ISO 17463:2022

Overview

ISO 17463:2022 - Paints and varnishes - Guidelines for the determination of anticorrosive properties of organic coatings by accelerated cyclic electrochemical technique (ACET) - provides standardized guidance for performing ACET on organic protective coatings applied to metals. The standard defines the AC/DC/AC cycle (EIS → cathodic polarization → potential relaxation → repeat EIS), specifies specimen and environmental control, test parameters and procedures, and recommends how to present experimental results (Bode plots, Nyquist plots, relaxation curves). Typical examples are given in Annex A.

Key topics and technical requirements

• Test principle: Cyclic sequence of Electrochemical Impedance Spectroscopy (EIS), a controlled cathodic polarization, and a potential relaxation period to accelerate and monitor coating degradation.
• EIS measurements: Follow ISO 16773‑2 procedures for data collection; report amplitude and phase data; present results as Nyquist and Bode plots.
• Cathodic polarization: Apply a constant cathodic potential (examples in the standard note ranges and typical practice); polarization times commonly range 20–60 minutes for high‑quality coatings. Electrolysis (H2/OH−) at the metal/coating interface is a key mechanism of accelerated damage.
• Relaxation: Disconnect potentiostat and record potential during relaxation. Typical relaxation times are 160–180 minutes; relaxation allows the system to re‑equilibrate before the next EIS measurement.
• Cycles and repetition: Cycles can be repeated (typically six cycles) to assess progressive degradation.
• Specimen preparation and environment: Measure and report film thickness (e.g., per ISO 2808); control temperature to ±1 °C (measurement) and ±2 °C (conditioning); maintain relative humidity ~50 ± 5 % when capacitance is a key parameter.
• Repeatability: Minimum of three replicate specimens is generally recommended; operators should verify repeatability (typical capacitance repeatability often better than 10 % for uniform coatings).
• Data presentation and reporting: Include Bode/Nyquist plots, relaxation curves and test conditions (potentials, times, temperature, humidity, specimen prep) in the test report.

Practical applications and users

ISO 17463:2022 is intended for:

• Coating manufacturers and R&D teams evaluating anticorrosive performance of organic protective systems.
• Corrosion engineers and test laboratories performing accelerated comparative testing.
• Quality control and product development groups assessing permeability, adhesion-related degradation, and coating life indicators.
• Specification writers and certification bodies needing standardized test guidance for coating qualification.

Use cases include comparative ranking of coating systems, formulation optimization, failure‑mode investigation (e.g., cathodic disbonding), and generating reproducible EIS/relaxation datasets for specification or regulatory purposes.

Related standards

• ISO 16773‑1, ISO 16773‑2 (EIS terminology and data collection)
• ISO 2808 (film thickness)
• ISO 3270 (conditioning humidity guidance)
• ISO 8044 and ISO 15711 (terminology related to corrosion and cathodic disbonding)

Keywords: ISO 17463:2022, ACET, accelerated cyclic electrochemical technique, anticorrosive properties, organic coatings, EIS, cathodic polarization, potential relaxation, Bode plots, Nyquist plots.