碳钢在冷凝水中的腐蚀电化学行为  

Electrochemical Corrosion Behavior of Carbon Steel in Condensate Water

作　　者：业成 陆晓峰[2] 廖明刚[2] 

机构地区：[1]南京市锅炉压力容器检验研究院,江苏南京210002 [2]南京工业大学机械与动力工程学院,江苏南京210009

出　　处：《材料保护》2013年第8期33-35,共3页Materials Protection

摘　　要：为了给20碳钢在冷凝水中流动加速腐蚀模型的建立奠定基础，在温度、压力可控的密闭腐蚀试验机上运用电化学测试手段（极化曲线、交流阻抗谱）研究20碳钢在不同温度、不同pH值的冷凝水中的腐蚀电化学行为，并通过扫描电镜（SEM）观察腐蚀产物膜形貌。结果表明：在80—125℃，pH值7-10的冷凝水中20碳钢的腐蚀反应基本受扩散控制，腐蚀产物膜均多孔疏松，在金属基体和腐蚀产物膜之间构成大阴极、小阳极的腐蚀系统，导致金属基体表面发生点蚀的倾向增大，腐蚀速率升高；pH=7时点蚀温度为90℃，pH=8，9时点蚀温唐均＊RnoCDH：10时占蚀濡唐为100℃．A sealed flow accelerated corrosion test apparatus whose temperature and pressure were controllable was performed to examine the electrochemical corrosion behavior of the carbon steel in condensate water with different temperature and pH value. The morphology of the corroded products was observed with a scanning electron microscope. Results indicated that,in condensate water with a temperature of 80 ~ 125 ℃ and pH value of 7 ~ 10,the corrosion reaction of the carbon steel was controlled by diffusion process and relevant corroded products were loose and porous. In this case,corrosion system consisting of large cathode and small anode was formed between the metal substrate and the corroded products,thereby leading to enhanced pitting of the metal surface and increased corrosion rate as well. Besides,in condensate water with different pH values( 7,8 ~ 9,10),pitting of the carbon steel occurred at a temperature of 90,80,100 ℃,respectively.

关 键 词：腐蚀电化学行为 20碳钢 冷凝水 极化曲线 交流阻抗谱 点蚀 

分 类 号：TG172.5[金属学及工艺—金属表面处理]