游离酸度对电站锅炉用低合金钢磷化膜性能的影响

Effect of free acidity on the properties of phosphating film on low alloy steel for utility boilers

通过对电站锅炉常用的低合金钢材料12Cr1MoVG进行不同条件下的磷化处理,并通过盐雾试验、极化曲线测试、扫描电镜等方法,对磷化膜的微观形貌和耐腐蚀性等进行对比分析。结果表明,磷化处理能够大幅度降低基体材料的腐蚀电流密度,材料的耐蚀性能得到显著提高,且磷化液的游离酸度在13.0点左右时,达到最佳的耐蚀效果。

By phosphating 12Cr1MoVG,a low alloy steel commonly used in utility boilers,under different conditions,and by means of salt spray test,polarization curve test and scanning electron microscope,the micro morphology and corrosion resistance of phosphating film were compared and analyzed.The results show that the corrosion current density of the base material can be greatly reduced by phosphating treatment,the corrosion resistance of the material can be significantly improved,and the best corrosion resistance can be achieved when the free acidity of the phosphating solution is about 13.0 point.