Continuous wire welding in a shielded atmosphere is often identified by the abbreviations M.I.G. (Metal Inert Gas) and M.A.G. (Metal Active Gas) or G.M.A.W. (Gas Metal Arc Welding). Continuous wire welding is a process in which the heat required to carry out the weld is supplied by an electric arc that is maintained between the piece to be welded and the wire electrode. The welding zone is constantly fed with the welding material (the wire electrode) by means of a special torch, which also supplies the flow of gas (or gas mixture) whose purpose is to shield the wire electrode, the weld pool, the arc and the area surrounding the base material from atmospheric contamination. The presence in the welding circuit of the gas cylinder (inert or active gas, or a mixture of the two) together with the use of solid wire electrodes, identifies the gas shield welding process (M.I.G. or M.A.G.).
The absence of the gas cylinder from the welding circuit, together with the use of tubular wire electrodes, identifies the welding process without gas shield (SELF SHIELDED WIRE, NO GAS or FLUX); in this case the gas shield is obtained by the action of the flux core contained in the wire.
