ELECTROCHEMICAL NOISE CHARACTERISTICS OF METASTABLE PITING OF 16Mn MILD STEEL
用电化学噪声研究16Mn钢的亚稳态孔蚀特征

The fluctuation of potential and current of 16Mn carbon steel were monitored in NaHCO 3+Na 2CO 3 aqueous solution with and without 0.5 mol/L Cl -.Noise current and noise potential patterns were experimentally observed which related to the incubation and die of metastable pitting,where the "transient" in ECN had generally characteristic of "fast down and slow recovery".The amplitude and lifetime of transient in ECN increased when addition of 0.5 mol/L NaCl.In addition,Surface potential and current mapping on passive film of 16Mn steel was also measured simultaneously by wire beam electrode,and the result showed the number of surface active points increased with addition of Cl -.Furthermore,dynamic potential scanning indicated that the addition of 0.5M Cl - would cause the passive film breakdown at more negative potential.