What is plasma cutting

Gas cutting VS plasma cutting

Plasma cutting has become widespread due to the accuracy and quality of the cut, but traditional gas cutting is still used in various technological processes.
Oxygen cutting is still widely used for jobs that require a high degree of mobility and maneuverability, especially cutting thick steel workpieces.

Both processes have their advantages and limitations: material thickness, cut quality, maneuverability and component cost are just a few things to consider when making your choice. Below we will consider the advantages and features of each.

What is oxygen cutting?

In oxyfuel cutting, the flame of the oxygen-fuel mixture preheats the steel to its ignition temperature.

A stream of oxygen is directed at the metal, creating a chemical reaction to form iron oxide, also known as slag. A powerful flow of oxygen removes slag from the cut.

When using oxy-fuel torches, cut quality, preheat time and metal thickness depend on the type of fuel gas. The process uses one of four fuel gases in combination with oxygen: acetylene, propane, propylene and natural gas.

What is oxygen cutting used for?

Manual oxygen cutting is common in low-volume projects when the use of expensive units is not economically justified. For example, preparing parts for subsequent forging and stamping, in foundries, cutting pipes.

Oxygen cutting is effective when working with thick steel and ferrous metals.

There are oxy-fuel torches that can be used for several processes such as cutting, welding and soldering.

Advantages of oxygen cutting:

• The undeniable advantage of this process is the low initial costs and portability of components compared to plasma cutting machines.
• The ability to quickly cut thicker steel, in addition to the versatility of the system.

What is plasma cutting?

At a basic level, plasma cutting is a process in which a high-velocity jet of ionized gas is delivered from the orifice of a constriction nozzle. High-speed ionized gas, plasma, conducts electricity from the torch of the plasma cutter to the workpiece.

The plasma heats the workpiece, melting the material.
Different gases are used for different types of metal: Ferrous metals and alloys are cut using active gases - oxygen.

Inactive, inert gases: nitrogen, argon, are used when cutting non-ferrous metals and alloys.

A high-speed plasma flow created by a built-in or separately connected compressor mechanically blows away the molten metal, separating the material.

What is plasma cutting used for?

Plasma cutting is performed on any type of conductive metal, such as: non-ferrous metals, mild steel, aluminum and stainless steel. Using a plasma cutter, mild steel is cut faster than alloys.

Plasma cutting is ideal for cutting workpieces less than 25mm thick. Plasma cutting is great for unusual tasks, such as cutting metal foam: a metal with a cellular structure that is almost impossible to cut using oxyfuel cutting. Compared to mechanical means, plasma cutting is generally much faster and easier to perform non-linear cutting.

Advantages of plasma cutting:

• Pros of plasma cutting include ease of use, better edge quality, and faster moving speeds.
• Plasma cutting does not rely on oxidation, so it can cut aluminum, stainless steel and any other conductive metal.
• Work with any metals: ferrous, non-ferrous, refractory.
• Productivity when cutting metal of small and medium thickness is 3 times higher than manual oxygen cutting.
• Point, local heating of the surface, without unnecessary deformation and overheating of all parts.
• Safety because there are no flammable gas cylinders.
• Possibility of cutting complex shapes.

Needed for periodic repairs, maintenance or projects that require large volumes of cutting.

Source: https://www.kuvalda.ru/blog/articles/polz/gazovaya-rezka-vs-plazmennaya-rezka.html

What is plasma cutting of metal: description and features of cutting

Several different methods are used for cutting metals, which differ from each other in efficiency and cost. Some methods are used only for solving industrial problems , while others can be used in everyday life.

The latter includes plasma cutting. The effectiveness of cutting using this method is limited only by the correct choice of installation and the experience of the master.

What is plasma metal cutting? What is the principle of work based on? In what areas is this metal cutting method used?

In order to understand the basics of cutting metal using the plasma method, you must first understand what plasma is? The final quality of cutting will depend on understanding how the plasmatron is designed and the principle of working with this device.

Plasma heat treatment of metals depends on certain parameters of the working jet of liquid or gas, which is directed under pressure onto the surface of the treated area. To achieve the required effect, the jet must be adjusted to the following levels:

1. Temperature - for plasma to appear, the air must be heated almost instantly to 5-30 thousand degrees. The increased temperature is achieved by creating an electric arc. When the required temperature is reached, the air flow is ionized and changes its properties, becoming electrically conductive. Plasma metal processing technology involves the use of dehumidifiers that remove moisture, as well as air injection systems.
2. Speed ​​- the jet is directed at the surface of the material under high pressure. We can say that plasma cutting of metal is based on heating the material to its melting point and instantly blowing it out. In this case, the operating speed of the jet is approximately 2−5 km/sec.
3. Presence of an electrical circuit. You can learn everything about cutting metal with plasma only in practice. But certain features need to be taken into account before purchasing the installation. Thus, there are direct and indirect plasma torches. And if for the former it is necessary that the material being processed be connected to a common electrical network (acting as an electrode) and pass electricity, then for the latter there is no such need. In this case, plasma for cutting metal is obtained using an electrode that is built inside the holder. This option is used for metals and other materials that do not conduct electricity.

Another important point that must be taken into account is that plasma cutting of thick material is practically not carried out, since it is ineffective and leads to high financial costs.

Principle of operation

The main operating principle of plasma metal cutting can be described as follows:

1. The compressor supplies air under pressure to the plasma torch burner.
2. The air flow instantly heats up due to the action of electric current on it. Taking into account the heating, the air mass begins to pass electricity through itself, as a result of which plasma is formed. In certain plasma torch models, inert gases are used instead of air flow.
3. Plasma cutting of metal, if we consider it in more detail, is carried out by a method of narrowly targeted rapid heating of the surface to the required temperature with further blowing out of the molten material.
4. During the work, some waste inevitably appears, which includes cutting or remnants of sheet material after cutting the required parts, as well as remnants of molten metal and scale.

Since the process is associated with instant heating of the processed material to a liquid state, its thickness when cutting should be:

• copper - 8 cm;
• aluminum - up to 12 cm;
• cast iron - up to 9 cm;
• alloy and carbon steel - up to 5 cm.

There are two main methods of processing materials on which the characteristics of plasma cutting will depend. Namely:

1. Plasma-jet - in this case, the arc appears directly in the plasma torch. The plasma-jet processing method is universal, as it makes it possible to process non-metallic materials. The only drawback is the need to regularly replace the electrodes.
2. Plasma-arc - this option is suitable for any type of metal that can conduct electric current through itself. As a rule, plasma arc cutting is used for industrial equipment. The meaning of this method is that plasma appears due to an arc that occurs directly between the plasma torch and the surface of the material being processed.

Plasma cutting works on the principle of conventional arc cutting, but without the use of conventional electrodes. Moreover, the effectiveness of this processing method depends directly on the thickness of the material being processed.

As with any other heat treatment method, during plasma cutting some melting of the metal occurs, which affects the quality of the cut. There are other features that are characteristic of this method. Namely:

1. Melting of edges - regardless of what modes of material processing are used, and the professionalism of the craftsman who performs the work, it is impossible to avoid a slight melting of the surface during the very beginning of the work.
2. Taper - taking into account the performance of the installation and the professionalism of the technician, the taper can vary between 4-12 degrees.
3. Speed ​​of work - conventional cutting of metal using a plasmatron is carried out quickly and with low power consumption. According to GOST and technical characteristics of manual equipment, the plasma cutting speed is no more than 6500 mm/min.
4. Cutting characteristics - the speed and quality of the cut will depend on what specific operations need to be performed. Therefore, the low quality parting cut is the fastest to make, with mostly manual machines able to cut metal up to 65mm. For shaped processing of parts, material thicknesses up to 45 mm are possible.

The quality of work will significantly depend on the level of professionalism of the master. An accurate and clean cut with minimal deviation from the required dimensions can only be made by a worker with specialized education. Without the necessary preparation, it is unlikely that it will be possible to make figured cutting.

Processing of non-ferrous alloys

When processing non-ferrous metals, various cutting methods are used, taking into account the density of the material, its type and other technical indicators. To cut non-ferrous metals, the following recommendations must be followed:

1. Cutting aluminum - for material up to 7 cm thick, compressed air can be used. Its use is impractical when the material density is low. High-quality cutting of aluminum sheets up to 2 cm is achieved using pure nitrogen, and with a thickness of 7-10 cm using hydrogen and nitrogen. Plasma cutting of aluminum with a thickness of more than 10 cm is carried out using a mixture of hydrogen and argon. The same composition is recommended to be used for thick-walled high-alloy steel and copper.
2. Cutting stainless steels - the use of compressed air is not recommended for the work; taking into account the thickness of the material, pure nitrogen or mixtures with argon can be used. It should be taken into account that stainless steel is quite sensitive to alternating current, which can lead to changes in its structure and faster decommissioning. Stainless steel cutting is carried out using an installation that uses the principle of indirect action.

The use of plasmatrons is so popular for a reason. With relatively simple operation, as well as the not very high cost of manual equipment (unlike other cutting devices), high performance can be achieved regarding the quality of the resulting cut.

The use of plasma metal cutting has become widespread in the following production areas:

1. Construction of metal structures.
2. Metal processing - using plasma you can cut almost any type of metal, including ferrous, refractory and non-ferrous.
3. Various areas of industry, aircraft manufacturing, capital construction of buildings, mechanical engineering, etc. - in all these areas it is impossible to do without the use of plasma cutters.
4. Processing of parts and artistic forging. Using a plasma cutter you can make a part of almost any complexity.

The use of plasma cutting machines has not replaced manual installations. Thus, artistic plasma cutting makes it possible to produce unique parts that exactly correspond to the artist’s plans for use as decorative decorations for stairs, railings, fences, railings, etc.

Advantages and disadvantages

Almost no industrial production that is somehow connected with rolled metal can do without metal cutting. Cutting precise holes, shaped decorative cutting, quickly cutting sheet metal into blanks - all this can be done quite quickly using a plasma torch. The advantages of this method are as follows:

1. Cost-effective - the plasma method has a significant advantage over standard methods of material processing. There is only one limitation, which is related to the thickness of the material. It is economically unprofitable and impractical to cut steel with a thickness of more than 50 mm using a plasma torch.
2. Mobility of plasma hand-held units.
3. High speed of parts processing and productivity. Unlike the conventional electrode method, the speed of work increases by 5–12 times.
4. Cut all types of metals (copper, aluminum, steel, stainless steel, titanium, etc.).
5. Safety.
6. Accuracy - deformations due to thermal load are almost unnoticeable and subsequently will not require additional processing. In this case, the accuracy of plasma cutting is 0.24−0.34 mm.

All these advantages of plasma cutting explain why this method is so popular not only for production purposes, but also for domestic needs.

But, speaking about the advantages, it is necessary to note certain negative points:

1. Clear requirements regarding the processing of parts. The master must strictly observe the angle of inclination of the cutter in the region of 10-50 degrees. Failure to comply with this rule will accelerate the wear of component parts and also affect the quality of the cut.
2. Limitations related to the thickness of the cut. Even with powerful equipment, the highest density of the processed material cannot be more than 10 cm.
3. In addition, the working equipment is very complex, which makes it absolutely impossible to use two cutters at the same time, which are connected to one unit.

Comparison of laser and plasma cutting

The difference between plasma and laser cutting of metal lies in the methods of action on the surface of the material. Laser equipment provides greater processing speed and productivity, and after completion of work there is a lower percentage of melting. The disadvantage of laser devices is their high price, and also the fact that the thickness of the material being processed must be no more than 2 cm.

A plasma torch, unlike a laser, is much cheaper and also has wider functionality and scope of application.

Source: https://tokar.guru/metally/osobennosti-plazmennoy-rezki-metalla.html

Plasma cutting – all the nuances of plasma metal cutting technology

Recently, the use of plasma flow for cutting materials has become increasingly popular. The scope of use of this technology is further expanded by the appearance on the market of hand-held devices that are used to perform plasma cutting of metal.

Plasma cutting of metal of considerable thickness

The essence of plasma cutting

Plasma cutting involves local heating of the metal in the separation zone and its further melting. Such significant heating is achieved through the use of a plasma jet, which is formed using special equipment. The technology for producing a high-temperature plasma jet is as follows.

• Initially, an electric arc is formed, which is ignited between the electrode of the device and its nozzle or between the electrode and the metal being cut. The temperature of such an arc is 5000 degrees.
• After this, gas is supplied to the equipment nozzle, which increases the arc temperature to 20,000 degrees.
• When interacting with an electric arc, the gas is ionized, which leads to its transformation into a plasma jet, the temperature of which is already 30,000 degrees.

The resulting plasma jet is characterized by a bright glow, high electrical conductivity and exit speed from the equipment nozzle (500–1500 m/s). Such a jet locally heats and melts the metal in the processing zone, then it is cut, which is clearly visible even in a video of such a process.

In special installations, various gases can be used to produce a plasma jet. These include:

• ordinary air;
• technical oxygen;
• nitrogen;
• hydrogen;
• argon;
• steam produced by boiling water.

Metal cutting technology using plasma involves cooling the equipment nozzle and removing particles of molten material from the processing zone. These requirements are ensured by the flow of gas or liquid supplied to the area where cutting is carried out. The characteristics of the plasma jet generated on special equipment make it possible to use it to cut metal parts whose thickness reaches 200 mm.

Design and principle of operation of plasma cutting

Plasma cutting machines are successfully used at enterprises in various industries. With their help, they successfully cut not only metal parts, but also plastic and natural stone products.

Thanks to such unique capabilities and its versatility, this equipment is widely used in machine-building and shipbuilding plants, in advertising and repair enterprises, and in the public utilities sector.

A huge advantage of using such installations is that they allow you to obtain a very smooth, thin and precise cut, which is an important requirement in many situations.

Plasma cutting equipment

The modern market offers devices that cut metal using plasma, of two main types:

• indirect action devices - cutting is performed in a non-contact manner;
• direct action devices - contact cutting.

The first type of equipment, in which an arc is ignited between the electrode and the torch nozzle, is used for processing non-metallic products. Such installations are mainly used in various enterprises; you will not find them in a home craftsman’s workshop or in a repairman’s garage.

Plasma cutting machine Resanta IPR-25

In devices of the second type, an electric arc is ignited between the electrode and the part itself, which, naturally, can only be made of metal. Due to the fact that the working gas in such devices is heated and ionized throughout the entire gap (between the electrode and the part), the plasma jet in them has a higher power. This type of equipment can be used to perform manual plasma cutting.

Any plasma cutting machine operating on the contact principle consists of a standard set of components:

• power supply;
• plasma torch;
• cables and hoses used to connect the plasma torch to the power source and the working gas supply source;
• gas cylinder or compressor to obtain a jet of air at the required speed and pressure.

The main element of all such devices is the plasmatron, which distinguishes such equipment from conventional welding equipment. Plasma torches or plasma cutters consist of the following elements:

• working nozzle;
• electrode;
• an insulating element that is highly heat resistant.

Manual plasma cutting torch

The main purpose of a plasma torch is to convert the energy of an electric arc into thermal plasma energy.

The gas or air-gas mixture coming out of the plasma torch nozzle through a small diameter hole passes through a cylindrical chamber in which the electrode is fixed.

It is the nozzle of the plasma cutter that provides the required speed and shape of the flow of the working gas, and, accordingly, the plasma itself. All manipulations with such a cutter are performed manually by the equipment operator.

Considering the fact that the operator has to hold the plasma cutter suspended, it can be very difficult to ensure high quality metal cutting.

Often, parts produced using manual plasma cutting have uneven edges, traces of sagging and jerking.

In order to avoid such disadvantages, various devices are used: stands and stops, which allow for smooth movement of the plasma torch along the cutting line, as well as a constant gap between the nozzle and the surface of the part being cut.

Air or nitrogen can be used as the working and cooling gas when using manual equipment. This air-gas jet is also used to blow molten metal out of the cutting zone. When using air, it is supplied from a compressor, and nitrogen comes from a gas cylinder.

Required Power Sources

Although all plasma cutter power supplies operate on AC power, some can convert it to DC power, while others can amplify it. But those devices that operate on direct current have higher efficiency. Installations operating on alternating current are used for cutting metals with a relatively low melting point, for example, aluminum and alloys based on it.

In cases where too high power of the plasma jet is not required, conventional inverters can be used as power sources. It is these devices, characterized by high efficiency and ensuring high stability of the electric arc, that are used to equip small industries and home workshops.

Of course, it will not be possible to cut a piece of metal of considerable thickness using a plasma torch powered by an inverter, but it is optimal for solving many problems.

A big advantage of inverters is their compact dimensions, which makes them easy to carry and use for work in hard-to-reach places.

Transformer-type power supplies have higher power, with the use of which both manual and mechanized cutting of metal using a plasma jet can be carried out. Such equipment is distinguished not only by high power, but also by higher reliability. They are not afraid of power surges that can damage other devices.

Any power source has such an important characteristic as on-time (ON). For transformer power supplies, the duty cycle is 100%, which means that they can be used the whole working day, without a break for cooling or rest. But, of course, such power supplies also have disadvantages, the most significant of which is their high power consumption.

How is manual plasma cutting performed?

The first thing you need to do in order to start using a machine for plasma cutting of metal is to put together all its component elements. After this, the inverter or transformer is connected to the metal workpiece and to the alternating current network.

Further, the cutting technology involves bringing the device nozzle closer to the workpiece at a distance of about 40 mm and igniting the so-called pilot arc, due to which the working gas will be ionized. After the arc has ignited, an air-gas flow is supplied to the nozzle, which should form a plasma jet.

When a plasma jet with high electrical conductivity is formed from the working gas, a working arc is created between the electrode and the workpiece, and the standby arc is automatically turned off.

The task of such an arc is to maintain the required level of ionization of the plasma jet. It happens that the working arc goes out, in which case you should shut off the gas supply to the nozzle and repeat all the described steps again.

It is best, if you have no experience in performing such a process, to watch a training video that shows in detail how to manually cut metal.

Source: http://met-all.org/obrabotka/rezka/plazmennaya-rezka-vse-nyuansy-tehnologii-rezki-metalla-plazmoj.html

Is it possible to carry out plasma cutting of metal at home?

In the past, factories used cumbersome equipment to cut metal sheets and blanks. With the development of technology, new ways of dividing parts into parts have emerged. Plasma cutting is used for this. Using special equipment you can cut metal of any thickness.

What equipment is used?

Typically two types of equipment are used:

1. Transformer. Can cut metal up to 40 mm thick.
2. Inverter. The efficiency is higher than that of transformer devices, however, it is impossible to cut a workpiece whose thickness is more than 30 mm.

The operating principle of these mechanisms is the same. They consist of a compressor, a power source and a plasma torch.

When choosing a tool, you need to study the markings of the device. Some devices are designed for cutting only. Other equipment allows arc welding. There are universal devices on sale, but they are inferior in quality to specialized devices.

The location of the compressor may change. In some models this element is built-in. These models have low power. A model with a built-in compressor is used in garages and small workshops. For industrial production, it is necessary to use devices with an external compressor.

Operating principle of a plasma cutter

The operating principle of plasma metal cutting depends on the equipment used. Before you start cutting metal sheets and workpieces, you need to study the design of the plasma torch:

1. The main part is the power source. This could be a transformer or an inverter. The first option has a bulky design and low efficiency. However, the transformer allows cutting thick workpieces. The inverter has many advantages. This is a high efficiency indicator, stable operation, small dimensions.
2. The plasma torch is the working part. This is a tool that consists of several parts. These include the electrode, cap, cooler and nozzle.
3. Compressor - supplies a stream of air that will heat up during operation. If there is no compressor, the plasmatron may stop working.

Hoses and wires are used to connect key parts of the device.

The principle of operation of the plasmatron is that with the help of the equipment a flow of heated ionized air is created.
The air itself ceases to be a dielectric and begins to conduct current. After turning on the device, an arc is formed, with the help of which the metal workpiece is cut. At the moment of contact between the plasma and the surface of the material being processed, it is exposed to a temperature of 30,000 degrees. ✅Plasma cutting device // Plasma cutter // How to cut metal

Types of plasma cutting

There are several types of manual plasma cutting:

1. Use of shielding gas flow. It protects the cutting site from environmental factors. This results in a better quality cut.
2. Plasma cutter using water. The liquid cools the surface being processed and the plasmatron itself. In addition, water protects the cut site from the effects of environmental factors during heating. Water prevents the molten metal from emitting harmful fumes.
3. Simple. The classic way to use a plasma torch. Electric current and air flow are used for cutting. Not suitable for cutting thick metal sheets and alloy steels.

When cutting workpieces, an arc can be used, which is formed between two electrodes.

Technology

When carrying out work, you should adhere to the following metal plasma cutting technology:

1. The nozzle, from which a stream of air will burst out, is located at the edge of the metal sheet.
2. The wizard starts the device using the power button. The initial arc is turned on, which gradually turns into a cutting arc.
3. The burner is tilted at 90 degrees. Cutting is done slowly and carefully.
4. The master must control the appearance of splashes of molten metal. If they do not appear, it means that the metal workpiece could not be cut through.
5. Do not touch the nozzle or point it towards other objects immediately after turning it off, as hot air will continue to flow from it for some time.

If you cannot cut through a metal sheet, you need to change the angle of inclination, slow down the pace of work, or increase the voltage.

Plasma cutting technology

Advantages

Plasma cutters for metal are often used on construction sites and in private workshops. The demand is explained by the advantages of the plasma cutter:

1. Using a plasmatron you can process different types of metals and alloys.
2. There is no need to prepare the work surface. High quality processing can be achieved without cleaning the metal from rust and paint.
3. By carefully and slowly moving the cutter along the surface being processed, a highly accurate cut is obtained. No scale or sagging remains.
4. Even if the metal sheet is not very thick, it will not be damaged due to strong heating. This is due to the characteristics of the equipment used.
5. Using a plasma cutter you can make smooth, shaped cuts.

During operation of the plasma torch, virtually no harmful substances are released, which makes the processing process safe for health.

Plasma cutting of metals is a technological process using a special tool that allows you to cut metal sheets. The choice of plasma torch depends on what materials will be processed. If the device is not selected correctly, the plasma arc will not be able to cut the metal workpiece.

Is it possible to carry out plasma cutting of metal at home Link to main publication

Source: https://metalloy.ru/obrabotka/rezka/plazmennaya

Technology and advantages of plasma metal cutting: what is it?

Plasma cutting is a modern method of thermal separation of metal workpieces. The method is based on the use of ionized gas energy and is characterized by an exceptionally high jet temperature (up to 30 thousand degrees), which allows you to quickly and accurately cut the most refractory alloys and metals.

Gas plasma cutting is used both on large stationary machines and in manual installations of limited power.

What is the process?

Two factors are used to ionize the gas flow:

• electric arc;
• narrowing of the nozzle at the point of exhaustion, significantly increasing the pressure in the jet.

Under this influence, gas atoms lose electrons from their orbits, turning into positively charged ions. The electrons themselves serve as negatively charged ions. The substance turns into plasma, heated to very high temperatures.

The plasma jet is directed at the workpiece, evaporates the metal in the contact zone and carries it outside the cut zone.

Comparison with laser

Plasma and laser cutting of metal are the two most modern cutting methods.

Laser metal cutting is based on the action of a high-energy light beam concentrated into a very narrow beam. The laser beam evaporates the molecules, leaving a very thin and smooth cut.

The workpiece thickness for modern laser cutters is limited to 20 mm. At the same time, they demonstrate high performance.

Laser cutting, due to its high energy concentration, heats up the workpiece very little, minimizing thermal deformation, especially for thin-sheet parts.

Plasma-forming gases

Gases for plasma cutting are divided into two groups. Feather includes inert and low-active ones, such as argon, nitrogen, hydrogen, and, less commonly, ammonia and helium. The second includes active gases: oxygen, carbon dioxide, water vapor, prepared air.

Applicability of gases and their mixtures for cutting.

The preparation of air masses consists of careful filtration from mechanical impurities and removal of oil and water particles on separators.

Direct cutter

The pilot arc will be ignited between the workpiece and the tungsten electrode. It ionizes the gas, and then the working discharge goes through it. Used for cutting metals with high conductivity.

Direct (left) and indirect (right) action.

Indirect

Low-conductivity metals and even dielectric materials can be cut using this method . The arc is ignited between a central infusible electrode and a brass nozzle. Only the plasma flow acts on the workpiece. Such plasma torches are more expensive both to purchase and to operate.

Selecting a device

To choose the right equipment, you need to base it on your needs. To evaluate them, you need to predict the volume and range of work that will be performed using the cutter.

For a limited amount of work, an inverter for plasma cutting is suitable . It is economical, compact, and easily transportable to the place of work. However, such devices overheat and require periodic cooling.

For serious work throughout the entire shift, a transformer device will be required . It has serious weight and size characteristics and can cut workpieces of large thickness.

By power

Power consumption determines the maximum operating current, and, consequently, the maximum thickness of the workpieces to be cut. Parts up to 3 cm can be cut with a 90 amp current. More substantial parts will require 100 to 170 amps.

The shape and size of the nozzle tip are selected according to the power.

By time and speed of material cutting

The cutting speed depends on the following factors:

• workpiece material;
• its thickness;
• operating current.

Thus, aluminum will be cut much faster than steel.

Burner

The burner power should be selected based on estimates of the volume of work and the average duration of the cut. It should be enough to complete this cut in one go, between two cooling stages.

Experienced carvers advise using a copper nozzle; it cools better than other materials..

The handle should fit comfortably in the hand and be equipped with a removable stop that maintains a constant distance to the part.

For short-term cutting of thin-sheet workpieces, an air torch is suitable. To work with thick parts, it is better to choose nitrogen.

External characteristics

If the cutting sites are far from each other, as is the case, for example, when dismantling metal structures, the weight and dimensions of the device become important parameters.

Technology properties

Professional and household grade devices have similar designs and operating principles:

• ignition of the initial electric arc;
• gas jet ionization;
• application of high-speed plasma flow for metal cutting.

The technology is characterized by:

1. Jet temperature . For non-ferrous metals and their alloys, 5 thousand °C is set, for high-temperature steel alloys - a maximum value of 30 thousand °C.
2. Jet outflow speed . It varies in the range of 450-1600 meters per second. Determined by the material and thickness of the part, the curvilinearity of the cutting line.
3. Cutting width . Determined by nozzle type.
4. Cutting speed. Reaches 6-7 meters per minute.

Surface quality

Determined by the qualifications of the carver and regulatory documents. Quality is important for subsequent welding. The following parameters are set:

• deviation of the cutting line from perpendicular to the surface;
• edge melting;
• roughness class.

The surface quality after plasma cutting is second only to laser cutting.

Kinds

The following subtypes of the method are distinguished:

1. Regular . Prepared air is used as a plasma-forming gas. Used for general structural mild steel.
2. Water . The created water curtain helps cool the nozzle and protects the cut from contact with air oxygen. Suitable for high alloy alloys.
3. In a protective gas environment . Plasma-forming inert (or low-active) gas creates a protective atmosphere that prevents. access of air to the cutting line. Used for non-ferrous and light metals, as well as their alloys.

Based on the method of creating an arc and the effect of plasma on the workpiece material, plasma-arc and jet cutting are also distinguished.

Laser plasma

This method consists of combining a plasma beam and a laser beam in one torch . The laser machine is used for cutting workpieces no thicker than 6 mm. If you need to cut more serious parts, a plasma cutter is used.

Such machines are beneficial for small enterprises with a wide range of products and an average volume of orders. They are equipped with a CNC system, which allows the use of computer programs for creating optimal cuttings.

A single grid for placing sheets allows you to save time on preparatory and finishing operations.

Areas of use

The technology is actively used in the following areas:

• cutting sheet metal;
• cutting of rolled profiles;
• dismantling of metal structures;
• artistic metal cutting, creation of decorative items.

Cutting blanks is used in all mechanical engineering industries, the production of complex building structures and vehicles.

With the increase in the production of manual plasma cutters, their price is becoming affordable for home craftsmen who perform many cutting or dismantling operations.

Accuracy and cutting speed

Accuracy and cutting speed are not strictly dependent on each other . If you run the torch too fast, there may be partial cuts. If, on the contrary, it is delayed in any areas, they will overheat and burn-through or thermal deformation may occur.

An experienced and qualified carver chooses the speed of work based on the material of the workpiece and its thickness. It drives the torch at a constant speed, level and at a constant distance from the workpiece.

The normal cut taper is from 3 to 10° . Melting of the edges at the beginning of the line is also allowed.

Subtleties of the metal cutting process

The tricky part of plasma cutting is choosing and maintaining the correct distance from the torch to the workpiece . When it is lowered, the width of the cut and the area of ​​temperature influence increase. This may cause thermal distortion.

When punching through holes, the distance is increased to 20-25 mm, then the burner is brought to the working distance.

The operating current should be set to the minimum possible for stable combustion of the arc and plasma beam. Exceeding the minimum values ​​leads to increased gas consumption and wear of the nozzles.

How to use a plasma cutter?

Experienced carvers have formulated a number of recommendations to make it easier for beginning craftsmen to master the technology:

• strictly maintain a constant distance from the burner to the workpiece;
• if necessary, use a stop that is attached to the side of the burner and limits the gap;
• operate the burner evenly, without jerking, at a given speed;
• monitor the perpendicularity of the plasma beam to the surface of the part; deviations lead to a decrease in the quality of the cut surface;
• monitor the beam of sparks flying from the back side of the part; if there are few of them or they disappear, the metal is not completely cut through and the cutting mode must be adjusted;

After completing the cut, the torch must be tilted to allow the gases accumulated in the hose to escape.

Source: https://svarka.guru/vidy/thermo/gazovaya/plazmennaya-rezka.html

Plasma cutting of metal: operating principle, technology, systems

Dear friends, in this article we will tell you everything about plasma cutting - how it works, where it is used, what is needed to use it and what results can be achieved, what are the main advantages of plasma cutting and what are the disadvantages, and much more.

The entire article is written in everyday language, without complex technical terms, and therefore it is understandable to any interested visitor, including those not related to metalworking.

:

1.1 Operating principle of plasma cutting

We will start with a brief explanation of the word “plasma”. So

Plasma is an ionized quasi-neutral gas that forms neutral molecules and charged particles. Plasma occurs when a quasi-neutral gas (for example oxygen) is heated to a sufficiently high temperature during its active ionization. Due to the mobility of particles in a gas, plasma has the ability to conduct electric current.

Are there many unclear words? Not scary! This definition is only needed to understand the essence - we heat the gas to about 10,000 oC, create pressure and ionization - we get plasma. Next we move on to the definition of plasma cutting.

Plasma cutting is one of the methods of cutting metal, in which a plasma jet acts as a cutting tool. An electric arc is ignited between the electrode and the nozzle, gas (air or oxygen) at 6-8 atmospheres is supplied to the nozzle, when interacting with the electric arc, the gas is heated to a temperature of 5000-30000 oC and turns into a plasma jet.

So, now, I think, you should already have an idea of ​​​​what plasma cutting is. If not, then I suggest you look at the material, which explains everything in detail.

1.2 Gases used in plasma cutting

Now let's take a closer look at the gases used in plasma cutting.

Air plasma cutting

In this case, air is used as the plasma-forming gas. This is perhaps the cheapest option for plasma cutting. Air is suitable for cutting almost all types of metals: black steel, stainless steel, copper, brass, etc. Air gives average results in terms of quality and cutting speed and is suitable for most plasma cutting users. You can read more about this cutting here.

Oxygen plasma cutting

Oxygen is used in more professional plasma cutting systems, where it is necessary to obtain the best quality and highest cutting speed. When we talk about quality, we mean the perpendicularity of the cut and the minimum amount of slag (burst) on the underside of the cut part.

Plasma cutting using shielding gases

This technology is used in advanced professional plasma cutting systems. Complexes of such equipment cost from 5 to 12 million rubles. The following cutting gases can be used: Oxygen (O2), Nitrogen (N2), Argon (Ar) and air. These same gases can be used as protective gases in certain proportions. The use of protective gases makes it possible to bring plasma cutting of thick workpieces (up to 50 mm) closer to the quality of laser cutting.

The most commonly used plasma cutting indicators are:

Thickness of cut metal	0.5-70 mm	Depends on cutting current
Plasma jet thickness	0.5-2 mm	Depends on the thickness of the metal
Plasma cutting speed	250-10000 mm/min	Depends on cutting current and metal thickness
Gas pressure	5-12 Atm	Depends on the power of the plasma source
Plasma cutting current	20-800 A	Depends on the thickness of the metal

1.3 Cutting different types of metals

Plasma cutting is suitable for cutting almost all metals, but each type of metal has its own characteristics. Let's look at the most popular metals.

Plasma cutting of steel

There are many types of steel, we will not delve into the grades and composition. The main importance for plasma cutting is the carbon content of steel - it is this parameter that determines the quality that can be achieved during plasma cutting.

Low carbon steel is most suitable for plasma cutting. It is this that all manufacturers of plasma sources focus on when creating cutting maps and tabular values ​​of current and cutting speed for different steel thicknesses.

High-carbon steel (including galvanized steel) is also amenable to plasma cutting, but to obtain a high-quality cut you will need to fine-tune the equipment and experiment with cutting modes.

Alloy steels can also be cut with plasma (the most famous is stainless steel). Since alloy steels are used much less frequently in industry, plasma device manufacturers do not provide tabular indicators for their cutting.

But from experience, we can say that the indicators differ from cutting low-carbon steel, in one direction or another, within 20%.

It is recommended to cut high-alloy thick-walled steel not with air, but with a mixture of gases: nitrogen, argon and, in some cases, hydrogen, so as not to damage its structure around the cut.

Plasma cutting of non-ferrous metals

When cutting non-ferrous metals, such as aluminum, copper, titanium, a mixture of gases is also used to obtain a high-quality cut: nitrogen, argon and hydrogen. This is due to the high cost of non-ferrous metals - unstable cutting can lead to significant financial losses in the form of damaged workpieces. It is also possible to cut these materials with air, but as a rule, in small volumes and with average edge quality.

2. Manual plasma arc cutting of metals

Manual plasma cutting is carried out using portable (mobile) plasma cutting machines, consisting of:

1. The main apparatus containing a transformer and a rectifier substation.
2. Power cable.
3. A hose package going from the apparatus to the plasma pistol. The hose package contains an air hose and a power cable.
4. Plasmatron (plasma pistol) – plasma is formed in it.

There are two main methods of manual plasma cutting:

1. Indirect cutting with a plasma jet. This method is mainly used for cutting non-
   metallic materials. In this case, the electric arc that forms the plasma lights up between the electrode and the plasmatron nozzle. The material being cut does not participate in the formation of plasma, and cutting is carried out by a plasma jet escaping from the cutter.
2. Direct plasma arc cutting. This is exactly our case, since this method is used for cutting metals. It is used in both manual and mechanized plasma cutting. An electric arc lights up between the electrode and the metal being cut and combines with a high-speed air flow to form plasma. The resulting plasma jet is so powerful that it literally evaporates the metal during the cutting process.

Manual plasma-arc cutting has proven itself so well that it is now used in almost all enterprises with a metalworking shop. A large number of private owners offer on-site plasma cutting services, because... hand-held devices are very mobile; they can be carried in the hands or on a shoulder strap.

The main advantages of hand-held plasma devices:

1. Mobility, portability (hand-held devices of low and medium power weigh from 10 to 25 kg).
2. Availability of use (operate from 220 V, current depends on the power of the device).
3. Versatility (can cut all types of metals).
4. Affordable price (manual plasma cutting machines made in Russia cost from 15,000 to 70,000 rubles.

3. Automatic plasma cutting

With the advent of manual plasma cutting, this technology began to be used in conjunction with CNC (computer numerical control) machines. The use of CNC machines in conjunction with a plasma cutter allows cutting sheet metal, round and profile pipes with high accuracy (±0.25-0.35 mm) and speed (up to 7 m/min).

The most common is automatic plasma cutting of sheet metal. Medium-power plasma machines cut sheet metal up to 30 mm for breakdown. More professional and powerful machines can cut sheets up to 70 mm with high quality.

The same plasma cutting machine can be used for both manual cutting and automatic cutting, with the exception of plasma torches, which are divided into manual and mechanized.

For CNC cutting, more powerful plasma devices are usually used than for manual cutting. The most in demand are devices with a power from 65 to 125 A, powered by 380 V.

Plasma cutting on a CNC machine allows you to cut metal up to 60 mm thick with high quality.

4. Application of plasma cutting

Due to its versatility and accessibility, plasma cutting is used today in almost all medium and large metalworking enterprises.
Using plasma cutting, metal structures and products are manufactured: doors, gates, gates, fences, artistic ornaments, patterns and weather vanes, hangers, ventilation outlets, piles and other metal products.

Many entrepreneurs build a business on plasma cutting, having their own equipment and accepting orders for metal cutting.

5. Advantages and disadvantages of plasma cutting

To talk about the advantages of plasma cutting and its disadvantages, we need to decide what we will compare with. Plasma cutting has three main competitors - oxy-fuel cutting, laser cutting and waterjet cutting. Each of the four types of cutting has its own specific application. We provided a detailed comparison in the previous article, we recommend that you familiarize yourself with it.

Here we will describe the main advantages and disadvantages of plasma cutting from the practical point of view of enterprises that use it. So

Advantages of plasma cutting

• Metal cutting from 0.5 to 50 mm;
• Cutting all types of metals (aluminum, copper, titanium, stainless steel, steel, etc.);
• Plasma cutting accuracy 0.25-0.35 mm;
• Cutting speed of thin metals up to 7 m/min, fast metal breakdown;
• Mobility of hand-held plasma devices;
• High degree of readiness of parts (minimal cleaning of slag).

Disadvantages of plasma cutting

• Relatively high cost of high-quality plasma devices;
• High cost of consumables (nozzle, electrode, protective screen);
• The presence of a minimum cutting taper;

Here, in general, are all the main points you need to know if you plan to use plasma cutting of metals in your tasks.

For all questions, we will be happy to advise you by phone 8 (800) 500-33-04!

Source: https://plazma-stanok.ru/plazmennaya-rezka-metalla-prosto-o-slognom/

Plasma cutting

Plasma cutting is a technological operation for separating materials, in which a plasma jet plays the role of a cutting tool.

The essence of the plasma cutting process is the high-speed passage of a stream of ionized gas, i.e., plasma, through a tapering hole (nozzle), which acts as a conductor of electric current between the torch (plasma torch) and the material being cut.

It heats and melts the products. A high-speed plasma stream then mechanically blows away the melt, separating it.

The temperature of the plasma flow varies from 5000 °C to 30000 °C, speed - from 500 m/s to 1500 m/s.

The main purpose of the operation is cutting metal elements with a thickness of up to 25 mm. The maximum material thickness for plasma cutting does not exceed 200 mm. The thickness of the metal cut by plasma depends on its thermal conductivity. Namely: the greater the thermal conductivity of the metal, the thinner the product that can be cut. To obtain a plasma jet use:

• inactive gases (nitrogen, hydrogen, water steam) - plasma cutting of non-ferrous metals;
• active gases (oxygen, air) for cutting ferrous metals.

Advantages and disadvantages of the plasma cutting method

Let us note the main advantages of this technological operation:

• Plasma cutting is used for both ferrous (steel, cast iron) and non-ferrous (aluminum, copper) metals. Non-metallic materials (concrete) can also be cut;
• high speed, productivity, accuracy;
• the ability to cut out shapes of complex configurations;
• excellent edge surface quality. The edge does not need to be subjected to additional machining;
• safety, environmental friendliness of the technological process. It does not use flammable gas or compressed oxygen, and there are practically no harmful emissions;
• versatility of the operation: the ability to cut large-width parts, pipe blanks, and perform cuts at a certain angle;
• The workpiece does not need to be preheated before use. This significantly saves the time of the technological operation.

But in the modern, innovative plasma cutting process there are also negative aspects:

• when cutting thick workpieces, it is necessary to use high-power sources of electricity;
• the need to attract trained qualified personnel for work;
• limitation on the thickness of processed parts;
• Plasma cutting work is accompanied by a high noise level;
• high price of equipment.

Equipment for plasma cutting of metal

To carry out cutting using plasma, it is necessary to obtain the plasma arc itself. For this purpose, a special apparatus is used - a plasmatron, which consists of:

• nozzle - plasma outlet;
• an electrode made of a metal with a high melting point (tungsten, zirconium);
• channel for supplying compressed gas (air, purified oxygen);
• an insulating element that simultaneously plays the role of a cooler.

Some of the structural elements of the plasma torch, which operate in areas of high temperatures and significant dynamic loads, may wear out and require periodic replacement. Such elements include:

— electrodes;

— plasmatron nozzle;

— insulating units;

— a diffuser where the swirling of the working gas flow occurs.

In addition, various protective screens and casings are considered consumable items, which make working with the plasma torch more comfortable.

Wear of consumable parts can lead to deterioration in cut quality and breakdown of expensive equipment. Therefore, it is necessary to promptly identify wear of consumables and replace them.

The installation for plasma cutting includes:

• transformer or inverter, current converter to create an electric arc;
• compressor for supplying gas under pressure;
• plasmatron for generating flow;
• air supply tube connected to an electrical cable.

Although the most important technological process occurs in the plasma torch, plasma cutting is impossible in the absence of any other piece of equipment.

Plasma torch operation process

After pressing the button, an electric current flows into the device and the primary electric arc with a temperature of about 8000 °C lights up inside and spreads over the entire area of ​​the channel.  

The compressor begins to supply compressed air into the channel with the primary arc, which, passing through the channel, heats up and acquires the properties of an ionized gas that conducts electric current. Due to high heating temperatures, air expands in volume by 50-100 times. This significantly increases gas pressure.

Then, through the channel, the hot, expanded gas flow enters the nozzle, which narrows it and makes it more concentrated. The air flow, converted into plasma, flies out of the nozzle opening at enormous speed (about 3 km/s). In this case, the temperature of the ionized flow increases several times.

It is this ionized gas, heated to enormous temperatures, that is the plasma through which cutting is carried out.

Types of cutting systems

Systems differ depending on the type of plasma gas provided by the technology.

Conventional systems use ambient air as gas. The current strength in this process ranges from 12-20 thousand A/in². The shape of the plasma flow depends on the nozzle opening. Such systems are used for both manual and mechanized cutting. Deviations in the dimensions of the cut part are allowed.

High frequency (high current density) systems are used for plasma cutting with increased precision. Purified air, oxygen, and mixtures of hydrogen and nitrogen are used as plasma gas. Plasmatrons and consumables of a more complex design are used in the technological process. The current strength for high-frequency separation is 40-50 thousand A/in². The main goal is to achieve increased accuracy when focusing the arc and obtain high quality cutting.

Application of plasma cutting

1. Plasma cutting method is widely used for pipe products. Special installations are used here - pipe cutters with centralizers. In addition to the main operation of pipe separation, installations can perform additional functions: cleaning seams, chamfering, cutting edges.

2. Plasma cutting is used to cut thin metal sheets into pieces. As a rule, CNC equipment is used for these operations, allowing for automated, high-precision cutting.

3. Flat figures of complex configuration cut out of metal, the so-called artistic plasma cutting, are widely used in construction.

4. Plasma cutting of cast iron is recognized as the most effective operation for this material. This method is used in heavy industry to separate scrap iron waste.

5. Plasma cutting technology is used when working with stainless steels of various thicknesses. High speed, environmental friendliness and safety of the process, accuracy, and cut quality are valued here.    

6. Cutting steel coils makes it possible to quickly obtain sheets of certain sizes, as well as the production of metal strips - narrow, long strips of steel.

7. Plasma cutting is used not only for separating metals. Relevant for non-metallic materials, in particular concrete. Here, a variant of jet cutting is used, in which an electric arc is formed between the electrodes.

8. Using plasma technology to produce holes in metal sheets.

Source: https://www.okorrozii.com/plazmennaya-rezka.html

What is plasma cutting of metals?

18.01.2016

Plasma cutting is a type of plasma processing of materials in which a plasma jet is used as a cutting tool instead of a cutter.

(Wikipedia)

Plasma cutting today is considered one of the most effective methods of straight and shaped cutting of metal. Allows you to cut all types of steel, aluminum, copper, cast iron, titanium, sheet and profile products, and bevel edges at a certain angle.

Characteristic advantages of the process

Plasma cutting of metal is characterized by the following features:

1. High performance. The cutting speed is 5-10 times higher compared to the oxygen gas method. In this parameter it is second only to laser cutting.
2. Versatility. It is possible to cut almost any material; it is enough to set the optimal process parameters - power and gas pressure.
3. The quality of preparation does not matter much - paintwork, dirt or rust on metal is not a problem for plasma cutting.
4. Increased quality and accuracy. Modern units provide a minimum cutting width, are relatively clean without an excessive amount of scale on the edges - in most cases they do not require additional machining or even cleaning.
5. A small heat-affected zone helps minimize deformation of cut workpieces as a result of exposure to elevated temperatures.
6. Possibility of curly cutting of complex geometric shapes.
7. Process safety in contrast to gas-oxygen cutting, where there are cylinders with compressed oxygen and flammable gas.
8. Units for plasma cutting of metal are easy to maintain and operate.

What is the process of plasma metal cutting?

Plasma is a conductive ionized gas of high temperature. A jet is formed in a special device - a plasmatron. It consists of the following main elements:

1. Electrode (cathode) – is equipped with an insert made of a material with high thermionic emission (hafnium, zirconium), which burns out during operation and requires replacement when more than 2 mm is produced.
2. Gas flow swirl mechanism.
3. The nozzle is usually isolated from the cathode by a special bushing.
4. Shroud – Protects internal components from molten metal splashes and metal dust.

Source: https://www.purm.ru/blog/plazmennaya-rezka-metallov/

Principle and technology of plasma cutting of metal

[Plasma cutting] allows you to cut metal, but not with a cutter - this unit has a plasma jet.

The essence of how a plasma cutter works is this: an electric arc is formed between the nozzle, electrode or material being cut.

Gas comes out of the nozzle, it is converted into plasma after exposure to electricity.

The metal is cut by plasma, the temperature of which can reach 30 thousand degrees.

The article discusses in detail the technology of plasma cutting of metal, the principle of its operation and some nuances.

Types of plasma cutting

There are several types of metal cutting using plasma.

It depends on the environment in which the process occurs:

• Simple - when cutting, electric current and air are used, sometimes nitrogen is used instead of air. With this method, the length of the electric arc is limited. If the sheet thickness is several millimeters, then the parallelism of the surfaces can be compared to laser cutting. This parameter can be met by cutting metal whose thickness is 10 mm. This method is used when cutting low-alloy or mild steel. Oxygen is used as a cutting element. After the cut, the edge remains smooth and no burrs are formed. In addition, the processed metal edge contains a reduced nitrogen content;
• With the use of protective gas - protective and plasma-forming gas are used as such gas. With the use of such cutting, the quality of metal cutting increases, since the cut is protected from environmental influences;
• With water - while cutting metal, water protects the cut from environmental influences, cools the plasma torch, and all harmful fumes are absorbed by water.

Plasma cutting can be separation or surface. Separation cutting is most often used.

Cutting is also divided according to the following methods: arc - when cutting metal, the material is part of the electrical circuit and jet - when cutting the metal is not part of the electrical circuit, an arc is formed between the electrodes.

Benefits of plasma cutting

Plasma cutting has its advantages over laser cutting:

• A plasma cutter can process any metal: non-ferrous, ferrous, refractory;
• cutting speed is faster than gas cutting;
• A plasma cutter can be used for artistic work - workpieces can be made of any geometric shape, figured cutting of increased complexity, artistic cutting of metal with plasma and parts are available;
• no matter what the thickness of the metal being cut, you can cut the workpiece quickly and accurately;
• A plasma cutter can cut not only metal, but also materials that do not contain iron;
• cutting materials using plasma is much more efficient and faster than conventional mechanical cutting;
• Compared to laser cutting, plasma cutting is capable of processing sheets of material of large width, at an angle. Products are obtained with the least amount of defects and contamination;
• during operation, a minimum amount of pollutants is released into the air;
• before cutting the metal, it does not need to be heated, thus reducing the burning time;
• safety during plasma cutting is at a high level, since there is no need to use gas cylinders, which are very explosive.

IMPORTANT TO KNOW: Waterjet metal cutting technology

Along with the advantages, plasma cutting has some disadvantages:

• high cost of the plasma torch;
• the thickness of the metal that can be cut with a plasma torch should not be more than 10 cm;
• during operation, the unit makes a lot of noise, since gas is supplied at high speed, close to the speed of sound;
• the plasma torch must be properly maintained;
• Cutters cannot be attached to the plasma torch to process the metal manually.

Operating principle of the plasma torch

Plasma cutting of metal is carried out by oneself, who do not have much experience in this matter. This section discusses the operating principle of a plasma cutting device.

If you have a special machine, you can easily cut metal, ceramic tiles, wood or plastic with your own hands; figure cutting is also available.

In addition, the device can weld non-ferrous and ferrous metals, harden elements, perform fire cleaning or annealing of surfaces, and perform artistic cutting.

An example of how a plasma cutter works can be seen in the video.

Unlike laser cutting, the principle of plasma cutting is to heat the heating site to a high temperature with plasma. It is formed in the nozzle from steam. The nozzle has a narrow channel.

An electric arc is formed in it. The steam passes through the channel under pressure, and at the same time the arc cools.

The steam is ionized upon exiting, then a plasma jet appears, which has a high temperature - up to 6 thousand degrees.

Diagrams and drawings will help you understand the design of a plasma cutter and the principles of formation of a cutting jet.

During work, the plasma does not heat a large area of ​​material. The place where the cut was made by a plasma cutter cools down much faster than cutting with laser or mechanical equipment.

The working fluid in a plasma cutter is designed to cool the nozzle and cathode, since these are the most loaded parts of the device.

The arc is stabilized as a result of a certain ratio of the cathode, nozzle and steam. The plasmatron reservoir contains a special material that absorbs moisture.

It helps the working fluid be transferred to the heater. A negative charge is formed on the cathode, and an opposite charge is formed on the nozzle, resulting in an arc.

When using a plasma cutter with your own hands, as with laser or mechanical cutting, you should be careful and follow safety rules.

The device is extremely traumatic for humans - high voltage, heating, molten material.

When cutting, experts recommend wearing a protective suit and having a special shield with tinted glass. The article will clearly show how to cut.

IMPORTANT TO KNOW: Metal cutting methods - laser, plasma

Before starting work, it is important to carefully study the diagrams of the device, inspect the nozzle, electrode, shield for fastening.

If they are not securely fastened, you cannot use a plasma cutter. Also, do not hit the device on metal to remove splashes - this could damage the device.

It is recommended to save material when working. To do this, do not frequently ignite the plasma arc and break it off.

Do-it-yourself plasma cutting will be done with high quality, there will be no scale or burrs on the cut, and the material will not be deformed if the current is correctly calculated during operation.

To do this, you need to apply actions according to the diagram: apply high current, make a couple of cuts. It will be clear from the material whether the current needs to be reduced or left high.

If the current for the material is high, then scale will form on it as a result of its overheating.

Plasma cutting technology

Before you start cutting with plasma, it is worth knowing how the whole process works. Unlike laser cutting, the plasma torch should be placed close to the edge of the material.

After turning on the “start” button, the pilot arc will be lit first, then the cutting arc. The torch with the cutting arc must be moved slowly across the material.

To adjust the cutting speed, it is recommended to control the appearance of sparks on the other side of the metal. When they are not there, it is not possible to completely cut the material.

Several reasons can be noted: high speed of passage of the apparatus, low current, the burner was not at an angle of 90 degrees. to the metal being cut. How to set the cutting angle correctly is shown in the video.

After completing the process, the burner must be tilted, as the diagrams show. It is worth remembering that after turning off the start, the air will continue to flow for some time.

The plasma cutter will be able to completely melt the metal at the moment when the inclination is 90 degrees or higher.

After turning on the device, wait for the cutting arc to appear, create a right angle between the torch and the material. So any shaped structure can get a hole.

When working with a plasma cutter, it is worth studying the diagrams of the device - they indicate the greatest thickness of metal in which a hole can be made. Plasma cutting technology is shown in detail in the video.

How to choose a plasma torch?

To cut metal with a plasma cutter yourself, it is important to buy equipment.

Before making a purchase, it is recommended to take into account the properties and parameters of the device. They will have a great influence on the functions of the plasma torch. The price will also vary.

Plasma cutting can be done by two types of plasma cutting machines:

1. Inventory - has a compact size, its operation requires a small amount of energy, the device is lightweight with an attractive design. At the same time, it does not turn on for long; voltage drops will negatively affect the device;
2. Transformer - long switching time, if the voltage jumps, the plasma cutter does not fail. The size and weight of the unit are quite large; such a plasma cutter also consumes a lot of energy.

IMPORTANT TO KNOW: Metal laser cutting technology

When choosing a plasma torch for cutting with your own hands, it is recommended to pay attention to the parameters.

Such a plasma cutter will be able to maximally satisfy the needs of the master and get the job done.

Power

Depending on the characteristics of the product that needs to be cut, the power is selected. The size of the nozzle and the type of gas will also differ.

So, with a power of 60-90A, a plasma cutter can cope with metal 30 mm thick.

If you need to cut a large thickness, it is recommended to buy a plasma cutter with a power of 90-170A.

When choosing a unit, consider the current strength and voltage that it can withstand.

Time, material cutting speed

This indicator is measured in cm, which the machine can cut in 1 minute. Some plasma cutters can cut metal in 1 minute, while others can cut it in 5.

In this case, the thickness of the material will be the same.

If it is important to reduce cutting time, then it is worth considering the cutting speed.
The devices differ in operating time - how long it takes to cut metal without overheating.

If it is indicated that the operating time is 70 percent, this means that the plasma cutter will operate for 7 minutes, after which it must cool down for 3 minutes.

If it is necessary to make long cuts, it is recommended to choose units with a long operating time.

Plasma cutter torch

It is worth assessing the material that will have to be cut. The plasma cutting torch must have the power to cut it efficiently.

It is worth considering that working conditions can be difficult and cutting can be intense.

It is believed that units with a copper nozzle are very durable, almost unbreakable, and are cooled by air very quickly.

Additional elements can be attached to the handles of such plasma cutters to support the nozzle tip at a certain distance. This makes the work much easier.

If a plasma cutter will be used to cut thin metal, then you can choose a unit whose burner receives air.

If you plan to plasma cut thick metal, you should prefer a plasma torch, the torch of which will be supplied with nitrogen.