ARC WELDING

Arc welding is one of the oldest, most established processes and applicable for a wide variety of applications and metals. Various types of equipment and methods exist going from rather basic (e.g. Shielded Metal Arc Welding – SMAW) to advanced (e.g. highly controlled pulsed Gas Metal Arc Welding - GMAW).

A power/current source is used to create an electric arc between an electrode and the base material in order to melt the metal(s) at the interface. Either direct (DC) or alternating (AC) current can be used and consumable or non-consumable electrodes. The electrode/arc is moved along a certain path in order to fuse the materials; the common weld pool then gradually solidifies and forms the metal joint. While welding the electrodes and metals are usually protected by some type of shielding gas, vapor, or slag. Arc welding processes may be manual, semi-automatic, or fully automated.

Brazing is another assembly method where an electric arc can be used to apply a local heat input (although also other methods exist based on the oxy-fuel process, heating oven, laser beam, …). This process is significantly different from welding because the base metal (parts to join) remains in the solid state. Only the filler metal will attain its fusion temperature and spread over the surfaces that are to be joined.

(image) Wire Arc Additive Manufacturing (WAAM) is also a manufacturing process based on an electric arc. The filler metal (consumable electrode or additional wire) is molten by the arc energy and deposited there where material is required. That way rather complex geometry can be manufactured (deposition/additive method vs. subtractive like machining) without the need for casting or forging tooling.

 

Application field and advantages

  • Well established methods and therefore many suppliers of equipment and materials. The organisation of the welding activities and related QA has been optimized over many years.
  • Very large welding capacities : from thin plates to important  thicknesses (several cm but then multiple passes)
  • Weldability: can be used for most metals as long as there are no metallurgical issues due to fusion and solidification. For example: steels, stainless steel, copper, aluminium, nickel, titanium and most of their alloys. Heterogeneous welds are often possible with the right equipment and choice of filler metals
  • Easy to automatize to various degrees and according to investment and performance requirements
  • Versatile process and generally easy to apply. Used for many applications such as steel and aluminium constructions, shipbuilding, machine building, pipelines, aeronautics etc.

 

CRM facility

Various welding methods and equipment are available:

  • Shielded Metal Arc Welding (SMAW): up to 500A
  • Gas Tungsten Arc Welding (GTAW): from 0A up to 50A (micro welding) and up to 350A (standard)
  • Gas Metal Arc Welding, MIG/MAG welding (GMAW): up to 500A
  • Plasma Arc Welding (PAW): from 0A up to 50A (micro welding)
  • Advanced welding methods: Fronius CMT (advanced GMAW, also used for WAAM), …
  • Mechanization and automation: welding boom, XY positioner, …
  • Additional equipment: clamps and tooling, welding tables,...

    arc welding