What is a plasma cutting machine. The principle and technology of plasma cutting of metal

You need high-quality and inexpensive plasma cutting in the city of Moscow, but you do not know who to turn to for this task and how much such services cost? The company "TD MEGAMETALL" is ready to help you with this, which offers you the best opportunities for long-term and profitable cooperation. Our specialists will prepare an individual project for you. We guarantee you impeccable quality and affordable prices.

Price list

Steel hot-smoked, hot-smoked

Plasma cutting prices are calculated based on lead time
The prices indicated in the price lists are indicative and may vary depending on the complexity and volume of the order.
The maximum size of a blank sheet is 6000x1500 mm.
The minimum order quantity for plasma cutting of metal is 5000 rubles
Prices for plasma cutting of metal are inclusive of VAT and without the cost of material.

The value of embedded parts

Today, metal rolling and processing of embedded parts are of great importance, because these methods are directly related to construction. multi-storey buildings And major centers. Practice shows that it is metal structures that have the appropriate strength and ease of assembly, which made them the best option in today's market conditions.

Given this, we can conclude that the manufacture of embedded parts plays a key role in this process. The integrity of the future design depends on the quality of such elements, therefore it is extremely important that the production of connecting components is carried out in compliance with all applicable norms and rules. A huge role here is played by plasma cutting of metal, with the help of which even complex tasks can be handled without too much effort.

What is this process?

The latest plasma cutting of metals is a special, innovative and high-tech type of processing of various alloys. For this, various active gases are used, which give an incredible combustion temperature. The unique feed method guarantees incredible cutting intensity as well as cut quality and amazing precision. It should be noted that the power cutting tool so high that it can even process parts twenty centimeters thick! Such a jet easily copes with both ferrous and non-ferrous metals.

In the modern production cycle, installations are used that are controlled by special software, which allows minimizing human factor. This leads not only to optimal savings in human resources, but also reduces the risk of traumatic incidents. Special software helps to cut metal parts exactly according to the specified parameters and in the required quantity, which makes this technology ideal for modern industry.

Summing up a small preliminary result, we can say that the latest plasma cutting of metal is an ideal method for rolling and processing workpieces, which has been repeatedly noted by foreign and domestic experts. The main advantages of this technology include the following:

Characteristics	Traditional Methods	Plasma cutting
Security
Low costs
Easy to operate
Online execution
High accuracy
No slag (chips, carcinogenic secretions, etc.)
Minimum probability of manufacturing defects
Huge possibilities (manufacture of the most unusual forms)
Work with any alloys
Possibility of serial production on an industrial scale

As you can see, this technology is really advanced, and this directly affects the fact that plasma cutting services are in great demand among entrepreneurs.

Unique specifics of metalworking

It is worth paying your attention to the fact that plasma cutting machines are characterized by large size and heavy weight, and also consume a large number of electricity. However, the production capacity is so high that all costs for the purchase or rental of such equipment pay off in the first month of operation. If we are talking about domestic use, then hand tools are suitable for these purposes, with the help of which plasma cutting of metals is not difficult. Of course, such devices are less powerful, but at the same time they allow you to cope with a wide variety of tasks:

dismantling of massive metal structures;
cutting of hulls and frames for subsequent disposal;
redevelopment of buildings, etc.

Note that the accuracy of work when using hand tools is somewhat lower than that of devices with a central processor, but the key advantage is the mobility of the unit (small dimensions ensure easy carrying and transportation of equipment). As for the speed of work, it is, of course, also somewhat lower than that of industrial models, but at the same time, such devices also help to solve even the most complex tasks. That is why today in search engines it is increasingly possible to meet such queries as "plasma cutting" and so on.

Description of the principle of operation

You already know that plasma cutting, which is affordable for everyone, is an ideal alternative to flame cutting. This result is achieved thanks to the plasma-arc cutting method. In other words, a heavy-duty electric arc is created between the treated surface and the electrode. At the same time, in order to achieve the best result (speed, quality, safety), gas is supplied from the nozzle under high pressure.

This allows you to create a stunning effect: a jet of ignited gas combined with an electric plasma gives a temperature of 5000 to 30,000 degrees Celsius! As for the velocity of the plasma jet, it reaches 1.5 km/s. Due to these characteristics, artistic plasma cutting allows you to work with even the most durable alloys known to man!

Based on this information, we can conclude that artistic plasma cutting of metal provides a great effect, and in addition to this, the quality of the cut remains not unprecedented. Experts say that this method is so pure and accurate that the workpieces and parts obtained with its help practically do not need post-processing. Due to this, the production of embedded parts has an enormous speed, which affects the increase in volumes. finished products at reduced costs, and this leads to the profitability of the enterprise.

It is important to note that, despite the gigantic temperature of the electric arc, the part itself heats up slightly and even in the immediate vicinity of the cut point (10 - 20 cm) remains cold, due to which automation of the work process is achieved (the use of a conveyor belt). In addition, this feature eliminates the melting of the workpiece, which is especially important when it comes to precious metals and the latest alloys:

Additional features

As mentioned above, artistic plasma cutting involves the formation of a plasma flow between the work item and the part, however, the latter acts as a component of the electrical circuit, which is not acceptable in all cases of metalworking. Especially for this, a new method was developed, with the help of which the production of plates became a simple and affordable task. In this case, a plasma torch is used, inside which an electric arc is created, breaking out through a special outlet designed to concentrate energy into a thin directed beam of incredible strength. This allows you to achieve the following:

work with non-conductive materials;
effective exposure to a high-speed electric arc.

This method is applied in hand tools, thanks to which artistic cutting of metal with plasma becomes a universal method of processing. Experts say that this technology helps to reduce power consumption and reduce the size of the equipment.

Note that industrial designs use nozzles - elements through which gas is supplied. These components need constant cooling because they directly interact with the plasma flow. For this, a water cooling system is used, which reduces the risk of failure and prolongs the life of the equipment. Thanks to this, plasma cutting, the price of which does not reach exorbitant heights, is the best choice for industry, and modern plate manufacturing - direct evidence this statement.

Profitable proposition

Are you in need of plasma cutting services, but have no idea who to contact for it? The company "TD MEGAMETALL" is ready to take over the solution of this problem! You no longer have to search the Internet for ads like "plasma cutting", because we are ready to offer you an option that you can hardly refuse.

The company "TD MEGAMETALL" is a leading leader in the field of rolled metal products. In our work we use the most advanced equipment, and our staff has the necessary qualifications. This helps us to guarantee our customers the highest quality.

I would like to draw your attention to the fact that for several years now we have been actively cooperating with the best metallurgical plants in Russia and neighboring countries. Due to this, we receive first-hand blanks, which allows us to reduce the final cost of finished products. Of great importance here is the well-functioning logistics system, which allows you to organize any supply of embedded parts and other products. In addition, the company "TD MEGAMETALL" provides you with your own transport for export. As for the advantages that TD MEGAMETALL has, the following should be noted here:

democratic value;
a wide range of products (black / non-ferrous / stainless steel, wire, mesh, corrugated board);
a wide range of services (laser / plasma / band saw cutting, drilling, processing on milling machines, cutting, bending);
prompt delivery;
Individual approach to each client;
personal discounts;
the possibility of deferred payment;
competent assistance of leading experts.

Together with our company, plasma cutting in the city of Moscow will become a simple and feasible task. If you have any questions, you can contact our managers. Additional information about the activities of our company you can find on the official website. "TD MEGAMETALL" is your reliable and trusted partner!

Recently, the use of plasma flow for cutting materials is gaining more and more popularity. The field of use of this technology is further expanded by the appearance on the market of hand-held devices with the help of which plasma cutting of metal is performed.

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 provided by the use of a plasma jet, which is formed using special equipment. The technology for obtaining a high-temperature plasma jet is as follows.

Initially, an electric arc is formed, which is ignited between the electrode of the apparatus and its nozzle, or between the electrode and the metal being cut. The temperature of such an arc is 5000 degrees.
After that, gas is supplied to the nozzle of the equipment, which increases the temperature of the arc already up 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 velocity 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 on the video of such a process.

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

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

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

Plasma cutting machines are successfully used in enterprises various industries industry. With their help, not only metal parts are successfully cut, but also plastic products and natural stone. Thanks to such unique capabilities and its versatility, this equipment is widely used in machine-building and shipbuilding plants, in advertising and repair enterprises, in the public sector. A huge advantage of using such installations is that they allow you to get a very even, thin and precise cut, which is an important requirement in many situations.

Plasma cutting equipment

On the modern market, devices are offered that are used to cut metal using plasma, of two main types:

devices of indirect action - cutting is carried out in a non-contact way;
devices of direct action - cutting by contact method.

The first type of equipment, in which the arc is ignited between the electrode and the torch nozzle, is used for processing non-metal products. These installations are mainly used in various enterprises, you won't find them in a DIY workshop or repairman's garage.

In devices of the second type, an electric arc is ignited between the electrode and the part itself, which, of course, can only be made of metal. Due to the fact that the working gas in such devices is heated and ionized over the entire gap (between the electrode and the workpiece), the plasma jet in them has a higher power. It is such equipment that 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 an air jet of the required speed and pressure.

The main element of all similar devices is a plasma torch, it is he who distinguishes such equipment from conventional welding. Plasmatrons or plasma cutters consist of the following elements:

working nozzle;
electrode;
insulating element, which is characterized by high temperature resistance.

The main purpose of the plasma torch is to convert the energy of the electric arc into thermal energy plasma. The gas or air-gas mixture leaving 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.

Given the fact that the operator has to hold the plasma torch by weight, it can be very difficult to provide high quality cutting of metal. Often, parts for which manual plasma cutting was used have edges with irregularities, traces of influx and jerks. In order to avoid such shortcomings, various devices are used: stands and stops, which make it possible to ensure smooth movement of the plasma torch along the cutting line, as well as the constancy of the gap between the nozzle and the surface of the part being cut.

Air or nitrogen can be used as working and cooling gas when using hand-held equipment. Such an air-gas jet is also used for blowing molten metal from the cut zone. When using air, it is supplied from a compressor, and nitrogen comes from a gas cylinder.

Required Power Supplies

Although all plasma cutter power sources are mains powered alternating current, some of them can convert it to permanent, while others can enhance it. But those devices that operate on direct current have a higher efficiency. Alternating current machines are used for cutting metals with a relatively low melting point, such as aluminum and alloys based on it.

In those cases where too high power of the plasma jet is not required, ordinary inverters can be used as power sources. It is these devices, which are characterized by high efficiency and ensure high stability of the burning of the electric arc, are used to equip small industries and home workshops. Of course, it will not work to cut a metal part of considerable thickness using a plasma torch powered by an inverter, but it is optimally suited for solving many problems. The big advantage of inverters is their compact dimensions, so they can be easily carried with you and used to perform work in hard-to-reach places.

Transformer-type power supplies have higher power, which can be used for both manual and mechanized cutting of metal using a plasma jet. Such equipment is distinguished not only by high power, but also by higher reliability. They are not afraid of power surges, from which other devices can fail.

Any power source has such an important characteristic as the duty cycle (PV). Transformer power supplies have a PV of 100%, which means that they can be used all day long, without a break for cooling and 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 to do in order to start using the machine for plasma cutting of metal is to put together all its constituent elements. After that, the inverter or transformer is connected to the metal workpiece and to the AC mains.

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

Types and methods of cutting with plasma

Plasma cutting is:

superficial;
separating.

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 in this way, the metal being cut is included in the electrical circuit. The arc forms between the torch's tungsten electrode and the workpiece.

plasma jet. The arc occurs in the torch between two electrodes. The product to be cut is not included in the electrical circuit.

Plasma cutting is superior in performance to oxygen cutting. But if a material of great thickness or titanium is being cut, then oxygen cutting should be preferred. Plasma cutting is indispensable for cutting (especially).

Types of gases used for plasma cutting.

Gases are used to form plasma:

active - oxygen, air. Used for 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. Applicable for cutting:

high-alloy steel up to 50 mm thick.

This gas mixture is not recommended for cutting copper, aluminium, and ferrous 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. Applicable for cutting:

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

The nitric mixture is unsuitable for cutting all steels and titanium.

Argon with hydrogen. Used for cutting:

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

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

Plasma cutting equipment: types and brief characteristics.

For the mechanization of 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 cubic meters / hour;
argon - 3 m3/hour;
hydrogen - 1 m3/hour;
nitrogen - 6 m3/hour.

Travel speed - from 0.04 to 4 m / min.
Working gas pressure - up to 0.03 MPa.
The weight of semiautomatic devices is 1.785 - 0.9 kg, depending on the modification.

2. Portable machines use compressed air.

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

For manual cutting two kits are available:

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

Plasma cutting

The device KDP-1 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.

Plasmatron RDP-1 works with nitrogen, argon or mixtures 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 device KDP-2 is inferior to the first one 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 on outdoors at any ambient temperature.

Completeness of manual cutting devices:

cutting plasma torch;
cable-hose package;
collector;
lighter for excitation of the cutting arc.

Sets for manual plasma cutting are produced without a console. Such constructive solution rational for performing a limited amount of work with equipment loading no more than 40 - 50%. But for the time of work they have to be understaffed with welding rectifiers and converters.

At the same time, it should not be forgotten that, from the point of view of safety, for manual cutting, the open circuit voltage of the power source is not more than 180 V.

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

The beginning of the process of cutting metals is the moment of excitation of the plasma arc. Starting cutting, 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 strength and air consumption, the service life of the plasma torch nozzle and electrode decreases. But at the same time, the current level must provide optimal cutting performance.
The most difficult operation is punching holes. The difficulty lies in the possible formation of a double arc and the 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. The screens are placed between the product and the plasma torch.
Nitrogen is used as the plasma gas for manual cutting of high-alloy steels.
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 nitric-hydrogen mixture. At the same time, brass is cut 20% faster than copper.
After cutting, copper must be cleaned to a depth of 1-1.5 mm. For brass, this requirement is not mandatory.

Plasma cutting is a great new technology that allows you to cut metals of solid thickness and any nature, even the most capricious. It is not a knife that acts as a cutting object, but a dense plasma jet, which allows you to form an ideally accurate cut pattern per unit of a given time.

This method of working with metal has many advantages, which we will discuss below. And now let's start with physics - you need to understand the essence of the process.

Plasma metal cutting technology gives the female lead to our beloved electric arc. It is formed between the electrode and the nozzle. Sometimes, instead of an electrode, there is metal that needs to be cut. Let's understand what plasma cutting is.

The beginning of the process is to turn on the electrical power source and apply high frequency current to the plasma torch. The power source turns on automatically after pressing the ignition switch in the device.

First, the so-called intermediate arc is formed - it is temporary and connects the electrode to the tip of the torch nozzle. This pilot arc is heated to a temperature level of about 8000°C.

This is an important point in the overall process of plasma cutting - you need to remember that the real arc between the electrode and the metal is not formed immediately, but through its intermediate version.

The next stage of the process is the intake of air from the compressor, which is usually attached to the metal cutting machine. The compressor delivers compressed air. This air enters the plasma torch chamber, in which a temporary electric arc is already heated.

The arc heats the compressed air, the volume of which increases many times over when heated. In addition to heating and increasing the volume, the air begins to ionize and transform into a real conductor of electric current. It turns into the same plasma

The small diameter of the nozzle makes it possible to accelerate the flow of this incandescent plasma to enormous speeds, with which the jet flies out of the apparatus. The flow rate can reach three meters per second.

Scheme of plasma cutting.

The air temperature is prohibitive, up to 30,000 ° С. Under these conditions, the electrical conductivity of the air-plasma is practically equal to the conductivity of the metal being cut.

A true end arc appears instantly as soon as the plasma flow reaches and touches the metal surface. The temporary arc, in turn, is automatically switched off. The metal begins to melt exactly at the cut point.

Liquid metal droplets are immediately blown away by compressed air. This is the principle of plasma cutting. As you can see, everything is simple, logical and understandable.

Classification of types of plasma cutting

The types of plasma cutting will depend on the environment in which metal work is carried out:

Simple

The main difference of the method is the limited electric arc. Used for cutting electricity and air. Sometimes gas in the form of nitrogen is used instead of air. If the metal sheet is thin - just a few millimeters, the process can be compared to laser cutting.

With this method, the thickness of the metals should not exceed 10 mm. The method works well for low alloy steels and other soft metals. The cutting element is oxygen, from which a compressed jet is formed, which eventually turns into a plasma.

In cuts, very smooth edges are obtained that do not require further refinement.

With shielding gas

In this method, protective gases are used instead of air, which turn into a plasma stream after conversion in a plasma torch. The quality of the cuts in this case is significantly improved due to the excellent protection of the process from environmental influences.

Plasma cutting gas is nothing unusual: it can be hydrogen or argon - "gas classics".

With water instead of air

An excellent method with many advantages, one of which is the absence of the need for an expensive and bulky cooling system.

There are other criteria for classifying plasma cutting. For example, types of cutting are separating and surface. The first one is used more often.

Another parameter is the cutting method. One type is arc cutting, in which the metal being cut acts as an element of an electrical circuit. Another type is jet cutting, when an electric arc connects the electrodes, and not the metal workpiece.

Plasma cutters are available on the market in a wide variety of options, so that they can be classified by brands, manufacturers and many other technical and commercial parameters.

There is, for example, manual plasma cutting - the most affordable way both in terms of price and ease of execution. There are machine automatic technologies, devices for which are much more expensive and more complicated.

Benefits of Plasma Cutting

Working principle of plasma cutting.

The closest technology is laser cutting of metals, so it would be logical to list the advantages in comparison with the "neighbor":

Plasma cutting on the shoulder of metals of any nature, including non-ferrous, refractory and others that are difficult to process.
The speed of the process is much higher than cutting with a gas torch.
One of the significant features is the ability to produce cuts of any shape, including both geometric patterns and figured cutting of the highest complexity. In other words, plasma cutting is the realization of the most daring creative ideas for metal and other difficult materials.
Plasma cutter can handle any metal thickness: speed and quality are not lost in any way.
This method lends itself not only to metals, but also to other materials: it is quite universal.
Plasma cutting is faster and more efficient in edge quality than any other mechanical methods cutting.
In this method, it is possible to work not only perpendicular to the metal surface, but at an angle, which helps to master wide sheets of metal.
From an environmental point of view, this is a completely safe type of metal work with minimal emissions. harmful substances or air pollution.
An excellent time saver due to the absence of the need to preheat the metal.
Since the method does not use explosive gas cylinders, it is significantly safer than other methods.

Disadvantages of a plasma cutter

No metal processing method is without drawbacks, and plasma cutting is no exception.

The disadvantages of plasma cutting are as follows:

The high cost of the entire range of plasma cutting machines, including even the simplest manual options.
Limits of metal thickness for plasma cutting: the maximum thickness is only 100 millimeters.
This is a noisy way of working because the compressed air or gas is delivered at a tremendous speed.
The equipment is not simple, expensive and requires competent and constant Maintenance.

Another distinctive positive characteristic of the method is that only a small local area is heated during the process. Yes, and this area cools down much faster than with laser or mechanical cutting.

Cooling is necessary only for two components - the cathode and the nozzle, as the most loaded. This is done without problems with the help of a working fluid.

Plasma arc and jet.

The arc begins to work stably as a result of the working ratio of the cathode and nozzle with steam from compressed hot air. A negative charge is localized at the cathode, and a positive charge is localized at the nozzle tip. As a result, an intermediate arc is formed.

Excess moisture is absorbed special material, which is located in the tank of the plasma torch chamber.

The safety rules for this method are of the strictest nature, because all plasma cutting machines can be very traumatic for the master. This is especially true for models with manual control.

Everything will be fine if you follow the master's protective equipment recommendations: face shield, tinted goggles, safety boots, etc. In this case, you can protect yourself from the main risk factors of this method - drops of molten metal, high voltage and hot air.

Another safety tip is to never hit the metal with a cutter to remove metal splashes, as some craftsmen do. You run the risk of damaging the apparatus, but the main thing is to catch pieces of molten metal, for example, on the face or other unprotected part of the body. Better save yourself.

Saving consumables is not the last place in efficient cutting. To do this, we ignite the electric arc not too often, but precisely and on time, so as not to break it unnecessarily.

The resource saving also extends to the strength and power of the current. If you calculate it correctly, you will get not only savings, but also an excellent cut without burrs, scale and metal deformation.

To do this, you should work according to the following scheme: first, apply a high power current, make a couple or three cuts with it. If the current strength and power are too high, scale will immediately form on the metal due to significant overheating.

After examining the sections, it will be clear whether to leave the current at this level or change it. In other words, we work experimentally - in small samples.

How to work with a plasma cutter?

Electrical circuit of the plasma generator.

Cutting metals with a plasma stream is too serious a business to do without prior study and thorough preparation. This will help you cut more efficiently from all points of view, and, most importantly, minimize the risks associated with occupational hazards.

First of all, you need to know the principle of plasma cutting - to see the whole picture of physical phenomena.

The plasma torch should be held very close to the surface and edge of the metal, unlike laser cutting. When the “start” toggle switch is turned on, the temporary electric arc will light up first, and only then the real one, which will be the main cutting element. The cutting arc torch must be driven smoothly and slowly over the material.

Cutting speed should be strictly controlled. This can be done by observing the sparks from the back of the sheet of metal being cut. If these sparks are not present, then this means that the cutting of the metal was incomplete.

This can happen for several reasons: due to too high speed of the burner or the passage of the apparatus, or too insufficient power of the supplied current, or non-compliance right angle 90° between torch and metal surface.

The fact is that complete melting of the metal occurs only when the plasma cutter is tilted to the metal surface at a right angle and not a degree more or less.

After the work is completed, the cutter must be tilted. Air will come out even after the device is turned off - for a short time.

Before work, it is not harmful to study the diagram of your device: it is in it that you can read the most reliable information on the permissible thickness of the metal, which can be cut or made a hole in it. The device of a plasma cutter may vary, it all depends on the functions of its purpose.

Choosing a Plasma Cutting Machine

Buying any technical equipment- a business for which you do not need to spare time and effort: the risk of an unsuccessful decision and loss of money is too high. And the money here is a lot, you will not find a plasma cutter cheaper than 500 USD in principle.

First, we deal with the parameters and technical characteristics of the device.

Two large groups of plasma cutters are inverter and transformer. The names speak for themselves.

Open and closed plasma jet.

If you're looking for a compact torch for cutting thin metals, you can opt for an inverter type torch. They take a little energy, light and with small dimensions.

However, they work intermittently and easily fail when the mains voltage drops. The price of such devices is quite moderate, of all plasma cutters, these are the most inexpensive.

Another thing is transformer cutters. Here, both with dimensions and with weight, “everything is in order”: serious devices in all respects.

They consume a lot of energy, but they can work almost without interruption for a whole day. And the thickness of the metal can be larger than when cutting with an inverter model. The cost of such devices is high - from 3000 to 20000 USD.

Choosing a plasma cutter by power

We start our reasoning with the properties and specifications parts that you plan to process and cut. It is precisely this that calculates the power of the cutting device, because it will differ in both the nozzle in its diameter and the type of gas used.

The application of plasma cutting is an extremely wide area, so you need to talk only about your specific needs.

For example, if the thickness of metal blanks is about 30 mm, a cutter with a power of 90A will be enough for you. He can easily handle your material.

But if your metal is thicker, look for a suitable model in the power range from 90 to 170A.

Torch selection by time and material cutting speed

The speed of plasma cutting of metal is measured in centimeters per minute. This speed is also different for different devices and depends on their total power and the nature of the metal being cut.

For example, all other things being equal, steel is cut the slowest, and copper and its alloys are slightly faster. And even faster - aluminum with its aluminum alloys.

Plasma cutting device.

If speed is important to you, do not forget about such an indicator as the duration of work without overheating, that is, without a break. If the technical specification for the device says that the duration of the work is 70%, this means that after seven minutes of cutting, the device must be turned off for three minutes to cool down.

Among the transformer cutters, there are champions with a run time of 100%. In other words, they can work all day long without shutting down. They cost a lot, of course. But if you have long cuts ahead of you, consider buying "champion" transformer plasma cutters.

A few words about the burner

Again, we evaluate the nature of the metal or other material that we plan to cut. The power of the plasma cutter burner will depend on this. It should be sufficient for a quality cut.

When calculating, you need to take into account the fact that you can meet with difficult conditions work, which, unfortunately, must be done in the shortest possible time, that is, cutting must be of a pronounced intensive nature.

We do not lose the burner handle from the zone of attention, this is an important part for comfortable, and therefore high-quality work. Can be attached to the handle additional elements, which will help keep the nozzle at the same distance from the metal surface. This advice only applies to manual models devices.

If you are going to cut thin metal, choose a model with a torch that is designed for air intake.

If your plans are connected with massive thick workpieces, buy a cutter with a torch to receive a protective gas - nitrogen, for example.

It is used in the processing of conductive metals. The processed material receives energy from a current source by means of ionized gas. The standard system includes an ignition circuit and a torch that provide the power, ionization, and control needed for high-quality, high-performance cutting on a variety of metals.

The DC output 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 a plasma state.

The torch holds the consumables—nozzle and electrode—and cools 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 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 drilled hole. An electric arc occurs between the electrode in the burner, to which a negative potential is applied, and the workpiece with a positive potential, and the material is cut by an ionized gas flow under pressure at a temperature of 770 to 1400 °C. A jet of plasma (ionized gas) is concentrated and directed through a nozzle, where it condenses and becomes capable of melting and cutting a wide variety of metals. This is the basic process for both manual and mechanized plasma cutting.

hand 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 perform various tasks. Their capabilities depend on the current strength of the cutting system. Manual cutting settings range from 7-25 A to 30-100 A. Some devices, however, can produce up to 200 amps, but these are not widely used. In manual systems, process air is usually used as the plasma and shield gas. They are designed in such a way that they can be used with various input voltages, which can vary from 120 to 600 V, and can also be used in single or three-phase networks.

Hand held metal cutting plasma is commonly used in metal fabrication workshops. thin materials, factory maintenance services, repair shops, scrap metal collection points, in construction and installation works, in shipbuilding, car repair shops and art workshops. As a rule, it is used to trim the excess. A typical 12 amp plasma machine cuts a maximum of 5 mm of metal at a rate of about 40 mm per minute. The 100 amp device cuts a 70 mm layer at speeds up to 500 mm/min.

As a rule, the manual system is selected depending on the thickness of the material and the desired processing speed. A device that provides high strength current, works faster. However, when cutting with high current, it becomes more difficult to control the quality of the work.

Machine processing

Mechanized metal cutting with plasma is carried out on installations, which, as a rule, are much larger than manual ones, and is used in combination with cutting tables, including those with a water bath or with a platform equipped with various drives and motors. In addition, mechanized systems are equipped with CNC and cutting head jet height control, which can include torch height presetting 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 the platform used. The panel saw can be smaller than 1200x2400 mm and larger than 1400x3600 mm. Such systems are not very mobile, therefore, before installation, all their components, as well as their location, should be considered.

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 the lower range, such as 15 to 50 amps. There are nitrogen cutting systems with currents of 1000 amps and above, but they are rare. The input voltage for mechanized plasma systems is 200-600 V in a three-phase network.

Gas Requirements

Compressed air, oxygen, nitrogen, and a mixture of argon and hydrogen are commonly used to cut mild steel, stainless steel, aluminum, and various exotic materials. Their combinations serve as plasma 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.

Oxygen is used for soft carbon steel because it produces high quality cuts in material up to 70 mm thick. Oxygen can also act as a plasma gas for stainless steel and aluminum, but the result is not entirely accurate. Nitrogen serves as the 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 sheet metal 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 of sheet metal up to 25 mm thick is performed, it leaves an oxidized surface. When cutting with air, nitrogen or oxygen, it is an auxiliary gas.

An argon/hydrogen mixture is typically used on stainless steel and aluminium. Provides a high quality cut and is essential for mechanized cutting of sheets over 75mm thick. Carbon dioxide can also be used as an auxiliary gas when cutting metal with nitrogen plasma, as it allows you to work with most materials and guarantees good quality.

A mixture of nitrogen and hydrogen and methane are also sometimes used in the plasma cutting process.

What else will be required?

The choice of plasma and auxiliary gases are only two of the most important decisions to be taken into account when installing or using a mechanized plasma system. Gas tanks can be purchased or rented and are available at various sizes, and to store them you need to create relevant conditions. Installing the system requires a significant amount of electrical wiring and piping for gas and coolant. In addition to the most mechanized plasma system, you need to pick up a table, a saw, CNC and THC. OEMs typically offer a variety of hardware options to suit any device configuration.

Is mechanization necessary?

Due to the complexity of choosing a mechanized plasma cutting process, a lot of time must be devoted to researching various system configurations and criteria. Consider:

types of parts to be cut;
the number of industrial products in the 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 produced can determine the required production industrial equipment- type of CNC, table and platform. For example, the production of parts small size may require platform specialized drive. The rack and pinion drives, servos, drive amplifiers and sensors used on the platforms determine the quality of the cut and the maximum speed of the system.

Quality and speed also depends on which CNC and gases are used. A mechanized system with adjustable current and gas flow at the beginning and end of the cut will reduce material consumption. In addition, with a CNC with a large amount of memory and a choice of possible settings (for example, the height of the flame 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 buy or upgrade a mechanized plasma cutting system or use a manual one must be a sound one.

Plasma cutting of metal: equipment

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

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

The Powermax45 torch is designed with double angle, which prolongs the life of the nozzle and reduces it. It is equipped with the Conical Flow function, which increases the energy density of the arc, which significantly reduces dross and produces high-quality plasma cutting. Price Powermax45 - $ 1800.

Hobart Airforce 700i

The Hobart AirForce 700i has the highest cutting capacity in the range, with a nominal cutting thickness of 16mm at 224mm/min and a maximum of 22mm. Compared with analogues, the operating current of the device is 30% less. The plasma cutter is suitable for service stations, repair shops and when building small buildings.

The device features a lightweight yet powerful inverter, an ergonomic start fuse, efficient air consumption and low cost consumables torches, thanks to which safe, high-quality and inexpensive plasma cutting is carried out. The AirForce 700i is priced at $1,500.

The kit includes an ergonomic hand torch, cable, 2 replacement tips and 2 electrodes. The 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 Xtreme

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 AC voltage 120-240 V, automatically adjusting to the applied voltage. Lightweight and compact design makes the device highly portable.

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

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

Lotos LTP5000D

Lotos LTP5000D is a portable and compact plasma machine. With a weight of 10.2 kg, there will be no problems with its movement. The 50 amp current generated by the digital converter and the powerful MOSFET provide efficient cutting of 16 mm mild steel and 12 mm stainless steel or aluminium.

The device automatically adjusts to the mains voltage and frequency. Hose length - 2.9 m. The pilot arc does not come into contact with metal, which allows the machine to be used for cutting rusty, raw 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 hit of dust and debris. The price of Lotos LTP5000D is $350.

When buying a plasma cutter, you should always prioritize quality. You should beware of the temptation to buy a cheap low-quality machine, as its rapid wear and tear in the long run will lead to much higher costs. Of course, it’s also not worth overpaying, there are enough worthy budget options without accessories and high powers that may never be needed.

home > healthcare