摘要
为探究纯铁腐蚀产物对其腐蚀行为的影响机理,采用扫描振动电极技术(SVET)考察了Fe_(3)O_(4)、β-FeOOH和γ-FeOOH对纯铁腐蚀行为的影响,并从腐蚀产物的半导体性质入手,采用扫描开尔文探针(SKP),Mott-Schottky曲线以及氧还原反应极化曲线,研究了产生该影响的机理。结果表明:这3种腐蚀产物均会促进纯铁的腐蚀,其对纯铁腐蚀的促进作用按照β-FeOOH、Fe_(3)O_(4)、γ-FeOOH的顺序依次减弱。腐蚀产物对纯铁的腐蚀促进作用取决于2个方面:腐蚀产物的功函数与纯铁的功函数的相对大小以及腐蚀产物的氧还原反应活性。当腐蚀产物的功函数大于铁的功函数时,电子倾向于从金属传递至腐蚀产物,促进了纯铁腐蚀过程的阳极反应。腐蚀产物的氧还原反应活性越高,越有利于电子的消耗,促进了腐蚀过程的阴极反应。
In order to explore the effect mechanisms of corrosion products of pure iron on its corrosion behaviors,the effects of Fe_(3)O_(4),β-FeOOH andγ-FeOOH on the corrosion behavior of pure iron were investigated using scanning vibration electrode technique(SVET).Based on the semiconducting properties of the corrosion products,the mechanism of this effect was studied by scanning Kelvin probe(SKP),Mott-Schottky curve and oxygen reduction reaction polarization curve.Results showed that all three corrosion products could promote pure iron corrosion,and the promotion effect of three corrosion products on pure iron corrosion weakened in order ofβ-FeOOH,Fe_(3)O_(4),andγ-FeOOH.The corrosion-promotion effect of corrosion products on pure iron depended on two factors:the relative magnitude of the work function of corrosion product and the work function of pure iron,and the oxygen reduction reaction activity of the corrosion product.When the work function of corrosion product was higher than that of pure iron,electrons were inclined to transfer from metal to corrosion product,accelerating the anodic reaction of pure iron corrosion process.In addition,the higher the oxygen reduction reaction activity of the corrosion product,the more favorable to the electron consumption,promoting the cathodic reaction of corrosion process.
作者
张心宇
王立达
孙文
贺永鹏
舒向泉
刘贵昌
ZHANG Xin-yu;WANG Li-da;SUN Wen;HE Yong-peng;SHU Xiang-quan;LIU Gui-chang(School of Chemical Engineering,Dalian University of Technology,Dalian 116024,China;Shandong Chambroad Petrochemicals Co.,Ltd.,Binzhou 256500,China)
出处
《材料保护》
CAS
CSCD
2021年第7期30-36,共7页
Materials Protection
基金
国家自然科学基金(21978036,51671047)资助。
关键词
铁
腐蚀产物
半导体性质
腐蚀机理
腐蚀促进作用
功函数
氧还原反应活性
iron
corrosion products
semiconductor properties
corrosion mechanism
corrosion-promotion effect
work function
oxygen reduction reaction activity
作者简介
通信作者:王立达,副教授,研究方向为金属腐蚀与防护,E-mail:ldwang@dlut.edu.cn。
