灰口铸铁在含乙酸初凝水中的腐蚀行为  

Corrosion Behavior of Gray Cast Iron in Early Condensate Water Containing Acetic Acid

作　　者：庹炜玲 曹顺安[1] 张达光 慕晓炜 陈皓 TUO Weiling;CAO Shun'ar;ZHANG Daguang;MU Xiaowei;CHEN Hao(School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China;East China Electric Power Test&Research Institute,China Da tang Corporation Science and Technology Research Institute Co.,Ltd.,Hefei 230022,China)

机构地区：[1]武汉大学动力与机械学院,武汉430072 [2]中国大唐集团科学技术研究院有限公司华东电力试验研究院,合肥230022

出　　处：《腐蚀与防护》2020年第5期22-26,39,共6页Corrosion & Protection

摘　　要：采用失重法,结合扫描电镜(SEM)、能谱(EDS)与X射线衍射(XRD)等研究了汽轮机低压缸和隔板用灰口铸铁在含不同量乙酸的模拟初凝水中的腐蚀行为。结果表明:灰口铸铁在含乙酸初凝水中会发生腐蚀,且腐蚀速率随乙酸含量的增加而增大,但灰口铸铁的腐蚀不仅仅是由低分子有机酸引起的,Cl^-也对腐蚀有很大影响。当溶液中不含Cl^-时,金属表面腐蚀产物较少,表面光滑、完整,腐蚀程度较轻,其在含1.0mg/L乙酸模拟初凝水中的腐蚀速率为0.045mm/a,腐蚀等级为四级;而当该溶液中加入0.1mg/L Cl^-后,灰口铸铁的腐蚀速率约为0.07mm/a,腐蚀等级为五级,且表面受到破坏,腐蚀加剧。Weightlessness method,combined with scanning electron microscopy(SEM),energy spectroscopy(EDS)and X-ray diffraction(XRD),were used to study the corrosion behavior of gray cast iron used in low-pressure cylinders and separators of steam turbines in simulated early condensate water containing different content of acetic acid.The results show that gray cast iron corroded in the acetic acid-containing early condensate water,and the corrosion rate increased with the increase of the content of acetic acid,and chloride ion also had a great influence on corrosion.When the solution didnt contain Cl,there were fewer corrosion products on the surface of the gray cast iron,the surface was smooth and complete,and the degree of corrosion was light.The corrosion rate of gray cast iron in simulated initial condensate water containing 1.0 mg/L acetic acid was 0.045 mm/a,and the corrosion grade was grade 4.However»when 0.1 mg/L Cl-was added to the solution,the corrosion rate of gray cast iron was about 0.07 mm/a,the corrosion level was grade five,and the surface was damaged and the corrosion was serious.

关 键 词：发电机组水汽系统 乙酸 初凝水 灰口铸铁 腐蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]