ISO/TR 22801:2026

Corrosion of metals and alloys — Testing methods for corrosion of conducting alloys in AC electric current condition

This document specifies testing methods for alternative current (AC) influenced corrosion of conducting alloys. The methods are applicable for testing the corrosion rate of specific conducting metals and alloys for high-voltage AC electric power transmission systems exposed to atmosphere. This document introduces corrosion testing methods for comparative study of corrosion rate of conducting materials such as aluminium, copper and their alloys.

Corrosion des métaux et alliages — Méthodes d'essai pour la corrosion des alliages conducteurs dans des conditions de courant alternatif

General Information

• Status: Published
• Publication Date: 06-May-2026
• ICS: 77.060 - Corrosion of metals
• Technical Committee: ISO/TC 156 - Corrosion of metals and alloys
• Drafting Committee: ISO/TC 156 - Corrosion of metals and alloys
• Current Stage: 6060 - International Standard published
• Start Date: 07-May-2026
• Due Date: 20-Jun-2026
• Completion Date: 07-May-2026

Overview

ISO/TR 22801:2026 is an important technical report issued by the International Organization for Standardization (ISO) that describes standardized methods for assessing the corrosion rate of conducting metals and alloys when exposed to alternating current (AC) electric conditions. Aimed at the needs of high-voltage AC electric power transmission systems, this document details practical procedures for comparative corrosion studies of key conducting materials, such as aluminium, copper, and their alloys, particularly as they are exposed to atmospheric conditions. The report establishes a reliable basis for performance evaluation, material selection, and optimization in the design and maintenance of energy infrastructure.

Key Topics

• Corrosion mechanisms under AC current: Outlines the impact of electric and magnetic fields, as well as Joule heating, on the corrosion behaviour of conducting materials.
• Salt spray (fog) and electrochemical testing: Provides methodologies for simulating service conditions to measure and compare corrosion rates, including step-by-step apparatus setup and specimen preparation.
• Test specimen preparation: Specifies required material properties, shape, size, and surface treatments to ensure reproducibility.
• Test parameters: Details criteria for current intensity, frequency, sample dimensions, and arrangement to closely mimic actual operating scenarios in power transmission.
• Interpretation of results: Establishes metrics for calculating uniform corrosion rates and provides guidance on comparative analysis between different alloys and current conditions.
• Reporting standards: Defines required content for comprehensive test documentation, ensuring clarity in interpretation and repeatability across labs.

Applications

The standardized testing methods described in ISO/TR 22801:2026 are crucial for:

• Material selection in power transmission: Providing utility companies, manufacturers of electrical conductors, and equipment suppliers with robust, comparable data to choose materials that offer optimal corrosion resistance under real-world AC conditions.
• Design optimization: Enabling the development of longer-lasting, safer, and more reliable transmission lines by establishing clear performance baselines for conducting alloys.
• Maintenance and inspection planning: Supporting asset managers and engineers in predicting equipment degradation, scheduling proactive maintenance, and reducing the risk of mechanical failure due to corrosion.
• Compliance and benchmarking: Allowing industry stakeholders to meet international standards and align with best practices in corrosion testing for high-voltage systems.

By faithfully simulating the actual operating environment-where AC currents induce specific corrosion mechanisms-these methods enable comparative analysis of materials, leading to informed decisions that improve efficiency and reduce costs in the electrical power sector.

Related Standards

Users of ISO/TR 22801:2026 may also benefit from consulting the following related standards:

• ISO 9227: Corrosion of metals and alloys - Corrosion tests in artificial atmospheres - Salt spray tests
• ISO 17475: Corrosion of metals and alloys - Electrochemical test methods - Guidelines for conducting potentiostatic and potentiodynamic polarization measurements
• ISO 9226: Corrosion of metals and alloys - Corrosivity of atmospheres - Determination of corrosion rate of standard specimens
• ISO 8407: Corrosion of metals and alloys - Removal of corrosion products from corrosion test specimens
• IEC 61089: Round wire concentric lay overhead electrical stranded conductor

These standards provide additional guidance on corrosion testing procedures, specimen preparation, and related materials and environmental considerations, supporting a comprehensive approach to corrosion management in electrical power systems.

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Keywords: ISO/TR 22801:2026, corrosion testing, AC electric current, conducting alloys, aluminium, copper, high-voltage power transmission, salt spray test, electrochemical test, corrosion rate measurement, international standards, utility asset management, electrical infrastructure longevity.

Standards Content (Sample)

Technical
Report
ISO/TR 22801
First edition
Corrosion of metals and alloys —
2026-05
Testing methods for corrosion of
conducting alloys in AC electric
current condition
Corrosion des métaux et alliages — Méthodes d'essai pour la
corrosion des alliages conducteurs dans des conditions de courant
alternatif
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Test specimens . 2
6 Specimen assembly . 2
7 Test parameters . 2
8 Salt spray test . 3
8.1 Test apparatus.3
8.2 Test procedure .3
9 Electrochemical test . 4
9.1 Test apparatus.4
9.2 Test procedure .4
10 Test report . 5
Annex A (informative) Calculation of corrosion rate . 6
Annex B (informative) Test results of aluminium alloys in AC electric current condition . 7
Bibliography .11

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 156, Corrosion of metals and alloys.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
As demonstrated in References [6] to [15], magnetic and electric fields influence corrosion behaviour in
metallic materials. Depending on the composition and microstructure of the materials, magnetic and electric
fields either increase or decrease the corrosion rate. In high-voltage power transmission systems (operating
at voltage ≥10 kV), the alternative current (AC) and direct current (DC) flowing through the conducting
materials (e.g. copper, aluminium and their alloys) generate intense magnetic and electric fields. These fields
induce distinct corrosion behaviours in the materials. The global high-voltage transmission lines exceed
4,7 million km. Corrosion of conducting materials/alloys leads to localized overheating and mechanical
failure, disrupting power supply reliability, accelerating equipment degradation and increasing costs.
A suitable testing method for conducting metals under an electric current is essential for selecting
and evaluating the performance of materials. However, the conventional corrosion test methods (e.g.
electrochemical test, salt spray test) do not take current-induced effects into consideration. This document
therefore proposes a corrosion test method designed to simulate the operating conditions of conducting
materials in high-voltage power transmission systems. Considering the global dominance of alternating
current (AC) in power transmission infrastructure, this testing method focuses on AC-induced corrosion.
This in turn provides comparative results that enable manufacturers to optimize material design, thereby
enhancing the longevity and reliability of power transmission equipment.

v
Technical Report ISO/TR 22801:2026(en)
Corrosion of metals and alloys — Testing methods for
corrosion of conducting alloys in AC electric current condition
1 Scope
This document specifies testing methods for alternative current (AC) influenced corrosion of conducting
alloys. The methods are applicable for testing the corrosion rate of specific conducting metals and alloys for
high-voltage AC electric power transmission systems exposed to atmosphere.
This document introduces corrosion testing methods for comparative study of corrosion rate of conducting
materials such as aluminium, copper and their alloys.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principle
Electric and magnetic fields influence material corrosion mechanisms through three primary pathways (see
References [6] to [15]):
— modification of redox reaction kinetics;
— altered mass transfer of corrosion products;
— changed formation of protective film.
During the operation of high-voltage power transmission systems, the current flowing through the
conducting materials generate both magnetic fields and electric fields. These fields induce distinct corrosion
behaviour in conducting materials compared to the same materials under normal operating conditions, such
as structural applications.
The corrosion test method proposed in this document aims to test the corrosion rates of conducting metals
and alloys for high-voltage electric power transmission systems by inducing AC into the salt spray test and
the electrochemical polarization test. The tests are designed as comparative tests for corrosion evaluations.
The density of applied currents can be determined by the load of conducting metals or alloys, such as
overhead power transmission lines or connectors.
An AC current affects the corrosion of conducting materials by the current-induced magnetic field and
electric field, as well as Joule heating due to electrical resistance. In this document, the salt spray test under
AC current conditions considers all the impacting factors. The aim of the electrochemical test is to investigate
the effect of the current-induced magnetic field and electric field on the corrosion of conducting materials.

5 Test specimens
The test m
...