广铁管内钢轨的腐蚀机理探讨

Analysis on corrosion mechanism for railways of Guangzhou Railway(Group) company

针对广铁集团管内大瑶山隧道、株洲北站等几个主要工段钢轨腐蚀伤损现象,对钢轨的腐蚀因素进行分析。分别采用腐蚀速率计算、硬度检测、XRD物相分析和SEM形貌观察等方法,结合钢铁的大气腐蚀规律和当地大气数据,探讨了钢轨腐蚀机理。研究结果表明:钢轨腐蚀的主要形式是伴随着机械和疲劳损伤出现的局部腐蚀,潮湿的空气、温差、降雨、大气污染和杂散电流等环境因素以及钢轨自身机械疲劳损伤情况综合作用于钢轨,致使并加剧钢轨腐蚀。

According to the damages caused by corrosion from DaoYaoShan Tunnel,ZhuZhou north station and etc.,which all affiliated to Guangzhou Railway（Group） company,factors of rail corrosion were investigated.The corrosion mechanism was studied through calculation of corrosion rates,detection of hardness,X-ray diffraction analysis and morphology image observation by SEM respectively.The result indlicates that there are mainly two forms of rail corrosion.One is the uniform corrosion of faces and waists as well as fix parts.The other one is the regional corrosion results from mechanical and fatigue damages.The former shares the same atmospheric corrosion mechanism with other steel products.The latter has a more complicated one that is related with environmental factors（including damp air,temperature and its range,rainfall,atmospheric pollution and stray current） and the mechanical and fatigue damages of the rail.