水冷壁管在CPT和NaOH水工况下的腐蚀特征

本文使用电化学工作站、XRD、SEM和EDS等方法,研究水冷壁管在CPT和CT处理下高温腐蚀特性,分析其形成机理,为电站化学工作者在选择水工况和金属防护方面提供一定的参考。结果表明:CPT条件下金属内壁表层呈现了较深的腐蚀坑(腐蚀深度达到了200μm)和凹凸不平的特征,有明显的冲刷痕迹,不均匀的氧化物颗粒镶嵌在金属表层处;CT形成的氧化物具有明显的8面体晶体结构,腐蚀深度在10μm左右,氧化物颗粒较大,不紧凑,中间存在多而大的孔隙,容易引起缝隙腐蚀,颗粒物的脱落也会对水质起到破坏作用。

The Characteristics of Water-wall Tube Corrosion in NaOH Treatment

Research the high-temperature corrosion oxide formed on water-wall tube （15CrMo） in CPT and NaOH water chemistry conditions by Electrochemical Workstation, XRD, SEM and EDS, and analyzed the formation mechanism, provide some reference in the choice of water chemistry conditions for the plant chemical workers. The results showed that： in CPT condition, the metal oxide formed on the metal wall inner surface was metal corrosion products, which presented the features of depth corrosion （the depth of corrosion is 200~tm） and rugged, and the metal was strong destructted. In CT, the mainly oxide is Fe304, with a significant 8-sided crystal structure, and the section corrosion depth is observed about 10μm, it is easy to cause crevice corrosion because of the size of oxide particles is large, not intensive and full of pores. Shedding of particles will damage the water quality.