阴极保护管线破损涂层下高pH环境形成规律

HIGH pH ENVIRONMENT UNDER DEBONDEDCOATING ON CATHODIC PROTECTED PIPELINES

采用模拟闭塞电池装置和自制的微型 pH和Cl-选择电极研究外部钢电位、闭塞区电流密度、闭塞度、时间及温度等因素对管线破损涂层下高 pH环境形成的影响 .获得微区内pH值上升和Cl-浓度下降的数学模型 .

An occluded cell,a DIY antimony mini-electrode and a Ag/AgCl mini-electrode were used to investigate the high pH local environment under debonded coating on cathodic protected pipelines.The effects of the exterior protected potential,cathodic protected current density,blocked resistance,environmental temperature and time on formation of high pH local aqueous environment were analyzed according to the result of the simulation tests.A mathematical model of the pH change of local environment was obtained.