Inadequate surface preparation will negatively affect the longevity and durability of a protective coating, increasing the risk of corrosion. The guidelines stipulate that each coating should be tested in laboratory conditions on smooth, galvanised, and rough surfaces to determine durability. There’s no such thing as permanent corrosion protection, so ISO 12944 includes a broad durability range for each coating: While these are only intended as guidelines, regulators often reference them in their directives, making the recently updated ISO 12944 standards a critical part of your legal requirements. If your surfaces are already deteriorating, it informs your spot repair and refurbishment strategies as well. It also specifies the performance tests and execution methods for each type of coating. ISO 12944 goes beyond environmental causes, providing guidelines for the design considerations, surface types, and preparation needs for every coating. Very briefly (as most steelwork used by our clients in the power generation sector is on land and above ground), these are: Lm1 (fresh water), Lm2 (brackish or sea water), Lm3 (immersion in soil) and Lm4 (deep sea water). Note: the above is an excellent guide for a majority of paint systems, but does not take into account specific chemical, temperature or mechanical needs.Ī separate set of risk categories are given for exposure to water or soil.

The ISO 12944:2018 (Part 2) standard broadly splits environmental corrosion risk into six categories, based on the time needed for untreated zinc or carbon steel to corrode under various atmospheric conditions: To cover those variations, the International Organisation for Standardisation (ISO) define standards governing corrosion resistant paint systems.Ĭorrosion Risk From Environmental Exposure The location of steelwork above or below ground, the pH level of the surrounding environment and the presence of microorganisms also affect susceptibility to corrosion. This means environmental conditions have an important effect on your plant/steelwork. Corrosion occurs when moisture, oxygen, and ferrous steel combine to cause oxidation – a process accelerated by surface pollutants.

Your steel plant and structures are only as durable as they are corrosion resistant, but corrosion prevention is no simple task.

Din en iso 12944 part 6