Carbon electrodes: properties and applications

Carbon electrodes are used for making air-blown metal cutting. In addition, they are used to weld metals, remove metal sheet defects, cut rivets and perform other operations. Carbon electrodes are made from electrotechnical amorphous coal. Finished products have a sheet-black surface and are round rods, the cross-section of which varies from 6 to 18 millimeters. The standard length of the rods is 25-70 centimeters.

For cutting various types of metal, carbon electrodes are sharpened at different angles. Thus, for processing ferrous metals, one end of the rod is grinded at an angle of about 65 degrees. To perform welding of materials from non-ferrous metals, including for surfacing hard alloys, the electrode is sharpened at an angle of 30 degrees.

In the process of making electrodes, the techniques of dextrusion or molding and heat treatment of the compositions are used. The basis of products include coke or coal, and add various binders (tar, tar, etc.). In some cases, the carbon electrode includes metal powder or chips.

Products are used in various industries. They are used for cutting steel materials, making holes in alloyed, carbon and low-alloy steels. In addition, they cut copper, stainless steel or low-carbon steel, as well as other alloys used in the manufacture of metal structures, in machine building, shipbuilding, and the steel industry.

Welding with a carbon electrode has proved to be very high quality. It has many advantages over other common types of cutting. When welding using carbon electrodes, carbon, compressed air or electric current is used, which makes it possible to perform excellent metal cutting with removal. Welding works are performed with the use of compressed air or electric arc, which not only melts the metal, but is also self-squeezed with an air jet.

This method of welding of metal products has its own characteristics. For example, all work can be carried out only with a constant current, and the length of the arc should be in the range of 6-15 millimeters. At the same time, the arc is ignited very simply and has sufficient stability. However, in the event of a reversed polarity, the arc will lose its stability, and the electrode will begin to burn and evaporate.

The arc formed when welding materials with carbon electrodes shows a high sensitivity to weather conditions (rain, magnetic blasting, gas flows). In addition, when performing welding operations where carbon electrodes are used, a lower arc efficiency is obtained than using conventional metal rods. However, the value of coal rods can not be underestimated. They allow to weld non-ferrous metal, thin-sheet materials, perform welding surfacing and hard alloys with current strength within 1 kA.