Traditional neutral salt spray tests fail to accurately simulate the accelerated corrosion that occurs under actual energized conditions. We have developed a salt spray test chamber capable of reducing the relative humidity (RH) in the testing environment to prevent short circuits, insulation failures, and other faults that lead to premature damage during testing. Initially, the effect of salt spray concentration on corrosion at 85 % RH was examined, and it was found that the corrosion rate does not increase when the concentration surpasses 50 mg/m ³ . The humidity-controllable salt spray test demonstrated a closer match to real environmental corrosion, judging by both the appearance of corrosion and the acceleration ratios across different metals, where the acceleration ratio difference between maximum and minimum values was reduced from 18.6 times to 1.4 times. The influence of RH on the corrosion rate was revealed, with the highest rate observed at 75 % RH. Lastly, we proposed optimal parameters for energized salt spray tests, evaluated the failure modes of several products under these tests, preliminarily confirmed the consistency and acceleration effects of this method for electrical products in real marine atmospheric conditions.

Intumescent fireproof coatings protect steel structures and cables by forming a thick, fire-resistant layer under high temperatures. These coatings can deteriorate over time, impacting their fire resistance. Current testing methods are largely lab-based, lacking in-service evaluation platforms. Laser-Induced Breakdown Spectroscopy (LIBS) is emerging as a promising in situ detection technology but is influenced by low air pressure in high-altitude areas. This study investigates how air pressure affects LIBS signals in intumescent coatings on galvanized steel. Using pressures between 35 and 101 kPa, a linear model was developed to correlate laser pulses to ablation depth for characterizing coating thickness. Results show that spectral intensity decreases with lower air pressure. However, a strong linear relationship persists between laser pulses and ablation depth, with a fitting accuracy above 0.9. The coating thickness is identified by the number of laser pulses required to detect the Zn spectral line from the underlying galvanized steel. As air pressure decreases, the ablation depth increases. The study effectively models and corrects for air pressure effects on LIBS data, enabling its application for field detection of fireproof coatings. This advancement enhances the reliability of LIBS technology in assessing the fire performance of these materials, providing a reference for their in situ evaluation and ensuring better fire safety standards for building steel structures and cables.