【目的】利用可膨胀石墨（ EG）增强膨胀型钢结构防火涂料的防火性能和耐盐雾性。【方法】利用锥形量热仪、热重分析仪、中性盐雾试验等分析了 EG对膨胀型防火涂料防火性能和耐盐雾性的影响。【结果】添加 EG可以有效增强涂层防火和抑烟性能，添加 1. 67%（质量分数） EG后涂层的峰值热释放速率和峰值生烟速率分别低至 96. 0 kW/m²和 0. 021 m²/s、700 ℃时的残炭率提升至 28. 3%，这主要是因为 EG在燃烧过程中可形成“蠕虫状”结构增强膨胀炭层的致密性从而更有效地阻隔热量和物质传递。盐雾试验表明，中性盐雾作用会破坏涂层结构的完整性，导致涂层热释放速率和生烟量增大，而添加 EG可以在一定程度上延缓盐雾对涂层的老化并使涂层老化后仍保持较低的热释放速率、生烟量以及较好的炭层稳定性，其中添加 EG的涂层在 700 ℃时的残炭率较未添加 EG的涂层提升 15. 4%。【结论】 EG作为膨胀型钢结构防火涂料的协效剂可以显著提高涂层防火性能和耐盐雾性。

［Objective］To enhance the fire resistance and salt spray resistance of intumescentfire-retardant coatings for steel structures using expandable graphite（EG）as a synergist.［Methods］ The effects and mechanisms of EG on the fire resistance and salt spray resistance were investigatedusing cone calorimetry，thermogravimetric analysis（TGA）， and neutral salt spray testing.［Results］ The addition of EG could effectively enhance the coating′s fire resistance and smoke suppressionproperties. The peak heat release rate and the peak smoke generation rate of the coating after the residual carbon rate at 700 ℃ was increased to 28. 3%. This enhancement was primarily attributed tothe formation of worm-like structures by EG during the combustion process，which reinforced the denseness of the expanded carbon layer to block the heat and material transfer more effectively. Saltspray tests revealed that exposure to a neutral salt spray environment could damage the structuralintegrity of the coating，leading to an increase in the heat release rate and smoke production. However， the addition of EG could delay the coating′s aging process induced by salt spray to a certain extent.Consequently，even after aging，EG-modified coatings maintained lower heat release，reduced smoke production，and superior carbon layer stability compared to unmodified coatings. Notably，the residual carbon rate at 700 ℃ for the aged EG-modified coating was 15. 4% higher than that of the aged coatingwithout EG.［Conclusion］ EG as a synergist of intumescent steel structure fire-retardant coatingscould significantly improve the fire resistance and salt spray resistance of the coating.