ISO 23449:2020

Overview

ISO 23449:2020 - Corrosion of metals and alloys - Multielectrode arrays for corrosion measurement defines the methodology for using multielectrode arrays (MEAs) to measure corrosion - with emphasis on localized and non‑uniform corrosion. First published in 2020, the standard describes device types (e.g., coupled multielectrode arrays (CMA) and coupled multielectrode array sensors (CMAS)), instrumentation, fabrication, and test procedures for laboratory and field monitoring. It covers immersion, thin‑film, spray and alternating wet–dry exposures, and is not intended for corrosion caused by non‑electrochemical mechanisms.

Key topics and requirements

• Principle and device types: Definitions and operating principles for MEAs, CMA and CMAS, and configurations for spatiotemporal studies (closely packed electrodes, wire‑beam layouts, random arrays).
• Instrumentation: Requirements for potential measurement and coupling current measurement, including use of zero‑voltage ammeters (ZVA) and zero‑resistance ammeters (ZRA), single or multichannel coupling and measurement strategies.
• Fabrication and design: Guidance on electrode preparation, number, mounting, electrode size and spacing (for spatiotemporal studies, oil & gas monitoring and high‑throughput testing), and surface coatings to avoid crevice corrosion.
• Test procedure and reporting: Standardized measurement procedures and recommended content for test reports; informative annexes provide typical results and example reports.
• Capabilities: Use for studying initiation/propagation of localized corrosion, long‑term field monitoring, high‑throughput screening of alloys and inhibitors, and assessing galvanic coupling currents and potential distribution of dissimilar metal pairings.
• Limitations: Explicit exclusion of non‑electrochemical corrosion mechanisms.

Practical applications and who uses this standard

ISO 23449:2020 is practical for organizations and professionals involved in corrosion assessment and control:

• Corrosion engineers and materials scientists studying localized corrosion mechanisms and spatiotemporal behaviour.
• Testing laboratories and R&D teams conducting high‑throughput alloy evaluation or inhibitor screening.
• Oil & gas, marine and infrastructure operators implementing long‑term corrosion monitoring (field CMAS deployments).
• Coatings and cathodic protection specialists evaluating protection effectiveness and stray‑current effects.
• Manufacturers of MEA sensors and electrochemical instrumentation designing arrays and measurement systems.

Benefits include improved detection and mapping of localized attack, quantification of galvanic interactions between dissimilar metals, and scalable approaches for lab and field monitoring.

Related standards

• ISO 8044 - Corrosion of metals and alloys - Vocabulary
• ISO 8407 - Corrosion of metals and alloys - Removal of corrosion products from corrosion test specimens

Keywords: ISO 23449:2020, multielectrode arrays, corrosion measurement, localized corrosion, CMA, CMAS, ZVA, ZRA, corrosion monitoring, galvanic coupling, high‑throughput corrosion testing.