Generally speaking, plasma cutting compared to oxygen-acetylene gas cutting, due to the difference in working principle, so it can cut many jobs that cannot be done by oxygen cutting, to complete the cutting of non-ferrous metals (such as: stainless steel, heat-resistant steel, titanium, tungsten, molybdenum, cast iron, copper, aluminum, etc.); at the same time has the following advantages: cutting speed (depending on the material, the speed can reach 3-15 of oxygen cutting The plasma cutting speed can reach 6350 mm/min for 6 mm mild steel plate, 200-300 m/h for 10 mm aluminium plate and 100-300 m/h for 12 mm stainless steel), narrow cutting seam (a fraction of that of oxygen cutting, determined by the accuracy of the cutting gun), and Flat kerf, small workpiece deformation (due to the fast cutting speed, the workpiece is basically free of deformation.) The cutting speed of plasma cutter is very fast and the workpiece is not deformed. The cost is low (depending on the material, the cost is generally only about 1/2 of that of oxygen or acetylene cutting).
A high no-load voltage is used to ionise the air and then compress the arc between the tungsten electrode and the workpiece through a small hole in the nozzle to produce a very high temperature to melt the metal and evaporate it, and then use compressed air to blow the molten metal away from the metal matrix to form a metal cut. Because the plasma arc is a compressed arc, the arc column temperature of the plasma arc is particularly high, reaching between 18,000°C and 23,000°C. This temperature is much higher than the temperature of any metal and its compounds known today, and the cutting can be completed without the aid of metal combustion, relying entirely on the heat of its own arc, so plasma cutting can cut almost any metal.
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At the same time, due to the rapid heating of the arc, the metal can be heated to its melting point almost instantaneously, so the plasma cutting machine can cut quite fast, especially when cutting sheet metal, in cutting mild steel sheet metal, the cutting speed of the plasma cutting machine can reach 3-15 times that of oxygen acetylene cutting. At the same time, due to the fast cutting speed, the heating area of the metal is very small, so there is basically no metal deformation, and the kerf is very narrow and very neat without hanging slag.
Because the arc of plasma cutting is more concentrated, the arc is basically submerged in the cutting slit, so plasma cutting can be made with insulating materials, and then cut by sample without damaging the material of the sample, which is very convenient for products that need to be cut in the same shape on a large scale, without drawing lines and placing samples, and is also very conducive to improving the working speed.
General as long as the conductive metal, can use plasma cutting, but due to the high power plasma cutting power supply is more expensive, so the current plasma cutting machine is generally only suitable for cutting medium and thin plate.
Generally plasma cutting machines are calibrated to cut below half of the maximum thickness for the best cutting thickness, e.g. 40A with a maximum cutting thickness of 12 mm, the best cutting thickness is below 6 mm. In addition, the general manufacturer's marked cutting thickness, the cutting thickness of carbon steel plate, if cutting some large thermal conductivity of metals, such as copper and aluminium, the actual cutting thickness to be less than the carbon steel plate cutting thickness of about one-third or so.
