BS EN ISO 4623-1:2018

What is ISO 4623-1 about?  

ISO 4623 discusses paint and varnishes. ISO 4623-1 is the first part of multi-series ISO 4623 and discusses the determination of resistance to filiform corrosion. Filiform corrosion is a type of corrosion that is normally linked to magnesium and aluminium alloys that utilize an organic form of coating. However, it can also occur on other coated metals such as steel, iron, and zinc. The mechanism for corrosion allows water and oxygen to migrate.  

ISO 4623-1 describes a test procedure for assessing the protective action of coatings of paints or varnishes on steel against filiform corrosion arising from a scribed mark cut through the coating. 

Note: Method in ISO 4623-1 is not suitable for predicting the performance of the coating on different substrates. 

Who is ISO 4623-1 for? 

ISO 4623-1 on paints and varnishes (resistance to filiform corrosion) is useful for: 

• Paint Manufactures 
• Steel product manufacturers (furniture, utensils, toys, tools, machines) 
• Interior and exterior designers 
• Quality control personnel  

Why should you use ISO 4623-1?  

A scribe mark cut through a coating of paints or varnishes on metal can give rise to various types of corrosion, such as blistering of the coating, corrosion of the metal under the coating, as well as filiform corrosion. Filiform corrosion tends to develop under specific conditions of temperature and relative humidity and when traces of acids, bases, or salts are present either under the paint coating or at breaks in the coating. These conditions are often found in marine and/or industrial environments. A certain amount of under-corrosion of the coating, starting from the scribe mark, will always occur. Filiform corrosion, however, is present only if the typical pattern in the form of threads is obvious. 

ISO 4623-1 provides a test procedure for assessing the protective action of coatings of paints or varnishes on steel against filiform corrosion arising from ascribed mark cut through the coating. 

ISO 4623-1 is suitable for assessing the performance of the coating/substrate combination tested. ISO 4623-1 helps you manufacture high-quality protective coatings for a steel substrate by determining the resistance of coatings to filiform corrosion.  

What’s changed since the last update?  

BS EN ISO 4623-1:2018 supersedes BS EN ISO 4623-1:2002, which is withdrawn. BS EN ISO 4623-1:2018 includes some technical changes with respect to BS EN ISO 4623-1:2002. These include: 

• The definition of filiform corrosion has been aligned with ISO 4623-2 
• The time of exposure of the test panels to neutral salt fog has been shortened from 24 h to 4 h 
• A reference to ISO 1787-2 for the cutting tool has been added 
• the introduction of ISO 4623-2 has been copied 
• The text has been aligned with ISO 4623-2