SCI reviews again the performance of Magnelis^® ZM310 as a Z600 alternative

ArcelorMittal has commissioned an independent review from the Steel Construction Institute (SCI) to assess the corrosion protection performance of Magnelis^® ZM310 (310 g/m²) as a potential alternative to the galvanized steel Z600 (600 g/m²) in steel construction applications.

The review, completed in December 2024, concludes that Magnelis^® ZM310 provides corrosion protection that is at least equivalent to Z600 in UK environments typically encountered in light steel framing and warm-frame applications. This applies to both surface protection and cut-edge performance.

Seeking a reliable Z600 alternative

Z600, a heavy zinc coating, is often required in more aggressive environments, particularly near ground level or in high-humidity settings. Magnelis^®, ArcelorMittal’s zinc-aluminium-magnesium (ZM) coating ZM120 (120 g/m²), has already proven successful as an alternative to Z275 (SCI RT1892, 2021). The latest review extends this evaluation to ZM310, with a coating weight of 310 g/m².

The SCI’s assessment included analysis of corrosion performance data provided by ArcelorMittal and compared it against existing performance expectations for Z600.

This assessment supports the growing acceptance of Magnelis^® coatings across the construction sector and aligns with ArcelorMittal’s commitment to delivering sustainable and high-performance steel solutions.

Accelerated and natural exposure testing

Magnelis^® ZM310 was tested under both accelerated laboratory conditions and long-term natural exposures. Results showed that:

• In cyclic and salt spray corrosion tests, ZM310 exhibited slower white rust formation and greater stability compared to Z600, with no red rust observed in either sample.
• Natural exposure tests across global sites, including Ijmuiden (Netherlands), Dubai, Cadiz, and Jiangjin, demonstrated that ZM coatings like Magnelis^®, have lower coating loss compared to zinc coatings across all environments, particularly in non-coastal regions representative of UK conditions.

Data from Ijmuiden, which closely matches UK environmental conditions, showed a thickness loss ratio of 2.4 (Z275 vs ZM250), suggesting that ZM310 offers equivalent or better long-term corrosion protection than Z600.

Cut edge protection

An important consideration in light steel framing is the protection of cut edges. The review confirms that Magnelis^® ZM310 provides effective “self-healing” at cut edges. Field tests in marine environments showed that ZM310 develops a white protective layer over time, effectively halting corrosion. This behaviour was observed over a five-year exposure period.