Surfacing Electrode

Surfacing welding is to weld a layer of special alloy surface to any part of the workpiece, and its purpose is to improve the wear resistance, corrosion resistance and heat resistance of the workpiece. For example, by overlaying a layer of wear-resistant alloy on the wear surface of ordinary carbon steel workpieces, not only can the cost be reduced, but also excellent comprehensive performance can be obtained. The use of surfacing welding technology to repair worn or corroded workpieces is a multi, fast, good and economical way

The surfacing workpiece and working conditions are very complicated, and suitable electrodes must be selected according to different requirements during surfacing welding. Different surfacing workpieces and surfacing electrodes must adopt different surfacing welding processes to obtain satisfactory surfacing results. The most common problem encountered in surfacing welding is dry cracking. The method to prevent cracking is mainly preheating before welding and slow cooling after welding. Cracking is related to the carbon content of the workpiece and deposited metal and the amount of alloying elements, so the preheating temperature is often estimated based on the carbon equivalent of the welding material used. The carbon equivalent formula is as follows:

Ceq=C+1/6Mn+1/24Si+1/5Cr+1/4Mo+1/15Ni

(This estimation method is suitable for low, medium and high carbon steel and low alloy steel materials)

The surfacing effect, such as the hardness, wear resistance and heat resistance of the surfacing layer, is related to the welding current, arc length and other operations. If the current is large, the arc is long, the alloy elements are easy to burn, and the current is small and the arc is short. The element transition is favorable.

Some surfacing metals can use different heat treatment methods to obtain different hardness. The hardness and chemical composition of the surfacing metal generally refers to the surfacing metal of more than three layers.