Innovative corrosion protection for C3 and C4 environments.

Protecting steel from corrosion is essential. Without the right corrosion protection, there is no assurance a carbon steel design will reach its intended lifetime. To select the most suitable coating, it is vital to evaluate the corrosiveness of the environment surrounding the application, as well as the choice of the material. This is due to several external factors such as temperature, humidity, chlorides etc., all of which affect the corrosion rates of zinc and steel products and, consequently, influence the choice of protection.

For low corrosive surroundings or indoor environments, processes such as phosphating, electro-galvanising or zinc-plating are the most suitable solutions. For outdoor environments, a more robust protection layer is needed to protect carbon steel from weathering.

Hot-dipped galvanising (HDG) is the most common method of protecting steel from corrosion in outdoor environments. In fact, by immersing steel in a bath of hot molten zinc (after being rolled and welded) the material acquires a protective layer which gives it a “spangle” – a crystallised surface pattern. This process is relatively low in cost compared to using stainless steel and is used in a variety of different industries.

However, there are also limitations to the quality of post hot-dip galvanising. Due to the nature of applying zinc through a dipping process, creating a 100% consistent and visually satisfying finish can be challenging.

One solution to this problem is to add a proportion of zinc, magnesium, and aluminum to create a zinc-magnesium (ZM) coating. ZM coating is becoming increasingly popular as a superior corrosion resistance solution for steel as it provides a significantly increased lifespan when compared to a normal zinc coating. ZM is therefore the preferred corrosion protection solution for Hilti Outdoor Coated systems.

From zinc to zinc-magnesium: better corrosion resistance and an optimised supply chain
ZM outperforms galvanised steel by up to a factor of three and potentially higher in more severe environments, making this coating especially suited for ammonic as well as chlorine-rich and alkaline-rich environments.

In addition to higher performance corrosion protection, zinc-magnesium coating is also lighter (stronger protection does not result in a thicker coating vs. HDG/other coating methodologies) and has a lower Co2 footprint. By eliminating the steps of hot-dip galvanising and its subsequent surface inspection, ZM helps eradicates the inconsistencies in quality that can occur with HDG solutions. It also simplifies logistics by dispensing with the intermediate transport stage.

Significant reduction in the production steps for ZM vs. hot-dip galvanization (HDG).

Hilti MT – the future generation of modular support systems
Hilti MT modular support systems are designed using the most innovative corrosion protection current technology offers for harshest outdoor conditions. For the MT system this means:

• Innovative zinc magnesium (ZM) Technology for MT profiles
• Tried-and-trusted HDG Technology for MT components such as baseplates and connectors

Hilti’s ZM coatings conform to EN 10346. It also combines perfectly with the HDG solution of Hilti components and leads to:

• Less rework - the self-healing characteristics of ZM mean that cut edges or damage require no post-treatment (such as cold zinc spray);
• Higher robustness – due to the greater surface hardness of ZM, damage to the coating during installation and operation is less likely;
• Environmental friendliness – lower CO2 emissions during production and simplified logistics;
• Cost optimisation – ZM is applied to the raw material as a pre-coating, eliminating the cost of post-forming processes and the associated logistics; and
• Higher corrosion resistance – ZM has up to two to three times the corrosion protection of HDG with the same thickness

The MT system is an ideal support solution for light utilities such as air ducts and communication cables, as well as for cable trays and heavier cable ladders – and even for larger, non-critical piping or heavier mechanical equipment. This is possible thanks to its ease of adaptability in terms of both loading capacity and weight. In addition, by choosing MT, you can seamlessly and simply combine your MEP utilities in a single support structure that has been engineered for optimal efficiency.

As a result, planning, managing and assembling your metal framing and support structures is easier than ever.

Are you interested in learning more about system MT or our other installation system design, you can find more information here.

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This article is part of an ongoing series dedicated to MEP topics. Find more here