Wu Xiangyang, Zhang Zhiyi, Qi Weichuang, Tian Renyong, Huang Shiming, Shi Chunyuan
CRRC Sifang Co. Ltd., Qingdao 266111, China.
School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China.
Materials (Basel). 2019 Sep 19;12(18):3043. doi: 10.3390/ma12183043.
Currently, high-speed trains work under various atmospheric environments, and the bogie as a key component suffers serious corrosion. To investigate the corrosion behavior of bogies in industrial atmospheric environments, the periodic immersion wet/dry cyclic corrosion test for SMA490BW steel and automatic metal active gas (MAG) welded joints used for bogies was conducted in the present work. Corrosion weight loss rate, structure, and composition of rust layers as well as electrochemistry parameters were investigated. The results showed that the corrosion weight loss rate decreased with increasing corrosion time; furthermore, the corrosion weight loss rate of the welded joints was lower than that of SMA490BW steel. The XRD results showed that the rust layers formed on SMA490BW steel and its welded joints were mainly composed of α-FeOOH, γ-FeOOH, FeO, and FeO. The observation of surface morphology indicated that the rust layers of the welded joints were much denser and had a much finer microstructure compared with those of SMA490BW steel. After corrosion for 150 h, the corrosion potential of the welded joints with rust layers was higher than that of SMA490BW steel. In short, the welded joints exhibited better corrosion resistance than SMA490BW steel because of the higher content of alloy elements, as shown in this work.
目前，高速列车在各种大气环境下运行，转向架作为关键部件遭受严重腐蚀。为研究转向架在工业大气环境中的腐蚀行为，本文对用于转向架的SMA490BW钢及自动熔化极活性气体保护焊（MAG）焊接接头进行了周期性浸泡干湿循环腐蚀试验。研究了腐蚀失重率、锈层结构和成分以及电化学参数。结果表明，腐蚀失重率随腐蚀时间的增加而降低；此外，焊接接头的腐蚀失重率低于SMA490BW钢。X射线衍射结果表明，SMA490BW钢及其焊接接头上形成的锈层主要由α-FeOOH、γ-FeOOH、FeO和FeO组成。表面形貌观察表明，与SMA490BW钢相比，焊接接头的锈层更致密，微观结构更精细。腐蚀150 h后，有锈层的焊接接头的腐蚀电位高于SMA490BW钢。总之，如本文所示，由于合金元素含量较高，焊接接头表现出比SMA490BW钢更好的耐腐蚀性。
