Shining a light on marine archaeological iron: understanding the kinetics and mechanisms of degradation to inform future conservation strategies

大型遗产结构的保护，如建筑物和船舶，对保护科学家提出了特殊的挑战。材料的规模和复杂性，它们独特的历史，以及研究系统的困难意味着对持续退化的潜在机制知之甚少-这反过来又导致非最佳保护选择。从海洋环境中保存考古铁是复杂的氯离子的进入，而在埋葬环境中从海水。尽管进行了大量的清洗，但残留的Cl通常仍然结合在这些结构中，并且在干燥时可以迅速与铁反应，形成膨胀的腐蚀产物-可能完全破坏珍贵的文化遗产。这个项目将集中在考古铁从玛丽玫瑰：亨利八世的旗舰。之前对一组经过不同保护处理的铁炮弹进行的X射线分析和调查，让我们了解了之前处理在形成的腐蚀产物方面的功效，无论是回顾性的还是实时实验的。下一步是了解形成产物的反应途径，并研究这些机制的动力学，作为各种保存参数（例如浸泡溶液，温度和相对湿度）的函数。除了单个物体（如炮弹），我们还将研究木材中的铁沉积物的行为，其总体目标是为保护众所周知的困难复合人工制品找到可行的解决方案，复合人工制品被定义为有机和无机材料的混合物，例如木制人工制品中的铁固定装置。为了实现这一目标，将开发原位电池，以便使用光谱和散射技术实时监测腐蚀。研究结果不仅将为玛丽罗斯项目提供未来的保护策略，还将为其他保护海洋考古铁和复合物体的遗产项目提供信息

The conservation of large scale heritage structures, such as buildings and ships present particular challenges for conservation scientists. The scale and complexity of materials, their unique histories, and the difficulties of studying the systems means that the underlying mechanisms of ongoing degradation are poorly understood - which in turn results in non-optimum conservation choices. The conservation of archaeological iron from marine environments is complicated by the ingress of Cl ions whilst in the burial environment from seawater. Despite extensive washing, residual Cl typically remains bound in these structures and this can rapidly react with iron on drying to form expansive corrosion products - potentially completely destroying precious items of cultural heritage. This project will focus on archaeological iron from the Mary Rose: Henry VIII's Flagship. Previous X-ray analysis, investigations of a set of iron cannonballs, which have been subjected to different conservation treatments, has informed us on the efficacy of previous treatments, both retrospectively and in real-time experiments, in terms of corrosion products formed. The next step is to develop an understanding of the reaction pathways to the products formed and to investigate the kinetics of these mechanisms as a function of the various conservation parameters (e.g. such as soaking solution, temperature and relative humidity). In addition to individual objects (such as cannonballs), we will investigate how iron deposits in wood behave, with the overarching aim to find viable solutions for conserving notoriously difficult composite artefacts, defined as a mixture of both organic and inorganic materials e.g. an iron fixture in a wooden artefact. To achieve this in-situ cells will be developed so that the corrosion can be monitored in real-time using spectroscopic and scattering techniques. The results will inform future conservation strategies not only for the Mary Rose project, but other heritage project conserving both marine archaeological iron and composite objects