Pearlitic Morphologies Found in Carbon Steel Artefacts More than 2,000 Years Old

Abstract

The results of this research reveal the possibility of observing another type of pearlite. Formed in archaeological steel pieces a few years old. Perlite resulting from diffusion over time at room temperature. For this we show the metallographic structure of archaeological samples that have remained buried in the soils of Roman Baetica for 2,000 years. Diffusion does not stop at a given moment but takes place, undoing structures that seemed to be stable; this diffusion produces new equilibrium structures that we cannot evaluate due to lack of time. The research was carried out as part of the Archaeological Analogues project for the Spanish National Nuclear Waste Company (ENRESA), revealing the alternation of structures of hot-worked and normalized carbon steels. The microscopy used is Scanning Electron Microscopy (SEM). The specimens, among many, two were selected because they have a good corrosion-free metallic core.