ISO 4628-10:2024
Paints and varnishes

Standard No.

ISO 4628-10:2024

Release Date

2024

Published By

International Organization for Standardization (ISO)  IX  /  ISO

Latest

ISO 4628-10:2024

Introduction

Analysis of the core content of the standard

The third edition of ISO 4628-10:2024 revised the assessment system for filiform corrosion of paint films. The main technical changes include:

• The title is simplified to "Assessment of degree of filiform corrosion"
• The definition of filiform corrosion is consistent with ISO 4623-1:2018
• Update normative references

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Comparison of assessment methods

Dimensions	Method 1 (Regular corrosion)	Method 2 (Irregular corrosion)
Applicable scenarios	Parallel equal length filament corrosion	Irregular distribution corrosion
Measurement parameters	L (average of the longest wire length) M (average of the high-frequency wire length)	L (same as method 1) M (weighted average calculation)
Calculation formula	L=(Ll+Lr)/2 M=(Ml+Mr)/2	Ml=Σ(xn*Mln)/z Mr=Σ(yn*Mrn)/z

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Key points of technical implementation

Measurement environment requirements

Must comply with ISO 13076 lighting conditions:

• Illuminance ≥ 1000 lux
• Color temperature 5500-6500K
• Color rendering index Ra> 90

Typical application scenarios

Accelerated aging test of a certain automobile electrophoretic coating:

1. Salt spray test for 240h after scratch treatment
2. Measured L=3.2mm/M=1.8mm
3. Compared to Figure A.1(c), the rating is L3/M2

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Standard evolution analysis

Main progress compared to the 2016 version:

• Precise definition: It is clear that corrosion must be caused by aggressive ions
• Improvement of methods: Added multi-region weighted calculation method
• Standardization of illustrations: Added transition state examples to the 12 rating illustrations

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Implementation suggestions

Optimization of operation procedures

1. Ensure consistent scratch depth in the pretreatment stage
2. Use a digital microscope to assist in measurement
3. Take the average value of at least 3 measurement points

Dealing with common problems

Problem phenomenon	Solution
Crossing of corrosion wires	Measurement in different areas according to method 2
Blurred boundaries	Observe with polarized light

ISO 4628-10:2024 Referenced Document

• ISO 13076 Paints and varnishes — Lighting and procedure for visual assessments of coatings

ISO 4628-10:2024 history

• 2024 ISO 4628-10:2024 Paints and varnishes
• 2016 ISO 4628-10:2016 Paints and varnishes - Evaluation of degradation of coatings - Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 10: Assessment of degree of filiform corrosion
• 2003 ISO 4628-10:2003 Paints and varnishes - Evaluation of degradation of coatings; Designation of quantity and size of defects, and of intensity of uniform changes in appearance - Part 10: Assessment of degree of filiform corrosion

Standard and Specification