中文摘要：

利用3.5%（质量分数）NaCl溶液室温周期浸泡试验及电化学试验研究了不同C、Si含量车轮钢的腐蚀行为。用失重法测量了试样的腐蚀速率；观察了不同腐蚀时间后试样的表面形貌及截面形貌；利用光学表面形貌仪观测了不同腐蚀时间后试样表面粗糙度和腐蚀坑尺寸。结果表明：随C含量的增加及Si含量的降低，车轮钢稳态腐蚀速率增大；Si含量的提高使车轮钢自腐蚀电位升高以及表面电荷转移电阻增大，从而提高了其耐蚀性；在试验周期范围内，不同试样在腐蚀3 d后表面均出现点蚀，并随腐蚀时间的延长，点蚀坑尺寸和表面粗糙度增大。点蚀坑的出现会破坏车轮钢表面的完整性，在腐蚀坑底部造成应力集中，危害车轮的安全运行。

英文摘要：

Corrosion behavior of wheel steel with different C and Si contents was investigated using alternate immersion test and electrochemical test in 3.5% （mass fraction） NaCl solution. The corrosion rate was calculated based on the weight loss measurement. The surface morphology and cross section of specimens corroded for different times were observed. The surface roughness and the size of corrosion pits on the surface of specimens corroded for different times were measured using optical metrology. The results show that the corrosion rate increased with the increase of C content and with the decrease of Si content. The free corrosion potential and charge transfer resistance increased with the increase of Si content, resulting in the improvement of corrosion resistance of wheel steel. Corrosion pits existed on the surface of specimens corroded for 3 days, and the surface roughness and the size of corrosion pits increased with the prolongation of corrosion time. Corrosion pits can destroy the integrity of wheel surface and make stress concentrate on the bottom of pits, which are harmful to the operation safety of the wheels.