论文部分内容阅读
研究了 H68 A 黄铜在含 Cl~-溶液中的闭塞阳极行为。结果表明,黄铜的闭塞阳极不存在加速腐蚀的自催化效应,而是使闭塞区表面保持活性状态。其电位随阳极液 Cu~+浓度升高而变正。闭塞区Cu~+和 H~+不能向外扩散时,EE_(Cu/CuCl/Cl~-)进行生成 CuCl[s]的溶解反应。Cu~+和 H~+能向外扩散时,E>E_(Cu/Cu_2O/h 即能发生溶解。此时闭塞室内生成 Cu_2O。闭塞区外有扩散出来的 Cu~+经二次反应后生成的沉积物。黄铜冷凝管点蚀的腐蚀产物分布情况符合后者,这种点蚀在 E>E_(Cu/Cu_2O)时即能形成。黄铜管表面有碳膜时容易形成闭塞区并使电位升高,起到促进点蚀发生和加速点蚀作用,而不是产生点蚀的必要条件。为防止点蚀必须促使黄铜表面生成完整的保护膜。
The occlusive anode behavior of H68 A brass in Cl ~ - containing solution was investigated. The results showed that there was no autocatalytic effect of accelerated corrosion on the occluded anode of brass, but rather the surface of the occluded area was kept active. The potential of positive electrode Cu ~ + concentration becomes positive. E <(Cu / CuCl / Cl ~ -) does not dissolve when Cu ~ + and H ~ + can not diffuse outward in the occluded region; CuCl [s] Dissolution reaction. When Cu ~ + and H ~ + can diffuse outwards, E> (Cu / Cu_2O / h can dissolve. At this time, Cu_2O is generated in the occluded chamber and Cu ~ + diffused out of the occluded area is generated by the secondary reaction Of the deposits.The distribution of corrosion products of the pitting corrosion of the brass condenser tube accords with the latter, and the pitting corrosion can be formed when E> E Cu (Cu / Cu 2 O) So that the potential increases, to promote the occurrence of pitting and accelerate pitting, rather than the necessary conditions for pitting. To prevent pitting must promote brass surface to generate a complete protective film.