N80钢沉积物下闭塞电池腐蚀影响因素研究

利用一种能模拟沉积物下腐蚀自催化过程的闭塞电池研究了N80钢在0.2mol/LNaCl水溶液中的垢下腐蚀行为。结果发现其腐蚀速度随阴阳极面积比的增加而增大,但只有当阴阳极面积比为一适当的值时,才能形成稳定的闭塞腐蚀电池;介质pH值升高会加速闭塞区的腐蚀。并从理论上对实验结果进行了解释。

STUDY ON THE INFLUENTIAL FACTORS OF UNDERSCALE LOCAL CORROSION FO N80 STEEL

The underscale corrosion behavior and influential factors of N80 steel in 0. 2 mol. L-1 NaCl solutions was studied by using an occluded corrosion cavity （ OCC） cell which could simulate the auto-catalyzing process of localized corrosion. The change of coupled current between the occluded anode and the bulk cathode at different area ratio （ Ac/Aa） and pH value was measured. The results showed that the corrosion rate in OCC increased with increasing the Ac/Aa and keep up at a high level steadily when Ac/Aa is a proper value. The corrosion process inside the OCC is exacerbated by increasing the pH of the NaCl solution. The changes of corrosion rate in OCC was discussed and clarified in theory.