硫蚀时间对镀锡板腐蚀产物成分的影响研究

The influence study of sulfidation corrosion time on the composition of tinplate corrosion products

通过研究镀锡板硫蚀时间对腐蚀产物成分的影响,可以促进对镀锡板硫蚀机理的理解和硫变发黑问题的解决。实验通过改变镀锡板在硫化钠-乙酸模拟溶液(pH 6)中的浸泡时间,使用X射线光电子能谱仪(XPS)对不同硫蚀时间下得到的产物主要元素质量分数及S的组元和价态进行刻蚀分析。结果显示在硫蚀时间由2、9d并延长到23d的过程中:S元素质量分数逐渐升高,O元素质量分数先降低再升高,在最终稳定的硫蚀产物中,金属元素Sn的质量分数接近于0,Fe元素质量分数在60%上下浮动,金属Sn只能为基体提供物理保护作用;硫蚀产物中S元素组元主要有S单质、S-和S2-构成且不发生变化,但各价态组分的相对含量发生改变,即低价态S质量分数降低,高价态S质量分数升高,S元素组合态在硫蚀过程中呈现被氧化的趋势。增大Sn层厚度和均匀性、在罐装物中添加还原性物质是改善硫蚀的有效途径。

The influence study of sulfidation corrosion time of tinplate on the composition in corrosion products could promote the understanding of sulfidation corrosion mechanism of tinplate and the resolution for the problem of sulfur blackening.The immersion time of tinplate in sodium sulfide-acetic acid simulated solution（pH 6）was varied in experiments.The mass fraction of main elements as well as the component and valence state of S in products obtained with different sulfidation corrosion times was analyzed by Xray photoelectron spectrometer（XPS）.The results indicated that when the sulfidation corrosion time was prolonged from 2 dand 9 dto 23 d,the mass fraction of S gradually increased,while the mass fraction of O firstly decreased and then increased.In finally stable sulfidation corrosion products,the mass fraction of Sn was near 0,and the mass fraction of Fe was fluctuated around 60%.Sn metal could only provide physical protection role on matrix.The components of S in sulfidation corrosion products mainly included S,S-and S2-,and had no change.However,the relative content of components in each valence state changed,i.e.,the mass fraction of low-valence S decreased and the mass fraction of high-valence S increased.In other words,the combination state of S showed the trend of being oxidized in sulfidation corrosion process.The increase of Sn layer thickness and uniformity as well as the addition of reducing substances in canned matter were effective routes to reduce the sulfidation corrosion.