循环水微碱化的换热器腐蚀控制

发布时间：2018-04-16 02:36

  本文选题：HO钝化 + 微碱化　； 参考：《材料保护》2015年10期

【摘要】：为实现循环冷却水微碱化调质的平稳控制,抑制换热器金属件表面的腐蚀,考察了H68黄铜在以H2O2为钝化剂的Na2CO3-Na HCO3缓冲溶液中的腐蚀行为。通过正交试验优选了H2O2浓度、温度及碱度等成膜条件;通过电化学试验研究了循环冷却水微碱化阶段换热器钝化膜形成及发展过程。结果表明:H2O2浓度为0.6%,溶液碱度为18 mmol/L,温度20~30℃条件下钝化后,H68黄铜表面产生了薄而致密的Cu2O膜,在碱度为3.0 mmol/L的碳酸盐溶液中挂片12 d后,其腐蚀速率仅为0.000 6 mm/a;在碱度为2.0~3.0 mmol/L的微碱化循环冷却水中,氧化膜的阻抗和厚度先逐渐降低,48 h之后最低,之后上升,至144 h后达到稳定,并恢复至初始水平,氧化膜转化为颗粒较粗Cu O膜;本工艺实现了循环冷却水微碱化过程中钝化膜形成与发展的平稳过渡,换热器H68黄铜件表面形成了致密的氧化膜,既防止了局部腐蚀又抑制了均匀腐蚀。
[Abstract]:The corrosion behavior of H68 brass in Na2CO3-Na HCO3 buffer solution with H2O2 as passivating agent was investigated in order to control the stabilization of microalkalization and tempering of circulating cooling water and to restrain the corrosion of metal parts in heat exchangers.The conditions of H2O2 concentration, temperature and alkalinity were optimized by orthogonal test, and the formation and development of passivation film of heat exchanger in micro-alkali stage of circulating cooling water were studied by electrochemical experiment.The results showed that the thin and dense Cu2O film was formed on the surface of Brass H68 after passivation at 20 ~ 30 鈩，

本文编号：1756958