Abstract: The invention relates to a ternary gaseous mixture formed from argon, helium and oxygen, characterized in that it is formed from between 19.5 and 20.5% of helium, between 2.7 and 3.3% of Oi, and argon for the remainder (volume %), and to the use thereof as gaseous protection in a method of electric arc welding of at least one steel part to carbon, using a fusible filler wire. Preferably, the welded parts overlap or cover each other and the rotary arc welding takes place where the parts overlap.

Abstract: The invention concerns a MIG/MAG-type electric arc welding method that uses a consumable filler wire and gas protection formed by a ternary gaseous mixture comprising 19 to 21% helium, 0.8 to 1.2% CO2 and argon for the remainder (% of volume), in order to weld one or more pieces of stainless steel. According to the invention, the arc is rotary, the consumable filler wire is melted by the arc such as to transfer metal by means of a rotating liquid flow, and the welded parts comprise overlapping ends.

Abstract: The invention relates to a device and a process for the arc welding of metal workpieces employing a MIG/MAG welding torch combined with a TIG welding torch so as to operate simultaneously and to obtain welded joints free of protruding defects.

Abstract: The invention relates to a ternary gaseous mixture formed from argon, helium and oxygen, characterized in that it is formed from between 19.5 and 20.5% of helium, between 2.7 and 3.3% of Oi, and argon for the remainder (volume %), and to the use thereof as gaseous protection in a method of electric arc welding of at least one steel part to carbon, using a fusible filler wire. Preferably, the welded parts overlap or cover each other and the rotary arc welding takes place where the parts overlap.

Abstract: Process for the MIG welding of nickel and nickel alloys, with the use of a gas shield for at least part of the welding zone, in which process the gas shield is a gas mixture containing from 0.05% to 0.5% CO2, the balance being argon. Advantageously, the gas mixture also contains, by volume, from 15 to 50% helium, preferably from 17% to 30% helium, or from 0.1% to 10% hydrogen by volume and preferably from 1% to 7% hydrogen by volume.

Abstract: The invention relates to a process and a unit for the MIG welding of aluminum and its alloys, employing gaseous shielding of the welded zone, composed of a central flow of gas consisting of argon and/or oxygen and of a peripheral gas stream consisting of argon or a mixture of argon and helium. The MIG welding process of the invention allows effective welding of workpieces made of aluminum or aluminum alloys by improving the penetration of the weld and the wetting of the weld bead, that is to say the angle of connection of the weld bead to the welded workpieces.