Welding is a joining process that produces coalescence of materials (typically metals or thermoplastics) by heating them to welding temperature, with or without the application of pressure or by the application of pressure alone, and with or without the use of filler material.
Most commonly, workpieces are welded by melting both of them and adding more molten metal or plastic to form a pool that cools to form a strong joint. The energy to form the joint between metal workpieces most often comes from a flame (e.g. oxy-acetylene) or an electric arc, but welding by laser beam, electron beam, ultrasound and friction processes is well established. Energy for fusion welding of thermoplastics typically comes from direct contact with a heated tool or a hot gas.
Welding differs from soldering and brazing in that enough heat is applied to melt the materials to be joined. Soldering uses solder, a lower-melting-point material.
Welding also is used to join beams when constructing buildings, bridges, and other structures, and to join pipes in pipelines, power plants, and refineries.
Skilled welding, soldering, and brazing workers generally plan work from drawings or specifications or use their knowledge of fluxes and base metals to analyze the parts to be joined.
Welding, soldering, and brazing workers often are exposed to a number of hazards, including the intense light created by the arc, poisonous fumes, and very hot materials.
Feeds |
Contact