Experimental study on the corrosion performance of weathering high-strength bolt connections

In this study, the influence of the corrosion performance of weathering high-strength bolt connections was investigated based on the periodic immersion accelerated corrosion tests. Weathering steel high-strength bolt connections were performed by periodic immersion accelerated corrosion tests and tensile tests. The macromorphology, micromorphology, corrosion products and mechanical properties were analysed and compared with ordinary carbon steel high-strength bolt connections under the same corrosion conditions. The results showed that the weathering steel exhibited slightly stronger corrosion resistance, and a conversion relationship between atmospheric corrosion time and periodic immersion-accelerated corrosion time was proposed. The slippage load of the weathering steel high-strength bolt connections fist decreased, then increased, and finally stablilized under corrosion damage conditions, in which the change trend was different from that of the carbon steel. The maximum reduction in the corroded weathering steel high-strength bolt connection with corroded and new bolts reached 16.9% and 12.3%, respectively, which no longer met the design requirements and exhibited certain safety hazards. However, when spraying zinc on the friction surfaces of the weathering steel high-strength bolt connections, the slippage load variation ranges of the connections remained within 10% throughout the corrosion period, with a stable trend and high reliability. The antislippage coefficient of the weathering steel high-strength bolt connection surface with spraying zinc was more stable than the sand-blasting treatment, and the zinc spraying treatment method exhibited excellent anticorrosion ability. Based on the variation laws, a formula was proposed for the change in the antislippage coefficient with corrosion time.