碳钢在NaHCO_3+NaCl溶液中的亚稳态孔蚀特征  

Feature of metastable pitting of carbon steel in NaHCO_3+NaCl solutions

作　　者：唐聿明[1] 刘秀英[1] 左禹[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029

出　　处：《北京化工大学学报（自然科学版）》2004年第2期36-40,共5页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：国家自然科学基金 (5 0 2 71 0 0 5 ) ;国家重点基础研究发展规划资助项目 (G1 9990 6 5 0 )

摘　　要：用动电位极化和恒电位极化法研究了A3碳钢在不同浓度NaCl的 0 5mol/LNaHCO3 溶液中亚稳态孔蚀行为。实验发现亚稳态电流波动峰具有快速上升、缓慢下降的特点。亚稳孔出现电位Em 服从正态分布 ,随着Cl-浓度的提高 ,Em 值向负方向移动。亚稳孔的峰频变化规律与电位关系不大。恒电位极化时 ,当电位高于Em 而大大低于孔蚀电位Eb 时 ,电流波动保持一定时间后会最终消失 ,并产生直径为微米级的小蚀孔。当电位接近孔蚀电位时 ,一段时间的电流波动后电流往往迅速上升 。The metastable pitting behavior of A3 carbon steel in 0 5?mol/L NaHCO 3 solutions containing different concentrations of NaCl were studied with the potentiodynamic and potentiostatic polarization methods. It is found that the current fluctuations of the metastable pitting occurred with a characteristic of quick increase and slow decrease. The occuring potential of the metastable pits E m obeys a normal distribution, and decreases with the increase of the chloride concentration. Potential has no apparent effect on the frequency of fluctuations. In potentiostatic test, when the potential is above E m and far below the pitting breakdown potential E b, the current fluctuations remain for a period then disappear, resulting in the pits with a diameter of microns. When potential is close to E b, the current may finally rise continuously after a certain time of fluctuations, and the metastable pitting is replaced by a stable piting.

关 键 词：A3碳钢 亚稳态孔蚀 电流波动 NAHCO3 

分 类 号：TG171[金属学及工艺—金属表面处理]