滨海电厂水系统碳钢管道的腐蚀控制

Corrosion Control of Steel Pipe for Water System in Coastal Power Plant

针对某滨海电厂海水及海水反渗透产水管道的腐蚀现象,采用失重法、扫描电镜、X射线衍射及电化学测试,对比研究了碳钢在其中的腐蚀差异。结果表明:在海水中锈层抑制氧的传递,对碳钢起保护作用;在反渗透产水中锈层起大阴极作用,加速基体腐蚀。实际工程中,海水反渗透产水比海水对碳钢管道更具侵蚀性。重新矿化反渗透产水是降低其腐蚀性的有效方法;另外,可考虑采用更耐蚀的不锈钢、碳钢衬塑管等作为管材。

To control the corrosion of water pipes in a coastal power plant,the difference of corrosion performance for carbon steel in seawater and seawater reverse osmosis（SWRO） water was investigated comparatively by means of weight-loss test,scanning electron microscopy（SEM）,X-ray diffraction（XRD） and electrochemical measurement.The results showed that the rust layer formed in seawater had a protective effect on iron by hindering the transfer of dissolved oxygen;but that formed in SWRO water could accelerate iron corrosion by providing a larger cathodic area.In practice,SWRO water showed more corrosive to carbon steel than seawater.Remineralization is a good choice for the post-treatment of SWRO water.Besides,corrosion resistant materials such as stainless steel and lined steel pipe could be designed to replace carbon steel as the material for SWRO water pipe.