Method for welding using a mobile vacuum chamber

A method for welding together two parts to be joined along a joining gap disposed therebetween, comprising illuminating the joining gap with an energy beam over an entire depth of the joining gap through a mobile vacuum chamber in which a vacuum is generated and which is moved on the parts to be joined, on the side to be welded, along the joining gap, wherein:

• a. the vacuum chamber, through which the energy beam is transmitted, forms a first vacuum chamber, in which, during welding, a vacuum having a first pressure level is generated;
• and
• b. a vacuum having a second pressure level is generated in a second vacuum chamber which adjoins the first vacuum chamber directly at a chamber wall thereof and surrounds at least a region of the first vacuum chamber and which, during welding, covers a region of the joining gap,
• c. the pressure levels in the two vacuum chambers being matched to one another or the first pressure level being raised to greater than the second pressure level by way of a pressure regulating system.