Laboratory and field assessment of corrosion resistance and durability for coated railway fastening systems in the sandy desert environment

Railway infrastructure in arid regions suffers from rapid material degradation due to sandstorms and salt-bearing dust. Fastening systems are especially prone to corrosion, leading to increased maintenance and safety concerns. This research evaluates the corrosion resistance and relative cost performance of three coating systems, nano coating, Dacromet, and hot-dip galvanizing, applied to steel fasteners used in desert railway tracks. Laboratory salt spray testing and three-year field exposure were conducted to assess performance. Nano coatings showed the highest lab resistance (up to 1,200 h), followed by hot-dip galvanizing (1,000 h) and Dacromet (500 h). In contrast, field tests showed that hot-dip galvanized components had the lowest surface corrosion (∼5%), while nano coatings (∼15%) and Dacromet (∼30%) were less durable in practice. Cost comparisons indicated that Dacromet had the lowest initial cost, hot-dip galvanizing had the highest, and nano coatings had a moderate increase. Overall, hot-dip galvanizing provided the best balance of durability and reliability for desert applications, while nano coatings offer potential with further improvements in mechanical resilience.