The Preparation And Performance Research Of Multifunctional Environment-Friendly Neutral Rust Remover

Metal corrosion had a great impact on human production and life.Therefore,metal corrosion protection was very important.Metal surface should be derusted before anti-corrosion treatment.Traditional strong acid rust remover would bring many problems such as metal over-corrosion,rust and environmental pollution in the process of rust removal.It could not meet the current national environmental protection requirements for the pickling industry.This topic aimed to prepare a safer and more environmental-friendly neutral rust remover,which had a multi-function such as rust and anti-corrosion.This paper mainly determined the optimized formula of multifunctional neutral rust remover by orthogonal test method,in which the acid was 20.0%,disodium edetate was 3.0%,sodium gluconate was 2.5%,sodium citrate was 1.0%and the self-made imidazoline anti-rust additive solution was 9.0%.For the C-grade steel plate,the time required for the completion of derusting at different descaling temperatures and the effect of different descaling agent concentrations on the derusting effect were investigated.In addition,the influence of the addition of external field ultrasonic on the derusting time was also studied.Secondly,it was found that the area of the steel plate treated by the rust remover can reach 200-500 m2/t,and the adhesion of the paint film of the steel plate after treatment reached level 1.Through comparison with the performance of various types of rust removers on the market,it was found that all aspects of homemade products had obvious advantages.At 30℃,the self-made product and the commercially available neutral rust remover had the same rust removal time.The SEM results showed that the metal surface of the self-made neutral rust remover was smooth and flat,and there was no obvious corrosion on the steel substrate.However,various types of rust removers on the market had different degrees of damage to the surface of the steel plate.At the same time,the results of electrochemical experiments and outdoor weathering tests showed that the surface of the steel plate was kept rust-free for one month after the self-made neutral rust remover was rusted,indicating that the rust remover had the function of preventing rust,which was superior to the commercial rust removal.The derusting and anti-rust mechanism of self-made neutral rust remover was preliminarily verified by XRD,SEM,EDS,XPS and other analytical methods.It was found that rust reacted with rust remover to form Fe-O-P and Fe-O-C with a thickness of about 23.11μm.A chelating protective layer such as Fe-O-P and Fe-O-C exhibited good outdoor corrosion resistance.The salt water corrosion resistance of the protective film layer was investigated by Tafel,EIS curve and salt water immersion test.It was found that chloride ion had strong destructive power and the salt water corrosion resistance of the film layer was poor.The salt water had a concentration of 3.5%(impedance was severe corrosion occurs when immersed for 3 hours in 525.7 Ω),but the protective film can also hinder the diffusion of electrolyte in the film layer to a certain extent,and played a role of rust prevention.