiang;HUANG Weiqing;ZUO Zhengxing;ZHOU Haitao;BAI Wenjun(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081;China North Engine Research Institute,Tianjin 300400)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2024年第6期261-270,共10页
Journal of Mechanical Engineering
基金
装备预先研究领域基金资助项目(61409220130)。
