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How to distinguish laser cutting, gas cutting and plasma cutting?

Dec 13, 2018

      In recent years, Chinese plasma cutting technology has developed rapidly, and laser cutting applications are relatively rare. Many companies have chosen plasma cutting machines. Plasma cutting has made great progress in cutting design of cutting torch structure, life expectancy of consumables and control. The range of applications is extremely wide.

The thermal cutting method mainly refers to gas cutting, plasma cutting, and laser cutting. Gas cutting mainly uses oxygen and gas to oxidize metal for cutting. The disadvantage is that the cutting speed is affected by the metal oxidation reaction rate. CNC plasma cutting machine cutting is the use of electric energy to melt metal for cutting. Laser cutting is the use of light energy to melt metal for cutting. The latter two cutting methods can increase the cutting speed as long as the cutting energy is increased. The cutting speed of gas cutting method is relatively slow, although abroad There are also beginnings to use liquid oxygen and gas to improve cutting efficiency and achieve high-energy cutting, but the price of such a cutting machine is very expensive.

In general, the plasma cutting surface is rough, the cutting thick plate has advantages, and the price is low, the laser cutting surface is smooth, the plasma is rough, and it is necessary to send a person to repair the burr. Laser cutting can cut heavy plates of more than 3MM, and plasma can cut heavy plates of more than 8MM. The laser cutting surface is smooth, and the compensation accuracy is relatively high and expensive. In terms of cost, plasma is about 1/3 cheaper than laser. The cutting surface of fine plasma is thinner than that of laser, especially in Japanese equipment. The disadvantage of plasma is that the slit is wide, about 3MM. The most important part of the plasma is the power supply, which is equivalent to the laser of the laser cutting machine. The power consumption of the plasma is quite powerful. The common spare electrode protection nozzle is also quite expensive, especially the electrode punching is very expensive.

The plasma cutting machine is a new type of thermal cutting device. Its working principle is that compressed air is used as the working gas, and the high temperature and high speed plasma arc is used as the heat source to partially melt the cut metal and simultaneously melt the high speed airflow. The metal blows away and forms a narrow slit. The plasma cutting machine can be used for cutting various metal materials such as stainless steel, aluminum, copper, cast iron, carbon steel, etc. It not only has high cutting speed, narrow slit, flat cut, small heat affected zone, low deformation of the work piece, simple operation, and remarkable Energy saving effect.

The plasma cutting machine is suitable for the manufacture, installation and maintenance of various mechanical and metal structures, and is used for cutting and cutting of medium and thin plates, opening, excavating, opening and cutting. Plasma cutting is a processing method that uses the heat of a high temperature plasma arc to locally melt (and evaporate) the metal at the work piece cut and to remove the molten metal by high-speed plasma momentum to form a slit. Plasma cutting machines are widely used in automobiles, locomotives, pressure vessels, chemical machinery, nuclear industry, general machinery, engineering machinery, steel structures and other industries!

Gas cutting is to use the combustion gas and the combustible gas to heat the metal at the required cutting point to the combustion temperature through the torch (for steel, the temperature is generally 1100-1150 ° C, and then the pure oxygen jet is sprayed to burn the metal at the slit. The metal cutting method is used to separate the metal work piece by using a high pressure of a pure oxygen jet to blow off the molten slag of the metal combustion to form a narrow slit.

Gas cutting is to make the heated metal into iron oxide slag and blown away. The flame at the time of gas cutting has different compositions at different stages. In the preheating stage at the beginning of gas cutting, it is also produced by the mixed combustion of oxygen and combustible gas. Its main purpose is to heat the work piece. When the temperature of the work piece rises to the ignition point of the material, the torch emits a stream of pure oxygen, the purpose of which is to help the metal to burn smoothly and to blow off the iron slag generated by the combustion.

Laser cutting uses a high power density laser beam to scan the surface of the material, heating the material to thousands to tens of thousands of degrees Celsius in a very short time, melting or vaporizing the material, and then melting or vaporizing the material from the slit with a high pressure gas. Blow away in the middle to achieve the purpose of cutting materials.

Laser cutting, because the invisible beam replaces the traditional mechanical knife, the mechanical part of the laser head has no contact with the work, and it will not scratch the working surface during the work; the laser cutting speed is fast, the incision is smooth and flat, generally no need Subsequent processing; small heat affected zone, small deformation of sheet, narrow slit (0.1mm~0.3mm); no mechanical stress in the slit, no shear burr; high processing precision, good repeatability, no damage to material surface; NC programming, It can process any floor plan and can cut the whole board with a large format without the need to open the mold, which is economical and time-saving.


In terms of cutting precision, the plasma can reach less than 1mm, and the laser can reach 0.2mm or less; at the cost, the plasma cutting machine is much cheaper than the laser cutting machine. In processing precision, the plasma cutting is rougher than the laser cutting. One is rough processing, one is fine processing!