This material has among its alloy elements low concentrations of Ai4 Bn4 Cu4 Mn and Co which helps in the development of a protective rust layer that avoids the corrosion of the metal.
Besides4 that coating <rings a characteristic te6ture and color which ma@e this steel very attractive for some constructions.
In this work four weathering steel facades e6posed to the ur<an atmosphere of Bil<ao were studied. These constructions are located in different places and affected <y several
pollution sources. Two of these facades are in a good conservation state. The others4 in contrast4 have their surface detached in steel chips. They are involved in a decay process4 promoting a serious damage of the protective layer. This study allowed us to identify which is
the fact that causes the decaying process of steel structures and helped us to relate pollution sources with decay processes.