Cutting Galvanized and Coated SteelsGalvanized and coated steels sometimes need to be cut to size or shape. The processes suitable for such purposes are oxygen gas cutting, laser cutting, and plasma cutting. The MMA process for gouging and cutting and air-arc cutting may also be used for less accurate metal removal procedures. Oxygen and plasma cutting is perhaps the most frequently used processes because of the thicknesses, applications, and industries where these materials are used. This is particularly true when cutting galvanised and coated sheet steel. Problems can occur when laser cutting these materials as the vapourised coating can condense on the lens affecting cut quality and efficiency. Gouging and cutting after welding to remove metal or to back-grind may be carried out with MMA electrodes or with the air-arc process. The main problems are the effect of the coating are on cut quality and the generation of fume, which from some coatings can be particularly toxic. The main safety issues are fume and hot metal, and, depending on the process, may also include, electrical, radiation, flammable gases, compressed gases, or noise.
|
