Corrosion Mechanism And Corrosive-inhibitive Of Lead Ingot

Surface of lead ingot and materials containing lead, are often corroded to form white rust by water rain, foggy of sea water and corrosion gases in atmosphere at high-temperature, high-humidity during store and transportation.By the methods of gas corroding, water dipping, foggy spraying and intermittent dry-humidity, the influence of temperature, humidity, acidity, distillated water, hand-made seawater, tap water, rain, dew, hand-made industrial atmosphere on corrosion of lead were investigated. The results showed that the white rust mainly consist of Pb(OH)2 in neutral water, 3PbCO3.2Pb(OH)2.H2O in high humidity atmosphere, Pb4(CO3)2(SO4)(OH)2 in the industrial exhausted gases,respectively .In a word , the first effect factor on corrosion of lead is water,the second is high temperature, high humidity,CO2 and O2 in atmosphere.In order to avoid the formation of white rust lead ingot, three corrosion-inhibitive agents such as ACH1, ACH2 and ACH3 for lead ingot,were selected.The results exhibit that ACH1 is optimum corrosion-inhibitive agent for lead coating.Its best filmed conditions are temperature to be 700C,5g/l of concentration ,and time being5mins.Under such conditions,the corrosion speed of lead ingot coated by ACH1 is only one-fortieth of that on the lead ingot without coating.Moreover,the corrosion-inhibitive cost less and the coating technology is simple.