![]() ![]() Cutting speed: The optimal cutting speed range can be selected according to the equipment description or determined by experiment. In addition to the influence of working gas on cutting quality, the effect of cutting speed on the processing quality of CNC plasma cutting machine is also very important. Therefore, it is now rare to use pure argon alone for plasma cutting. Even cutting with a mixture of argon and other gases will have a tendency to stick to the slag. In addition, in the argon gas protection environment, the surface tension of the molten metal is relatively large, which is about 30% higher than that in the nitrogen environment, so there will be more slag hang problems. Compared with air cutting, the thickness of the cutting will be reduced by about 25%. However, the voltage of argon plasma arc is low, the enthalpy value is not high, and the cutting ability is limited. Moreover, the nozzles and electrodes used have a long service life. Argon gas hardly reacts with any metal at high temperature, and the argon plasma arc is very stable. Sometimes nitrogen is also used as the starting gas for oxygen plasma arc cutting.Į. These two gases have become the standard gas for high-speed cutting of carbon steel. For example, nitrogen or air are often used as working gases during automatic cutting. Nitrogen can be used alone or mixed with other gases. Under the condition of higher power supply voltage, nitrogen plasma arc has better stability and higher jet energy than argon, even when cutting liquid metal with high viscosity materials such as stainless steel and In the case of nickel-based alloys, the amount of dross at the lower edge of the cut is also small. If a water jet is used to further compress the argon + hydrogen plasma arc, a higher cutting efficiency can also be obtained.ĭ. Generally, for metal materials with a thickness of more than 70mm, argon + hydrogen is commonly used as the cutting gas. When mixed with argon, its plasma jet cutting ability is greatly improved. Because hydrogen can significantly increase the arc voltage, the hydrogen plasma jet has a high enthalpy value. For example, the well-known gas H35 (hydrogen volume fraction is 35%, the rest is argon) is one of the gases with the strongest plasma arc cutting ability, which mainly benefits from hydrogen. Hydrogen is usually used as an auxiliary gas to mix with other gases. The high-temperature and high-energy plasma arc makes the cutting speed faster, but it must be used with an electrode that resists high-temperature oxidation, and at the same time, the electrode is protected against impact during arcing to extend the electrode Life.Ĭ. When using oxygen for cutting, the cutting mode is very similar to flame cutting. Oxygen can increase the speed of cutting mild steel materials. However, when using air cutting alone, there will be problems such as slag hang, cut oxidation, nitrogen increase, etc., and the lower life of the electrode and nozzle will also affect the work efficiency and cutting cost.ī. Because of the presence of oxygen, the air is used for cutting The speed of low-carbon steel materials is also very high CNC plasma cutting machine at the same time air is also the most economical working gas. The air contains about 78% of nitrogen by volume, so the slag formed by air cutting is very similar to that when cutting with nitrogen the air also contains about 21% of oxygen by volume. The most commonly used working gases are: argon, nitrogen, oxygen, air, H35, argon-nitrogen mixed gas, etc.Ī. If there are other special applications, the gas pressure needs to be determined by the actual cutting test. The gas pressure used to cut a certain thickness of material is usually selected according to the data provided by the customer. The current plasma cutting machines mostly rely on gas pressure to control the flow rate, because when the torch aperture is fixed, the gas pressure also controls the flow rate. The depth becomes shallower, and it is also easy to produce slag therefore, the gas flow must be well matched with the cutting current and speed. Excessive gas flow will take away more arc heat, making the length of the jet shorter, resulting in reduced cutting capacity and arc instability too small gas flow will cause the plasma arc to lose its straightness and cut. The gas must not only ensure the formation of the plasma jet, but also ensure that the molten metal and oxide in the cut are removed. Usually, the appropriate work is selected according to the type of cutting material, thickness and cutting method. Some equipment also requires arc starting gas. ![]() The working gas includes gas and auxiliary gas. It is widely used because of the relatively low cost of use. At present, the general use of air plasma cutting is only one of many working gases. The working gas and flow rate are the main parameter that affects the cutting quality. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |