Study Of Industrial Process Technology And Performance Of Hot-dip Galvanized And Zn-Al Alloy On The Small Diameter Steel Wire

Hot dip galvanized is a kind of economic and effective corrosion resistance technology which has also been applied in industry.The small diameter wire steel is required good corrosion resistance and plasticity,high strength,excellent mechanical properties,etc.There is no ready-made hot dipping technology for it.The technology of hot dipping Zn and Zn-Al alloy on small diameter steel wire and its percentage elongation and tensile properties were studied in this paper.The best process parameters have been studied by the way of orthogonal experiment.The influence of process parameters on thickness and quality of coatings was researched.Results showed that the coating weight increased with the wire speed grew faster.When the speed exceeded 50 m/min,the coating weight increased slowly.The coating quality was the best when the steel wire speed was 45 m/min.The liquid flow of Galfan alloy was the best at 450℃,and the coating quality was the best as well.When hot-dip temperature exceeded460℃,the coating quality declined,due to the serious segregation of aluminum at this temperature.Besides,the wiping techniques adopted gas wiping,high purity nitrogen was used at 420℃,the air pressure and air flow was respectively 0.8 MPa and 1 m~3/h.Results showed that,the plasticity of as-cast zinc was obviously lower than that of Galfan alloy.The plasticity of Galfan alloy coating was better than that of galvanized coating,and it had better synergistic deformation ability with the substrate,which was favorable for the drawing of steel wire.The percentage elongation increased after hot dipping,but when hot-dip Galfan alloy exceeded 440℃,the percentage elongation changed stable at round 7%.The tensile strength and bending torsion properties were reduced.With regard to hot dip galvanized steel wire,as the extension of hot-dip time,coating weight grew augment,meanwhile,the elongation of the steel wire was also reduced due to the increase of the thickness of the hard-brittle phases.Besides compared with the galvanized layer,the transition layer was more affected by the percentage elongation.But the filmy transition layer of hot-dip Galfan alloy had little effect on the percentage elongation,and zinc weight had also little effect on the percentage elongation of hot-dip Galfan alloy steel wire.