The lift arc method features a DC+ nozzle with a DC- electrode inside. Thus, starting methods that eliminate the potential problems associated w ith high frequency star ting circuits m ay be advantageous. However, high frequency can interfere with computers or office equipment that may be in use in the area. Most plasma cutters have a pilot arc that utilizes high frequency to conduct electricity through the air. The higher the duty cycle, the longer you can cut without taking a break. For example, a 60 percent duty cycle at 50 amps means you can cut with 50 amps output power continuously for six minutes out of a 10-minute period. Duty cycle is rated as a percentage of a ten-minute period. Duty cycle is simply the time you can continuously cut before the machine or torch will overheat and require cooling. If you are performing long, time-consuming cuts or are cutting in an automated set-up, be sure to check into the machine's duty cycle. For example, to perform long, fast, quality production cuts on ¼" steel, choose a 1/2” class (60 amp) machine. For production cutting, a good rule of thumb is to choose a machine, which can handle approximately twice your normal cutting thickness. If the metal you cut most frequently is ¼", a machine that offers higher amperages will be able to cut through the metal much faster than one rated at a lower amperage, although both will do the job. However, for heavy sections of steel (1 inch and greater), oxyfuel is still preferred since oxyfuel is typically faster and, for heavier plate applications, very high capacity p ower supplies are required for plasma cutting applications.ĭo you perform most of your cutting in a production environment or in an atmosphere where cutting speed isn't as critical? When buying a plasma cutter, the manufacturer should provide cutting speeds for all thickness of metal measured in IPM (inches per minute). Plasma cutting is typically easier for the novice to master, and on thinner materials, plasma cutting is much faster than oxyfuel cutting. In most shops, compressed air is readily available, and thus plasma does not require fuel gas and compressed oxygen for operation. While different gasses can be used for plasma cutting, most people today use compressed air for the plasma gas. Plasma cutting, however, does not rely on oxidation to work, and thus it can cut aluminum, stainless and any other conductive material. Metals like aluminum and stainless steel form an oxide that inhibits further oxidization, making conventional oxyfuel cutting impossible. It is therefore limited to steel and other ferrous metals which support the oxidizing process. Oxyfuel cuts by burning, or oxidizing, the metal it is severing. With mild steel, operators will experience faster, thicker cuts than with alloys. Plasma cutting can be performed on any type of conductive metal - mild steel, aluminum and stainless are some examples.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |