锅炉水冷壁管在含SO_4^(2-)溶液中的点蚀特性研究  

Study of the Pitting Characteristics of Boiler Water-wall Tube in SO_4^(2-)-contained Solution

作　　者：熊书华[1] 朱志平[1] 荆玲玲[1] 张辉[1] 

机构地区：[1]长沙理工大学化学与生物工程学院,湖南长沙410076

出　　处：《热能动力工程》2012年第1期91-95,138-139,共5页Journal of Engineering for Thermal Energy and Power

基　　金：湖南省自然科学基金资助项目(09JJ6067);湖南省科技攻关项目基金资助(2010GK3171)

摘　　要：为研究水冷壁管材料15CrMo在含SO24-溶液中的点蚀特性,通过常温电化学实验和高温挂片实验,对常温性能和高温腐蚀特性进行分析,用透反射金像显微镜、SEM、EDS、XRD对试片表面形态和组分进行表征与分析。结果表明:常温条件下,SO42-主要以氧化作用为主,抑制不锈钢的腐蚀,材料的耐蚀性增加;高温条件下,SO24-为侵蚀性离子,将加速材料的点蚀,形成带有锯齿状边缘的点蚀坑,其点蚀临界浓度为1mg/L;常温下SO24-抑制Cl-点蚀的机理是竞争吸附,高温条件下SO42-促进点蚀的机理为局部酸化理论。To study the pitting characteristics of waterwall tube material 15CrMo in SO2-4-contained solution,through a normal temperature electrochemical test and a high temperature plate-hanging test,an analysis was performed of the normal temperature performance and high temperature corrosion characteristics of the material in question.By using a lens reflection-based metallogenetic microscope,SEM,EDS and XRD,the morphology and constituents of the surface of the test piece were represented and analyzed.The research results show that at a normal temperature,the oxidation action of SO2-4 will mainly dominates to contain the corrosion to the stainless steel,thus enhancing the corrosion-resistant property of the material.At a high temperature,SO2-4 will become corrosive ions to quicken the pitting of the material,thus forming pittings with serrated rims,of which the critical pitting concentration will be 1 mg/L.At a normal temperature,the mechanism to contain the Cl-pitting by SO2-4 lies in its competitive adsorption while at a high temperature,the mechanism to promote the pitting by SO2-4 lies in its local acidification theory.

关 键 词：水冷壁管 15CrMo SO42- 点蚀 

分 类 号：TK224.9[动力工程及工程热物理—动力机械及工程]