Hot-dip Galvanized Base Alloy Ammonium To Help The Process And The Principle Of The Plating Agent

With the increasing environmental awareness and stringent national environmental requirements, the mass gas and dust produced from ammonium chloride under high temperature during batch hot dip galvanized zinc-ammonium fluxing process needed to be processed, in order to meet the clean production requirements of hot-dip galvanizing industry. Currently, batch hot dip galvanized research is focused on developing ammonium-free and low smoke fluxing which is environmental friendly. Nowadays, scholars and engineers both domestic and overseas have done series of research on the component of fluxing and fluxing process, however, no new fluxing process can replace the traditional zinc ammonium fluxing process.This paper is based on researching fluxing process of batch hot dip galvanized, the analysis is from removing the traditional zinc-ammonium chloride fluxing components proceed with an analysis using the single factor experiment and the orthogonal test. Design-Expert 6.0 Test Experimental design combined with factory test approaches are used to research and test their formula fluxing process research and validation, we preferably choose the new technology ammonium-free fluxing and proposed hysical conditions of ammonium-free fluxing mechanism. Respectively studied ammonium-free plating process parameters and applications as well as the impact of coating micro structure and properties. Finally, the technical reliability and stability of the ammonium-free plating process is analysed and evaluated; its resulting economic and environmental benefits are comprehensively assesed. The results show that:After abandoned the ammonium chloride in the zinc ammonium fluxing, we take advantage of of fluoride-carbon chains and carbon-hydrogen chains surfactant to form a composite surfactant Fc and ZnCl2-NaCl-NaF system, consisting of double salt ammonium- free fluxing agent. After small batch verification the plant can replace the traditional of zinc-ammonium fluxing process. Optimal formula of ammonium-free fluxing agent are as follows:zinc chloride 19.16R g/L, sodium chloride as 5.07R g/L, sodium fluoride as 3.48R g/L, Fc was 5.9n g/L.The process is of high reliability and stability. also of wide temperature range, for instance room temperature can also be used; and maintain system balance under lower pH and higher free acid content, the resulting seamless plated coating. Ammonium-free fluxing agent allows a higher content of ferrous ions than the tradition fluxing agent; and can obtain better coating under high humidity condition and after smearing. Ammonium-free plating process can replace zinc-ammonium assisted deposition process but not changing the traditional zinc-ammonium fluxing technology production processes, equipment and layout, dust emissions during dip plating process reduced 70% than the zinc ammonium process.Ammonium-free plating process not only greatly help reduce the pollution of the environment, but also refine the coating, and improve corrosion resistance. Zinc ammonium fluxing pure zinc coating under the condition of the grain size is 1.5 times of ammonium-free fluxing; Zn-0.05% Al coating grain size is 1.2 times of the ammonium-free fluxing; and pure zinc coating corrosion resistance increase 10% compared to zinc-ammonium fluxing; Al coating corrosion resistance of Zn-0.05% increased about 40% than zinc-ammonium fluxing. Ammonium-free fluxing coating thickness obtained under more zinc-ammonium fluxing is slightly tend to be thinner, but the of higher aluminium stability.Fluxing agent devoid of ammonium component, surfactant Fc fluxing agent plays an important role in improving the wetting properties and the thickness of the coating, zinc chloride influences the coating thickness and the leakage rate significantly, sodium chloride exert great impact on surface quality. Fluxing agent and surfactant sodium synergies Fc fluxing exert more significant effect on the evaluation. Ammonium as a hot dip fluxing agent must meet the following requirement:σi-m>σi-z plus adhesion; solvent temperature should be lower than the temperature of hot-dip galvanized, hot dip galvanized solvent should be presented under molten state.