Hybrid arc/laser-welding method for aluminized steel parts using gammagenic elements and a gas containing less than 10% of nitrogen or oxygen
The invention relates to a hybrid laser/arc-welding method using an electric arc and a laser beam that are combined together within a single welding melt to which molten metal is supplied by melting a filler wire, wherein the welding melt is provided on at least one steel part including an aluminum surface coating, and a protective gas is used, characterized in that the filler wire contains at least 3 wt % of one or more gammagenic elements, in particular the gammagenic elements selected from C, Mn, Ni and N, and the protective gas consists of helium and/or argon with the addition of at least 10 vol % of nitrogen or oxygen. The method of the invention is particularly suitable for welding end-welded flanks used in the field of manufacturing automobiles or for tube welding.
1. A laser/arc hybrid welding process using an electric arc and a laser beam in combination together in a single weld pool, comprising;
providing the weld metal by melting a consumable wire,
producing the weld pool in at least one steel workpiece comprising an aluminum-based surface coating, and
using a shielding gas,
wherein the consumable wire contains at least 3 wt % and at most 20 wt % of one or more gammagenic elements and the shielding gas is formed of at least 2 vol % to less than 10 vol % of nitrogen or oxygen, and helium or argon,
thereby promoting the formation of a uniform martensite microstructure in a weld-metal zone formed by hot-drawing and quenching.
2. The process of claim 1 , wherein the gammagenic elements are chosen from C, Mn, Ni and N.
3. The process of claim 1 , wherein the one or more steel work pieces comprise an aluminum-based surface coating having a thickness of between 5 and 100 μm.
4. The process of claim 1 , wherein the one or more steel work pieces comprise an aluminum-based surface coating having a thickness of 50 μm or less.
5. The process of claim 1 , wherein the one or more metal work pieces are made of steel with a surface coating based on aluminum and silicon (Al/Si).
6. The process of claim 1 , wherein the one or more metal work pieces are made of steel with a surface coating based on aluminum and silicon, the surface coating containing more than 70 wt % aluminum.
7. The process of claim 1 , wherein the consumable wire is melted by the electric arc.
8. The process of claim 1 , wherein the laser generator generating the laser beam is of the CO2, fiber, or disk type.
9. The process of claim 1 , wherein the one or more work pieces to be welded are chosen from tailored blanks and exhaust pipes or tubes.
10. The process of claim 1 , wherein the consumable wire contains a plurality of gammagenic elements chosen from C, Mn, Ni and N.
11. The process of claim 1 , wherein the consumable wire contains at least 5 wt % of one or more gammagenic elements.
12. The process of claim 1 , wherein the consumable wire at least contains Mn.
13. The process of claim 1 , wherein the consumable wire furthermore contains iron.