ABSTRACT
The work analyses the atmospheric corrosion resistance of two widely used weathering steels: ASTM A-242 and ASTM A-588. The steels were exposed for up to 5 years in different types of atmosphere: rural, urban, industrial and marine. The atmospheric corrosion resistance of the steels was evaluated and the rust layers formed on them were characterised by X-ray diffraction, optical microscopy and scanning electron microscopy. The most relevant conclusions reached include the following: (a) the visual appearance (colouring) of the rust, rust texture, nature of the corrosion products and compactness of the rust layers formed are similar in both types of weathering steel. (b) No great differences are observed in the corrosion resistance. Slight differences occur in the industrial atmosphere, where ASTM A-242 presents 10–13% less corrosion than ASTM A-588. (c) In the C2-C3 ISO corrosivity atmosphere both types of weathering steels are adequate for unpainted use. However are not suitable in higher ISO corrosivity atmosphere.
Acknowledgements
The authors gratefully acknowledge the financial support for this study from the Ministry of Science and Innovation of Spain (CICYT-MAT 2008-06649). The authors would like to express their gratitude to Patrimonio Nacional, Arcelor-Mittal, SVUOM (Czech Republic), ENEL and Gas Natural-Fenosa for the facilities provided and for allowing the location of the corrosion stations. They also wish to thank Drs. J.A. Jiménez and I. Llorente from CENIM’S X-ray laboratory for the performance and interpretation of the X-ray analysis, and Prof. P. Adeva, A. Tomás, C. Zea and P. Lopesino for the performance of SEM analysis.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
Ivan Díaz http://orcid.org/0000-0003-3981-985X
Heidis Cano http://orcid.org/0000-0003-2811-5769
Daniel de la Fuente http://orcid.org/0000-0003-4540-3180