氯化物与硫酸盐浓度比对黄铜-铅电偶腐蚀的影响

Effect of Chloride-to-sulfate Mass Ratio on Galvanic Corrosion of Brass-Lead Joints

以供水管道中黄铜与铅焊接的电偶连接为研究对象,探究不同氯化物与硫酸盐浓度比(CSMR)对黄铜-铅电偶腐蚀的影响。分析了黄铜-铅电偶腐蚀的金属释放量、电化学行为及腐蚀产物。结果表明,CSMR使得多电偶对中阳极极性改变。在CSMR=0~0.5时,铅锌同作为阳极;CSMR=1时锌单独作为阳极;而CSMR=∞时,铅单独作为阳极。铅的腐蚀产物为棒状的PbCO_(3)及片状的Pb_(3)(CO_(3))2(OH)2,锌的产物为板状的ZnO_(2),而铜和锡的产物分别为颗粒状Cu2O和块状SnO_(2)。当供水管道中黄铜与含铅材料电偶连接时,为减少铅的释放,建议将CSMR控制在1左右。

Taking the galvanic coupling connection of brass and lead soldering in water distribution system as the object,the effect of different chloride to sulfate mass ratio(CSMR)on the brass-lead galvanic corrosion was investigated.The metal release,electrochemical behavior and corrosion products of the brass-lead galvanic corrosion were analyzed.The results show that CSMR makes the anodic polarity change in the multi-electrode pairs.At CSMR of 0-0.5,lead and zinc are acted as anode simultaneously;at CSMR=1,zinc is acted as anode alone;and at CSMR=∞,lead is acted as anode alone.The corrosion products of lead are PbCO_(3) in the form of rods and Pb_(3)(CO_(3))2(OH)2 in the form of flakes.The product of zinc is flat ZnO_(2),the product of copper is granular Cu2O,and the product of tin is lumpy SnO_(2).When brass is galvanic connected to lead-containing material in the water supply pipeline,it is recommended to control the CSMR around 1 to reduce the release of lead.