CAJ | 학술논문

以2A12/45和2A12/40CrNiMoA为研究对象，采用电偶腐蚀实验方法系统研究了溶液浓度、pH值以及材料特性和外力等因素对电偶腐蚀行为的影响。结果表明：pH值不变，随着溶液浓度的升高，两个偶对的电偶电流密度增大；溶液浓度不变，随着溶液pH值的降低，两个偶对的电偶电流密度增大；从腐蚀形态来看，不同浓度下2A12表面的腐蚀形态主要是不均匀的点蚀，pH=2时为均匀腐蚀，而在pH=4和pH=7时为局部的点蚀；应力的变化不仅对电偶电流密度有明显影响，而且承受的应力水平增大，电偶电流密度增加，电偶腐蚀敏感性提高，无应力时，作为阳极的2A12铝合金表面的腐蚀形式是局部的点蚀，且腐蚀产物附着在金属表面，当外加应力增加到75％σs时2A12铝合金表面腐蚀明显加剧，且随着腐蚀产物的脱落，局部区域出现较大的蚀坑。
이2A12/45화2A12/40CrNiMoA위연구대상，채용전우부식실험방법계통연구료용액농도、pH치이급재료특성화외력등인소대전우부식행위적영향。결과표명：pH치불변，수착용액농도적승고，량개우대적전우전류밀도증대；용액농도불변，수착용액pH치적강저，량개우대적전우전류밀도증대；종부식형태래간，불동농도하2A12표면적부식형태주요시불균균적점식，pH=2시위균균부식，이재pH=4화pH=7시위국부적점식；응력적변화불부대전우전류밀도유명현영향，이차승수적응력수평증대，전우전류밀도증가，전우부식민감성제고，무응력시，작위양겁적2A12려합금표면적부식형식시국부적점식，차부식산물부착재금속표면，당외가응력증가도75％σs시2A12려합금표면부식명현가극，차수착부식산물적탈락，국부구역출현교대적식갱。
Galvanic corrosion behaviours of 2A12 aluminum alloy coupled with 40CrNiMoA steel under different solution concentrations and pH value and tensile stress levels were studied by galvanic corrosion test. The experimental results show that the couple current density increases with the decrease of pH for the same solution concentration,and increases with the increase of solution concentration at the same pH. Observing the corrosion appearance,it is found that with changing solution concentration,obvious localized corrosion and pitting corrosion are observed for specimens 2A12. General corrosion plays a key role in acidic solutions(pH=2),and the major corrosion form of specimens 2A12 in both neutral and slight acidic solutions (pH=4 and pH=7)is pitting corrosion. The magnitude of external stress has important effects on couple current density and galvanic corrosion sensitivity. Without the effect of external stress,the corrosion forms of the couple of 2A12/45 steel is the localized corrosion with the corrosion products attaching to the surface of the steel. As stress is applied to specimens 2A12,the pitting corrosion of 2A12 develops into larger dimension,and when the external stress increases to 75%σs,the corrosion product falls from metal surface,the larger pits are distributed on the surface of specimens 2A12.