铁道建筑

为了掌握普速铁路锈蚀断轨的伤损类型及分布规律，本文对近7年普速铁路锈蚀断轨数据进行了统计，分析了季节、服役环境、通过总质量等对锈蚀断轨的影响，以及锈蚀断轨发生位置分布特点、断裂形式、裂纹源特征。结果表明：受低温与轨温急剧变化的影响，每年10月至次年2月是锈蚀断轨高发时段。亚湿热区域的锈蚀断轨占比远高于其他区域，高湿、高温、多雨的环境更容易诱发钢轨腐蚀和疲劳失效。通过总质量3亿～9亿吨时，钢轨疲劳与腐蚀损伤交互作用显著，断轨风险较高。76%的裂纹源位于轨底中心区域，约54%的裂纹源处蚀坑深度小于1.0 mm，97%的断轨为疲劳断裂，这说明即使是较浅的蚀坑，也会成为疲劳裂纹的起始点，在一定应力条件下可能诱发钢轨断裂。

To identify damage types and distribution laws of corrosion-induced rail fractures on conventional-speed railways， this study analyzes 7-year data and investigates the effects of seasons， service environments and cumulative passing tonnage， as well as fracture locations， modes and crack origin characteristics. The results reveal that corrosion-induced rail fractures occur frequently from October to next February due to low temperature and drastic rail temperature fluctuations. Subtropical humid regions have a far higher fracture proportion， and hot， humid and rainy environments accelerate rail corrosion and fatigue failure. Significant corrosion-fatigue interaction and high fracture risk appear under cumulative passing tonnage of 300–900 million tons. Around 76% of crack origins lie at the rail base center; corrosion pits at 54% of crack origins are shallower than 1.0 mm， and 97% of fractures are fatigue fractures. This demonstrates that shallow corrosion pits can initiate fatigue cracks and cause rail fracture under specific stress conditions.