模拟高温炉水中Cl^-对20A碳钢的腐蚀研究

Corrosion of 20A Carbon Steel in Boiler Water Containing Cl-at High Temperature

采用高压釜静态挂片试验和EPMA ,XRD分析方法 ,模拟研究了高温炉水中Cl- 对无Fe3O4 膜和有膜 2 0A碳钢的腐蚀作用。结果表明 :在 36 0± 3℃ ,pH =9.4 0± 0 .10 ,O2 <0 .0 2 0mg/L条件下 ,无膜试片当Cl- >0 .2mg/L时 ,点蚀密度随Cl- 浓度增大而增大 ;具有完整膜的试片 ,当Cl- 浓度高达 0 .8mg/L时 ,膜未明显溶解 ;对于有蚀点的成膜试片 ,当Cl- 浓度为 0 .4mg/L时 ,膜即开始溶解 ,因此Cl- 的最高允许浓度应为 0 .2mg/L。

The corrosion of 20A carbon steel specimens with or without surface oxide film was studied statically in simulated boiler water containing Cl- in the autoclave at high temperature.The SEM and XRD results indicated that under 360 ± 3 ℃ , pH=9.40± 0.10,CO 2<0.020 mg/L conditions,the pitting density increased with Cl- increasing at Cl- >0.2 mg/L for the specimens without oxide film,but not for the specimens with oxide film.The result also showed that the maximum Cl- concentration allowance should be 0.2 mg/L.