Degradation state evaluation, corrosion diagnosis methods' reliability, and also the development and improvement of conservation strategies are dramatically important to preserve iron archaeological objects. In this way, dechlorination processes for iron artefacts are traditionally used in conservation workshops to stabilize objects retrieved from archaeological excavations. This paper aims at presenting unpublished results but also to give an overview of the last 10 years study of stabilization processes using synchrotron X-ray absorption spectroscopy at the Cl K-edge as a key approach: first to decipher the corrosion patterns involving Cl ions on iron artefacts, and second to understand, mostly by in situ observation, the dechlorination processes. Wrought iron bars found on Gallo-Roman shipwrecks were studied. The difference in reactivity involved in the corrosion processes make it essential to distinguish and locate the phases in the heterogeneous corrosion layers. XANES at the Cl K-edge is a relevant technique to determine the Cl chemical form, distribution and its role in each phase's stability. Chloride ions may be trapped inside the structure of iron oxyhydroxide as akaganeite β-FeO_1−x(OH)_1+xCl_x and β- or γ-ferrous hydroxychlorides β-Fe₂(OH)₃Cl. Some Cl may also be adsorbed at the surface of the grains of the various phases present, i.e. not only the previsouly cited Cl-containing phases but also other oxyhydroxydes as lepidocrocite and goethite as shown by the XANES spectra.

中文翻译：

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Cl K边缘的XANES作为揭示铁考古文物脱氯处理的相关技术

退化状态评估，腐蚀诊断方法的可靠性以及保护策略的发展和改进对于保护铁考古物体具有极其重要的意义。这样，在保护车间中传统上使用铁制品的脱氯工艺来稳定从考古发掘中回收的物体。本文的目的是发表未发表的结果，但同时也概述了近十年来在Cl K边缘使用同步加速器X射线吸收光谱作为关键方法进行的稳定过程研究：首先破译涉及Cl离子的腐蚀模式。铁制品，其次是了解，主要是在原地观察，脱氯过程。研究了在加洛罗马沉船中发现的锻铁棒。腐蚀过程所涉及的反应性不同，因此必须区分和定位异相腐蚀层中的相。Cl K边缘的XANES是确定Cl化学形式，分布及其在每个相稳定性中的作用的相关技术。氯离子可能被困羟基氧化铁的结构akaganeite内部β-FeO的_{1- X}（OH）_{1+ X}氯_X和β-或γ-亚铁羟基氯化物β-的Fe ₂（OH）₃氯。一些Cl也可能吸附在存在的各种相的晶粒表面，即 XANES谱图不仅显示了先前提到的含Cl相，还显示了其他羟基氧化物如纤铁矿和针铁矿。