Shortcomings of International Standard ISO 9223 for the Classification, Determination, and Estimation of Atmosphere Corrosivities in Subtropical Archipelagic Conditions—The Case of the Canary Islands (Spain)

Juan J. Santana,Helena C. Vasconcelos,Vicente Mena,Ricardo M. Souto,Bibiana M. Fernández-Pérez,Alejandro Rodriguez-Gonzalez,Alejandro Ramos

doi:10.3390/met9101105

Abstract

The classification, assessment, and estimation of the atmospheric corrosivity are fixed by the ISO 9223 standard. Its recent second edition introduced a new corrosivity category for extreme environments CX, and defined mathematical models that contain dose–response functions for normative corrosivity estimations. It is shown here that application of the ISO 9223 standard to archipelagic subtropical areas exhibits major shortcomings. Firstly, the corrosion rates of zinc and copper exceed the range employed to define the CX category. Secondly, normative corrosivity estimation would require the mathematical models to be redefined introducing the time of wetness and a new set of operation constants.

Highlights

Atmospheric corrosion is a process caused by the interaction of metals with the atmosphere causing their degradation
Due to the big microclimatic variability existing in the Canary Islands and the subtropical conditions determined by the trade winds, the corrosion rates for carbon steel, copper, and zinc from 74 corrosion exposure sites exceeded the ranges contained in the ISO 9223:2012 standard
In the case of carbon steel, corrosivity categories were observed to range between C2 and CX

Summary

Introduction

Atmospheric corrosion is a process caused by the interaction of metals with the atmosphere causing their degradation. 5% of the gross domestic product (GDP) in Western countries, China, and India per year [1]. Even if this process was not producing the costs of material replacement, it would account for production losses, energy-based costs, and the release of toxic substances to the environment. Numerous studies on atmospheric corrosion are available in the scientific and technical literature [2,3,4,5,6,7,8,9,10], often directed to the acquisition of atmospheric corrosivity maps for a given geographic region. Metals 2019, 9, 1105 methodology required to perform these studies is established by a series of international standards (namely ISO 9223 to 9226) that were first published in 1992, and subjected to technical revision in. The revised ISO 9223 contains substantial changes from its first edition [15]

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