Liyun ZHENG
金属学报(英文版)
The corrosion behavior of zinc and its alloy under thin electrolyte layers (TEL) in 0.1M NaCl solution was investigated by cathodic polarization curves and EIS. There was only one phase in pure zinc while zinc alloy consisted of eutectic phase and primary phase. Corrosion rate of zinc alloy was faster than that of pure zinc due to the effect of the micro-galvanic couples between the primary phase and the eutectic phase. The results indicated that corrosion rate of zinc alloy was greatly enhanced under TEL than that in bulk solution. Pure zinc exhibited minimum corrosion resistance as TEL decreased to 198 μm. Zinc and its alloy exhibited localized corrosion under TEL while it was more uniform in bulk solution. There were two capacitive loops in high frequency (HF) and middle frequency (MF) respectively, with finite length diffusion in low frequency (LF) presented in EIS. For pure zinc under TEL below 300 μm an additional inductive loop presented in MF-LF. The corrosion products and morphology were respectively examined by X-ray diffraction (XRD), FTIR (Fourier Transform Infra Red) and SEM-EDS. FTIR micro spectroscopy results indicated that the component of the corrosion products was similar at different section of the specimen surface but different in content.
关键词:
Thin electrolyte layers
,
EIS
,
Cathodic polarization
,
FTIR micro spectroscopy
,
SEM
魏学军
,
李劲
,
柯伟
中国腐蚀与防护学报
测量了A537钢在恒ΔK控制下单次拉伸超载对腐蚀疲劳裂纹扩展的影响,研究了阴极极化及自腐蚀条件下材料在3.5％NaCl水溶液中的超载延迟扩展规律与特点。结果表明:单次拉伸超载裂纹扩展延迟效应的作用距离大于塑性区尺寸。空气中与阴极极化条件下,超载后裂纹扩展过程由超载扩展、减速扩展与恢复三阶段组成,而自腐蚀条件下只有减速扩展与恢复两个阶段。与空气中的结果相比,阴极极化与自腐蚀条件下的裂纹扩展延迟幅度与延迟距离均明显减小。分析表明,塑性诱发裂纹闭合在腐蚀条件下的变化是造成超载后裂纹扩展规律变化的主要原因之一。
关键词:
腐蚀疲劳
,
Overload retardation
,
Cathodic polarization
,
Free corrosion condition
