Plasma cutting of steel. Gases are used to form plasma. Plasma Metal Cutting Basics

For efficient processing For a number of metals, plasma cutting is often used, the operating principle of which is the use of a plasma arc.

1 Metal plasma cutting technology

The plasma arc cutting process that interests us in world practice is “hidden” under the abbreviation PAC. Plasma is a high-temperature ionized gas that can conduct electric current. A plasma arc is formed in a unit called a plasmatron from a conventional electric one.

The latter is compressed, and then a gas is introduced into it, which has the ability to form plasma. Below we will talk about the importance of such plasma-forming gases for the plasma cutting process.

Technologically, there are two cutting methods:

2 Plasma cutting - the principle of operation of the plasma torch

A plasma torch is a plasma cutting device, in the body of which a small cylindrical arc chamber is placed. At the exit from it there is a channel that creates a compressed arc. On the back side of such a chamber there is a welding rod.

A preliminary arc is ignited between the tip of the device and the electrode. This stage is necessary, since it is almost impossible to achieve the initiation of an arc between the material being cut and the electrode. The specified preliminary arc comes out of the plasma torch nozzle, comes into contact with the torch, and at this moment the working flow is directly created.

After this, the forming channel is completely filled with a plasma arc column, the gas forming the plasma enters the plasmatron chamber, where it is heated, and then ionized and increased in volume. The described scheme causes a high arc temperature (up to 30 thousand degrees Celsius) and the same powerful speed of gas flow from the nozzle (up to 3 kilometers per second).

3 Plasma-forming gases and their effect on cutting capabilities

The plasma-forming medium is perhaps the key parameter of the process, which determines its technological potential. The composition of this environment determines the possibility of:

indicator settings heat flow in the metal processing zone and the current density in it (due to a change in the ratio of the nozzle cross-section to the current);
varying the volume of thermal energy over a wide range;
regulation of surface tension, chemical composition and viscosity of the material being cut;
control of the depth of the gas-saturated layer, as well as the nature of chemical and physical processes in the treatment zone;
protection against the appearance of underwater marks on metal and (on their lower edges);
formation optimal conditions for removing molten metal from the cutting cavity.

In addition, many technical parameters of the equipment used for plasma cutting also depend on the composition of the medium we describe, in particular the following:

design of the cooling mechanism for the device nozzles;
option for mounting the cathode in the plasmatron, its material and the level of intensity of coolant supply to it;
control circuit of the unit (its cyclogram is determined precisely by the flow rate and composition of the gas used to form the plasma);
dynamic and static (external) characteristics of the power source, as well as an indicator of its power.

It is not enough to know how plasma cutting works; in addition, you should select the right combination of gases to create a plasma-forming environment, taking into account the price of the materials used and the direct cost of the cutting operation.

Typically, semi-automatic and manual processing of corrosion-resistant alloys, as well as machine and economical manual processing of copper and aluminum, use a nitrogen environment. But low-alloy carbon steel is better cut in an oxygen mixture, which absolutely cannot be used for processing aluminum products that are resistant to corrosion of steel and copper.

4 Advantages and disadvantages of plasma cutting

The very principle of operation of plasma cutting determines the advantages of this technology over gas methods for processing non-metallic and metal products. The main advantages of using plasma equipment include the following facts:

universality of technology: almost all known materials can be cut using a plasma arc, from cast iron and copper to aluminum and steel;
high speed of operation for metals of medium and small thickness;
the cuts are of truly high quality and high-precision, which often makes it possible not to carry out additional mechanical processing of products;
minimal air pollution;
there is no need to preheat the metal to cut it, which makes it possible to reduce (and significantly) the burning time of the material;
high safety of work due to the fact that cutting does not require gas cylinders, which are potentially explosive.

It is worth noting that according to some indicators, gas technologies are considered more appropriate than plasma cutting. The disadvantages of the latter usually include:

the complexity of the plasmatron design and its high cost: naturally, this increases the cost of each operation;
relatively small cutting thickness (up to 10 centimeters);
high noise level during processing, which occurs due to the fact that gas flies out of the plasmatron at transonic speed;
the need for high-quality and most competent maintenance of the unit;
increased level of release of harmful substances when nitrogen is used as a plasma-forming composition;
impossibility of connecting two cutters for manual metal processing to one plasma torch.

Another disadvantage of the type of processing described in the article is that deviation from the perpendicularity of the cut is allowed no more than an angle from 10 to 50 degrees (the specific angle depends on the thickness of the product). If you increase the recommended value, there is a significant expansion of the cutting area, and this becomes the reason for the need for frequent replacement of the materials used.

Now you know what plasma cutting is and are well versed in all its features.

The use of plasma cutting is widespread. It is used in mechanical engineering, utilities, shipbuilding, and the manufacture of metal structures. Plasma cutting is based on the principle that ionized air begins to conduct electrical current.

Metal cutting is carried out by plasma, which is heated ionized air, and a plasma arc. The operating principles characteristic of plasma cutting of metal will be described below.

What is plasma cutting

When cutting metal with plasma, the electric arc intensifies. This is possible due to the action of gas under pressure. The cutting element is heated to high temperatures, resulting in high-quality and fast cutting of metal.

Unlike its plasma counterpart, it does not contribute to overheating of the entire processed product. High temperature occurs directly at the place where the metal is cut, and the remaining parts of the product do not heat up and are not deformed.

The principle of plasma cutting of metal is based on:

delivery of the required voltage by a current source (standard voltage - 220 V, increased voltage - 380 V, for cutting metal at large enterprises);
transmitting current to the plasma torch (torch) through cables, as a result, an electric arc lights up between the anode and cathode;
supply of air flows through hoses by a compressor to the device;
the action of swirlers inside the plasmatron that direct flows to the electric arc;
the passage of vortex air flows through an electric arc and the creation of ionizing air heated to high temperatures;
closing the working arc between the electrode and the surface being treated when the plasma torch is brought to it;
exposure of air under high pressure and high temperature to the product being processed.

The result is a thin cut with minimal sagging.

The arc can burn in standby mode if the device is not used at a specific time. During standby mode, combustion is maintained automatically. When the torch is brought to the workpiece, the arc instantly goes into operating mode and instantly cuts the metal.

After turning off the device, it is purged to remove debris and cool the electrodes.

The electric arc is universal in its action. It is capable of not only cutting, but also welding metal products. For welding, filler wire suitable for the specific type of metal is used. It is not air that is passed through the arc, but an inert gas.

Plasma cutter structure

The name given to the apparatus used to cut metal products different ways. The unit structure includes the following elements:

electrical power source;
compressor;
plasmatron;
cable hoses.

Several devices act as power sources:

inverter;
transformer.

Each device has a number of advantages and disadvantages. The advantages of the inverter include:

cheapness;
arc stability;
ease of use in areas with difficult access;
light weight;
high efficiency, exceeding that of a transformer by 30%;
efficiency.

What are the disadvantages and limitations?

The main disadvantage of the inverter is the inability to use it for cutting thick metal products.

The transformer is effectively used when cutting thick-walled metal that an inverter cannot handle. It can withstand fluctuations in mains voltage, but is characterized by low efficiency. Transformers are inconvenient due to their heavy weight.

A compressor is a device that supplies air to an electric arc. The mechanism contributes to the creation of vortex air flows directed towards it. The compressor ensures that the arc cathode spot is clearly located in the center of the electrode. If the process is disrupted, consequences arise in the form of:

formation of two electric arcs at once;
weak arc burning;
plasma torch failure.

During the operation of a conventional non-industrial plasma cutter, only compressed air is passed through the compressor. It creates plasma and cools the electrodes. Industrial units use mixtures of gases based on oxygen, helium, nitrogen, argon, and hydrogen.

The plasma torch performs the main function of the device - cutting the product. His device includes:

cooler;
electrode;
cap;
nozzle.

The plasmatron contains a hafnium electrode that excites the electric arc. Zirconium, less often beryllium and thorium electrodes are used. Their oxides are toxic and even radioactive.

A plasma jet passes through the plasmatron nozzle, cutting the products. The quality of cutting, technology, speed of operation of the unit, width of the cut and cooling rate depend on its diameter.

The cable carries current coming from the inverter or transformer. Compressed air moves through the hoses, forming plasma in the plasma torch.

A sequential study of the stages of plasma cutting of metals allows you to understand how it works:

the ignition button is pressed, leading to the start of current supply from the transformer or inverter to the plasmatron;
a pilot electric arc with a temperature of 70000C appears inside the plasmatron;
an arc is ignited between the nozzle tip and the electrode;
compressed air enters the chamber, which passes through the arc, heating and ionizing;
in the nozzle the incoming air is compressed, escaping from it in a single stream at a speed of 3 m/s;
the compressed air escaping from the nozzle heats up to 300,000C, turning into plasma;
when the plasma comes into contact with the product, the pilot arc goes out and the cutting (working) arc lights up;
the working arc melts the metal at the point of impact, the result is a cut;
parts of the molten metal are blown away from the product by air currents escaping from the nozzle.

Any plasma metal cutting technology depends on the cutting speed and air flow. High speed promotes the appearance of a thinner cut. At low speed and high amperage, the cutting width becomes wider.

With increased air flow, the cutting speed increases. The larger the nozzle diameter, the lower the speed and the wider the cut.

Cutting techniques

In practice, two methods of cutting metal with plasma are used:

plasma jet;
plasma-arc method.

Plasma jet cutting has found application in the processing of non-metallic products that are not capable of conducting electric current. With this processing method, the product is not part of the electrical circuit. The arc burns between the electrode and the tip of the plasma torch. The product is cut by a plasma jet.

The plasma-arc method is widely used. It is used for:

cutting profiles, pipes;
manufacturing products with straight contours;
casting processing;
forming holes in metal;
production of welding blanks.

The arc burns between the electrode and the workpiece. The arc column is combined with the plasma jet. The jet occurs due to the gas blown through the operating compressor, which becomes very hot and ionized in the process. Gas promotes the formation of plasma, and due to its high temperature the cutting speed of the metal being processed increases. This method involves the use of an arc direct current with straight polarity.

Types of plasma cutting

There are three types of process:

simple - using electric current and air (an alternative is nitrogen);
using water, which performs the function of cooling the plasmatron, protecting it and absorbing emissions;
with the use of protective gas, which improves the quality of the cut.

Pros and cons of plasma cutting machines

pros	Minuses
Versatility of use (intended for processing any metal products, provided that the device is selected correct power with the required air pressure).	Small range of cutting thickness (no more than 100 mm).
Minimal harm to the environment.	Harm to the environment and health (a master who worked with a plasma cutter, for which nitrogen is provided as a gas, receives serious poisoning).
High productivity, second only to laser cutting, but superior in cost.	High price of the unit.
High quality of work, characterized by a small cut width and the absence of severe overheating of the entire product during plasma processing.	Complex design.
There is no need to warm up the entire product, which affects its quality.	Increased noise level during operation.
Process safety due to the absence of the need to use gas cylinders.	The maximum permissible angle of deviation from the perpendicularity of the cut is only 100-500, depending on the thickness of the product.

One of the popular types of metal processing is its cutting. There are many ways to obtain the required shape from a single sheet, but in this material we will look at the principle of operation of plasma cutting.

Plasma cutting. In fact, there is a golden mean. The advantages of cutting metal with plasma combine all of the above technologies. The main advantage is that there are no restrictions on the type of material processed. Just in terms of thickness.

aluminum alloys 120 mm
copper alloys 80 mm
steel 50 mm
cast iron 90 mm

The equipment varies from industrial to household, so the technology is accessible to everyone. Let's take a closer look at it.

Plasma cutting of metal - operating principle

A two-component medium acts as a cutter:

An electric arc operating according to the classical scheme - a discharge between the cathode and anode. Moreover, the material itself can act as an anode if it is a conductor.
Gas arc. Heating under the influence of an electric arc (temperature reaches 25000º C), the gas is ionized and turns into a conductor of electric current.

The principle of operation of plasma cutting is shown in detail in this video.

As a result, plasma is formed, which is fed under high pressure into the cutting area. This hot gas stream literally evaporates the metal, and only in work area. Despite the fact that the temperature of plasma cutting is measured in tens of thousands of degrees, there is practically no impact on the boundary zone.

Important! Correctly selected speed allows you to get a very narrow cut without damaging the edge of the material.

The source of plasma cutting is a plasma torch.

Its task is to light the arc, maintain the operating temperature, and blow molten metal out of the cutting area. Since plasma cutters are designed for processing any solid materials, including dielectrics, the formation of an electric arc is carried out in two ways:

Figure a) shows a direct action cutter. Cathode assembly (8) along with the assigned cathode (6) are one of the electrodes. The second electrode (anode) is workpiece (4)– a metal with good electrical conductivity.

The power cable of the plasma torch is connected to it. Plasma cutting tip (5) in this scheme it acts as a housing. From separated from the cathode insulator (7). Gas is supplied inside fitting (1) and forms a plasma jet consisting of electric (2) and gas (3) arc.

) plasma jet is called plasma cutting. The plasma flow is formed as a result of gas blowing into a compressed electric arc. The gas then heats up and ionizes (breaks down into negatively and positively charged particles). The temperature of the plasma flow is about 15 thousand degrees Celsius.

Types and methods of cutting using plasma

Plasma cutting can be:

superficial;
dividing

In practice, separation plasma cutting has found wide application. Surface cutting is used extremely rarely.

The cutting itself is carried out in two ways:

plasma arc. When cutting steel using this method, the metal being cut is included in an electrical circuit. An arc is formed between the tungsten electrode of the torch and the workpiece.

plasma jet. An arc occurs in the cutter between two electrodes. The product being cut is not included in the electrical circuit.

Plasma cutting is more productive than oxygen cutting. But if thick material or titanium is being cut, then preference should be given to oxygen cutting. Plasma cutting is indispensable when cutting (especially).

Types of gases used for plasma cutting.

Gases used to form plasma are:

active - oxygen, air. Used when cutting ferrous metals
inactive - nitrogen, argon, . Used for cutting non-ferrous metals and alloys.

Compressed air. Used for cutting:

copper and its alloys – with a thickness of up to 60 mm;
aluminum and its alloys – with a thickness of up to 70 mm;
steel – with a thickness of up to 60 mm.

Nitrogen with argon. Used for cutting:

high-alloy steel up to 50 mm thick.

It is not recommended to use this gas mixture for cutting copper, aluminum, and black steel;

Pure nitrogen. Used for cutting (h=material thickness):

copper h equal to 20 mm;
brass h equal to 90 mm;
aluminum and its alloys h equal to 20 mm;
high-alloy steels h equal to 75 mm, low-alloy and low-carbon steels - h equal to 30 mm;
titanium - any thickness.

Nitrogen with hydrogen. Used for cutting:

copper and its alloys of medium thickness (up to 100 mm);
aluminum and alloys of medium thickness – up to 100 mm.

Nitrogen mixture is not suitable for cutting any steel or titanium.

Argon with hydrogen. Used for cutting:

Copper, aluminum and alloys based on them with a thickness of 100 mm and above;
High-alloy steel up to 100 mm thick.

It is not recommended to use argon with hydrogen for cutting carbon, low-carbon and low-alloy steels, as well as titanium.

Equipment for plasma cutting: types and brief characteristics.

To mechanize plasma cutting, semi-automatic and portable machines of various modifications have been created.

1. can work with both active and inactive gases. The thickness of the cut material ranges from 60 to 120 mm.

Gas consumption:

air – from 2 to 5 m3/hour;
argon – 3 m3/hour;
hydrogen – 1 m3/hour;
nitrogen – 6 m3/hour.

Travel speed – from 0.04 to 4 m/min.
Operating gas pressure – up to 0.03 MPa.
The weight of semi-automatic machines is 1.785 - 0.9 kg, depending on the modification.

2. Portable machines use compressed air.

The thickness of the material to be cut is no more than 40 mm.
Compressed air consumption – from 6 to 50 m3/hour;
Cooling of plasma torches – with water or air.
Travel speed – from 0.05 to 4 m/min.
Operating gas pressure – up to 0.4 – 0.6 MPa.
The weight of portable machines is up to 1.8 kg, depending on the modification.
Water-cooled plasma torches can only be operated at positive temperatures environment.
Semi-automatic and portable machines are suitable for industrial use.

For manual cutting, two sets are available:

KDP-1 with plasma torch RDP-1;
KDP-2 with plasmatron RDP-2.

Plasma cutting

The KDP-1 device is used for cutting aluminum (up to 80 mm), stainless and high-alloy steels (up to 60 mm) and copper (up to 30 mm).

Maximum operating current – 400 A.

The maximum open circuit voltage of the power supply is 180 V.

The RDP-1 plasma torch operates with nitrogen, argon or a mixture of these gases with hydrogen.

The RDP-1 plasma torch is cooled with water, so it can be used at temperatures above 0 degrees Celsius.

The KDP-2 device is inferior to the first in terms of arc power (only 30 kW). The advantage of this model is that the RDP-2 plasma torch is cooled by air. As a result, the kit can be used outdoors at any ambient temperature.

Complete set of manual cutting devices:

cutting plasma torch;
cable-hose package;
collector;
lighter to excite the cutting arc.

Kits for manual plasma cutting are produced without remote control. This constructive solution rational for performing a limited amount of work with equipment loading no more than 40 - 50%. But for the duration of work they have to be supplemented welding rectifiers and converters.

However, we should not forget that from a safety point of view, for manual cutting, the no-load voltage of the power source is allowed to be no more than 180 V.

Do-it-yourself plasma cutting of metals: some subtleties of the process.

The beginning of the metal cutting process is considered to be the moment of initiation of the plasma arc. Once cutting begins, it is necessary to maintain a constant distance between the plasma torch nozzle and the surface of the material. It should be from 3 to 15 mm.
It is necessary to strive to ensure that the current is minimal during operation, because with an increase in current and air flow, the service life of the plasma torch nozzle and electrode decreases. However, the current level must ensure optimal cutting performance.
The most difficult operation is punching holes. The difficulty lies in the possible formation of a double arc and failure of the plasma torch. Therefore, when punching, the plasma torch must be raised above the metal surface by 20 - 25 mm. The plasma torch is lowered into the working position only after the metal has been pierced through. When punching holes in thick sheets, experts recommend using protective screens with holes with a diameter of 10-20 mm. Screens are placed between the product and the plasma torch.
For manual cutting of high-alloy steels, nitrogen is used as a plasma gas.
When manually cutting aluminum using an argon-hydrogen mixture, the hydrogen content should not exceed 20% to increase the stability of the arc.
Copper cutting is performed using hydrogen-containing mixtures. But brass requires nitrogen or a nitrogen-hydrogen mixture. At the same time, cutting brass occurs 20% faster than copper.
After cutting, the copper must be cleaned to a depth of 1-1.5 mm. For brass this requirement is not mandatory.

Used when processing conductive metals. The material being processed receives energy from a current source through ionized gas. Standard system Includes an ignition circuit and torch that provide the electrical power, ionization, and control necessary for quality, high-performance cutting of a variety of metals.

The output of the constant current source sets the thickness and speed of the material and maintains the arc.

The ignition circuit is made in the form of a high-frequency alternating voltage generator of 5-10 thousand V with a frequency of 2 MHz, which creates a high-intensity arc that ionizes the gas to the state of plasma.

The cutter is a holder for consumable parts - nozzle and electrode - and provides cooling of these parts with gas or water. The nozzle and electrode are compressed and support the ionized jet.

Manual and mechanized systems serve different purposes and require different equipment. Only the user can determine which one is best suited to his needs.

Plasma metal cutting is a thermal process in which a beam heats an electrically conductive metal to a temperature above its melting point and removes the molten metal through a hole made. Between the electrode in the torch, to which a negative potential is applied, and the workpiece with a positive potential, a electric arc and the material is cut by an ionized gas flow under pressure at a temperature from 770 to 1400 °C. A jet of plasma (ionized gas) is concentrated and directed through a nozzle, where it is compacted and becomes capable of melting and cutting a wide variety of metals. This is the basic process for both manual and mechanized plasma cutting.

Manual cutting

Manual cutting of metal with plasma is carried out using fairly small devices with a plasma torch. They are maneuverable, versatile and can be used to carry out various tasks. Their capabilities depend on the current strength of the cutting system. The parameters of manual cutting units vary from 7-25 A to 30-100 A. Some devices, however, allow up to 200 amperes, but these are not widely used. In manual systems, industrial air is usually used as plasma-forming and shielding gas. They are designed to accommodate a variety of input voltages, ranging from 120V to 600V, and can be used on single or three phase systems.

Handheld plasma for cutting metal is usually used in workshops involved in processing thin materials, factory services Maintenance, repair shops, scrap metal collection points, during construction and installation work, in shipbuilding, auto repair shops and art workshops. As a rule, it is used to trim excess. A typical 12 Amp plasma cutter cuts a maximum of 5 mm layer of metal at a speed of about 40 mm per minute. The 100-amp device cuts a 70-mm layer at speeds up to 500 mm/min.

Typically, a manual system is selected based on the thickness of the material and the desired processing speed. A device that delivers high amperage works faster. However, when cutting with high amperage, it becomes more difficult to control the quality of the work.

Machine processing

Mechanized metal cutting with plasma is carried out on machines that are usually much larger than manual ones, and is used in combination with cutting tables, including a water bath or a platform equipped with various drives and motors. In addition, mechanized systems are equipped with CNC and cutter head jet height control, which may include preset torch height and voltage control. Mechanized plasma cutting systems can be installed on other metalworking equipment, such as stamping presses, or robotic systems. The size of the mechanized configuration depends on the size of the table and platform used. The cutting machine can be smaller than 1200x2400 mm and larger than 1400x3600 mm. Such systems are not very mobile, so before installation, all their components should be provided, as well as their location.

Power Requirements

Standard power supplies have a maximum current range of 100 to 400 A for oxyfuel cutting and 100 to 600 A for nitrogen cutting. Many systems operate in a lower range, such as 15 to 50 A. There are nitrogen cutting systems with amperages of 1000 A and higher, but they are rare. The input voltage for mechanized plasma systems is 200-600 V in a three-phase network.

Gas requirements

For cutting soft and of stainless steel, aluminum, as well as various exotic materials, compressed air, oxygen, nitrogen and a mixture of argon and hydrogen are usually used. Their combinations serve as plasma-forming and auxiliary gases. For example, when cutting mild steel, the starting gas is often nitrogen, the plasma gas is oxygen, and compressed air is used as an auxiliary gas.

Oxygen is used on mild carbon steel because it produces high quality cuts in material up to 70mm thick. Oxygen can also act as a plasma-forming gas for stainless steel and aluminum, but the result is not entirely accurate. Nitrogen serves as a plasma and assist gas as it provides excellent cutting performance on virtually any type of metal. It is used at high currents and allows processing rolled sheets up to 75 mm thick and as an auxiliary gas for nitrogen and argon-hydrogen plasma.

Compressed air is the most common gas, both plasma and auxiliary. When low-current cutting is performed sheet metal up to 25 mm thick, leaves an oxidized surface. When cutting with air, nitrogen or oxygen, it is an auxiliary gas.

A mixture of argon and hydrogen is typically used to process stainless steel and aluminum. Provides a high-quality cut, and is necessary for mechanized cutting of sheets with a thickness of more than 75 mm. Carbon dioxide can also be used as an auxiliary gas when cutting metal with nitrogen plasma, as it can work with most materials and guarantees good quality.

Nitrogen-hydrogen mixtures and methane are also sometimes used in the plasma cutting process.

What else is needed?

The choice of plasma and auxiliary gases are just two of the critical decisions that must be taken into account when installing or using a motorized plasma system. Gas tanks can be purchased or rented and are available in a variety of sizes and require appropriate storage conditions. Installing the system requires a significant amount of electrical wiring and piping for gas and coolant. In addition to the mechanized plasma system itself, you need to select a table, cutting machine, CNC and THC. OEMs typically offer a variety of hardware options to suit any device configuration.

Is mechanization necessary?

Due to the complexity of selecting a mechanized plasma cutting process, considerable time must be spent researching various system configurations and criteria. Please note:

types of parts that will be cut;
number of industrial products in a batch;
desired cutting speed and quality;
cost of consumables.
the total cost of operating the configuration, including electricity, gas and labor.

The size, shape and number of parts to be produced may determine the type of industrial production equipment needed - the type of CNC, table and platform. For example, production of parts small size may require a platform with a specialized drive. Rack drives, servos, drive amplifiers and sensors used on platforms determine cut quality and maximum speed systems.

Quality and speed also depend on what CNC and gases are used. A mechanized system with adjustable current and gas flow at the beginning and end of cutting will reduce material consumption. In addition, a CNC with a large memory capacity and a choice of possible settings (for example, the height of the torch at the end of the cut) and fast data processing (input/output communications) will reduce downtime and increase the speed and accuracy of work.

Ultimately, the decision to purchase or upgrade a mechanized plasma cutting system versus a manual one should be an informed one.

Plasma cutting of metal: equipment

Hypertherm Powermax45 is a portable device with a large number of standard components based on an inverter, i.e., an insulated gate bipolar transistor. It is very easy to work with, whether cutting thin steel or 12mm thick sheets at 500mm/min or 25mm at 125mm/min. The device is capable of generating high cutting power various types conductive materials such as steel, stainless steel and aluminum.

The power system has an advantage over analogues. Input voltage - 200-240 V single-phase current with a power of 34/28 A with a power of 5.95 kW. Variations in mains input voltage are compensated for by Boost Conditioner technology, which allows the torch to exhibit increased performance at low voltages, when input power fluctuates, and when powered by a generator. Internal components are effectively cooled using the PowerCool system, providing increased performance, runtime and reliability of the device. Another important feature This product features a FastConnect torch connection that facilitates mechanized use and increases versatility.

The Powermax45 torch features a dual-angle design that extends nozzle life and reduces nozzle life. It features Conical Flow, which increases arc energy density to significantly reduce dross and produce high-quality plasma cutting. Powermax45 price - $1800.

Hobart AirForce 700i

The Hobart AirForce 700i has the highest cutting capacity in this line: a nominal cutting thickness of 16 mm at a speed of 224 mm/min, and a maximum cutting thickness of 22 mm. Compared to analogues, work force device current is 30% less. The plasma cutter is suitable for service stations, repair shops and for the construction of small buildings.

The device features a lightweight yet powerful inverter, ergonomic starting fuse, efficient air consumption and low cost consumables torches, resulting in safe, high-quality and inexpensive plasma cutting. The AirForce 700i is priced at $1,500.

The set includes an ergonomic hand torch, cable, 2 replacement tips and 2 electrodes. Gas consumption is 136 l/min at a pressure of 621-827 kPa. The weight of the device is 14.2 kg.

The 40 amp output delivers exceptional sheet metal cutting performance - faster than other manufacturers' mechanical, gas and plasma devices.

Miller Spectrum 625 X-treme

The Miller Spectrum 625 X-treme is a small machine powerful enough to cut a variety of steel, aluminum and other conductive metals.

It is powered by an AC mains voltage of 120-240 V, automatically adjusting to the supplied voltage. The lightweight and compact design makes the device highly portable.

With Auto-Refire technology, the arc is controlled automatically, eliminating the need to constantly press a button. The nominal cutting thickness at 40 A is 16 mm at 330 mm/min, and the maximum cutting thickness is 22.2 mm at 130 mm/min. Power consumption - 6.3 kW. The weight of the device in manual version is 10.5 kg, and with a machine cutter - 10.7 kg. Air or nitrogen is used as plasma gas.

The reliability of the Miller 625 is ensured by Wind Tunnel technology. Thanks to the built-in high-speed fan, dust and debris do not get inside the device. LED indicators provide information about pressure, temperature and power. The price of the device is $1800.

Lotos LTP5000D

Lotos LTP5000D is a portable and compact plasma device. With a weight of 10.2 kg, there will be no problems moving it. The 50 amp current produced by the digital converter and the powerful MOSFET transistor ensure efficient cutting of 16mm mild steel and 12mm stainless steel or aluminum.

The device automatically adjusts to the voltage and frequency of the network. The length of the hose is 2.9 m. The auxiliary arc does not come into contact with metal, which allows the device to be used for cutting rusty, untreated and painted materials. The device is safe to use. Compressed air used for cutting is not harmful to humans. And the strong shock-resistant case reliably protects the device from dust and debris. Price Lotos LTP5000D - $350.

When purchasing a plasma cutter, you should always prioritize quality. You should beware of the temptation to buy a cheap, low-quality device, as its rapid wear and tear will lead to much greater costs in the long run. Of course, you shouldn’t overpay either, there are quite decent budget options without accessories and high powers that may never be needed.