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

保护大型遗产结构，如建筑物和船只，对保护科学家来说是一个特别的挑战。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人们对持续降解的潜在机制知之甚少，这反过来又导致了非最佳的保护选择。海洋环境中考古铁的保护由于海水中Cl离子的侵入而变得复杂。尽管进行了大量的洗涤，但残留的Cl通常仍然束缚在这些结构中，并且在干燥时与铁迅速反应形成膨胀的腐蚀产物-可能完全破坏珍贵的文化遗产。该项目将重点关注玛丽玫瑰号的考古铁：亨利八世的旗舰。之前的x射线分析，对一组铁炮弹的调查，经过不同的保护处理，告诉我们以前的处理的有效性，无论是回顾性的还是实时的实验，就形成的腐蚀产物而言。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），我们将研究木材中的铁沉积如何表现，总体目标是找到可行的解决方案，以保存众所周知的困难复合人工制品，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夹具。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情况。研究结果将为未来的保护策略提供信息，不仅适用于玛丽罗斯项目，也适用于其他保护海洋考古铁和复合材料的遗产项目

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