Cutting thick metal with a gas torch
Gas cutting equipment
So, in Russia, since the times of the USSR, the P1-01 cutter was considered the most common. It is manual with an injection nozzle, which gives a high pressure jet, which cuts metal “like a hot knife of oil.”.
powerful models are P2-01 and P3-01P. Their main difference is the size of the nozzle, the operating pressure of oxygen in the system, and the operating pressure of the heating mixture supply.
There are also stand-alone tables. these are gas equipment for cutting metal in automatic mode, which is produced without the participation of an operator.
The control of such a table is numerical-programmed. That is, a person simply sets the cutting parameters.
Such oxygen cutting equipment is used exclusively on sheet metal, where either straight cutting or arc cutting is performed.
It is worth noting that there are a huge number of models of these tables, but almost all of them are analogues of the AN-01, which was developed by Shepelev back in the USSR.!
Oxygen cutter schematic
These, for example, are “Change”, “Orbit”, “Secator”, “Quicky-E”. All of them have an operating temperature in the range of 1000-3200 degrees Celsius. Works with both acetylene and propane heaters.
The Quicky models also use mixed-acetylene-propane heating. In this case, only a split nozzle is used. That is, acetylene is supplied to one of them, propane is supplied to the second.
By the way, it is worth noting that in such cutting, the heating mixture lends itself from the center (that is, from the oxygen jet).
Also, the so-called stationary torches for gas cutting of metal are also noted.
Cutting 2 inch plate
They differ from the mobile one, it is not difficult to guess, in that they are built into a special niche-machine, which can be moved by the operator of the device.
These cutters are more convenient to work with, but are very expensive. But their cutting power is more than enough to cut a thick layer of high-strength metal!
This became possible due to the fact that in such cutters an additional blower is used, with the help of which both the heater and the oxygen stream are supplied under even greater pressure.
An additional compressor is powered by electricity, moreover. three-phase (380 volts). Because of this, it cannot be mobile! This cutter is used exclusively in professional enterprises.
Portable cutter. Gugark
Gugark is the most popular representative of such cutters.
By the way, a gas torch for cutting metal also comes in two types. the so-called straight and bent:
- The first is the one you are all used to seeing. Represents the letter G and works with the help of the operator direction.
- Well, the second, direct, is a nozzle-type burner, which is used on cutting tables.
It is also worth noting that straight nozzles use twin tips to ensure that the nozzle angle is not disturbed one-to-one when moving.
By the way, keep in mind that each of the cutters has its own coefficient of work and power with each metal.
For example, when using the standard P1-01, to cut copper, a coefficient of 0.5 acetylene is sufficient, but for aluminum, as much as 0.7 is required.
Most of all, of course, will go to tungsten. as much as 1.4! In this case, the heating will be in the region of 3800 degrees Celsius (use only specialized tips)!
Gas cutting technology
The modern technology of gas cutting of metal is somewhat different from the one described above. For example, to work with “light metals” temperatures of 1000 degrees Celsius and above can simply destroy the metal you are working with (melt and vaporize).
In these cases, the cutting itself is performed with simultaneous heating. Torch tip is pyramid shaped with 3 nozzles.
A heating mixture is supplied through two side ones, and a thin nozzle is mounted in the center for supplying oxygen under high pressure.
Oxy-fuel cutting technology
In modern cutters, oxygen is supplied under a pressure of 12 atmospheres! Simply put. even the skin can be damaged under a stream of air (meaning an unlit stream).
The flux that forms during such cutting is either thrown out by the heating flame to the sides, or is burned directly through the entire metal (if through cutting is performed).
Don’t forget that gas cutting metal has a big advantage over electric cutting. What?
No “torn” seam is created. And if you additionally use overlays (stencils, as professional welders call them), then the cutting seam turns out to be very neat!
But keep in mind that cutting metal with oxygen does not involve using metals that melt below 600 degrees Celsius. In this case, a simple removal of the top layer of metal will be performed, rather than cutting it.
In such cases, it is recommended to use the so-called mobile heaters. ordinary cans with compressed gas and a nozzle at the end of the tube.
Standard oxyfuel cutting technology uses a pilot controlled torch. The gas supply is regulated by means of two valves (in some models. one common).
The handle of the cutter itself has two tubes, which are just built into the handle. The first handle supplies fuel for the heater, the second (usually the central one) supplies oxygen. That is, as many as 3 tubes are supplied to the main nozzle!
Through two, propane is supplied, through the third, oxygen. Older cutter models used two tips that worked in a similar way.
What is the gas consumption when cutting metal? It depends on the temperature to which the metal itself is heated during operation.
In a standard R1-01 cutter, an average of 10 cubic meters of oxygen and 0.7 cubic meters of acetylene are consumed in one hour of operation (when using propane, 1 cubic meter of fuel).
But in the P2-01 cutter the consumption is much higher. 21 m3 of oxygen and 1.2. of acetylene! The heater consumption depends on the heating temperature and the plane that is cut.
In “older” cutters, the so-called nozzle direction is also used, which also partially affects the flow rate (the closer to the oxygen stream, the larger the jet has to be supplied).
Gas (oxygen) metal cutting
So [flame cutting] is the most popular right now. Why?
Because it is extremely simple to perform, you do not need to use any phase inverters (as in an electric cutter), you do not have to comply with the mandatory room standards (presence of a central grounding cable).
And almost all torches are mobile, that is, they can be transported by regular transport.
When cutting, a gas torch uses two gases. directly oxygen, with the help of which the metal separation process is carried out, as well as a heater, which is most often propane or acetylene.
The heater heats the surface to be cut to a temperature of 1000-1200 degrees, after which a stream of oxygen is supplied. On contact with a heated surface, the jet ignites.
Photo of gas cutting
It turns out. a burning jet that easily cuts the metal. At the same time, the most important thing is to observe a continuous supply of oxygen.
If there is an interruption, the flame can simply go out, after which the surface will have to be heated again.
Standard oxygen cutting of metal is performed using the R1-01P torch. It is best suited for working with hardened steel, including cast iron!
This torch is not used as a welding machine.
But it is suitable for precise cutting of the pipe. for this, a special articulated pad RF7 is used, which is made of steel, but covered with a layer of tungsten.
By the way, lately [gas welding] and metal cutting is carried out by combining acetylene and propane. But such equipment is used exclusively for working with high-strength metals (for example, steel for copulating knives).
The equipment that supports this gas is not cheap! So we won’t talk about him especially.
Services popular on the market
If you need to cut metal, then the easiest way is to hire a craftsman or specialist who will provide you with the services you need. After all, not every house in the garage has a cutter with two oxygen cylinders and a heater.
over, it is very dangerous to work with such equipment without experience! If you do not know how, then it is better not to take up this business. entrust the work to professionals!
Well, on average, the price of gas cutting of metal consists of the following indicators: the metal that will need to be worked with, the cutter used, the thickness of the metal, the quality and type of cut.
For example, conventional sheet cutting is the cheapest. Pipe cutting. it is much more expensive, since additional linings are used during such work!
But cutting in depth is an expensive pleasure, since it uses expensive equipment.
over, if such work is performed “on the road”, it will be very expensive. Cars that can transport cutting stations need to be additionally refitted.
Oxygen cutting of metal.
Well, gas cutting of sheet metal can be performed even with an ordinary gas soldering iron. If you are using aluminum or copper, then it should be enough for this job.
In some cases, you can use gas welding. But instead of carbon dioxide, propane, acetylene or butylene is supplied (not every gas welding supports the use of such gas, be careful)!
By the way, if you need to do not cutting, but cutting, then in some cases it will be much easier and cheaper to use a knife for cutting metal, and not a gas cutter. In more detail about this, you can find out directly from the master, whom you would like to entrust the performance of the work.
Now many enterprises offer on-site gas cutting of metal.
Here it is, assessed by the following parameters:
- the metal with which you will need to work;
- the complexity of the work;
- used cutter.
By the way, it is recommended to buy gas cylinders yourself! Many companies sell it at too high a cost (about 1000 rubles for a cylinder of acetylene, although its market value).
It also takes into account how long the work will take. On average, an hour of work of the master is paid at about 300 rubles. Here you can calculate in advance how much metal cutting services will cost you!
And finally, we should talk about those cases when poor-quality work is performed. Very often, many people use instead of acetylene. its cheap analogue is propane or propylene. Or they use cheaper cutters than they themselves announced.
For example, instead of P2-01, P1-01 or the like is used. This, by the way, is the most common problem! You can distinguish these two cutters from each other by visual inspection.
The P1-01 model has a double nozzle with a gold mount (golden color), while the P2-01 model has a steel mount (it has a black or copper tint).
By the way, the P1-01 cutter is not so expensive, so you can even get it! Average per piece. Well, of course, you will need to purchase two cylinders. with oxygen and a heater, and a transport cart.
On average, the whole set will cost you 3000 rubles, not more. It will be enough for 3 hours of metal cutting. than enough for home needs.
And when working with a gas torch, be sure to follow the safety rules! And this is the use of a protective mask, overalls and gloves. Gloves are a must!
Pros and cons
Gas cutting and metal welding has many advantages, but we are only interested in cutting, which has the following advantages:
- It is in demand when a thick metal is cut or a stencil cut is needed, and the grinder cannot cope with curved sections.
- The gas analogue is much more convenient for work, has a low weight, acts twice as fast as equipment with a gasoline engine.
- Propane is cheaper than acetylene and gasoline, so its use is more cost-effective.
- The cut edge is much narrower, and the structure is cleaner than from a grinder or gasoline equipment.
Disadvantages. a narrow range of metals subject to similar processing.
How much gas is consumed
Gas consumption when cutting metal with a propane-oxygen cutter depends on the thickness of the structure and the configuration of the cut. For clarity, we present the table below:
|Workpiece size (thickness), mm||Time per hole, sec||Cut size (width), mm||Consumption, per m 3 cut|
Gas consumption is significantly reduced when surfacing or brazing is performed.
How to set up a torch for cutting metal. first of all, you need to make sure that the product is in good condition, ready for work, then the following procedure is performed:
- The hoses from the cylinders are connected to the cutter by pre-blowing the product to remove foreign inclusions from the inside.
- Oxygen is connected to the right hand thread and propane to the left hand thread.
- Set the propane supply level to 0.5, and oxygen supply to 5.0 atmospheres.
- We check connections for leaks, as well as the operation of reducers and pressure gauges.
If gas leaks are found, then the nuts are tightened or the gaskets are changed.
The diagram shows the correct connection of the cylinders to the cutter.
They are similar to safety precautions for welding, but have specific additions:
- It is not recommended to neglect protective equipment, since this leads to injuries in the form of skin burns or damage to the cornea of the eyes by flying sparks, therefore glasses and gloves with long sockets to the elbow are required.
- The performer’s clothes and footwear are made of non-combustible material.
- Gas cylinders are located at least five meters from the cutting site.
- The torch flame is directed only in the opposite direction from the hoses.
- Cutting is carried out in rooms equipped with strong ventilation or in open areas.
If the equipment is idle for a long time, it is necessary to carry out preventive work before using the torch for its intended purpose.
Users, of course, are interested in such a question. how to use the cutter during shape cutting. This technique is performed by the nozzle of the tool, while the molten slag heats the metal, but without exceeding the melting temperature. The cutter is located at an angle of up to 80 degrees, and after the supply of oxygen, the angle changes in the range of 18-45 0.
The grooves are formed when adjusting the cutting speed, if you need a larger size, then change the angle of the nozzle and slightly slow down the cutting speed by adjusting the oxygen supply. The width of the grooves is changed by adjusting the flow of a stream of burning gas through the nozzle, this parameter is equal to 1 to 6, while it is necessary to ensure that there are no inflows.
[stextbox notch edges were clean, oxygen supply should be increased. [/ stextbox]
Danger of kickback
If the jet burns incorrectly, cotton occurs and the flame is drawn into the inside of the product, which leads to an explosion, since the fire spreads through the hoses and reaches the containers with gases. To prevent a hazardous situation, the torch is equipped with a non-return valve to isolate the flame and prevent it from spreading.
The equipment is classified as explosive, so the work site must be equipped with the following accessories:
- fire extinguisher;
- sand box;
- fire stand with appropriate tools.
Each performer must have a set of protective clothing.
It is not allowed to wear under the protection of clothing made of easily flammable material, for example, from synthetics, and the edges of the sleeves should tightly fit the body so that sparks do not get inside.
To cut metal with gas, you must have one cylinder of propane and one oxygen, high pressure hoses (oxygen), the cutter itself and the mouthpiece of the required size. Each cylinder must be equipped with a reducer to regulate the gas supply. Please note that the thread on the propane cylinder is reverse, so it is impossible to screw another reducer onto it.
The design of gas equipment for cutting metal from different manufacturers differs slightly. Usually all of them have 3 valves: the first one is for supplying propane, followed by a regulating oxygen valve, and after it is a cutting oxygen valve. Most often, oxygen valves are blue, the same that open propane, red or yellow.
The metal is cut using a jet of hot flame that is generated by the cutter. During the operation of the apparatus in a special mixing chamber, propane combines with oxygen, forming a combustible mixture.
The propane cutter can cut metal up to 300 mm thick. Many parts of this device are replaceable, so the device, in the event of a breakdown, can be quickly repaired right at the workplace.
It is very important to choose the right mouthpiece. When choosing it, one should proceed from the thickness of the metal. If the object to be cut consists of parts of different thickness, which varies from 6 to 300 mm, you will need several mouthpieces with internal numbers from 1 to 2 and external numbers from 1 to 5.
Nuances of metal cutting
Flow diagram of the separation oxy-fuel cutting process.
You need to cut the metal at the right speed. You can determine the optimal speed visually by how the sparks fly away. A stream of sparks at the correct speed flies out at an angle of approximately 88-90 ° to the cut surface. If the sparks are flying in the opposite direction of the torch, the cutting speed is too slow. If the angle of flow of sparks is less than 85 °, this signals an overspeed.
When working, it is always necessary to be guided by how thick the metal is. If over 60 mm, it is better to arrange the sheets at an angle to ensure the drainage of slags, and do the job as accurately as possible.
Cutting thick metal has its own characteristics. You cannot move the torch before the metal has been cut to full thickness. By the end of the cutting process, it is necessary to smoothly reduce the advance speed and make the cutter tilt angle more by 10-15 °. It is not recommended to stop during the cutting process. If work is interrupted for any reason, do not continue cutting from the point at which you stopped. It is necessary to start cutting again and only in a new place.
After finishing cutting, first shut off the cutting oxygen, then turn off the regulating oxygen, last turn off the propane.
How to properly cut metal with an Oxy-propane cutter?
Compared to gas welding, gas cutting requires much less skill from a person. Therefore, mastering a gas torch is not that difficult. It is enough to understand how to do it correctly. The most widespread in our time are propane cutters. They use propane and oxygen together, since their mixture gives the highest combustion temperature.
The propane cutter is designed for manual separation oxyfuel cutting of carbon and low-alloy steels using propane.
Preparation for work
Insert cutter diagram.
Before starting work, it is imperative to inspect the device to make sure that the torch is fully functional. Then follow these steps:
- The first step is to connect the hoses to the cutting machine. Before attaching the hose, you need to purge it with gas to remove any debris or dirt that has got there. The oxygen hose is attached to the right-hand thread with a nipple and nut, the second (for propane) hose to the left-hand thread. Remember to check the torch passages for leaks before attaching the gas hose. To do this, connect the oxygen hose to the oxygen connection, and the gas connection must remain free. Set the oxygen supply to 5 atmospheres and open the gas and oxygen valves. Feel the free fitting with your finger to see if air is leaking. If not, clean the injector and blow out the torch passages.
- Next, check the detachable connections for leaks. If you find a leak, tighten the nuts or change the seals.
- Do not forget to check how tight the mountings of the gas reducers are and whether the pressure gauges are in good working order.
Advantages and disadvantages
The advantages of cutting metal with propane over other methods are obvious:
Assembly diagram of a hand torch for cutting steel.
- Gas cutting is used when you need to cut a rather thick metal or cut something according to templates, when a curvilinear cut is required, which simply cannot be done with the same grinder. A gas cutter is indispensable if you need to cut a disc from thick metal or punch a blind hole 20-50 mm.
- Light weight and ease of use of the torch is another indisputable advantage. Those who have worked with gasoline counterparts know how heavy, clumsy and noisy they are, vibrate strongly, forcing the operator to make significant efforts during work. Gas models are devoid of all these disadvantages.
- In addition, cutting metal with gas allows you to work 2 times faster than when using a device with a gasoline engine.
- Propane is much cheaper not only than gasoline, but also other gases. Therefore, it is beneficial to use it for large volumes of work, for example, when cutting steel for scrap.
- Propane cut edges are slightly worse than acetylene cutters. Nevertheless, the cut is much cleaner than that of gasoline burners or a grinder.
The only drawback of gas cutters (including propane ones) can be considered the limited range of metals that can be cut with their help. They can only handle low and medium carbon steels, as well as ductile iron.
Oxygen-propane soldering and welding plant.
It is impossible to cut high-carbon steels with gas, because their melting point is quite close to the flame temperature. As a result, the dross is not ejected in the form of a pillar of sparks from the back of the sheet, but is mixed with molten metal along the edges of the cut. This prevents oxygen from reaching deep into the metal to burn through. When cutting cast iron, the process is interfered with by the shape of the grains and the graphite between them. (An exception is ductile iron). Aluminum, copper and their alloys are also not amenable to flame cutting.
It should be recalled that grades from 08 to 20G belong to low-carbon steels, grades from 30 to 50G2 belong to medium-carbon steels. In the designations of grades of carbon steels, the letter U is always put in front.
Surface and shape cutting
Surface oxygen cutting scheme.
Sometimes it becomes necessary to cut through the metal not through and through, but only to create a relief on the surface by cutting grooves on the sheet. With this method of cutting, the metal will be heated not only by the flame of the torch. The molten slag will also serve as a heat source. Spreading, it will heat the lower layers of metal.
Surface cutting, like conventional cutting, begins with the desired area warming up to the ignition temperature. By turning on the cutting oxygen, you will create a metal burning center, and by moving the torch evenly, you will ensure the stripping process along the specified cut line. In this case, the cutter must be positioned at an angle of 70-80 ° to the sheet. When supplying cutting oxygen, you need to tilt the torch, creating an angle of 17-45 °.
Adjust the dimensions of the groove (its depth and width) with the cutting speed: increasing the speed, decreasing the size of the groove and vice versa. The depth of the cut will increase if the angle of inclination of the mouthpiece increases, if the cutting speed decreases and the oxygen pressure increases (of course, the cutting). The width of the groove is controlled by the diameter of the cutting oxygen jet. Remember that the depth of the groove should be about 6 times less than its width, otherwise sunsets will appear on the surface.
how to cut with a torch. oxygen acetylene welding cutting torch
You can cut a figured hole in the metal as follows. First, we outline a contour on the sheet (when marking a circle or flanges, the center of the circle should also be noted). Hole punching should be done prior to cutting. It is always necessary to start cutting from a straight line, this will help to get a clean cut on the curves. You can start cutting the rectangle anywhere except at the corners. Last but not least, the outer contour should be cut. This will help to cut the part with the smallest deviations from the intended contours.
We set 5 atmospheres on the oxygen reducer, and 0.5 on the gas reducer. (Typically a gas to oxygen ratio of 1:10.) All torch valves should be closed.
To work with a cutter, set 5 atmospheres on the gearbox, and 0.5 atmospheres on the gas.
Take the cutter, first open the propane a little (by a quarter or a little more), set it on fire. We rest the nozzle of the cutter against the metal (at an angle) and slowly open the regulating oxygen (do not confuse it with the cutting one). We adjust these valves one by one to achieve the flame strength we need. When adjusting, we open alternately gas, oxygen, gas, oxygen. The strength (or length) of the flame is selected with the calculation of the thickness of the metal. The thicker the sheet, the stronger the flame and the higher the oxygen consumption with propane. When the flame is adjusted (it turns blue and crown), metal can be cut.
The nozzle is brought to the edge of the metal, it is kept 5 mm from the object being cut at an angle of 90 °. If a sheet or product needs to be cut in the middle, the metal should be heated up from the point from which the cut will go. We heat the upper edge up to 1000-1300 °, depending on the metal (up to the temperature of its ignition). Visually, it looks as if the surface has started to “get wet” a little. In terms of time, warming up takes literally a few seconds (up to 10). When the metal ignites, open the cutting oxygen valve, and a powerful narrowly directed jet is applied to the sheet.
🔥 Tips for Oxy-Fuel Cutting Thick Steel
The valve of the torch should be opened very slowly, then the oxygen will ignite from the heated metal on its own, which will avoid a blowback of the flame, accompanied by a pop. We slowly move the oxygen stream along a predetermined line. In this case, it is very important to choose the right angle of inclination. It should be at first 90 °, then have a slight deviation of 5-6 ° in the direction opposite to the cutting direction. However, if the thickness of the metal exceeds 95 mm, a deviation of 7-10 ° can be allowed. When the metal has already been cut by 15-20 mm, it is necessary to change the angle of inclination by 20-30 °.
Conditions for the performance of work
For successful work, it is necessary to achieve a higher melting point than the ignition temperature. Low-carbon alloys, which melt at 1500 ° C, and are capable of igniting at 1300 ° C, perfectly meet this requirement. Steel with medium and high carbon will be less cut by gas because a high percentage of carbon contributes to a lower melting point and an increase in the degree of ignition.
The next requirement is the presence of not very high thermal conductivity. Otherwise, heated slag is actively separated and the operation becomes unstable, which can contribute to the termination of cutting. Optimum thermal conductivity is observed for steel and iron. Gas cutting of metal with propane of other metals is basically impossible.
It is also necessary to comply with the following conditions for cutting:
- Oxygen (gas) jet burns a certain volume of metal. In this case, a constant release of such an amount of heat is necessary, which will be sufficient for continuous operation. Only 30% of the heat energy is generated by the torch flame, the remaining 70% is generated by the combustion of metals.
- High level of fluidity of the resulting slag. This is required for easy slag blowing out of the working area.
Cutting metal with a gas cutter is accompanied by the use of a number of additional and basic components. In general, the equipment consists of:
- Reducer. required to lower the pressure to the required values. Has 2 pressure gauges for monitoring input and output data.
- Gas and oxygen cylinder.
- Connecting hoses. Hose length should not be more than 30 meters.
The reducer is necessary to regulate the pressure and maintain it in automatic mode at the set values. It can consist of 1 or 2 cameras. In the case of two cameras, the device has increased reliability.
Steel cylinders have a volume of 0.4 to 55 dm3. They have a shut-off valve, which can be of various configurations, depending on the type of gas used.
Varieties of gas cutting
Flame cutting of metal can be classified according to several criteria, based on the type of gas used and a number of other nuances. Each method best solves certain problems. For example, with a possible connection to the electrical network, it is possible to use oxygen-electric arc cutting; when processing low-carbon steel, it is advisable to use a propane-based gas-air mixture. The most common are:
- Propane is the most popular way to work. There are a number of specific limitations. The technique is applicable to titanium alloy, low carbon and low alloy steels. In the presence of carbon, alloying component more than 1%, other methods should be used. Cutting and welding by this method may involve the use of other gas mixtures with methane, acetylene and other.
- Air arc. Quite an effective way of cutting metal parts. The product is exposed to an electric arc, and the residual elements are removed by air jets. Oxygen electric cutting involves the supply of a gas mixture along the electrode. The disadvantages of the method include a rather shallow cut, but its width can be almost unlimited.
- Oxygen-flux. It differs in that additional components. fluxes. are supplied to the working area. This is often a powdery material. Thanks to them, the best pliability of the metal is formed during the cutting process. The technology is good for cutting alloys in which a hard-melting oxide is formed: cast iron, alloy steel, aluminum, copper and its alloys.
- Spear. Oxygen lance cutting is used when separating large volumes of steel. The main feature is a significant increase in the speed of work. This technology of gas cutting of metal forms an energy-intensive jet, which reduces the consumption of lances from steel. The increased speed of work is also achieved due to the complete and rapid combustion of the metal.
Due to the thermal effect on the workpiece, the deformation process will be quite natural and difficult to avoid. When heated, the shape may change. As a result, you can get an inverted and concave cut out part.
Deformation processes are facilitated by:
- Conducting uneven heating;
- Rapid movement of the torch;
- High cooling rate at the end of work.
In the process of work, it is necessary to exclude the influence of these factors as much as possible. Otherwise, you will need to fix the behavior of the stub. There are a number of methods for eliminating or eliminating defects:
- Vacation or firing;
- Correction of sheet products on the rollers;
- Secure fastening before starting work;
- Observance of the correct sequence of actions in accordance with the thickness and type of metal.
Without proper experience in performing this operation, it is recommended to start with small parts, and not immediately with massive products.
Flame cutting technology
Oxygen gas cutting of metal involves heating the part to about 1100 ° C. After that, an oxygen stream is supplied to the working area, in contact with the heated surface and subsequently igniting. The burning stream cuts the metal part with ease. This requires a constant and stable flow of the gas mixture.
The metal must have a lower combustion temperature than the melting temperature. Otherwise, it will be difficult to remove the molten, not burnt mass from the surface.
Based on this, oxy-fuel cutting of metal is carried out due to the combustion of the gas mixture. The main element of the equipment is the gas cutter, which provides regulation and formation of the gas-air mixture. This tool ignites and moves the jet in the working area.
Gas-plasma cutting of metals is one of the heat treatment operations. The main advantage is that it allows you to cut material of any thickness, while maintaining high efficiency. Another advantage will be complete autonomy and independence from a third-party power source.
The technology can be used for cutting various materials. Exceptions are brass, stainless steel, copper and aluminum.
Advantages and disadvantages of technology
Cutting metal with gas has several advantages:
- An excellent solution when you need to cut thick products or curved cuts according to templates. Blind holes up to 5 cm deep.
- The torch weight is not large, it is convenient and mobile. There is no bulkiness, large weight and increased noise inherent in electric and gas powered tools.
- The technology allows you to increase the speed of work up to 2 times in comparison with a gasoline tool.
- Refueling a gas cylinder is cheaper and lasts for large volumes of work than in the case of refueling with gasoline.
- The gas torch allows for a narrow and clean cut edge.
The disadvantages include the possibility of an explosion of gas-air mixtures, heating of large areas of products, a limited range of metals available for processing, which were discussed above.
Cutting metal with a gas torch: features, advantages, basics of work
Due to the fact that the operation is not complicated and there are no strict requirements for the places of work, gas cutting has gained wide popularity in many works. Next, we will analyze the technology of gas cutting of metal, its features, the devices used and the principles of its operation.
Cutting metal with gas is simple, as it does not require the use of additional energy sources and sophisticated equipment. This type of processing is popular with many professionals in all industries. Almost all cutting equipment is mobile and easy to transport.
How much gas is consumed
The amount of gas consumed will depend on how the work is done. For example, air arc cutting will generate more gas than oxy-flux cutting. In the main, the consumption will depend on:
- The experience of the welder. Without proper experience, more gas is traditionally consumed.
- Integrity and technical parameters of the equipment used.
- Type and thickness of workpieces.
- Widths and depths of cut.
Surface and shape cutting
With gas processing, complex products can be formed. The technology is applicable to non-ferrous metals if their properties allow this procedure to be carried out. Oxygen-flux cutting is used for copper, brass and bronze. Aluminum and its alloys are most often exposed to plasma arc cutting.
Working with a gas treatment plant requires compliance with safety rules. It is necessary to monitor the oxygen pressure in the system and the operation of the reducer. Excessive gas supply can be hazardous to the life and health of personnel. For this reason, the following conditions must be met:
- The work area must be well ventilated to quickly evacuate gas in the event of a leak.
- It is necessary to remove all flammable substances from the room, and place flammable objects at a distance of at least 5 m from the installation.
- Work should be carried out in fireproof clothing, protective mask or goggles.
- The flame must be directed away from the gas source.
- Hoses should be positioned in such a way that there is no possibility of accidental kinking during operation.
- If there is a break, you need to completely extinguish the burner flame and close the cylinders.
Welding methods for various seams
Using this technology, you can weld various seams. There are several ways to do this. “Left welding” is used to work with low-melting materials. In this case, the gas burner is led from right to left in front of the flame, welding the seam section. “Right hand welding” is done in the opposite direction and more heat is retained. “Right hand welding” is suitable for metal parts with a thickness of 3 mm and above.
Gas mixing from cylinders is carried out through a hose equipped with an oxygen reducer. With this device, you can control the force with which the oxygen jet is supplied, depending on the task at hand. In addition, the reducer allows you to control the burning rate of the workpiece and maintains a constant pressure in the system. If, during the process of cutting metal with a torch, the oxygen consumption falls below the set level, the part will quickly cool down and the process will be interrupted.
The cutting unit is designed with gas cylinders. Their capacity depends on the expected volume of work. If cutting metal with propane is envisaged, then one cylinder must contain oxygen, and the other must contain propane gas.
Gas cutting technology for metal parts
Flame cutting is the process of separating metal elements into small fractions. This technology is implemented by using a directed oxygen flow with an admixture of gas, for the formation of which special equipment is required.
Cutting steel with a gas torch
When carrying out gas treatment, the technology includes several stages. The heated metal passes into the combustion stage, after which the molten slag is blown out. The burning of the surface layer leads to the heating of the part to the full depth, due to which the cut is carried out.
When metal rolling burns, a small amount of heat is released, so the flame is not extinguished during the gas cutting process. The technology allows processing parts with a cut thickness of up to 200 cm.After cutting thin sheets, the steel is straightened on rollers.
This device allows you to direct an oxygen-gas jet to a metal part in order to achieve acid release on the cut surface. In the process of work, the layers of metal are heated to the full depth, which leads to a through cut.