The demand for iron and steel in modern society is increasing. In daily life, many things are made of metal, and many metals cannot be cast at one time. Therefore, this needs to be completed by welding. The role of the electrode in the process of electric welding is very important.
The electric welding rod is a metal bar which is melted by electric current and high temperature during arc welding. The corresponding welding electrode is usually selected according to the material of the welding workpiece. The welding electrode can be used for welding the same steel or between different steel Welding.
Structure of the electrode
The electrode is composed of an internal metal welding core and a coating on the outside. The shape of the welding core is a steel wire with a certain diameter and length. The main function of the welding core is to conduct current to heat and melt it. It melts together to form a weld.
The welding core materials used for welding can generally be divided into carbon steel, alloy steel and stainless steel, but in order to meet the welding requirements, there are special requirements for the material and metal elements of the welding core, and there are also strict requirements for the content of some metal elements. Because the metal composition of the core will directly affect the quality of the weld.
There is a layer of coating on the outside of the electrode, and this layer of coating is called a coating, which plays a very important role in welding. If the workpiece is directly welded with an electric welding core, air and other substances will enter the molten metal Also, chemical reactions will occur in the molten metal, which will directly cause quality problems such as pores and cracks in the weld, and directly affect the strength of the weld. The coating with special elements will decompose and melt into gas at high temperatures. And slag, can effectively prevent air from entering and improve welding quality.
The composition of the coating includes: silicic acid, fluoride, carbonate, oxide, organic, iron alloy and other chemical powders, etc., which are made by mixing according to a certain formula ratio, and the composition of different types of electrode coatings is also different.
There are generally two types of coatings on the surface of the core, and the main components of the coatings are basically the same.
There are three common types, namely slag agent, gas generator, and deoxidizer.
Slag flux is a kind of compound, which can protect the molten metal liquid from air ingress when the electrode is melting, thereby improving the quality of welding.
The gas generating agent is mainly composed of substances such as starch and wood flour, and this substance has a certain reducing performance.
The deoxidizer is composed of titanium iron and manganese iron. Generally, this material can improve the wear resistance and corrosion resistance of the metal.
In addition, there are other types of coating on the electrode surface, and the composition and proportion of each type will be different.
Welding rod manufacturing process
The manufacturing process of the welding rod is to manufacture the welding core and prepare coatings according to the design requirements of the welding rods, and uniformly coat the coating on the welding cores, so that the welding rods can meet the design requirements.
First, the rolled steel bar is pulled out from the reel, the rust on the surface of the steel bar is removed in the machine, then it is straightened, and the steel bar is cut to the length of the electrode by the machine.
Next, the coating on the surface of the electrode needs to be prepared. The raw materials of the coating are sieved to remove impurities, and then poured into the machine according to the proportion. A binder is also added, and all the powdery raw materials are stirred by the machine. Mix well.
Put the mixed powder into a mold and press it into a cylindrical barrel with a circular hole in the middle after pressing by the machine.
Put the pressed multiple barrels into the machine, put the welding core neatly into the feeding port of the machine, the welding cores enter the machine in turn from the feeding port of the machine, and the welding core is squeezed by the machine when it passes through the middle of the barrel. The powder is evenly coated on the passing welding core, and it becomes a coating.
During the coating process of the electrode, the entire core is covered with a coating. In order to facilitate the clamping and conduction of the electrode, the head and tail of the electrode need to be polished to expose the core.
After the coating is applied, the electrodes after the grinding head and the tail are uniformly arranged on the iron frame and sent to the oven for drying.
In order to be able to easily distinguish the specifications and models of the welding rods, it is necessary to print on the welding rods. During the movement of the welding rods on the conveyor belt, each welding rod is printed by the rubber printing roller on the conveyor belt.
The printed electrodes are completed and can be packaged for sale after passing the inspection of the electrodes.
