埋地高温供水钢管的腐蚀产物分析

Corrosion product of the underground thermal pipeline

采用扫描电子显微镜(SEM)、X射线能谱仪(EDX)、X射线衍射(XRD)技术对杭州市热力管网的埋地高温供水钢管腐蚀产物进行了分析,发现有质量分数达3%的NaCl结晶相存在;对现场的进一步调查分析发现,钢管腐蚀是介质Cl-导致的电化学腐蚀,高温环境下闭塞区内Cl-和Na+随溶液的不断蒸发,最终以NaCl形式结晶析出夹杂在钢管腐蚀产物中.在对NaCl结晶相形成机理分析的基础上得出了相应的埋地高温供水钢管腐蚀过程模型.

With SEM, EDX and XRD technologies the corrosion-product of the steel pipeline, supplying high temperature water(≯120℃) by The Thermodynamic Energy Company of Hangzhou,was analyzed.In the corrosion-product NaCl crystal phase (about 3%, quality percent) was discovered.It's found that the steel pipe decay is the result of the electrochemistry-corrosion caused by Cl^-, and under the high temperature environment the Cl^- and Na^+ in the groundwater separated out with the NaCl phase as continuously evaporating of the groundwater around the pipeline and entered in the steel rust.The corrosion model of the pipeline and its mechanism are discussed.