变电站接地网的防腐方法研究

利用埋片失重法及电化学法测定接地网试片的腐蚀速率，对比分析了缓蚀剂、牺牲阳极阴极保护法及缓蚀剂-牺牲阳极阴极保护联合保护3种方法的优缺点。结果表明：分别采用1%钼酸钠、2%六偏磷酸钠和4%硅酸钠作为缓蚀剂，Q235钢接地网在土壤中的缓蚀效果均较好，接地网试片的腐蚀速率均减小至0.1200 mm/a，保护度能达到约70%；采用六偏磷酸钠+钼酸钠的复配缓蚀剂，Q235钢的腐蚀速率从0.4667 mm/a减小至0.0873 mm/a，保护度达到81.3%；采用镁牺牲阳极阴极保护技术，Q235钢的腐蚀速率从0.2671 mm/a 减小至0.0639 mm/a，保护度为76.1%；采用复配缓蚀剂-牺牲阳极法联合保护，Q235钢的腐蚀速率从0.3342 mm/a减小至0.0260 mm/a，保护度可达92.2%。

Comparison of Corrosion Protection Measures of Grounding Grids for Electric Power Station

In order to prolong the service life of grounding grid for electric power station, the corrosion rate of grid without and with protection measures was evaluated by weight-loss method and electrochemical method respectively. The advantages and disadvantages of corrosion inhibitor, sacrificial anode cathodic protection and combined measure of corrosion inhibitor and sacrificial anode cathodic protection are compared and analyzed. The results show that three inhibitors of 1% of Na₂MoO₄, 2% of (NaPO₃)₆ and 4% of Na₂SiO₃ all show good efficiency in corrosion inhibition on Q235 steel grounding grid. The corrosion rate of grounding grid nearly decreased to 0.1200 mm/a with an inhibition efficiency about 70%. When (NaPO₃)₆+Na₂MoO₄ is used as mixed inhibitor, the corrosion rate of Q235 steel decreased from 0.4667 to 0.0873 mm/a with an inhibition efficiency up to 81.3%. Furthermore, by using magnesium sacrificial anode for cathodic protection, the corrosion rate of Q235 steel decreased from 0.2671 to 0.0639 mm/a with an inhibition efficiency up to 76.1%. By using combined protection measure of corrosion inhibitor plus sacrificial anode，the corrosion rate of Q235 steel decreased from 0.3342 to 0.0260 mm/a and inhibition efficiency is up to 92.2%.