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.
