L'air Liquide, Soci&#xe9;t&#xe9; Anonyme Pour L'etude Et L'exploitation Des Proc&#xe9;d&#xe9;s Georges Claude

L'air Liquide, Societe Anonyme a Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude

L'air Liquide, S.a.

L'air Liquide, Soci&eacute;t&eacute; Anonyme {overscore (a)} Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Proc&eacute;d&eacute;s Georges Claude

Air Liquide Welding France

Karim Chouf

Philippe Lefebvre

Francis Briand

Eric Verna

Hakim Maazaoui

Françis Briand

The invention relates to a laser cutting method for cutting a stainless steel workpiece using laser beam generation means comprising a silica fiber with an ytterbium-doped core to generate the laser beam. Preferably, the laser beam generated by the ytterbium-based fiber has a wavelength between 1.07 and 1.09 &#x3bc;m, a quality factor of the laser beam is between 0.33 and 8 mm&#xb7;mrad, and the laser beam has a power of between 0.1 and 25 kW. The assistance gas for the laser beam is chosen from nitrogen, helium, argon and mixtures thereof, and, optionally, it further contains one or more additional compounds chosen from O, CO, Hand CH.

Method for cutting stainless steel with a fiber laser

The invention relates to a method for the laser welding of metal parts that comprises generating a CO2 laser beam, dispensing a protection gas jet made of said gas or gas mixture in the direction of the junction plane between the parts, melting and evaporating the metal of the metal parts with the laser beam in order to generate a metal vapor capillary with the simultaneous generation of a metal plasma that propagates outside the metal vapor capillary and thus forms a metal plasma plume above said junction plane. The protection gas jet is further directed towards the metal plasma plume forming above the junction plane. The gas jet is preferably directed so that the latter comes flush with the top of the metal plasma plume and impinges on the part(s) at a location where the metal of said parts has not been molten by the beam.

[object Object]

The invention relates to a laser cutting method for cutting a C&#x2014;Mn steel workpiece, characterized in that laser beam generation means comprising at least one silica fiber with an ytterbium-doped core is used to generate the laser beam. Preferably, the ytterbium-based fiber has a wavelength between 1.07 and 1.1 &#x3bc;m, preferably 1.07 &#x3bc;m, the quality factor of the laser beam is between 0.33 and 8 mm.mrad, and the laser beam has a power of between 0.1 and 25 kW. The assistance gas for the laser beam is chosen from nitrogen, helium, argon, oxygen, COand mixtures thereof, and, optionally, it further contains one or more additional compounds chosen from Hand CH.

Method for cutting C&#x2014;Mn steel with a fiber laser

The invention relates to a method for welding with a laser beam, using a welding nozzle comprising: a nozzle body having an axis and including at least an upper surface, a lower surface and a peripheral wall; an axial cavity extending between the upper and lower surfaces of the nozzle body so as to define an outer channel recessed from the surface of said peripheral wall; and a plurality of inner passages drilled through the nozzle body between the upper and lower surfaces. The laser welding method of the invention provides a dynamic gas jet mechanically interacting with the molten metal bath, and further enables better control of the bath hydrodynamic flows, and thus better laser-welding efficiency.

Method for laser welding using a nozzle capable of stabilizing the keyhole

The invention relates to method for cutting a part using a laser beam, involving the use of laser beam generation means comprising at least one ytterbium-based fibre having a wavelength of between 1 and 4 &#x3bc;m in order to generate the laser beam. The laser beam is selected to have a power of less than 100 kW, a power density of at least 1 MW/cm2, a focused beam diameter of at least 0.1 mm and a quality factor (BPP) of less than 10 mm&#xb7;mrad.

Cutting method using a laser having at least one ytterbium-based fiber, in which at least the power of the laser source, the diameter of the focused beam and the beam quality factor are controlled

A method and an apparatus for welding with a laser beam. A shielding gas mixture of nitrogen and helium is used and the proportions of the component gases are modified depending on the laser beam's power or power density. Plasma formation in the shield gas is minimized by increasing the proportion of helium as the laser beam's power or power density increases.

Binary gas mixture for welding using a laser beam of up to 12 kW, consisting of 30% to 60% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

Use of helium/nitrogen gas mixtures in up to 12 kW laser welding

Process for welding together the two longitudinal edges of a sheet of austenitic, ferritic or martensitic stainless steel so as to obtain a welded pipe, employing at least one laser beam having a power ranging up to 12 kW, and in which a gas mixture is used that consists of 30% to 80% nitrogen by volume and of helium for the remainder (up to 100%). The stainless steel sheet has a thickness of 0.5 to 4 mm and the pipe obtained has a diameter of 5 mm to 50 cm. The welding is full-penetration welding.

Use of helium/nitrogen gas mixtures for the laser welding of stainless steel pipes

Method of welding tailored blanks consisting of a material mostly containing steel and a proportion greater than 0.015% aluminium by weight, using at least one laser beam, in which at least one weld joint of the full-penetration type is made using a gas mixture consisting of 30% to 80% nitrogen by volume, the rest being helium (up to 100%) in order to assist the said laser beam. The method of the invention is particularly recommended for welding motor vehicle elements, especially bodywork, doors, bonnets or the like.

Use of helium/nitrogen gas mixtures for laser welding tailored blanks

Binary gas mixture for welding using a laser beam of up to 8 kW, consisting of 60% to 80% nitrogen by volume, the remainder (up to 100%) being helium. Application of this gas mixture to the welding of steel, stainless steel or titanium.

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Montmorency, France

Karim Chouf