铁器文物脱盐清洗溶液中硅酸盐缓蚀性能的研究

Corrosion inhibition of silicate in the desalination cleansing solution for iron antiques

硅酸盐是一种环保型的缓蚀剂,研究水溶液中硅酸盐与铁表面氧化物的相互作用对铁器文物脱盐清洗液的实际应用有较大的指导意义。本工作研究了羟基氧化铁对硅酸盐的吸附作用以及多种因素对Fe/FeOOH/Na_2SiO_3体系电化学行为的影响,并运用XRD技术分析研究了硅酸盐水溶液处理对钢铁表面氧化物形态的影响。结果表明,在Fe/FEOOH/Na_2SiO_3体系中,硅酸盐吸附在钢铁表面羟基氧化物上,反应生成了新的物质,形成了较为致密的缓蚀膜,可同时抑制钢铁的阴、阳极反应,且对阴极反应的抑制作用较强。

It is a general problem that iron antiques is difficult to be conserved for long. Iron antiques conservation is affected not only by its metallurgic factors and the surface oxide layer formed before excavated, but also by the kinds and content of contaminants on iron surface, and by the pollution degree of the conservation environment. The basic state of Chinese iron antiques corrosion was introduced, the iron corrosion in natural environments was compared, and the stability of corrosion products on iron surface was analyzed with thermal dynamics in this paper. XRD( X - ray diffraction) technique was used to measure the components of surface corrosion products of several typical iron antiques. The surface oxide layer interior conversion among the rust compositions was also discussed. Desalination cleansing is one of the important pretreatment processes to inhibit iron atmospheric corrosion for long time' s conservation iron antique. Silicate is a kind of environmental friendly corrosion inhibitors and it can be used in corrosion inhibition for iron in the desalination cleansing solution. It has great significance for its application in the desalination treatment to study the interaction between silicate and the iron surface oxides in the solution. In this research the main composition of corrosion products, hydroxyl ferric oxide (FeOOH), was simulated and manufactured. The adsorption of silicate on the FeOOH in aqueous solution and the electrochemical behaviors of Fe/FeOOH/Na2SiO3 system were studied. And the effects of silicate solution treatment on the forms of iron surface oxides were also investigated with XRD technique. Test results showed that in the near neutral aerated aqueous solution at room temperature , the stable adsorption capacity of silicate on the FeOOH was much more higher and the inhibition effectiveness of iron measured by polarization curves was the maximum reached 97.0% . In the system of Fe/FeOOH/Na2SiO3, some new substances were formed as a result of surface adsorption reaction between silicate and hydroxyl ferric oxide, the corrosion inhibition film formed in this reaction was much more compact. It can inhibit both anodic and cathodic reactions, especially for cathodic process. After desalination cleansing treatment of the iron boundary tablets (manufactured in the Guang - Xu period of Qing Dynasty and Ming Guo period respectively) , the treatment effects demonstrated that silicate used as corrosion inhibitor in the cleansing solution could inhibit the corrosion effectively and may be profitable for later treatments.