高温炉水的性质及其对炉管腐蚀的影响

Characteristic of HighTemperature Water and Its Influence on Corrosion of Tube in Boiler

国内外对炉水性质及炉水中微量组分对腐蚀的影响报导较少 ,为了弄清微量组分对水冷壁腐蚀的影响 ,在对高温炉水性质分析的基础上 ,对炉水中的微量组分溶O2 ,Cl-,SO2 -4和pH值及温度对水冷壁腐蚀的影响进行试验。结果表明 ,溶氧在 0 .0 4 0mg/L以下 ,CCl- <0 .2mg/L ,CSO 2 - 4 <0 .4mg/L ,pH值在 9.2 0 10 .0 0之间碳钢溶解速率最低。炉水中微量溶氧有利于保护膜的形成 ,碳钢的溶解速率随温度的升高而降低。温度高 ,有利于均匀成膜 ,炉水在临界点附近碳钢的溶解速率最小。本研究为现场炉水控制提供了依据。

Effects of micro components in boiler water such as dissolved O_2, pH value, Cl^-, SO^(2-)_4, and temperature on the corrosion of water cooled wall were studied on the basis of characteristics of high temperature water. Results show that the corrosion rate of carbon steel is the lowest under the conditions of dissolved O_2 below 0.04 mg/L, Cl^- content below 0.2 mg/L, sulfate content below 0.4 mg/L and pH value between 9.20 and 10.00. The minute O_2 dissolved in water is favorable to form the protection film. Corrosion rate of carbon steel decreases with raising temperature. High temperature makes for uniform film, the corrosion rate is the smallest while water temperature reaches near critical temperature.