Metal and corrosion: Implications for industry and cultural heritage

Metal is a living material… With the exception of pure gold in its natural state, all metals are derived from the transformation of mineral ores. Once altered, from ore into semi-finished products such as ingots, billets, blooms or slabs, and then into objects or structural elements, metals will continually seek, throughout their service life, to return to their natural state as mineral ore (hydroxides, oxides, sulphides, carbonates, etc.). A leopard cannot change its spots!

This process of ‘returning to its natural state’, from metal to ‘mineral ore’, is called corrosion. From an etymological perspective, the term corrosion comes from the ancient Latin verb corrodere, which means the ‘action of gnawing’. According to current norms, especially standard ISO 8044, corrosion is defined as the result of the physico-chemical interaction between a metal and its environment leading to modifications in the proprieties of the metal that can result in deterioration of its function, the surrounding environment or the technical system to which it belongs.

The term corrosion includes a myriad of different mechanisms: uniform corrosion, corrosion by differential aeration or by galvanic cell, pitting corrosion, corrosion under deposits, crevice corrosion, erosion corrosion, cavitation corrosion, filiform corrosion, localised corrosion, etc.

Identifying and diagnosing corrosion in a system involving of one or more metals, and one or more environments, requires studying the nature of the metal(s) present and the environment(s) encountered.

As both a consulting firm and a conservation-restoration laboratory, A-CORROS is here to help you identify and diagnose any corrosion pathologies, and understand the causal mechanisms in order to determine the best recommendations to successfully combat corrosion.