为理解耐候钢在多因素苛刻环境下的腐蚀行为和耐腐蚀机理，进行了微纳米尺度腐蚀行为机理研究，研究发现纳米析出相、夹杂物颗粒无法诱发稳定的蚀坑。析出相与夹杂物的结合体诱发腐蚀的方式及腐蚀的形貌存在差异。铁素体与少珠光体组织中珠光体内部的渗碳体片层电位明显高于铁素体相，在腐蚀介质中会出现明显的电偶腐蚀效应，腐蚀优先发生在珠光体组织处，而GB 组织不同相之间则没有较大的电位波动。合金化对提高钢的耐蚀性有较大的效果，Sb 元素在内锈层出现了明显富集，改善了锈层结构，提高钢材的耐蚀性，Cr 有助于提高耐候钢初期的耐蚀性能，Cr 元素能加速缺陷的愈合，使锈层致密；Cu 在钢的表面及锈层中富集，形成保护性较好的锈层，Cr、Cu 元素结合均可提高钢种基体的耐腐蚀能力，降低腐蚀速度。在耐候钢苛刻环境的耐蚀机制研究的基础上，研发出500MPa 级高强耐蚀车体用钢和390MPa 级别易焊接高韧性转向架构架使用耐候钢，并对新研发的车体用钢和转向架构架用钢进行了相变规律、组织性能调控方法研究，对材料各项力学性能检测与耐蚀性检测与分析发现各项指标均满足任务书要求。新研发钢种的焊接性能优于现役同类铁道车辆用钢。

此外，进行户外暴露试验以及多种室内加速腐蚀试验，研究受到不同环境因素的影响所生成锈层的差异，并试图找到腐蚀动力学和锈层特性之间的相关性。通过西沙、青岛户外不同时间暴露试验研究对比材料Q345B 和货车车体用钢S500AW、转向架用钢G390NH 的腐蚀行为，对比完成了室内加速相关性测试与计算，建立货车车体用钢S500AW 和转向架用钢G390NH 基于不同苛刻腐蚀环境的寿命预测模型。

In order to understand the corrosion behavior and corrosion resistance mechanism of weathering steel in multi factor harsh environment, the micro nano scale corrosion behavior mechanism was studied. It was found that nano precipitates and inclusion particles could not induce stable corrosion pits. The combination of precipitates and inclusions induces corrosion in different ways and corrosion morphology. The cementite lamellar potential inside pearlite in ferrite and less pearlite is significantly higher than that in ferrite phase, and there will be obvious galvanic corrosion effect in corrosive medium. Corrosion occurs preferentially in pearlite structure. But there is no large potential fluctuation between different phases of GB structure. Alloying has a great effect on improving the corrosion resistance of steel. Sb element is obviously enriched in the inner rust layer, which improves the corrosion resistance of steel. Element Cr helps to improve the initial corrosion resistance and compact the rust layer of steel; Cu is enriched on the surface and rust layer of steel to form a rust layer with good protection. The combination of Cr and Cu can enhance the corrosion resistance of steel. Based on the research on the corrosion resistance mechanism of weathering steel in harsh environment, 500MPa high-strength corrosion-resistant wagon steel and 390mpa easily welded high toughness bogie frame weathering steel were developed. The phase transformation, structure and performance control method of newly developed steel for wagon and bogie frame were studied. it is found that all indexes of steels meet the requirements of the assignment. The welding performance of the newly developed steel is better than that of the same kind of railway vehicle steel in service. In addition, outdoor exposure tests and a variety of indoor accelerated corrosion tests are carried out to study the differences of rust layers affected by different environmental factors, and try to find the correlation between corrosion kinetics and rust layer characteristics. Through the outdoor exposure tests in Xisha and Qingdao at different times, the corrosion behavior of Q345B, truck body steel s500aw and bogie steel g390nh is compared, the indoor acceleration correlation test and calculation are completed, and the life prediction models of truck body steel s500aw and bogie steel g390nh based on different harsh corrosion environments are established.