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

La Soudure Autogene Francaise

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

Eric Verna

Karim Chouf

Philippe Lefebvre

Francis Briand

Jean-Marie Fortain

Thomas Jouanneau

Isabelle Debecker

Hakim Maazaoui

Françis Briand

Christian Reymond

Gaia Ballerini

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

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.

Use of helium/nitrogen gas mixtures in up to 8kW laser welding

The invention relates to a plasma arc welding process and a plasma arc welding device for aluminum and its alloys, which process comprises at least one step of initiation of a pilot arc by means of an auxiliary current which is delivered by an auxiliary current source and flows in a pilot-arc circuit, one step of feeding with plasma gas, one step of initiation of a main arc by means of a main current which is delivered by a main current source and flows in a main circuit, one step of cyclic variation of the polarity of the main current so as to obtain at least one phase of descaling the material to be welded with a first current polarity and at least one phase of welding the material with a second current polarity, and in which process the supply of auxiliary current to the pilot-arc circuit is stopped during the descaling phase and the main circuit and to the pilot-arc circuit are supplied with main current.

Growing community of inventors

Boissy l'Aillerie, France

Eric Verna