Abstract:

The immersion and electrochemical methods has been used to study the corrosion behavior of automotive steel Q255 in different content of snow melting salt (NaCl) solution. Immersion test show that, the snow melting salt solution is more corrosive than the natural snow solution. The corrosion rate of Q255 steel in the natural water water is smaller than that of the snow melting salt solution, with the corrosion rate of 0.021 07 mm/a after the immersion of 168 h.The corrosion rate increased with the increase of NaCl concentration of the snow solution. The corrosion rate of Q255 steel could reach 0.039 71 mm/a in 3%NaCl solution, the value of which was almost double to the natural snow solution. Electrochemical experiments show that, the presence of chloride ions accelerated the dissolution and mass transfer process of F e 2+ corrosion products, subsequently reduced the adhesion of the corrosion product. Accordingly, the corrosion products would not be able to protect the steel surface, thus the corrosion rate accelerated.

Key words: Snow-melting salt,  Snow water, Electrochemical methods, Immersion test, Automobile 

摘要： 采用浸泡法和电化学实验研究了汽车用 Q 2 5 5钢在不同融雪盐( N a C l ) 质量分数雪水溶液中的腐蚀行
为。浸泡实验结果表明, 含融雪盐的雪水溶液比天然雪水更具腐蚀性, Q 2 5 5钢在天然雪水中腐蚀速率较小, 浸泡
1 6 8h后的腐蚀速率为0. 0 2 10 7mm / a; 随着雪水中 N a C l质量分数的增加, 腐蚀速率也随着增大, 在质量分数为3%
N a C l雪水溶液中, Q 2 5 5钢的腐蚀速率为0. 0 3 97 1mm / a, 比纯雪水中 Q 2 5 5钢的腐蚀速率高出将近1倍。电化学实
验结果表明, C l -的存在加速了腐蚀产物F e 2+的溶解和传质过程, 减弱了腐蚀产物的附着, 使腐蚀产物起不到保护作
用, 加快了 Q 2 5 5钢的腐蚀速度。

关键词: 融雪盐, 雪水, 电化学实验,  , 浸泡实验, 汽车用钢