Hydrogen Permeation of Iron Caused by Atmospheric Corrosion

摘要

The rusting of iron and its relationship with hydrogen permeation rate (HPR) during simulated wet - dry cycles was investigated. Different amounts of NaCl sa 0.9 and 9.3 mg/cm2 (equal with 500 uL of 0.1 M and 1 M), were employed in this study to accelerate the rusting. Double electrodes and plates of Fe were used to monitor the corrosion process and HPR, respectively. It was found out that when corrosion process proceeded, the HPR increased significantly. Corrosion and HPR are relative humidity-dependence variable. At high RH; 95% (wet condition), corrosion progressed and HPR increased. On the contrary, at low RH; 55% (dry condition), corrosion was inhibited and HPR reduced. In first few wet-dry cycles, some corrosion parameters were up and high due to the rapid corrosion took place on the fresh surface and then slowed down by the formation of rust layers. The amount of NaCl salt was also determined the corrosion rate and HPR. The HPR of 9.3 mg/cm2 of NaCl was about 3 times larger compared to 0.9 mg/cm2. The corrosion potential showed a change by two different mass of salt. It is suggesting that corrosion potential was affected by the amount of salt.