F.H. Cao
,
L. Guo
,
L.J. Zhang
,
Z. Zhang
,
J.Q. Zhang
金属学报(英文版)
The corrosion behavior of two different aged LY12 alloys in EXCO (234g/L NaCl, 50g/L KNO3, 0.1M HNO3) and MIL-H-600 (35g/L NaCl, 5g/L (NH4)2SO4) solutions were studied using electrochemical impedance spectroscopy (EIS) in conjunction with SEM technique respectively, and the pH variation of the above accelerated corrosion solution during materials corroding was also measured to characterize the corrosion processes. At the beginning of corrosion, EIS plots exhibited two capacitive arcs in the high frequency range (Cdl) and mediate frequency range (Clf) originating from the original corroded surface and the newly formed interface respectively, and a low frequency inductive loop due to the relaxation phenomenon of reaction intermediates. In the EXCO solution, the EIS results showed that once the exfoliation corrosion occurred, the inductive loop disappeared. The results also showed that the exfoliation corrosion susceptibility of state T6 is much higher than that of state T3, but the intergranular corrosion susceptibility has a reverse order. Based on the relationship of EIS results with SEM and metalloscopy morphologies of the corroding substrates and physic-chemical meaning of EIS parameters, an index (Clf / Cdl) has been proposed to characterize the extent of the localized corrosion, which variation tallies with the real corrosion extent correctly. Meanwhile, good agreement was found between the experimental results and the electrochemical model proposed and, good coherence between the electrochemical features and the distribution type of constituent particles of corroding material was observed.
关键词:
electrochemical impedance spectroscope
,
null
,
null
高健
,
康健
,
吴学玲
,
徐競
,
李邦梅
,
邱冠周
中国有色金属学报
以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.
关键词:
L.ferriphilum YSK菌株
,
Fe2+
,
生长活性
