炉水中侵蚀性阴离子对碳钢腐蚀的试验研究

Study on the corrosion of carbon steel by erosive anions in boiler water

为了研究低磷酸盐—低氢氧化钠水处理工艺下侵蚀性阴离子对碳钢的腐蚀 ,通过高压釜静态试验 ,计算在不同浓度下碳钢的腐蚀速度 ,测定溶液中总铁离子浓度以及对表面的 EPMA(Electron probe microanalysis,电子探针微量分析 )分析。结果表明 :高温下 ,Cl-、SO42 -是引起碳钢腐蚀的主要原因。它们能阻碍膜的形成。随着离子浓度的增大 ,当 CCl- >0 .4m g/L 时 ,碳钢的腐蚀速率明显增加 ,蚀孔增多 。

In order to study the corrosion of carbon steel caused by the erosive anion with low phosphate and low NaOH water treatment technology,the total iron ions in the solution are determined through autoclave static experiments and by measuring the corrosion rate in different solution concentrations,and the surface analysis is done with electron probe. The results show that the Cl - and SO 4 2- are the main causes of corrosion,especially pitting. They can interfere with the film forming. The corrosion rate and the number of voids increase and the anti corrosion performance decreases when the ion concentration gets higher and Cl -,SO 4 2- >0.4 mg/L。