湿蒸汽发生器辐射段弯头腐蚀原因分析  

CORROSION CAUSE ANALYSIS OF RADIATING ELBOW OF A WET STEAMER

作　　者：潘治国[1] 胡传顺[1] 朱健 张淑娟[1] 季明[1] 

机构地区：[1]辽宁石油化工大学机械工程学院,抚顺113001 [2]抚顺市技术监督局特检所,抚顺113006

出　　处：《腐蚀科学与防护技术》2006年第5期377-379,共3页Corrosion Science and Protection Technology

摘　　要：对壁厚明显减薄的湿蒸汽发生器辐射段弯头进行了现场取样及腐蚀原因分析.结果表明,其材质符合要求;造成腐蚀的原因是辐射弯头遭受汽水腐蚀、氧腐蚀、氯离子腐蚀,使蚀坑底部形成了酸性环境;腐蚀产物覆盖下的内壁表面管材基体形成由内向外的微裂纹,沿晶开裂,呈现氢腐蚀特征;向火面温度高,腐蚀严重;三相微粒流造成已形成的腐蚀膜剥离,并使因氢蚀后形成晶界裂纹失去联系的晶粒与金属分离;如此反复作用使炉管内壁材料被除去,炉管迅速减薄.Several parts of corroded radiating elbows of a wet steamer after service were taken for analysis. Result shows that the quality of the tube is accord with standard. The corrosion cause of elbows was resulted from vapor and water corrosion, oxygen corrosion, chlorine ion corrosion. So that acid environment induced pits on their bottom. Beneath the corrosion products, inner surface of the elbows existed micro cracks from inside to outside inter-granularly, which displayed the characteristic of hydrogen corrosion. Because the temperature of flame facing side is high, electrode potential is low, thereby it resuled in corrosion much seriously. Three phase flow consisted of vapor, water and solid particle induced corrosion products spalling off from the substrate as well as the isolated grains detaching from the metal matrix after hydrogen corrosion. Then the new revealed surface was broken and then seperated from elbow, so that the wall thickness of elbow decreases rapidly.

关 键 词：湿蒸汽发生器 弯头 腐蚀原因 

分 类 号：TE963[石油与天然气工程—石油机械设备]