Abstract: The invention relates to an arc welding method that implements an arc welding torch provided with an electrode, in which a central gas flow is supplied so as to contact the electrode and an annular gas flow is supplied on the periphery of said first gas flow. The central gas flow contains only argon and hydrogen (H2), the hydrogen content being 2 to 8 vol %. The sheath gas flow only contains argon and 1.8 to 3 vol % of carbon dioxide (CO2) or 0.9 to 1.5 vol % of oxygen (O2). The method is used for welding parts made of steel, in particular stainless steel or carbon steel, as well as steel coated with zinc or aluminium or any other material for preventing the corrosion of said steel.

Abstract: The invention relates to an electric arc welding method for welding at least one metal part including an aluminum based surface coating, using a shielding gas. According to the invention, the metal of the aforementioned metal part is melted by the electric arc alone without the use of any laser beam. The invention is characterized in that the shielding gas comprises a mixture of argon and/or helium, nitrogen, and an oxidizing compound selected from oxygen and carbon dioxide.

Abstract: The invention relates to a method for electric arc welding, without a laser beam, one or more metal parts, in particular made of steel, including an aluminum surface coating, in particular a coating consisting of aluminum and silicon, using a protective gas, characterized in that the protective gas consists of a mixture of argon and/or helium, and additionally of nitrogen, in particular less than 30 volume % of nitrogen, typically 2 to 10 volume % of nitrogen.

Abstract: The invention relates to an arc welding method that implements an arc welding torch provided with an electrode, in which a central gas flow is supplied so as to contact the electrode and an annular gas flow is supplied on the periphery of said first gas flow. The central gas flow contains only argon and hydrogen (H2), the hydrogen content being 2 to 8 vol %. The sheath gas flow only contains argon and 1.8 to 3 vol % of carbon dioxide (CO2) or 0.9 to 1.5 vol % of oxygen (O2). The method is used for welding parts made of steel, in particular stainless steel or carbon steel, as well as steel coated with zinc or aluminium or any other material for preventing the corrosion of said steel.

Abstract: An arc welding process using a consumable electrode, in which welding cycles follow one after another over the course of time, each comprising an arc period and a short-circuit period in which the liquid metal establishes a short-circuit between the end of the electrode and the workpiece or workpieces. Each cycle comprises the steps of: maintaining an arc current I2 at the same time as the consumable electrode is moved towards the workpiece; reducing the current so as to reach a minimum current I1 at the start of the short-circuit; reducing the speed of the consumable wire electrode; increasing the current over the short-circuit period in order to reach a maximum value I4; and then reducing the current over the short-circuit period in order to reach a minimum value I1.

Abstract: An automated method for detecting the wear of a non-consumable electrode of an arc welding torch and for automatically replacing or remachining the electrode when it is eroded with a fresh electrode includes the following steps: a) the number of strikes performed by the electrode in question, and possibly the arc time of the electrode and the strike time for establishing the arc, is measured or counted during welding; b) the value of at least one of the wear-indicating parameters determined in step a) is compared with at least one preset respective reference value; and c) the eroded electrode is replaced with a fresh or sharpened electrode when the value of at least one of the wear-indicating parameters is equal to or exceeds at least the preset respective reference value.