Zinc-aluminum-magnesium alloy cable trays, owing to their outstanding corrosion resistance, have gradually become the preferred material for industrial plants, chemical workshops, and coastal environments. They significantly outperform standard hot-dip galvanized cable trays in moisture resistance and rust prevention, with a service life exceeding 20 years. However, a common question arises at construction sites: Does high-temperature exposure affect the lifespan of zinc-aluminum-magnesium cable trays?

I. Corrosion Resistance Advantages of Zinc-Aluminum-Magnesium Cable Trays

1. The ternary alloy protective layer—a composite coating of zinc, aluminum, and magnesium—forms a dense protective film on the cable tray surface. Even if locally scratched, it self-passivates to prevent steel corrosion.

2. Moisture and Corrosion Resistance

Ideal for high-humidity and salt-fog environments, particularly coastal factories and underground workshops. While conventional hot-dip galvanized or powder-coated cable trays may experience zinc flaking and corrosion, zinc-aluminum-magnesium trays demonstrate robust performance.

3. Extended Lifespan

Under normal conditions, service life exceeds that of hot-dip galvanized trays by 2-3 times, reducing long-term maintenance and repainting costs.

II. Impact of High-Temperature Environments on Service Life

Although zinc-aluminum-magnesium cable trays offer excellent corrosion resistance, high-temperature environments may still pose potential impacts:

1. Increased thermal expansion of the metal causes the tray to expand and contract. If design does not account for expansion allowance, prolonged thermal cycling may lead to localized deformation or loosening of connection points.

2. Accelerated alloy layer oxidation: At temperatures exceeding 120°C, the alloy surface oxidizes more rapidly, potentially causing slight aging of the passivation film. However, it remains more stable than standard galvanized cable trays.

3. Changes in mechanical properties: Extreme heat may slightly reduce local hardness, though this has negligible impact on typical industrial facilities (where temperatures generally remain below 60°C).

Overall, high temperatures do affect zinc-aluminum-magnesium cable trays. However, as long as temperatures are maintained within reasonable limits, their service life remains significantly longer than that of standard cable trays.

III. Engineering Selection Recommendations

1. Normal temperature and high humidity environments: Zinc-aluminum-magnesium cable trays offer the best cost-performance ratio, featuring strong corrosion resistance and minimal maintenance.

2. High-temperature and high-humidity environments (e.g., boiler rooms, drying areas): Extend service life by incorporating expansion allowances in design, adding cover plates, and avoiding heat sources.

3. Extreme high-temperature environments (>120°C): Consider stainless steel or special heat-resistant alloy cable trays to ensure structural integrity and safety.

Additionally, regular inspections of connection points, supports, and surface conditions are crucial for maintaining the service life of cable trays.

IV. Conclusion

Zinc-aluminum-magnesium cable trays offer superior corrosion resistance, making them the preferred material for high-humidity and highly corrosive environments. However, high-temperature conditions do exert certain effects, primarily manifested as thermal expansion, accelerated oxidation of the alloy coating, and a slight reduction in mechanical strength.

Engineers selecting cable trays must comprehensively consider environmental factors, temperature, humidity, and budget to design and install solutions that maximize the advantages of zinc-aluminum-magnesium trays. This approach ensures long-term durability, low maintenance costs, and reliable safety.