Process Research Of Galfan Alloy Coating With Ong-Step Hot-Dipping On Steel Wire

Galfan coating (Zn-5%Al-RE) is an appropriate substitute for the hot-dipping galvanizing coating because of its excellent corrosion resistance. Using Galfan coating can not only decrease energy consumption but also maintain the mechanicial property of wire due to lower menlting temperature of Galfan alloy than that of pure zinc. Moreover, the forming property of Galfan alloy coating is also better than that of the hot-dipping galvanizing. Using common plating aid cannot get Galfan alloy coating on wire because aluminum changes the property of the liquid metal. It mainly comprises two aspects, in one way, as for the addition of aluminum, molten zinc has bad wetting property, that is, interfacial junction problem; in anther way, as for the surface quality problems of Galfan alloy coating layer. At present, in the hot-dipping galvanizing double steps is used commonly. But it has many problems, such as technical complex, influence on properties of steel wire, etc. However, one-step method has been studied less at present. There are lots of problems in it. For this actuality, this paper studies the flux and properties, and put forward our solutions.The research in flux is mainly to change the original double hot dip coating technique, and change the first hot-dip galvanizing into electrolyzing flux. On the basis of studying prescription, testing through simulate continuous production line has been done. In research, we find that flux composed of ZnSO4, H2SO4 and NaCl is stable and the composition is simple. In a certain range, the higher electrical density and the longer time, the better the quality of galvanizing coat. In the mean time, considering the relation between fluxing time, galvanizing bath and padding speed, also the length of bath is certain, and so the research on the padding speed is more important.Using Galfan coatings can serve to decrease the energy consumption and to maintain the mechanical properties of wire due to the lower melting temperature of Galfan alloy than that of pure zinc. Moreover, the forming properties are better than those of the hot-dip galvanizing coating. It is difficult to control the surface quality of Galfan coated steel wire by single step, which lies on some aspects such as the process of air knife, precleaning condition of the steel subrate, the bath temperature, the cooling rate, the flux process and so on. Among them, the process of air knife is a key aspect. In this paper, focus on studying the process to affect the Surface Quality of Galfan Alloy Coated Steel Wire by One-step Dipping.The testing result expresses that, when fluxed, the electricity density is between 1000-2500A/m2, and when the padding speed is controlled between 10-15r/min, when adopt nitrogen&carpolite smearing, the fluxing liquid is the most stable, the steel wire get is mostly good, there are no bugs in neither surface quality nor coating quality, and the anti-corrosion, equality are good. So in the actual production, can make reference of the single-coating parameter above and can do adjustments according to the actual condition.