Application of gases

The use of gases in the cutting industry

Industrial gases are usually used in cutting for the purpose of oxidation and heat increase. Therefore, the research and development team of Parsia Gas will help you to provide solutions and advice on the amount of gas consumption and their purity percentage to improve your process.


Oxygen 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.

Nitrogen in the cutting industry

Nitrogen is generally used when cutting stainless steel or aluminum in order to achieve excellent quality. Unlike oxygen, nitrogen acts as a shielding gas in the photometer material to stop the burning process and allow the laser to vaporize the material. This means that power is the determining factor in cutting speed. More power equals more speed.

As previously stated, oxygen cutting speed is limited by the force that can be applied while nitrogen cutting speed is directly related to strength. In some cases, higher laser powers where nitrogen is used in low steel cutting allow the laser user to anticipate processing speeds three times faster than when using oxygen. However, nitrogen laser cutting of steel is not limited to raw materials. Nitrogen can be used as an auxiliary gas for thicker steels, with the maximum thickness depending on the available laser power. While nitrogen provides a faster processing speed in steel up to 1/8, this is not the case in thicker materials, where oxygen will provide faster speeds as the material thickness increases.

Nitrogen will provide a high edge quality of any impurity. This edge is highly receptive to powder coating color and also ensures a proper weld surface. This cutting method generally eliminates the need for any secondary operations. But the oxide surface produced by oxygen cutting can affect the powder color as well as welding. Generally, steels larger than 14 gauge require this surface to be removed for powder coating painting.

The main factor contributing to operational costs is gas consumption. There is a significant difference between oxygen and nitrogen. Oxygen processing can result in the lowest operating costs as the gas consumption rate can be up to 10 times lower than nitrogen requirements. In general, by increasing the thickness of nitrogen, it helps to increase gas consumption.