Stuty On The Environmental Friendly Flux For Hot Dipping Zinc And Alloy

Hot-dipping as a kind of economic and effective anticorrosion technology is widely used in metal protection.Traditional fluxing produces a large number of ammonia and hydrogen chloride smoke during hot dipping,which causes environments pollution.The traditional solvent method is no longer applicable along with the application environment and the use of new coating alloy replaced pure zinc.Therefore the development of an environmentally friendly fluxing used in hot dipping zinc and alloy is the main research direction.A large number of domestic and foreign scholars have conducted a series of studies on this work.But there is not a kind of stable fluxing agent can completely replace zinc ammonium fluxing.The effect of each component in hot dipping was studied through single factor analysis.Then a series of fluxing solution was selected.To optimize the ideal fluxing,the quantity of zinc dust and slag,and coating quality were evaluated.The wettability,SEM,EDS,AFM and simultaneous thermal analysis were used to analyze the fluxing effective.The environment friendly fluxing could completely replace zinc ammonium fluxing in the actual test conditions.The following advantages of the environment friendly fluxing:?1?this hot dip process basically did not produce smoke with less slag which reduced the pollution of the environment;?2?fluxing had good thermal stability,could withstand higher drying temperature;?3?fluxing had good antioxidant,guaranteed not to leakage phenomenon in hot dipping;?4?the salt film of fluxing was thinner,shortened the hot dipping process;?5?the components of fluxing was simple,improved the efficiency of hot dipping.The coating was surface and bright without leakage using environmental friendly fluxing in hot dipping.In order to ensure the use of fluxing,an optimized coating which had a favorable quality can be obtained after dipping 30s and drying 20s.The results showed that the environment friendly fluxing which had a good ability to withstand high ferrous ion was better than that of zinc-ammonia fluxing.Electrochemical tests showed that when the Fe²⁺was 20-40g/L,it was helpful to improve the corrosion resistance of the coating.The X1 was added to the environmental friendly fluxing,the growth of the alloy layer was suppressed,the thickness of?phase of the coating was increased,and the corrosion resistance of the coating was improved.Based on the environment friendly fluxing in hot dip galvanizing,and according to the principles of preparation of hot dip aluminum fluxing,finally the environment friendly fluxing was prepared.Smooth,bright Zn-5Al and Zn-6Al-3Mg coatings were prepared by using this new fluxing which solved the problem of traditional fluxing.