Spectroscopy investigations reveal unprecedented details in the corrosion of AISI 1012 UPN profiles installed in a modernist building of beginning of 20th century

Abstract

n the present work, the corrosion affectation of an artistic and historical building, declared UNESCO World Heritage Site and constructed with AISI 1012 UPN profiles, was investigated. Micro-Raman and microscopy approaches highlight the complementarity and versatility of these techniques to evaluate the macroscopic and microscopic effect of the corrosion products in such reinforcing structures. The rust phases have been assessed by separating the oxide layers according to their environment placement and contaminants contact. The composition of iron oxides and oxyhydroxides in the metal surface depend not only on the oxygen concentration, but also on other elements that penetrated into the porous layers, as for example, chorine ions, sulfur ions, and microorganisms. Taking into account the scarce information on the indoor corrosion of AISI 1012 steel, results obtained in this work are expected to help for understanding the long-term impact of such oxides and oxyhydroxides on the material durability, as well as on its structural maintenances.