Pipe Tube Angel Steel Automatic Galvanizing Equipment

Metal Melting Process of Zn-Fe Alloy Reaction

The process of hot-dip galvanizing is actually the melting process of the zinc liquid on the iron-based surface of the workpiece material. According to production practices and experiments, this process is divided into five categories in the industry:

The first type is the melting process that occurs below the temperature of the molten zinc at 480°C. In this case, the structure of the Zn-Fe alloy phase on the iron-based surface is compact and firmly adhered to the iron substrate. Therefore, in this case, if no other additives are added to the zinc solution, the galvanizing speed is relatively slow and the galvanized layer is relatively thick.

The second type is the melting process that occurs at a temperature of about 540°C in the molten zinc. In this case, the resulting Zn-Fe alloy phase layer is tight and firm, and because of the better fluidity of the zinc liquid, the distance for the melting and diffusion of zinc to the iron matrix is shortened, so the melting speed of this type is faster than that of the first type. be quick. In other words, the time for galvanizing is shorter.

The third category is the intense malignant melting process. The peak value of this malignant melting generally occurs at a temperature of about 495°C in the molten zinc. In this case, the formed Zn-Fe alloy phase is porous, the texture is quite loose, the binding force with the iron matrix is poor, and it is easy to fall off. At the same time, at this temperature value, the corrosion and melting of the zinc liquid on the surface of the iron substrate is carried out continuously, so it is very unfavorable for galvanizing.

The fourth category refers to the melting process that occurs when the temperature of the molten zinc is higher than 620°C. In this case, the Zn-Fe alloy phase will form soon, which is the fastest zinc dipping temperature. Easy to peel off, peel off and so on.

The fifth category is a sharp and destructive melting process, the temperature of the molten zinc in this process is above 660°C. At this time, the formed Zn-Fe alloy phase layer will be directly diffused or taken away by the zinc liquid, and the melting and alloying reaction between Zn-Fe will proceed continuously and rapidly. The surface of the iron matrix loses the opportunity to hang zinc, and the zinc liquid cannot adhere to the surface of the iron matrix. This is the type of metal melting that destroys the galvanizing conditions. More importantly, under this temperature condition, the zinc vapor will increase substantially, the environmental impact will increase, and a large amount of zinc will be consumed at the same time.

Therefore, in the whole hot-dip galvanizing process, selecting and controlling the appropriate temperature of the zinc solution is the key to ensuring product quality, improving operating efficiency and reducing production costs.

The first category is the process temperature range for normal hot-dip galvanizing when we are hot-dip galvanizing steel workpieces; the second category is the hot-dip galvanizing process temperature we choose when we are hot-dip galvanizing steel workpieces, cast iron workpieces, etc. scope. The other three categories are the temperature ranges that we need to pay special attention to and avoid in production.

Our company is specializing in designing, manufacturing, installing, commisioning galvanizing line. Our engineers are trained in German, and currently we have expanded our business to Australia, Russia, India and so on. Adopting the German technology, our hot dip galvanizing line is the best with advanced technology.

Our company mainly business scope is as follows: 
1) The design, manufacture, installation, commissioning and training of the hot dip galvanizing lines, redesign and improve of the old galvanizing plants. 
1. Jobbing galvanizing line for construction parts: such as steel tower , tube tower parts, high rails and lighting poles , etc. 
2. Galvanizing lines for steel tubes:suitable for 1/2"-8" steel tube.

  Pipe tube galvanizing Plant Video online: https://youtu.be/fB62qUYyYeE 
3. Galvanizing lines for small parts:suitable for bolts, nuts and other small parts. 
2) The related chemical preprocessing of products and alloy 
Our main products are : chemical pretreatment tanks, galvanizing furnace, zinc kettle, utilisation of fuel gas from the fuel furnace, drying pit. 

If you have any questions, please contact our engineers for consultation, online.