Characterization of electron-beam welds on booster cases of Ariane-5

As a part of the experimental work done in the course of the qualification of a "Fitness for Service" assessment of electron beam welded ARIANE 5 booster cases the investigation of the strength, deformation and toughness properties of individual material zones of the weld was performed to characterize and identify critical material zones in the joints. It turned out that strength decreases in the so called subcritical heat affected zone as well as in the weld metal, due to annealing effects. The highest strength and deformation capabilities were demonstrated by the fine grained heat affected zone. The properties presented in this contribution represent a basis for respective numerical analyses of the booster cases load capabilities.