低强度直流杂散电流对Q235钢在SO_2大气中腐蚀行为的影响  

Influence of Low Intensity DC Stray Current on Corrosion Behavior of Q235 Steel in Atmosphere Containing SO_2

作　　者：张明[1] 余建飞[1] 张予[1] 詹约章[1] 唐从明[1] 

机构地区：[1]国网湖北省电力公司电力科学研究院,湖北武汉430077

出　　处：《材料保护》2015年第9期18-21,7,共4页Materials Protection

摘　　要：目前,就SO_2大气环境下杂散电流对碳钢腐蚀影响的报道较少。采用户外暴露、室内周期浸泡加速腐蚀并结合表面滴加腐蚀溶液的方法,研究了施加不同强度直流杂散电流后的Q235钢在SO_2大气环境下的腐蚀行为,计算了腐蚀失重,对不同阶段腐蚀后的试样进行了交流阻抗和锈层X射线衍射分析。结果表明:只有在较高SO_2浓度的户外大气环境和室内加速腐蚀条件下,并且表面通入至少30 m A直流杂散电流时,才能引起Q235钢腐蚀行为的轻微变化,在这种条件下,腐蚀初期试样表面因电解作用形成较多的亚稳相造成腐蚀加速,后期则由于较多亚稳相转变为稳态相提高了锈层致密性,使得腐蚀相对放缓。Different intensities of DC stray current were applied to Q235 steel,and the corrosion behavior was investigated by means of exposure test,wet-dry cyclic accelerated corrosion test and dripping corrosive solution test. Weight loss,electrochemical impedance spectroscopy of the corroded samples and X-ray diffraction of the corrosion products were carried out. Results showed that corrosion behavior of Q235 steel changed slightly when the samples were applied by at least 30 mA DC stray current and exposed in high SO2 concentration. Under this condition,more metastable phases were formed in virtue of electrolytic chemical corrosion at the initial stage. But later,the compactness of the rusts was enhanced and the corrosion rate became slower with the metastable phases converting to stable phases.

关 键 词：直流杂散电流 Q235钢 SO2 大气腐蚀 

分 类 号：TG142.1[一般工业技术—材料科学与工程]