Development Of The Peen Forming Process For Spherical Shaped Components

Author:  Hornauer, K.P. and Kohler, W.
Source:  Conf Proc: ICSP-4, (p.585-594)
Doc ID:  1990020
Year of Publication:  1990
Abstract:  
The main tank H-155 of ARIANE 5 containing cryogenic propellants is built of weldable A1-alloy 2219. With its size (diameter 5.4 m) the tank exceeds all tanks for launchers built in Europe for the time being. For forming the spherical shaped segments of the tank bulkheads of the ARIANE 5 launcher, different forming processes, like spin forming, stretch forming and peen forming were investigated. The reasons, which have led to the application of the peen forming process for forming the segments, will be described in the following paper; further, the development of the peen forming strategy and the process parameters will be referred to. With respect to parameters and contour measurement, great efforts were required to reach the desired high form accuracy of the components. The expectations on the formed material have been very high and the properties achieved in the segments will be reported in this paper. For the forming process a new computer-controlled peen forming machine was built and qualified. Finally the technique and the possibilities of this machine will be explained briefly. Descriptors: Peen forming, Spherical shaped components, Forming methods, A1-alloy 2219, Peening parameters, Peening strategy, Material Properties, Residual stresses, Peen forming machine