Metal cutting bases: inverter, plasma, gas

Metal cutting with welding up to a certain time was actively used as the main method of processing metal structures at home. The resulting cut was not distinguished by beauty, so the use of the grinder was noticeably welded. To the proven year, the method is still resorted, its capabilities expanded through the use of new equipment.

With welding, metal cut in the following cases:

• in field conditions, when there are no electricity sources,
• it occurs, it is necessary to cut a very thick metal,
• when cutting, you need to get a piece of complex shape,
• it is necessary to cut the metal in a hard-to-reach place.

Welding refers to universal processes, which can be used both to connect and divide parts into parts. The most applies at home the following versions of metal cutting equipment:

1. arc (inverter),
2. gas cutter
3. plasmorez.

In this article, we will talk in detail about the features, technologies and basic principles of metal cutting with a welding inverter, a gas cutting of a metal with oxygen and propane, and plasma cutting of metal. After studying the basic principles of working with different types of equipment, you can carry out metal cutting with your own hands.

Cutting arc

When training the basics of welding, the newcomer is most afraid of burning the metal and completely destroy the connection. When cutting metal, the goal of the welder is burning, cutting the metal.

In order to cut the metal with welding arc, it is necessary to heat it up to the melting point and remove the molten metal from the welding zone. Removal is performed under its own weight of the molten metal, due to the pressure from the arc side or the flow of air supplied to the welding zone.

Such electrodes are used for metal cutting:

• metallic coated
• carbonic,
• tubular,
• tungsten.

This method cut steel, including alloyed, non-ferrous metals and alloys.
The disadvantages include low quality cut, uneven edges, the presence of scale. Therefore, if the metal in the future goes to create structures, the edges must be additionally processed, for example, to clean.

The cutting is performed on the same equipment as welding, in all spatial positions. As an equipment at home, a transformer or rectifier was previously used, now the inverter is most often used.

Basics of arc cutting

In order to cut the metal arc set the current strength by 30-40% higher than when welding. They light a powerful arc on the top edge of the metal and deepen down, while cutting the edge.

Metal cutting with welding inverter

For cutting, the electrode of a small diameter is chosen, but the current, on the contrary, exhibit more than necessary for welding. For example, the diameter of the electrode is 2.5 mm, 140a is installed.
Light the arc and leave the electrode in one place. You try to keep the arc to deepen, no matter how the metal has lived.
If the plate is placed vertically, the molten metal will be gently dragged. With a horizontal cutting of metal, the welding inverter will be collected at the bottom of the plate.
To ensure the best heat heating, the straight polarity is absorbed. In this case, the metal warms deeply, but the cut is obtained narrow.

The video shows what opportunities are opened when the cutting of the arc is applied. The plate at 10 - 20 mm thick is cut literally in a few minutes with ease and beautiful.

Cutting gas cutter

Until recently, the metal gas cutter remained the main method of the metal partition, especially if it was necessary to perform a sharp circuit, to handle the edge or get a hole. The advantage is that there is no need for the work in the source of electricity.
Metal cutting with a gas cutter is performed as follows: a mixture of oxygen with a combustible gas, the resulting torch heats the metal in the cut zone to the combustion temperature, not less than 12000c. Feed a jet of oxygen.

Metal flammifies and turns out the cut line. Most often for cutting uses oxygen in a mixture with propane. Gas cutting are treated with steel, both carbon and alloyed, titanium alloys.

Gas cutting of metal on a mixture of propane and oxygen

Prior to work, the metal is prepared: purified dirt, fat, scale, rust.

Gas cutting equipment

It takes less skills to perform a gas cutting than when welding, because there is no need to ensure the tightness of the connection. The equipment will require gas cutter, oxygen cylinders and propane.

Each cylinder has a reducer to regulate pressure. Gas from the cylinder to the reducer is supplied by high pressure hose.
Before starting work, the hoses blow up to clean from dirt. All hoses are inspected, connectivity with gearbox, all detachable connections are checked for tightness.

Check the condition of the risker itself and purged with oxygen. For this, the cylinder with oxygen is connected to the place of attachment of the oxygen hose. Balon with flammable gas is not connected. Install on the gearbox 5 atm and open both valves on the cutter. Driving a finger to the second pieceing can be observed whether there is a subsidence. With its absence, the cutter channels must be purned.

Operating procedure

Gas cutting is performed, withstanding the proportion: 10 parts of oxygen per 1 part of the gas. Therefore, they are installed on a gas gearbox 0.5 ATI, and on the oxygen gearbox 5 ATI.
For a start, a slightly opened the supply of propane and gas is ignited. The nozzle rests on the metal and the oxygen is tightly begin. With the help of rotation of the valves, you can adjust the flamber value and get the necessary flame to work. The thicker the metal is assumed to be cut, the stronger the flame should be, for which a large supply of gas and oxygen is necessary.
ATTENTION: The flame is adjustable using the pressure of the regulating oxygen, not the cutting.

The burning flame is made to the metal in the place where it is necessary to perform the cut, withstanding the distance between the nozzle and the metal in 5mm. Under the action of the flame, the metal is heated to the desired temperature. This happens quickly, seconds for 10. Watching the process notice that at that moment the metal as it becomes wet. Only metal will ignore, immediately include cutting oxygen.
In order to avoid the reverse strike of a flame that can be accompanied by cotton, includes cutting oxygen gradually.

In this case, oxygen itself will light up as soon as it is touching the hot metal surface. The video shows how using a gas cutting you can cut out the shapes of the most complex shape.

The quality of the cutting is affected by the speed of welding. Control speed focusing on the sparks in the cutting zone. If the sparks are ahead, it means that the speed is insufficient. At high speed, Sparks are behind the cutter, in this case it is difficult to qualityly cut the blanks.
In order to perform a hole, the place is heated to the desired temperature, cutting oxygen is supplied. Metal flammable. The cutter is fed to the metal zone and the hole makes itself.

Metal cutting with plasma cutter or plasmoresis

About the possibilities of plasma torus is well told in the video. After reviewing the video, you will definitely want to have such wonderful equipment in the farm, even despite its big price.

Metal cutting occurs under the action of plasma energy. It turns out as follows. When the ignition button is pressed, a duty welding arc is formed inside the plascript. The compressed air passes through it, ionized, and the plasma is pulled through a nozzle at high speed. Plasma has a temperature of over 10 thousand degrees and a speed of two times the speed of sound. This energy is enough for the metal to melt and even evaporated.

The operator brings plasmorez to the place where it is necessary to perform a cut and metal begins to melt. The speed of manual movement should ensure the cutting of the metal. Cutting parameters There are current strength and air pressure.
Details on how the plasma is obtained and the cutter is well shown in the video.

With incorrectly selected parameters on the edge can form a scale. After the end of the cut is not immediately turned off the supply of compressed air. It is served for some time to cool the metal.

Plasmore Technology

Before starting work, the edges are cleaned, remove pollution and rust from them.
Plasma cutting operations of any metal start with the installation of current power. The principle is simple: the current is calculated depending on the thickness of the metal. The amount of current force, which is necessary for cutting 1 mm metal thickness, is multiplied by the metal thickness to be cut. If it is necessary to cut 25 mm steel, then you need to multiply on 4a (current required for cutting 1 mm steel or cast iron). Total on the equipment exhibit 100a.

The speed at which it is necessary to perform cutting directly affects the quality of work, but depends on the skill of the carver. Specialists advise at the initial stage of performance to focus on the presence of sparks on the reverse side of the product. If they are missing, the metal is cut completely completely.

Before the arc is ignited for half a minute, the cutter is blocked by gas to remove dirt and possible condensate. Next, the operator presses the ignition button of the duty arc, it burns 2 sec. If the cutting arc is not formed, the process is repeated again.

Depending on the model, the approach is the contact and contactless:

1. The contact requires a short circuit. As soon as the plasma came out of the nozzle between the metal and the electrode, a plasma arc is formed and the cutting process begins.
2. With a contactless arc ignites between the nozzle and the electrode. When the nozzle approaches the metal, the working arc is formed.

During cutting, it is necessary to maintain a constant length of the arc. If it is not provided with a special focus, this parameter is withstanding the cutter, it must be from 1.6 to 3 mm.
When working, it is necessary to keep the nozzle to the metal at an angle of 900c. In order to reduce deformations on a thin metal, the burner is kept under a small angle. During cutting, pay attention to the metal does not climb the nozzle burner.

For details about the work of Plasmatron, see the video.

With the help of the considered methods of cutting, you can cut the metal from the most complex contour. These works are able to fulfill with their own hands, after a small theoretical and practical training. The main thing is the availability of equipment and related materials.