Plasma cutting is a way of cutting tool instead of using as a cutting tool of the plasma jet.Between the electrode and the nozzle unit or the surface of the cut metal ignites the arc.The nozzle unit in turn is fed under pressure, which is converted into a plasma under the influence of an electric.The plasma is heated to 5 - 30 000 degrees, and the speed of operation is within 500-1 500 meters per second.
- concept of plasma cutting
- Advantages plasma cutting
- The principle of plasma cutting machine
- Selection of plasma cutting machine
- Types of plasma systems
- power unit
- speeds and cutting
- plasma torch
- OutSite apparatus
- Using the machine for plasma cutting
concept of plasma cutting
There are superficial and separating plasma cutting.The widespread practice is found the second method.The very cutting can be done in two ways: a plasma jet or arc.In plasma arc cutting of metal included in the metal being cut circuit.
conventional plasma cutting is carried out in the atmosphere.Cutting the application of additional protection advocates further improvement - with the help of such a medium is limited arc length.When the thickness of the metal sheet in a couple of millimeters, and the use of oxygen as the parallelism of the surfaces treated with the comparable parameter during laser cutting.Preparation of parallel surfaces is possible when cutting sheets which have a thickness up to 10 millimeters.
in plasma cutting low alloy and mild steel is preferable to use as a cutting gas oxygen.The molten iron is different reduced viscosity, so the liquefied material from the slot easily removed.As a result, the edges are formed with almost no burrs.Another advantage is the reduced use of oxygen content in the treated edges of nitrogen.
as cutting nitrogen dioxide is sometimes used.At the same time cutting the same thickness of the sheet requires less force of electric and spend less thermal stress on the electrodes, which service life is substantially increased.If you do not reduce the load, it is possible to increase the nitrogen content of the edge, which affects when performing further work.Sometimes as cheaper gas air is used, but it reduces the life of the nozzle and electrode, and increases the content of nitrogen in the chopped edges compared with oxygen.
Advantages plasma cutting
With plasma cutting equipment you can handle almost any metals - ferrous and non-ferrous and refractory metals.Through the plasma cutting process metals can several times faster flame cutting.Plasma cutting technology produces billets without any restrictions on the geometric form.Chance of a complex process and shape cutting.
Such technology allows to cut metal quickly and accurately, and the procedure is effective when working with metal of different thickness - close to 0.5 - 50 mm.Methods of plasma cutting, unlike the oxygen cutting technology allows to cut ferrous materials and materials that do not contain iron.The application of plasma technology for cutting metal, non-ferrous, is more fast, safe and effective alternative to mechanical cutting.
Plasma cutting of metal on the technical characteristics and the cutting speed is particularly efficient for straight cuts, for example, for cutting and stripping edges of the sheets for processing profiles.Important advantages in comparison with the laser cutting is possible to process a wide sheets of metal sheet cutting angle for future welding and receiving parts with small defects on the surface of scale and dirt.
in plasma cutting to receive much lower cost per meter length of metal.Therefore, this technique has recently received widespread in major industries.When using the optional plasma cutting medium may be applied in air or even under water.It is the water that falls between the nozzle and the plasma acts as an additional medium for cutting aluminum and alloyed steel, low-alloy processing and soft steels.
The principle of plasma cutting machine
device for plasma cutting is intended for the high local heating of the plasma jet surfaces of materials that are thin, during the heat treatment.Application of the device for plasma cutting - cutting electrically conductive and non-conductive material, soldering and welding of high temperature solder, surface heat treatment (hardening, annealing of local, scarfing), welding of black and nonferrous metals and other works that are associated with a high local heating.
implemented in the plasma torch technology for production of water vapor plasma.The principle of plasma cutting can be broadly described as follows: in a narrow channel of the nozzle ignited electric arc through this channel is blown steam rapidly cooling the arc.The water vapor thus ionized and thereby creating a plasma jet, which has a temperature of about 6000 degrees.
During plasma cutting does not heat the vast areas of metal.The material that is cut plasma torch capable cool much faster than the metal that is cut oxygen cutting.The function of the working fluid vapor is reduced to cool the busiest parts of the burner - the cathode and nozzle, the stabilization of the discharge column and blowing from the nozzle of the arc.The system operates by supplying vapor "open circuit": gravity from the tank vapor enters the cooling channels to the discharge chamber and is discharged through the nozzle into the atmosphere.Stabilization
arc center axis relative to the nozzle and the nozzle provided soosnosheniem cathode of special design and a spiral flow of steam by means of a tangential flow into the chamber.The reserve tank positioned burners working fluid.The tank gun is capillary-porous liquid-absorbing material which serves to transport the working fluid to the heater surface by capillary effect.Power supply to the cathode has a negative potential and a positive nozzle.
Choice plasma cutting machine
If you decide to buy such equipment to get started is to carefully analyze some parameters that will influence the quality of plasma cutting machine.There are options that are fundamentally important for the cutter is - more that in your working conditions are simply not needed.
Forms plasma systems
plasma cutting devices are divided into two types: inverter and transformer.
The advantages of inverter plasma cutting machines include parameters such as compactness, low energy consumption, attractive design and low weight.Disadvantages rank low duty cycle especially at high current and the maximum power limit - no more than 70 amps.But the main drawback appears that the inverter plazmorezy are very sensitive to voltage drops.
The advantages transformer plasma systems include high continued on and significant reliability.In addition, when the voltage breakdown device does not occur, only reduced its capacity.Settings enable the continuation of more than 70% can be used for automatic cutting, where the duration of continuous operation of the plasma torch is much more than manual cutting.The disadvantages are size and weight, which is considerably larger than the plasma inverters, as well as higher power consumption.
Pick up the rated power unit is necessary depending on the thickness and type of metal being cut.The thickness of the metal determines the type of gas flow (nitrogen, air), and the nozzle diameter.Determine what you will cut metal, and check the power of your hardware.For example, an apparatus which has an input power of 60 or 90 amps, capable of cutting metal which is different in thickness to 30 millimeters.
device of this type is intended for use in various industries, for work in the automotive repair and home workshops.If you want to cut thick metal, then you should choose the device with a rated capacity of 90 or 170 amps, as in the photo plasma cutting on our site.Using this unit, you will be able to cut metal which has a thickness of 50 millimeters.
Always worth checking the primary voltage and amperage that is required for the power supply.Also it is necessary to determine whether you need a universal device that is able to work with different current and voltage.Some phones can only work with a voltage of 380 V or 220 V, single-phase or three-phase current supply.In some foreign-made devices provides the function Auto-Line, which allows you to connect any equipment to the power grid.
speeds and cutting
Before buying a machine welding cutting is necessary to check the speed of the cutting equipment.Typically the indicator is measured in centimeters per minute.Some devices can cut the metal which has a thickness of 30 millimeters, for 5 minutes, the other - one minute.Cutting speed is a very important feature, especially when you need to reduce the cost of time.
When buying a plasma cutting machine to pay attention to the duration of his work - the time during which the machine can operate without overheating.If the running time is 60%, the machine can operate without interruption 6 minutes and 4 minutes he needs to cool.Very important for the long duration, the length of the cuts or operation at elevated temperature.
running time is indicated, usually for maximum power unit.If you use equipment with lower power, the duration of his work will increase accordingly.The temperature of the environment where the unit is operated plasma cutting, also affects this indicator.
Select plasmatron necessary depending on the characteristics of products or materials which you are cutting.The plasma torch must always have sufficient capacity to ensure high-quality cutting in difficult conditions and be resistant to shocks during intensive use.You can use various design plasma torches.
Plasmatrons copper nozzle are more robust than a ceramic nozzle apparatuses, practically unbreakable, are air-cooled.Handles can be equipped with additional elements that are attached to the plasma torch tips and maintained at a desired distance from the working surface - 1,6-3 mm.Watch a video on the plasma cutting - it greatly facilitates the work of the operator.
length of the additional element, that is, the distance between the plasma torch and the work surface depends on the current strength and the necessary thickness of the metal being cut.When using small currents can touch the nozzle to the metal surface.When using high current (more than 60 amps) the distance between the metal surface and the plasma torch must be at least 1,6-4,5 mm.
When selecting a plasma torch is recommended to determine for what purpose it would serve, because there may be different design solutions.If the burner is used only within a small current and cut extremely thin sheet metal, the shielding gas to cool the plasma torch is not required and the burner is supplied only air that is required for cutting.If you use a plasmatron for cutting thick sheet metal, the more current is needed, and preferably in the plasma torch feed nitrogen rather than air.
apparatus for plasma cutting requires compressed air and other components - electrodes for cutting and tip.Damaged and worn parts affect the cutting quality.The low level of operator skill, high humidity, the process of cutting a metal plate with an intensive regime accelerated wear of the component parts.Watch the video of manual plasma cutting - best quality cutting can only be achieved by simultaneously replacing the electrode and nozzle.
If you need a portable unit, very important factors in favor of its size and weight.You can buy a small portable unit that weighs less than 40 kilograms.Also on sale are powerful machines that weigh more, they are stationary cutting stations and are able to carry out high quality cutting of metals that are different thicknesses up to 50 millimeters.
Using the machine for plasma cutting
manual plasma cutting metal with the help of special equipment can even take a man with no experience in welding.With plasma cutting machine for domestic purposes, you can make cuts metal and other materials - plastic, wood, ceramic tiles.But sometimes I can not afford to buy ready-made unit because its value, and so the price is too high for plasma cutting.In this case, you can make your own plasma cutter, buying a power supply and a nozzle.
plasma cutter by their own hands, not inferior to the power of the factory.As the working material for the plasma apparatus using a homemade air.For cooling liquid applied system: the cavity of the anode made to fill antifreeze or plain water.Arc in the nozzle can be obtained using a tungsten rod, for the manufacture of electrodes which take piece.The remaining parts are sold in stores as accessories.It remains only to bring them together.
working with plasma cutting machine, it is necessary to strictly adhere to safety rules, because when this work is a large number of factors that pose a risk to human temperature, high voltage, the molten metal and ultraviolet radiation.It is recommended to wear a welder and have a hand welding shield with tinted windows.
Before starting the process of plasma cutting with their hands should be inspected shield electrode and the nozzle!You can not start a job, if the electrode or nozzle insufficiently secured.It is not advisable to knock the plasma torch to remove spatter, because you can damage it.To save the materials you need to avoid breakage and frequent ignition of the plasma arc.
In preparation for the plasma cutting machine it is supplied with compressed air.You can select one of three sources of compressed air: the connection to the compressed air system, which has at the factory compressed air cylinder or air compressor.The lion's share of devices have control, which is required for the supply and distribution of air in the system.
when calculating certain current and cutting speed is recommended to perform several test cuts with high currents.If necessary, depending on the cutting speed, you can reduce the current.If it is too high or cutting speed appears small, cut metal will overheat and scale can occur.Correctly identifying the current and the cutting speed, you can get a clean cut, which almost does not occur slag and metal being cut is not deformed.
plasma cutting sheet metal is customary to begin by placing the torch close to the edge of the cut metal.Then you need to press the torch switch, then ignite the arc on duty, and then cutting the arc.After cutting arc ignited, the burner must inching along a desired cutting line.