模拟地热水中304不锈钢管和镀锌钢管的腐蚀与结垢

Scaling and Corrosion of 304 Stainless Steel and Galvanized Steel Pipes in a Simulated Geothermal Water Environment

采用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和电化学测试的方法研究了304不锈钢管和镀锌钢管在模拟地热水(我国中部平原地热水的环境条件)中的腐蚀与结垢行为.结果表明,不锈钢管的结垢产物为"针"状物,其组成主要为CaCO3和MgCO3;镀锌钢管的腐蚀与结垢产物为"球"状物和"针"状物,其组成主要为Zn(OH)2、ZnO和CaCO3;腐蚀产物与结垢产物在晶核的形成生长过程中往往存在相互作用,同时它们在基材表面的分布对镀锌钢管的进一步腐蚀产生一定的抑制作用.

Steel pipe corrosion and scaling is a universal problem during the exploitation and use of geothermal resources.Scanning electron microscopy（SEM）,energy dispersion spectrometry（EDS）,X-ray diffraction（XRD）,and electrochemistry test were used to characterize and investigate the scaling and corrosion behaviors of galvanized steel and 304 stainless steel pipes in a simulated geothermal water environment（Chinese central plain geothermal water）.Results indicated that the scale formed on the 304 stainless steel pipe consisted of a needle-like substance and its main components were CaCO3 and MgCO3.The corrosion and scaling morphology of the galvanized steel pipe consisted of a ball-like substance and a needle-like substance with main components of Zn（OH）2,ZnO,and CaCO3.Corrosion and scaling often appeared simultaneously and acted synergistically during the formation and growth of the crystal nuclei and they prevented further corrosion of the galvanized steel pipe in geothermal water.