摘要
用恒电位和动电位下的电流 -时间记录法研究了表面粗糙度对 316不锈钢亚稳态孔蚀行为的影响 .结果表明 ,表面粗糙度增大使亚稳孔的形核数明显增加 ,亚稳孔电流峰值也有所增大 ,亚稳孔生长速度则略有下降 .提出了一个表征表面沟槽“开放度”的参量w/d ,w/d值越大则表面越平坦 ,亚稳态小孔越难于形核 .一定的电位和溶液条件下存在一个临界w/d值 ,只有w/d值低于此临界值的表面才能形成亚稳态小孔 .随w/d值增大 ,亚稳态孔蚀电位Em 和稳定孔蚀电位Ep 都逐渐正移 .用w/d值定性解释了表面粗糙度与亚稳态小孔形核速率。
The metastable pitting behavior of 316L stainless steel with different surface roughness in 0.01 mol/L NaCl solution was studied using potentiostatic and potentiodynamic polarization methods and statistical treatments.As surface roughness decreased,the nucleation rate of metastable pits decreased.The peak current of metastable pits also decreased,but the average growth rate of metastable pits showed a slight increase.An openness parameter, w/d ,was suggested to characterize the openness of surface grooves,in which w is the width of the groove at the opening and d the depth of the groove.Bigger w/d value means more smooth surface,and it is more difficult for micro-pit to nucleate.Under certain condition of solution and potential,there is a critical w/d value.Metastable pits may nucleate only on those surfaces whose w/d values are lower than the critical value.As the openness parameter w/d increases,the nucleation rate of metastable pits decreases linearly,and both metastable pitting potential E m and pitting potential E p move in the positive direction.
出处
《中国腐蚀与防护学报》
CAS
CSCD
2002年第3期158-161,共4页
Journal of Chinese Society For Corrosion and Protection
基金
国家自然科学基金 (5 97710 63 )
国家重点基础研究规划(G19990 65 0 )资助项目
关键词
不锈钢
孔蚀
亚稳态
表面粗糙度
stainless steel,metastable pitting,surface roughness
