Plasma cutting of metal: types and principle of action, plasmatron device, video plasma cutting technology
Even in the recent past for that, to cut metal, had to resort to completely inconvenient bulky devices, running on gas. At the same time, such cutters could not always cope with the task. Today as in small businesses, and plasma cutting is widely used in industrial facilities, by means of which it is possible to process as much as possible precisely metal of any configuration and thickness.
The principle of action of plasma cutting
Plasma cutting is a distributive treatment of metal using a thermal process. The role of the cutting tool here is played by a jet of low-temperature plasma.
The principle of operation of the plasma apparatus:
Between the metal, an electric arc with a temperature of 5000C is created by cutting and an electrode or a nozzle of a plasmatron.
- Gas enters the nozzle under pressure, due to which the temperature of the electric arc rises to 20 000 WITH.
- The gas is ionized and converted into high-temperature gas or low-temperature plasma.
- Ionization increases from the heated arc, and the temperature of the gas jet rises to 30 000WITH. During this process, the plasma flow has a high thermal conductivity and glows brightly.
- Plasma at a speed of 500-1500 m / s arises from the nozzle, falls on the prepared metal, heats it up and melts it at the incision site.
The process of cutting metal with a plasmatron can be seen more clearly in the video.
Types of plasma cutting
Plasma cutting of metal is of several types:
- Simple. This method uses electric current and air. The length of the electric arc during this process is limited, therefore, with a sheet thickness of a few millimeters, the surface treatment is compared with a sharp laser. A simple method is used to process only mild or low-alloy steel. When cutting the material burrs are not formed, the edge remains smooth. Sometimes nitrogen can be used instead of air.
- With the use of water. During cutting, water is used to cool the plasmatron and protect the cut from the negative effects of the environment. exept this, water absorbs all harmful fumes.
- Using protective plasma-forming gas. The cut during such cutting is protected from the environment, therefore, the quality of metal cutting increases.
You can also cut metal with an arc or jet. In the first case, the processed material is part of a circle, in the second - an arc is formed between the electrodes.
Device for plasma cutting of metals
The main element of the equipment is a plasma cutter, which is called a plasmatron. Its main components:
Electrode, which is located in the back of the camera. It forms an electric arc.
- The nozzle is responsible for the shape of the plasma flow and its speed.
- The heat-resistant insulator is located between the nozzle and the electrode.
In addition to the plasmatron, the device for cutting metal is equipped:
- compressor or gas cylinder;
- power supply;
- set of hoses or cables, designed to connect the plasmatron to the compressor and power supply.
As by means of the device it is necessary to work on weight, the cut may be uneven. Therefore, it is recommended to use stands or special stops to improve the quality of cutting, which are put on the nozzle.
You can watch the video, how to cut material with a plasmatron.
Advantages and disadvantages of plasma cutting
Compared to laser cutting, Plasma metal cutting works have many advantages:
- The material can be cut accurately and quickly, regardless, how thick it is.
- Any metal is cut with the help of plasma: refractory, black, non-ferrous.
- Not only metal can be processed with a plasma cutting machine, but also other materials.
- Plasmatron easily cuts materials of different widths and angles.
- During the work, almost no pollutants are released into the air.
- The products are obtained almost without contamination and with the least number of defects.
- Plasmatron can perform artistic work. With its help artistic cutting of details is available, complex figured cutting.
- Since the metal does not need to be heated before work, recording time is reduced.
All the advantages of plasma cutting can be seen in the video below.
Like any device, along with the benefits, plasmatron has its drawbacks:
- the need to comply with the rules of service;
- big noise, created by the device during its operation;
- metal thickness, the cut should not be more 10 centimeters;
- high cost of the plasmatron.
Plasma cutting technology
It is recommended to watch and study the video before using the plasmatron for the first time, how the whole process takes place.
The plasma burner is placed close to the edge of the workpiece.
- The "Start" button is included. After that, the next arc will light up first, and then cutting.
- The burner made of the processed material should be driven slowly, with a slope of 90 degrees.
- With the help of splash control, the cutting speed is regulated. If on the other hand there is no spray of metal, then the material could not be completely cut. The reasons may be: wrong torch angle, low current, high speed device.
- After the process, the burner must be tilted, as the air will go for some time.
If the plasma arc goes out during operation for any reason, then you need to stop the gas supply, then turn on the machine again and start processing.
Some useful tips
Before starting work on the device for plasma cutting of metal it is necessary to study carefully the connection scheme and to check up serviceability of hoses and cables..
The quality of cutting directly depends on the type and configuration of the nozzle. Its diameter affects the formation of the arc and the rate of its formation, as well as the width of the cut and the volume of gas or air passed. Therefore, after using the nozzle with the right diameter, you can get a quality and clean cut with smooth edges.
The nozzle length can be increased to improve the cutting characteristics, and it can be changed at any time.
That as a result of work the material was not deformed, there were no burrs or scale, it is necessary to calculate the current correctly. To do this, first a high current is applied and a pair of incisions are made. The result will show - to leave the current high or need to reduce it.
Of course, the price of equipment for plasma cutting is quite high. However, the purchased device will pay off quickly, therefore, when buying, its value should not be a determining factor.
