摘要
目前,关于镀锡板腐蚀行为的研究报道较少,而研究镀锡板在NaCl溶液中的腐蚀行为具有重要意义。采用交流阻抗谱(EIS)、计时电位法、莫特-肖特基(Mott-Schottky)曲线、扫描电镜(SEM)以及X射线衍射分析(XRD)等方法研究了镀锡板在NaCl溶液中的腐蚀倾向、腐蚀过程、腐蚀机理及镀锡板表面钝化膜的半导体特性。结果表明:有氧条件下,铁基体在NaCl溶液中具有更低的自腐蚀电位,具有更高的腐蚀倾向,镀锡板在氯化钠溶液中的腐蚀类型为点蚀;浸泡20 d后腐蚀产物主要由γ-FeOOH、α-FeOOH和Fe2O3组成;浸泡初期EIS谱呈现双容抗弧特征,说明腐蚀初期溶液已经渗透到铁基体;反映锡层阻挡作用的膜层电阻Rf值变化不大,说明锡层仅起到表面机械阻挡作用;浸泡4 h时,镀锡板表面载流子浓度已经很高,钝化膜的导通能力已经很强,钝化膜的阻挡作用基本失效。
The corrosion tendency,corrosion process and corrosion mechanism of tinplate in 3.5%NaCl solution were studied using the electrochemical impedance spectroscopy(EIS),chronopotentiometry,Mott-Schottky curve,scanning electron microscopy(SEM)and X-ray diffraction analysis(XRD).Results showed that under aerobic conditions,the iron substrate had a lower self-corrosion potential in sodium chloride solution and presented a higher corrosion tendency.The corrosion type of tinplate in sodium chloride solution was pitting type.After immersed for 20 days,the corrosion products were mainly composed ofγ-FeOOH,α-FeOOH and Fe2O3.The EIS spectrum at the beginning of the immersion showed double-capacity and anti-arc characteristics,indicating that the solution had penetrated the iron substrate at the initial stage of corrosion.The Rf value of the reaction layer did not change much,indicating that the tin layer only acted as a surface mechanical barrier.When the immersion time was 4 h,the carrier solubility on the surface of the tin plate was already high,and the conduction capacity of the passivation film became very strong,revealing that the barrier effect of the passivation film was basically ineffective.
作者
石云光
方圆
宋浩
王雅晴
吴志国
孙超凡
SHI Yun-guang;FANG Yuan;SONG Hao;WANG Ya-qing;WU Zhi-guo;SUN Chao-fan(Shougang Group Co.,Ltd.Research Institute of Technology,Beijing 100043,China;Beijing Key Laboratory of Green Recyclable Process for Iron&Steel Production Technology,Beijing 100043,China)
出处
《材料保护》
CAS
CSCD
北大核心
2019年第8期69-73,共5页
Materials Protection
关键词
镀锡板
点蚀
活性
交流阻抗谱
腐蚀机理
tinplate
pitting corrosion
activity
electrochemical impedance spectroscopy
corrosion mechanism
