Development And Application Of Compound Corrosion Inhibitor

An important method of protection of metals against corrosion is by using inhibitor. Using industrial wastewater as inhibitor can not only reduce cost, but also lower the environment pollution. It is a good way of comprehensive utilization of waste resource.The research of pickling inhibitor preparation chose the 6-nitrly concentrated liquid as main agent. Through the initial experiment, the formulation of mixed compound was determined as: urotropine, potassium iodide and OP. The orthogonal experiments had been adopted to develop TZ inhibitor by using the weight loss method. The optimum formulation was as follows: the 6-nitrly concentrated liquid 14ml, urotropine 2.1g, potassium iodide 0.105g, OP1ml. The optimum concentration was 0.5%. When temperature was 60℃, the inhibiting rate and anti-acid fuming rate could be 99% and 98% respectively. The experimental results indicate that: it can be used for steel pickling in 20%H2SO4 and 10%HCl. 30℃~80℃is suitable for acid pickling.Electrochemical performance and inhibition mechanism of TZ inhibitor were studied by using electrochemical measurements, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis. Compared electrochemical method with the weight loss method, the conclusions were consistent .It was an anodic inhibitor. The inhibition efficiency of TZ inhibitor was increased with raising concentration. It was little affected by temperature. SEM confirmed its effectiveness. EDS analysis proved that it was physical adsorption.The effect of TZ inhibitor on phosphatization and blackening was investigated. The corrosion resistance of phosphating film was enhanced with inhibitor. Corrosion resistance of room temperature blackening film was decreased with inhibitor. It was little affected on alkaline blackening at high temperature.