通过电化学噪声测量研究表面粗糙度对2205双相不锈钢点蚀的影响。

Tang Yiwei, Dai Nianwei, Wu Jun, Jiang Yiming, Li Jin

Department of Materials Science, Fudan University, Shanghai 200433, China.

Materials (Basel). 2019 Mar 4;12(5):738. doi: 10.3390/ma12050738.

The influence of surface roughness on the pitting corrosion behaviour of 2205 duplex stainless steel (DSS) in a chloride-containing environment was investigated using electrochemical noise (EN) techniques and morphology observation. A rougher surface condition increased the frequency of pit initiation because of the increase in more occluded pit sites. Rough surface finish also accelerated pit growth by increasing the actual dissolution rate in the pit. Metastable pits on rougher surfaces had longer lifetimes and grew to larger sizes, as their inner chemical environment was more easily maintained. However back-scatter images showed that pitting initiates on DSS 2205 regardless of the roughness condition.

采用电化学噪声（EN）技术和形貌观察方法，研究了表面粗糙度对2205双相不锈钢（DSS）在含氯环境中点蚀行为的影响。由于闭塞小孔位置增加，更粗糙的表面状况提高了点蚀萌生的频率。粗糙的表面光洁度还通过提高小孔内的实际溶解速率加速了小孔的生长。较粗糙表面上的亚稳态小孔具有更长的寿命且尺寸长得更大，因为其内部化学环境更容易维持。然而，背散射图像显示，无论粗糙度条件如何，2205双相不锈钢上都会发生点蚀。