One of the oldest gas cutting processes around is oxyfuel—but in the past few decades, it has been replaced with plasma cutting in many industrial applications. Why has this new technology overtaken the old one? At EZ Cut CNC, we know that there are many reasons why plasma cutting can be better than oxyfuel.
Oxyfuel cutting involves a gas heating the metal to a desired temperature, before a pressurized stream of pure oxygen oxidizes a small area and blasts away the metal. On the other hand, plasma cutting involves forming an electrical circuit with a jet of plasma gas and the metal that is being cut. This circuit creates extremely high heat at a localized point, melting the metal; the molten material is then carried away by the plasma jet.
Types of Metal
One advantage that plasma cutting has over oxyfuel is the ability to cut through a wide range of different metals. In order for oxyfuel cutting to work, the metal has to have a low melting point and the ability to oxidize, meaning that its use is basically limited to carbon steel. Plasma cutting, however, can work with any electrically conductive material, meaning that stainless steel, copper, brass, and aluminum can also be easily cut.
Plasma cutting is also much faster than oxyfuel is. Generally speaking, an oxyfuel cutting system can cut about 20 inches per minute of one-inch-thick steel—while plasma can cut almost four times that, at 80 inches per minute. In addition, plasma cutting does not require preheating like oxyfuel does, meaning that the process can happen much more quickly.
This increased speed leads to enhance productivity, which can actually lower your cost per foot of cutting. This means that you can save money over time by using a plasma cutting system for your operations.
Additionally, plasma cutting creates higher quality parts than oxyfuel cutting. Oxyfuel creates a heat-affected zone around the cut, an area where residual heat affects the chemical composition of the metal. This can cause discoloration and warping, and often makes the piece unsuitable for welding or other processes unless the zone is removed. Because a plasma cutter moves faster than an oxyfuel one, the heat-affected zone is smaller, meaning that you have cleaner cuts and less waste.
Finally, plasma systems offer a great deal more flexibility, since they can also gouge, mark, and dimple your parts. In addition, plasma cutters can be configured for curved or beveled cuts, while oxyfuel cutters cannot. When it comes to metal fabrication, plasma cutters have a clear advantage.