The use of gases in the cutting industry

Usually, a mixture of oxygen and a combustible gas (acetylene, propane, propylene MAPP or methane) is used to preheat the metal to its ignition temperature, which is much lower than its melting point. A jet of pure oxygen is then directed into the preheated area, which burns through the spot, and the molten metal and resulting slag are removed by the high-velocity oxygen stream. The cutting speed is primarily determined by the oxygen jet, but since the gas/oxygen flame of the external fuel determines the amount of preheating, the choice of fuel gas has an important effect on the time required to initiate the cutting operation. This is especially important if the designed cut starts with a hole. Therefore, oxygen is used in two cutting processes using combustible gas and oxygen and plasma arc cutting, with the difference that the plasma arc method is used due to the production of more heat in the work piece. This method can be used for cutting all metals, but its main application is cutting non-ferrous metals and stainless steels. Metal laser cutting machines can use oxygen or nitrogen gas as an auxiliary gas. Thick metals, aluminum and even thin copper need oxygen to cut. Other substances can be cut with both oxygen and nitrogen. What matters is how you plan on the surface for your cut metal. Cutting with oxygen causes the edges of the cut to become glassy, ​​but it may be troublesome during the metal painting stage and may not be painted. The powder coating process may not be effective. On the other hand, cutting with nitrogen is quick and easy, and none of these problems will happen to you.
The purity of the gas used plays a significant role in the cutting quality. In the case of low purity nitrogen gas, it leads to yellowing of the edges of the cutting site, which is caused by the oxidation of the metal.