Drawing process of hot-dip galvanized steel wire

The surface of hot-dip galvanized steel wire is smooth, smooth, without cracks, knots, thorns, scars and rust. The galvanized layer is uniform, strong adhesion, long-term corrosion resistance, excellent toughness and elasticity. The following describes the drawing process of hot-dip galvanized steel wire and the reasons for unevenness.

　　Drawing process of hot-dip galvanized steel wire

　　First plating and then drawing process: In order to improve the performance of galvanized steel wire, the process of using steel wire to be subjected to lead annealing, galvanizing and then drawing to the finished product is called the first plating and then drawing process. The typical process is: steel wire-lead quenching-galvanizing-drawing-finished steel wire. The process of plating first and then drawing is the shortest process in the method of drawing galvanized steel wire. It can be used for hot-dip galvanizing or galvanizing and drawing. After hot-dip galvanizing, the mechanical properties are better than that of the first-plated steel wire. After galvanizing, the zinc layer is dense and resistant. Both can obtain a thin and uniform zinc layer, reduce zinc consumption, and reduce the load on the galvanizing line.

　　The process of drawing after the plating: The process of drawing after the plating is: wire-lead quenching—one-time drawing—galvanized—second-time drawing—finished steel wire. The feature of drawing after medium plating is that the lead-hardened steel wire is galvanized once and then drawn twice to the finished product. The galvanization is between the two drawing, so it is called ‘medium plating’. The steel wire zinc layer produced by middle-plating and later-drawing is thicker than that of first-plating and then-drawing. Hot-dip galvanizing and drawing after plating can give a high total compression ratio (from lead quenching to finished product), which is better than steel wires that are plated and then drawn.

　　Hybrid plating and drawing process: In order to produce ultra-high strength (3000 N / mm2) galvanized steel wire, a "hybrid plating and drawing" process is used. The typical process flow is as follows: lead quenching-primary drawing-pre-galvanized-secondary drawing-final galvanized-three drawing (dry drawing)-water tank drawing a finished steel wire. The above process can produce an ultra-high-strength galvanized steel wire containing 0.93 to 0.97% carbon, a diameter of 0.26 mm, and a strength of 3921 N / mm2. The zinc layer protects and lubricates the surface of the steel wire during drawing, and no wire breakage occurs during drawing.

　　Causes of unevenness of hot-dip galvanized steel wire

　　1. The lead of the steel wire is not perpendicular to the surface of the zinc liquid. In this way, the plating solution brought out when the wire is pulled out can not flow uniformly along the circumference of the wire under the gravity when it is not solidified, causing the coating to deviate from the geometric center of the wire after solidification;

　　2. Differences in wiping conditions (such as the size of charcoal particles, the tightness of the contact between charcoal and steel wire, the flow rate and pressure of air scrubbing) in all directions of the wire circumference;

　　3. Zinc liquid level fluctuation and steel wire jitter, zinc liquid level scum sticking on the surface of the steel wire, etc .;

　　4. Uneven deformation of the scraped zinc and zinc layer caused by various reasons when the steel wire is first plated and then drawn after being drawn after plating. In severe cases, even the local pure zinc layer is completely lost.

　　The above is the introduction of the hot-dip galvanized steel wire drawing process and the reasons for the unevenness. I hope everyone understands the hot-dip galvanized steel wire drawing process and the reasons for the unevenness, and it will be helpful to everyone.